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ONLINE

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CONTENTS Adobe Builder Online Issue #1 Winter 2012

Page 2 - Building the Rumford Fireplace - SWSA & Jim Buckley Page 7 - Claude Hayward’s Adobe/ Straw Hybrid at Anton Chico, NM Page 10 - Taking a Solaradobe home through HERS with A.B. Editor Joe Tibbets of Bosque, NM and Jane Whitmire of Placitas, NM Page 14 - Solar Plan 1310 by builder Sean Kaltenbach of Cochiti, NM Page 16 - Soledad Canyon Earth Builders of Las Cruces, NM Page 18-19 - Adobe Palaces and Ernesto Aragón of Albuquerque, NM Page 20 & 22-25 - Region-wide Resource Directory /Services and Suppliers Page 26 - Earth & Sun Construction of Las Cruces, NM Page 27 - Adobe Casita Kits with New Mexico Earth of Albuquerque Page 28 - An old Terrón bites the dust

Above: At the SWSA Count Rumford Fireplace Class. From left to right, Raul Muro, Junior Zermeno and Antonio Rodriguez, all of Soledad Canyon Earth Builders (see p.16). Far right: Carl Clark of Southwest Adobe Supply in Las Cruces, NM. Below: Rammed Earth home interior by Soledad Canyon Earth Builders in Las Cruces, NM. See page 26 for rammed earth news from Earth & Sun

Above: Lime work over adobe in Bernalillo, NM by the Youth Conservation Corps, under the direction of Rick Catanach, adobe restorer and woodworker. See page 31 for a related article.

Page 31-40 Limewash: Compatible Coverings for Masonry and Stucco, by Peter Mold and Richard Godbey

©SWSA 2012 Write us at: SWSA PO Box 153 Bosque, NM 87006 Email: adobebuilder@juno.com www.AdobeBuilder.com Advertising 505/861-2287


BUILDING THE RUMFORD These photos and notes were collected at the SWSA Count Rumford fireplace workshop held at an under-construction earth block home site in Santa Fe County, New Mexico in late summer, 2010. Jim Buckley, a veteran mason and nationwide Rumford expert from Port Townsend, Washington, traveled to New Mexico to lead the class. Article and photos by Joe Tibbets, Southwest Solaradobe School Photoshop technician Doug Purdy, Graphic Artist

Photo to right: the fireplace will sit on the circular concrete pad where the14" thick exterior wall (partly visible,right bottom) and the 10" interior wall (extending to top left) join. Already poured was the footing, pad and stem of 2,500 p.s.i. concrete, with code required steel (see drawing further). While fireplace anatomy is delicate, its components are heavy, so footings under the stems are a minimum12" in depth, as compared to adjacent footings at 8" deep. Stems then rise from the footings to a minimum height of 8" above grade. As the fireplace rises, all elements are lapped, tied and integrated into the adjacent running walls. Should a seismic event occur, the fireplace acts as a buttress, rather than a separate, heavy element that could detach and sway. Photo below: Required are four vertical, #4 rebars, placed at back and sides of the firebox, and visible here where student Michelle Brown works on the firebox.1 The rebars rise ‘continuously’ to the chimney top. ‘Continuous’ means that the rebar is lapped and wire-tied all the way to the chimney top, usually in segment lengths handy to the mason. On their way up, rebars also pass through and tie to the bond beam (typically near ceiling height), unifying the fireplace with the top of the structure. Bond beams are required on adobe or other earthen structures.

Welding rebar can make it more brittle, unless the builder obtains a “weldable” grade of steel. A typical overlap is 40X the rebar diameter, or 20” for ½” rebar. Tie or baling wire is used to tightly wrap the rebar laps before concrete is poured or mortar is troweled on.

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Photos by Adobe Builder


Photo above: Blacksmith Brad Casey (black T shirt) and another SWSA student work on the fireplace. Since its start, some peripheral tasks were accomplished, including the masonry ‘box’ to the back-right of the fireplace to house underfloor hydronic stub outs and the start of the adobe banco visible at right-bottom. As can be seen, the compressed earth block (CEB) walls are rising with the fireplace.

Photo to left: Completed firebox. Firebrick may be laid flat, but it’s more economical to turn them on edge, since they will be backed with solid masonry. The floor of the firebox is also firebrick. A refractory mortar that will take the heat must be used with firebrick. It’s thinly spread on both surfaces, with the bricks tightly fitted. Joints should be thin- 1/16” to 1/8”. A wet saw on site makes the necessary brick cuts. Some artisans use the chisel and hand sledge (by hand is greener only if you don’t mess up your cuts at $1.70 per firebrick). Standard firebrick are larger than ordinary brick, measuring 4 1/2 “ wide X 9” long X 2”+ thick. Other sizes are available.

Five critical features, make this a Rumford firebox. They are: the widely coved sides, the shallow firebox, the larger height and width of the opening, and the straight fireback. Count Rumford said that a plumb bob, hung from the chimney top, should touch at the center of the firebox floor. This is not possible with conventional fireplaces, because they have 3 slanted firebacks.


Conventional fireplace masons often shy away from a Rumford job, worried about building a fireplace that might smoke. The shallowness and height of the firebox scares them. But Rumfords draw better than low and deep fireboxes, which lack the aerodynamic features designed by the Count back in the mid1700’s. The Venturi-like throat piece can be seen in the photo to the right. Hand-shaped in terra cotta, it sits atop the firebox. It’s is a creation by Jim Buckley, (www.buckleyrumford.com) and the Superior Clay Corp. of Uhrichsville, Ohio (www.superiorclay.com). It combines the aerodynamic curve that Rumford likened to the “breast of a dove” and a narrow throat (4" wide). As Buckley will tell you, the throat becomes a nozzle, creating a laminar airflow and very hot flame that burns up most pollutants. A traditional throat is built with corbeled red brick. The mason must then parge the jagged interior with masonry cement for a smooth airflow. Working with Superior Clay, Buckley has developed several sizes of the smooth, fired ceramic piece pictured for different sized fireplaces. They save time and hassle compared to the red brick approach and simplify the task for owner-builders. In the photo below, Buckley muds up around the throat piece with 10" x 4" x 14" compressed earth block that weigh 40 pounds apiece. Note that a red brick arch has been built around the fireplace opening (wood form still in place). Ties are placed in areas close to heat and where masonry junctions take place. One commonly used masonry tie is Dur-O-Wal™, seen as the zig/zag silvery wire (truss type) in the photo. It comes in corner turns, straight lengths and ‘T’ shapes to tie intersecting walls. About twice the diameter of clothes hanger wire, it is galvanized and available in different widths from 4" to 16" (www.Dur-O-Wal.com). Dur-O-Wal adds ductility to the wall system.

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The Smoke Chamber. In the photo above, Buckley begins to build the smoke chamber. Like the throat, smoke chambers are conventionally constructed with corbelled red brick, then parged on their interiors to cut turbulence. And again, Buckley and Superior Clay combined talents to create ceramic smoke chambers- formed and fired just like ordinary chimney flues, in different shapes and sizes for a variety of fireplaces. To ship these heavy pieces and cut down on breakage, Superior Clay makes them in two halveseasier to cushion and wrap for a long rail trip. This owner found his Rumford components at Builders’ Materials, an Albuquerque masonry and fireplace supplier located next to the rail line. Check them out at www.buildersmaterials.com. Their store is like a masonry museum. In the photo to the left, Buckley stands in back of the finished smoke chamber. Note that the two halves of the smoke chamber are mortared together. All of the smoke chambers are made so that when joined, their top dimensions fit standard chimney flue liner sizes, such as 8" x 8", 8" x 13" and 13" x13".

STEEL LAYOUT for a CORNER or KIVA FIREPLACE 4, 1/2" diameter vertical rebars required from footings to chimney top. Cut to lengths handy for mason. Lap and tie with baling or tie wire to code as fireplace rises.

Edge of trench

Establish a "grid" of 1/2" diameter rebar under the fireplace on roughly 12" centers. It should be raised 2" above bottom of trench.

2, 1/2" diameter rebar continuous in footing pour, lapped and tied. Raised 2" above bottom of trench.

Note: Codes vary. Steel requirements and concrete strength in foundations vary according to seismic zone and soil conditions. This sketch is only one example. Check your local code before drafting your fireplace section.

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Above, the Rumford is basically finished (in the rough), although more flue liners and mud work will follow as the fireplace attaches to and rises through the bond beam and roof structure to become an exterior chimney. Later, the owner finished and exposed the earth block walls in their natural color, but plastered the fireplace and banco with a smooth, hard plaster for easier cleaning. The red brick arch was left exposed. Builders should acquaint themselves with the code in reference to clearances around fireplaces as well as structural requirements. Unless a fireplace has been specially engineered, you cannot use the fireplace mass as a bearing

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surface for roof beams. Plan checkers will look at your Fireplace Sectional Drawing and Roof Framing Plan to see if wood framing or vigas used in your design could pose a fire hazard where they come close to a fireplace. The current national code is the 2009 International Building Code (IBC). On page 438 is Section 2111, which covers masonry fireplaces. Count Rumford fireboxes are defined under 2111.6 (p. 439). Fireplace clearances start at 2111.11 (pp.439-440). Masons should be thankful to Jim Buckley who worked with the International Code Council (ICC) to write the Rumford paragraphs in this code, as well as update the clearances section. He has also been responsible for the inclusion of Rumford fireplaces under several states’ clean air laws.

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Fiber and Earth Block ~

Claude Hayward’s Adobe/Straw Hybrid Wall by an Adobe Builder Staffer Recent history One thing that Southwestern builders had learned by 1980 was that mass and insulation together work better than either one alone. Thermal testing at Tesuque Pueblo in the early 80’s further confirmed that placing mass to the inside, with insulation to the outside, works better than the reverse. Use the inner adobe or other earthen wall as a “storage” or battery bank and contain its warmth or “coolth” by insulating on the outside. In a cold winter climate, the general solution was (and still is) a choice of various insulation covers, nailed or foamed to the wall exterior, then finished with standard 3-coat stucco over 17-gauge wire netting. While one could argue that this is a de-facto hybrid wall system (vs. straight adobe), it became the “standard” adobe wall in Central and Northern New Mexico for new construction. While building this type of wall is partly the result of more stringent energy codes, it also has become a vital part of the success of passive solar designjust add big glass on the south with a climate-designed overhang and you can knock 60% off your heating requirement in January. The system also works because of a certain social/historical acceptance in New Mexico for plastering walls. The tradition stems from a long mud plaster history, in which teams of enjarradoras, maintained the sacrificial mud layers throughout many rural villages every few years, depending on weather wear. Manufactured and Hand-tamped fiber insulations As interest in Green Building accelerated in the late 1990’s, so did the cost of foam and insulation board, most of which is petroleum based. Products such as Agriboard began to appear. Agriboard is a stiff, straw board set in a plant-based resin, offering a decent R factor and no petrol materials www.agriboard.com. Agriboard gives the builder a greener choice, but is new and not yet cost competitive. The cost factor of the new natural fiberboards has led to experimentation with locally built wall insulations using natural fiber, such as Light Clay. An old technique, Light Clay uses a high percentage of locally gathered straw and can be done by the homeowner or builder. A light clay fill is basically 90% straw and 10% clay and will not burn. While damp, the mix is rammed into a frame or void, using hand tampers. Contractor Scott Cherry, of Lightfoot, Inc. near Santa Fe, builds a 12” wide wall using Light Clay with mud plaster and lime stucco scott@lightfootinc.com. His home won “ Best of Show” award in the U.S. Green Built Tour of 2010.

Using Light Clay with Adobe or other earthen walls To build an Adobe/Light Clay hybrid wall, the light clay is rammed into a non-bearing frame void, which sets on an exterior extension of the stem. New Mexico has a Light Clay Standard, which calls for the addition of Boric Acid in the light clay mix. This environmentally friendly chemical deters insects and is a fire retardant. One advantage to finishing a Light Clay wall (under a good eave) is its green simplicity: the direct application of a mud plaster as a scratch coat, followed by lime stucco. No wire is necessary. While the R factor isn’t as high, 6” of Light Clay can add an R-10 to the wall (R 1.8 per inch). This figure does not count the mass R factor from the adobe or earthen masonry, surface air films, plaster finishes, etc. Such a system will pass the NM energy code in colder winter climates. Using cellulose with Adobe or other earthen walls Another approach utilizes cellulose fill in an exterior wall cavity, next to the inner adobe or CEB wall. Cellulose has been around for years and is one of the original “greener” insulations, made of shredded recycled newsprint and cardboard. Like Light Clay, it also deploys Boric Acid. It has a higher R factor (R 3.4 per inch). Installation is usually subbed out to an insulation company, which has the proper blowing equipment. Lately, some big box building stores are renting out pumping equipment for cellulose-based insulation that do-it-yourselfers can handle. Adobe Builder has discussed the cellulose choice with several installers, who cannot agree (as yet) about whether you should build the non-bearing frame/cellulose wall first and then the adobe wall, or lay up the adobe wall first, then build the frame/cellulose wall last. The argument stems from each applicator’s different approach to spraying the cellulose into the cavities. More about this wall type in the next issue.

The coming insulation market Yet another group of green insulation materials are plant derived. An example is derivatives of the castor bean plant, which are coming on the market as insulating foams. They will be proprietary in nature and while getting off the petroleum base is a positive, they are likely to require certified applicators. However, plant-based spray foam insulations will join cellulose as one of the greener insulation choices.

In summary, a cellulose system does not use as many local materials, and is generally a “paid” service. However, it supports a local business, uses recycled paper materials and provides a higher R factor.

A local, simple, cheap and green approach Enter adobe contractor and TEG member Claude Hayward, whose project near Anton Chico, NM is pictured here. The structure is

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Top Photo - Building the flagstone shelf and a view of the pump house foundation. Note how the ground around the construction has been built up, with the flagstone leveled and dry stacked without mortar. The loose stacking in layers provides aeration and deters rising moisture. A vapor barrier will be placed over the flagstone and innerfoundation before walls rise further. Middle Photo - Tying adobe to straw bales. In this view, adobe walls are up about 14" or roughly the height of a bale. Note the welded wire placed over the top, which will tie adobe and straw bales together. The wire has highembodied energy, but not much of it is necessary when used every 14". Bottom Photo - Repeating the tie at second bale height. Walls are up to the second bale height and welded wire tie is repeated.

the family pump house and cold pantry. It did not freeze within despite the 18° F. below zero cold in the 2010/2011 winter.

To be fair about energy use, one should look at the embodied energy in the average straw bale. Is there a figure? For example, a 10x4x14” adobe block is estimated to consume about 2500 B.T.U.s. An 8x8x16” concrete block consumes about 29,000 B.T.U.s*. Most enthusiasts forget that bales consume energy in their manufacture. Mother nature grows the plant, but has anyone yet pro-rated the energy consumed by field equipment and irrigation power? What about the embodied energy in manufacturing a baling machine, followed by its consumption of petrol fuel? Baling machines are not cheap ($17,000 and up). However, as mentioned, bales are a local product and usually do not have to be transported over long distances to the building site. Making up straw bales creates a useful product as opposed to burning off chaff filled fields that lower air quality. If you’d like to talk to Claude Hayward about building his system, give him a ring at 575-427-4202 or drop him an email at Chayward45@gmail.com

*McHenry, P.G., Adobe, Build-it-Yourself. Univ. of AZ Press, 1973. Continued next page

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Photos by Claude Hayward

Claude Hayward is owner of the Earthspace Construction Company and has been a New Mexico adobe builder for some thirty years. As hybrid wall design becomes more complicated (and sometimes costly), he finds his Adobe/Straw bale Wall a relatively direct and simple approach. Obviously, the insulation system is practical, as the blocklike nature of the bales eliminates the need for a frame housing. A wider supporting base must be provided, which would cost more in concrete, but using Claude’s dry-stack method (see drawing and photos) the flagstone is locally gathered (green), while providing aeration to stop rising damp. The method uses local labor, and most of the materials (bales included) are local. And of course, the adobes are made right on the site.


CORRECT PROPORTION BUT NOT TO SCALE NOT FOR A SPECIFIC PLAN

Legend Note: Not all aspects of a structure are shown. For example, roof insulation scheme or roof framing details. Consult your local codes before final drafting. Know local site requirements if building in a flood plain.

1. ½" anchor bolts, 24" O.C. 2. Wood Nailer Plate, typically 2" x 6" 3. Steel Form Clip (see number 19) Remove after concrete has set. 4. Form board. Jammed in between adobe and straw bale. Level for screeding concrete. Attached by screws through inner side of gringo block left partially filled. Leave in place. 5. Concrete bond beam as per code. 6. Gringo Block set in course every third block of top course, plus two in each corner, partially filled as attachment for bond beam form boards and to allow concrete into top hollow of each gringo block. (see number 20) 7. Provide min. 18" overhang. 8. ½" dia. Rebar driven into bales vertically. 2 per bale. Drive through 2 bales and half way into third. 9. Adobe wall, 10" minimum width. Plan 3 courses to equal 14". 10. 6x6/10x10 remesh spans both adobe and bale widths as a bond. Every bale course equals 3 adobe Courses. 11. Mud plaster or stucco. 12. Straw bales typ.18" wide x 14" tall. 13. Vapor barrier across top of stem wall and flagstone. Leave protruding over stone as a drip edge. 14. Compacted fill at least 8” above original grade. Compact ground around stem before placing. 15. Original grade line. 16. Concrete stem to code. 17. 3 courses, dry stacked flagstone scrap. 18. Concrete footing to code. 19. Steel form clip. Comes in 2" width increments. 20. Wood gringo block, made of 2"x4". Forming up bond beam. By referring back and forth between this photo and the wall section drawing, the reader can locate #6, or the gringo block. In the photo, the worker’s right leg is coming down in front of the gringo block, which is a wood nailer to which the bond beam form boards are attached. The hollow interior of the nailer is half-filled with mud. The stones serve to keep the steel rebar raised so that the bond beam concrete will flow around the rebar. The bond beam is #5 on the wall section drawing. In this photo, the outer bond beam wood forming has not yet been placed and a wood “bottom” has not yet been built under the forming where it goes over the door. The wood forming is tilted so that the resulting bond beam will create a sloped, shed roof. Anchor bolts will be set in the void before the concrete pour, providing attachment for a wood nailing plate, followed by an insulated roof. Note the ladder adobe forms in the right photo background and the adobe mud pit at upper left.

THE EARTHBUILDERS' GUILD

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TAKING A SOLAR ADOBE PLAN THROUGH HERS (HOME ENERGY RATING SYSTEM)

Photo by H.Y.

By Adobe Builder editor, Joe Tibbets and certified HERS Rater, Jane Whitmire With quotes from Architect, Mark Chalom

South or solar side of plan 1870

Why passive solar? ince about 1976 in the Southwest, the earthen home with its tons of mass, has been regarded as a natural for passive solar design. Perhaps I should say starting around 1000 A.D., as Anasazi cliff dwellers utilized passive solar principles. Today, Passive Solar can be defined as a solar system with “no moving parts”. It uses the calculated placement of adobe or rammed earth walls (mass), insulation, overhangs and glass. Then, secondary solar technologies, such as PV, wind, and solar hot water can be added.

Day charts. If you stay above certain minimums set by the IECC, your design will pass the energy code. If it doesn’t, the designer may add insulation, reduce the size of north windows, or otherwise rework the design to pass.

While a good passive solar design can knock up to 60% off your January heating bill in a Northern New Mexico winter, there’s another big reason to use it when applying for energy rebates. Simply put, if you don’t deploy passive solar in your design, you may not attain the required rating on your HERS report that will qualify you for available tax credits/rebates, or in some cases, even a building permit. That is one of the startling facts that I learned when HERS was applied to Solar-adobe Plan 1870*.

The energy calculations are submitted to the building dept. along with the working drawings and permit application. The only cost in doing the energy calcs is the time required to do them.

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TYPES OF CODES AND PROGRAMS Minimum Required Codes are adopted by states, counties and cities to cover all new construction where spaces must be heated and cooled. These codes work off the International Building Code or “I” codes, which have become the dominant code family in the U.S. The 2009 International Energy Conservation Code (IECC) is in use now (2012). It sets a minimum standard for building energy conservation, such as minimum R values for roofs, walls, and foundations, along with minimum U-factors for windows and doors. The IECC does recognize some aspects of passive solar design, such as a credit for mass. Required Rs or Us are set by climate zone or more accurately, via Heating Degree

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“Tradeoff Worksheet”, popular with builders. This sheet allows the designer to juggle components in the thermal envelope to reach compliance.

States, counties and cities adjust the “I” code to fit their local usages, but cannot drop below the national standards when modifying. The general supposition is that regional modifications are desirable, given the great diversity of climate regions across the country.

Higher performance programs The other type of energy programs is not codes, but may set standards as codes do. Some are free, some cost a little and some are expensive. They can be written by private companies or by non-profit organizations. Some require you to buy and learn software. Others require a paid, third party to work with the designer or draftsperson and HERS is one of those. In some cases, building departments accept them in lieu of a minimum required code.

The 2009 Residential Applications Manual by the New Mexico Energy and Minerals Dept. is an example of a practical publication that recognizes passive solar. While not a professional design manual, it lays out certain basic parameters. It gives credit for solar gain through south glazings. It ties to the 2009 International Energy Conservation Code. It also provides a

Many of these programs have been around for years. One example, dating to the 1980’s is the Sustainable Industries Building Council headquartered in Washington,D.C.or www.sbicouncil.org/ The SBIC is a non-profit association of designers, architects, engineers, product manufacturers and professional building associations. Architect Mark Chalom of Santa Fe, points out that the SBIC builder guidelines are user-friendly, “allowing the


designer a way to design good passive homes simply”. He sees the SBIC guidelines “as the most used program during my career” (Mark has been designing with passive solar since the mid-1970’s). The cost of the SBIC program is affordable and comes with a CD and passive solar design manual. SBIC’s guidelines have become popular across the Southwestern Region. Energy 10 is a successful software for earthbuilders who design with passive solar. As expected, the software must be purchased and learned. Mark Chalom calls it “a very good design tool, sophisticated enough to seriously fine tune any aspect of a passive solar building.” But he also warns the novice that “Energy 10 is not a friendly program for the average contractor to want to deal with”.

Jane Whitmire is a certified HERS Rater, NAHB Certified Green Verifier, and Certified Green Professional. She is also a member of The Earthbuilders’ Guild. Photo by H.Y.

HERS also sets a higher bar and its objective is to quantify the energy use of a home, typically by a “third party”. The goal may be energy rebates or a desire by the architect or dweller to document a higher energy saving standard (valuable later, if and when the home is sold). HERS is different in that it requires you to work with a third party, known as a ‘rater’. Going through the HERS process is more involved and may require you to pay more for energy conserving mechanical equipment to achieve a desired level as compared to a “minimum” code. The credits and rebates exist to reimburse you for the extras you may have to buy and apply to achieve the higher standard. Many green building certification programs, such as LEED, ENERGY STAR Homes or Build Green New Mexico require a HERS score as part of the certification process. Is Passive Solar credited? The various RESNET approved HERS programs probably give different “weight” to passive solar design factors. REMRate was used for this project, and while there are varied opinions regarding if enough credit is given for mass and passive solar features, the program is regularly updated when new data comes to light, according to Jane Whitmire. Finding an appropriate HERS subject For this article, we utilized a Solar-adobe just being finished in Santa Fe County (plan 1870). By the time our article was under way, the owners had moved in, so inspections typically done during the construction process to verify the quality of insulation installation could not be done. However, HERS rater Jane Whitmire suggested that we take the home through all of the calculations to reach a projected score, which would be likely to mimic the final score, assuming a tight home.

of the home in square feet. The combined glass area of all south-facing windows, doors and Trombe walls (see plan) make up about 15% of the total heated interior square footage (roughly 1,500 sq. ft. not counting space lock entry). The floor plan shows that 1870 has 14" thick pressed earth block walls on exteriors with R-10 insulation outside and a hard plaster cover. There is also a large amount of interior wall mass in 10" earth block. The floors are red brick (a solar absorber), placed by brick floor installer Lorraine Duran (Lduran5563@aol.com). Underground rated insulation (blueboard- R5) is buried under 4" of packed dirt (all floors), with an under floor radiant heating system in the sand bed under the brick. A bright spot is the Count Rumford fireplace, which the dwellers love for its

visible flame and radiant output. There is a space lock entry room on the north side, which the owners feel is very effective against cold, north winds. The home has 6"x10" exposed wood beams under a 1x8" rough-cut deck and a well-insulated ceiling. The roof pitches to the south over a designed solar overhang (cuts high summer sun, lets low sun in during winter). Those are the Plan 1870 basics*. First, a little about Jane Whitmire, followed by her words about HERS and Plan 1870. Jane is a certified HERS Rater, NAHB Certified Green Verifier, and Certified Green Professional. She is a past Co-Chair of the Education Committee of USGBC-NM, and an active member of the Green Build Council of the Central New Mexico HBA. She is a member of The Earthbuilders Guild. Her words will be in blue. Continued next page

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Solar Adobe Plan 1870 The home is at 6,300’ elevation, close to mountains known for wind and snow during winter.1870 represents the overall footprint

Space lock entry room on north side of plan 1870

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F1

F15

F16

F3

F5

Here are some of the most common questions I’m asked about HERS:

F10 F2

F4 F14

What is a HERS Rating? A HERS (Home Energy Rating System)

16 Key Features that make this Passive Solar Home Work

F7

F6

Jane: After living in a well intentioned but poorly built passive solar home for 14 years, my husband and I knew what we wanted when we built our current home. We worked closely with our designer and our builder to create a sustainable, efficient home, which led me into the growing field of energy rating and green building in New Mexico

F1 Windows reduced on west wall (less summer heat gain, less winter heat loss) F2 Windows reduced on north (less winter heat loss, less heat gain on summer afternoons).

F5 F8

F13

F4 French door also used as one-lite solar door (for added winter solar gain). Dbl. glazed, tempered.

F9

F10

F14

F15

F7 Interior adobe wall mass around home interior. (they act like storage batteries to retain winter heat and “coolth� in summer. Thermal moderators. Also excellent for acoustics throughout home).

F16

F8 Pantry acts as buffer on north of kitchen (cooler spot for stored foods, reduces heat loss from kitchen to north in winter).

F6

F10

F5 Most of south wall in Direct Gain glass or Trombe Wall - fixed and openable units. (For solar gain, the total sq. ft. of all south glass amounts to about 15% of heated and cooled space in this climate). F6 Floors are brick over sand over 4" of packed earth, underlaid with R-5 underground-rated insulation board. Hydronic radiant system in sand bed under brick. (masonry floor means less heat loss vs a hollow underfloor crawl space. Floor mass with adobe walls and perimeter insulation (F15) act to keep energy inside as well as radiant system heat).

F4

F7

F3 Closet areas used as buffers on north side (to reduce winter heat loss).

F12

F9 Thermal Space Lock on North (serves as mud room, but acts as buffer to keep entry cold out of living area. Helps as thermal buffer for living room).

F5

F10 Well insulated (cellulose) ceiling above. R-45 + F11 This was intentionally left out

F14 F6

F2 F3

F5

F12 Count Rumford fireplace- (puts out much more radiant energy than average fireplace. Set in corner to radiate out to all other corners of living space). F13 Half wall here (allows more open space and air flow through central portion of home for better heat/cool distribution). F14 Designed solar overhang projects over entire array of south-facing glass. (this is a climate-specific overhang designed by seasonal sun angles, in this case, about 24" wide. Shades south wall all summer). F15 Code required perimeter insulation around entirfoundation/stem of home. In this climate, it is R-10

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F16 14" exterior adobe walls (mass), plus R-10 cover (insulation) makes an effective thermal team.


rating is a uniform way of quantifying or rating the energy performance of a home. The HERS Rater gathers data about the home from blueprints and information provided by the builder, and enters it into a home rating computer program. The rating program compares the home being rated with a reference home, and assigns the rated home a point score depending on its relative efficiency. The reference home is a virtual home that is “built” by the home energy rating computer program as a duplicate of the home to be rated. The reference home, built to the 2004 International Energy Conservation Code (IECC) standards, is given an index of 100. A zero energy home, which requires no outside energy source, represents an index of 0. Each one percent improvement in performance of the home being rated compared with the reference home decreases the index of the home being rated by one point. Therefore, a home that is 40 percent more efficient than the reference home would have an index or rating of 60. The information contained in a projected rating, or rating based on plans, must be verified by field inspection and air tightness testing before a confirmed rating is issued. What Does HERS Look For? HERS programs weigh the components that predict the energy efficiency of a home, including: The geographic location of the home with heating and cooling degree-days The building shell measurements and materials (including R-values) Window values, orientation, and shading. Mechanical equipment, and loads from lighting and some major appliances. Infiltration rates and duct system tightness are added after final testing. Thermal mass from walls and floors, and power generated on-site from wind or solar can also play a significant part in reducing a HERS index. The rating does not include occupant influence on energy use, including plug loads, clothes washing and drying, cooking, or factors outside the conditioned space.

Don’t just build to code minimums – when installed correctly, additional insulation will slow heat transfer into or out of the building and impact the HERS index. Take advantage of proper solar orientation and shading whenever possible. Mass walls and floors can have a big impact on heating and cooling loads and be positive factors in the HERS rating. Windows matter – lower U-factors mean less heating and cooling loss. Windows with higher solar heat gain coefficient (SHGC) will transmit more radiant heat through the window vs. the radiant heat striking the window, so use them properly. Be careful that your south solar gain windows are allowing the maximum insolation, not reflecting the sun back out. Use the highest performance mechanical equipment and water heater you can afford. The HERS index rewards high efficiency and the homeowner will appreciate it for years to come. The Blower Door Test Blower door testing measures the amount of air leakage in cubic feet per minute (CFM) of a building at a consistent pressure (generally 50 Pascals). Contrary to popular belief, doors and windows are typically not the major leakage sites in new homes. As mentioned above, adobe is generally more air tight, but you should check any wiring and plumbing penetrations, chimney chases, recessed light fixtures, and other gaps in the building’s exterior, floor, walls or ceiling. After any framing is complete but before insulation is installed, larger gaps should be identified and blocked with a solid air barrier like OSB, or Thermoply; smaller holes can be filled with expanding foam or caulk. Unless they are mechanically fastened, changes in materials should be foamed to seal. Don’t forget that vented attic space and garages are outside the thermal envelope and should be sealed from conditioned space. The Thermal Enclosure System Guide, which is available on the ENERGY STAR website (www.ENERGYSTAR.gov) can be very helpful when identifying common problem areas. A few more words can be added about Solar Adobe Plan 1870. Before the interior mass (adobe walls and brick floors) was added, 1870 earned a projected HERS index of 68, based on the specs and plans. When I added the mass from the floor and walls, it dropped to a 52, which is a HUGE drop. So the program recognized that giving the solar gain from south windows/solar features somewhere to go

besides carpet or drywall would make a huge difference in heating loads. If we had included some sort of mechanical cooling, it would have done the same for cooling loads (in shaded rooms). This was with R14 walls as noted on the plan (opposite page), not some massively insulated beast. My guess is that more insulation would improve the rating further, but is obviously not required. Assuming reasonable blower door test results, Plan 1870 would easily qualify in the energy section of the New Mexico Sustainable Building Tax Credit, which requires a score of HERS 60 or less. For the record, it would have qualified for the $2000 federal energy efficient tax credit for new homes that expired on 12/31/11, which was much harder to achieve. With Plan 1870, the effectiveness of adobe and other mass in a house properly glazed and oriented to take advantage of solar gain made the difference. Architect Mark Chalom of Santa Fe, along with other passive solar professionals, has had insightful questions about HERS, which has come under its share of criticism. While software is not always updated as quickly as we might wish, I believe that programmers of energy modeling software are dedicated to making their products as accurate as possible. Below are Mark’s statements and questions in brown, with my answers in blue. Joe has added further words in black at the end of this article. Mark: I feel that HERS is limited because it is not a design tool a contractor can use independently. One must hire a HERS rater and pay for each run. This is expensive and HERS raters are not always trained in building science. Is it true that they receive just a one-week course in using the software? Jane: Well, after a rigorous certification program with a heavy emphasis on building science, RESNET requires that HERS raters earn CEU’s to maintain their certification. In combination with approved software, this knowledge directly benefits the designers and builders working with those raters. Mark: HERS will pass a building with poor energy performance if they buy down their energy use with PV. This is very wrong, don’t you agree? Jane: HERS ratings measure net energy use, but don’t judge how that level is achieved. While the ideal might be a totally passive solar home, some dwellers may still need PV for electrical needs. HERS looks at the bottom line. Mark: The third party verification may become a reality. How would you justify that? Continued on Page 21

▲ ▲

Things To Do or Not Do Build it tight! Air movement through and around insulation will dramatically reduce performance. The ENERGY STAR Thermal Enclosure System Guide has some excellent information regarding common problem areas and how to fix them. Adobe is often tighter

than frame, but mud joints should be air tight, and areas around window and door bucks should be well sealed.

13


Contractor Profiles ~

Above: South view showing bays for large glass doors that bring in the low winter sun.

Sean Kaltenbach of New Mexico Earth Works in Cochiti, New Mexico Lic. # 368104

W

hen Sean Kaltenbach and crew show up on your site, you know some work is going to get done. Sean, a native of Las Cruces, New Mexico, learned construction from his father, a now retired homebuilder. Frame construction was their mainstay in past years and Sean grew up around those trades, while learning about banking and the business aspects of building. “The allure of Adobe was always around”, Sean told Adobe Builder, “but at some point I couldn’t resist getting into it and now with multiple earthbuilding projects under my belt, new doors continue to open. I like the idea of adding new skills that are traditional and green at the same time and of course, solar design potentials are always there in our sunny, Southwestern climate.” Sean’s deference to tradition is reinforced

by his predominately Native American crew, from Santo Domingo Pueblo. With a wry sense of humor and a steady work ethic, their skills might challenge a few adobelaying records. This last summer (2011), they laid up the adobe walls on a 1310 square foot passive solar home at Quemado, NM in 66 hours. And most of the walls were 14” thick, not 10”, including a large, interior adobe wall and some substantial buttress work. Sean’s knowledge of framing comes in handy on a job like Quemado, where viga ceilings and exposed deck support a gable style roof, with storage space above. The clients, whom we can mention here as Marilyn and Nancy, had become their family’s representatives for the project. They enjoy camping out on the site during

Above: Nancy and Sean stand under the passive solar cut-off point indicated where the two strings cross above them. Left: Interior view of the main south room, looking east.

summers at the 7300-foot elevation and have been open to green solutions, such as lime stuccos and earthen plasters.

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Adobe Builder visited the site while framer Gene Currie helped with projecting the roof rafters down on the south to set the proper solar overhang. Using the classic sun angles of 35° and 73°, which work well in Arizona and New Mexico’s more Northern elevations above 5000 feet, the crew pitched in to fix that magic cut-off point in the sky. “This is probably as close as the Adobe Industry comes to the old joke about a sky hook”, stated one crewmember, as he held up a


vertical piece of lumber on which to mark the edge of the overhang. And while the rig of strings, nails and boards was temporary, the point set is important. It will allow in the low winter sun, but create a shade zone on the south in the summer. “The three, eight foot by eight foot sliding glass doors do let in quite a chunk of warmth in the winter”, says Sean- “ and the views out over the mesas and surrounding hills seem to give everyone that extra kick of energy.” Working by stages on the Quemado job has allowed Sean to pursue projects on his own home at Cochiti near Santa Fe and at Lake Valley and Las Cruces to the south. “It’s been interesting to work with the different types of earth block on the market,” says Sean. “Right now, I’m tending to favor the workability of the emulsion stabilized adobes because of their more sculptural qualities. The Portland stabilized block worked well on our contemporary style adobe at Cochiti. But they are very hard and if you don’t use the right set of tools and fasteners, you will bend nails and lose some time.”

Above: Sean Kaltenbach and Nick Quint at the new Cochiti adobe. Below: Two views of the children’s bedrooms at the Cochiti adobe.

With the NM Earthen Building materials Code now requiring straight and level masonry work, Sean uses tall speed leads, common in neighboring Arizona, which maintain a craftsman’s standard of plumb walls. Wall surfaces are worked according to whether they will be exposed or covered, with joints left partially open as “keys” when a plaster is applied. Sean has spent considerable time studying lime stuccos and used them extensively with organic dyes on the Quemado project. “At one point, I had many barrels of lime putty out here, and I developed recipes mixing the lime with certain sands and organic dyes to get desired effects. It’s a bit like eating potato chips- once you start, it’s hard to put that bag down!” Below: View of the west side of the Quemado project. Note 14" thick adobe wall with massive lintel above the doorway. Rather than use trusses, Sean deployed a ridge board and TJI beams which allowed more room for attic storage. Insulation board, wire and stucco were applied later to adobe walls.

Sean serves as a Board member on The Earthbuilders’ Guild and supports the concept that a trade must accept the responsibility for protecting itself. “Today, with the code cycle changing every three years, and with market and political influences on-going, you have to be proactive about staying up with your trade. Add to that all of the interesting green innovations coming on line. Start ahead of time to ask yourself how a particular green application will meld with traditional forms of adobe architecture. If one becomes popular, we might have to deal with it in our codes and staying on top of a new trend does give you a certain edge.” Married with two daughters, Sean’s ability at multi-job coordination means he’s not home as often as he’d like, given that the jobs are spread around. Says he, “I think

during these times, the Earthbuilding contractor needs to stay nimble and versatile. Gone are the days when customers lined up with their bank loans approved and at the ready. Be willing to figure in ample petrol for your supply and building budget, as you may have to drive the many miles between job sites.”

Sean Kaltenbach 505-490-0238 Adobe & Compressed Earth Block Construction Earth & Lime Plastering, Custom Plaster Finishes www.newmexicoearthworks.com info@newmexicoearthworks.com

k

THE EARTHBUILDERS' GUILD

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Thirty Years of Rammed Earth & Adobe Solidity ~

SOLEDAD CANYON EARTH BUILDERS

of Las Cruces, New Mexico NM Lic. No. 56340

Below: Livingroom of the Williams/Perry home in Old mesilla.

S

oledad Canyon Earth Builders began in the early 1980’s in Las Cruces, New Mexico, when Patricia Martinez met Mario Bellestri and their common interest around adobe and rammed earth inspired the company. Their first project was their own home. By the late 1980’s, rammed earth had become well established in this part of the Rio Grande Valley as an alternative to adobe, largely thanks to their efforts. Mario’s interest in rammed earth peaked after attending the Earthen Technology Conference at the University of Arizona in Tucson. Pat’s abilities at organization, marketing and public relations laid the groundwork for Soledad’s almost continuous exposure in home shows and tours, and as Pat would tell you, “this is such a critical part of this business- it’s important for interested parties to realize how strong and comfortable these houses are. And here in Las Cruces, the eighteen inch plus walls are perfect for our long, desert summers.” Today, after 73 completed homes in rammed earth, (and adobe) a Soledad Canyon home has become one of the premier real estate investments in the Mesilla Valley. An indication of this was that during their early years, it was difficult to get an accurate appraisal on their homes because the dwellers didn’t sell- they were content in their “forever” dwellings. “Once moved in,

Over time, the company developed several handsome home profiles, characterized by stepped parapets in what one could call Pueblo~Contemporary style. Mario and Pat retained some traditional New Mexico elements- shaped corbels, vigas, latillas and the artistic tile, but their use of open space, with a variety of ceiling and alcove effects has always been a trademark. Mario also contributed new construction details, now a part of the New Mexico Earthen Building Materials Code. One example is the bond beam detail he developed for extra wide walls. It’s use of anchors, laminated

plywood, and wood rails offered an inexpensive, off-the-shelf solution that was less time consuming for the builder and expanded the choices for double adobe walls as well.

Back porch of the Armijo Street home

Patio fountain in courtyard of the Armijo Street home

Although most projects the company builds average 2,500 sq. ft. in size, they are capable of smaller, efficient dwellings. Working with Habitat for Humanity several years ago, their small home design was constructed in rammed earth in the Las Cruces downtown area, where it was at home with the older adobe structuresand celebrated for its efficient use of space.

Pat Bellestri-Martiniez (l.) with friend Jane Whitmire during and Earthbuilders Guild meeting.

our clients were happy in their homes. Without any of them selling, there could be no comparables for appraisal purposes. It was and is a great compliment, but at that time, a little frustrating”, remembered Pat. She also acknowledged that “with our sub-contractors, we create quality homes. They are a talented and dependable group of craftsmen and most of them have been with us for years – for example, our Electricians have been with us from the beginning.”

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In the late 1990’s, Mario served on the executive board of the New Mexico Homebuilders Association, and in 1998 as its President, which helped rammed earth gain wider acceptance among builders and increased its visibility to coding officials. After Mario’s passing in 2008, Soledad Canyon was able to continue and grow the business, in spite of this untimely loss. Pat obtained her New Mexico Contractors License within 90 days of Mario’s passing in order to continue the business of building rammed earth homes. Their son Max had grown up in the business and decided at that point to join Soledad Canyon in an official capacity. Melissa began working with Pat & Mario in 2004. Today, Pat, Melissa (Max’s wife) and Max Bellestri are all co-owners of Soledad Canyon Earth Builders. As a team, Max, Melissa and Pat work with the clients in placing the home on the building site, designing and making selections for the home. Melissa is the Estimator. Pat & Melissa share construction management. Max’s duties center around financial, technical and web site management. When The Earthbuilders’ Guild needed a web site, Max went to work and TEG was on line faster than you could tamp a section of twofoot thick wall. Max has been a key aide for Pat in her work as a board member in The Earthbuilders’ Guild.

Above: Entry to Armijo Street home.

Below: Max Bellesri

Soledad Canyon also blends adobe accents with their rammed earth work including adobe fireplaces. If the client wants a curving adobe wall that disappears into a rammed earth wall, they can do it artistically. The Armijo Street home (see photos bottom right, opposite page) is a custom home built on an in-fill lot in the Alameda historical district of Las Cruces. It’s a 2,107 sq. ft. home (heated area) with 3 bedrooms, 2 1/2 baths, a 475 sq. ft. garage and 438 sq. ft. of portales (porches). It is constructed of 18” rammed earth walls. Other components of this sustainable home include: tankless on-demand hot water heater, aluminum clad/wood casement windows with low-e glazing, dual flush commodes, open cell spray foam insulation, water saving plumbing fixtures, Manabloc plumbing system, energy star appliances, energy efficient HVAC package and xeriscaping. The Williams/Perry home (see top photo, opposite page) is located in historic Old Mesilla (site of the Gadsden Purchase signing) next to Las Cruces. Today, Mesilla nurtures its history along with numerous adobes new and old, mixed in with Pecan groves, cotton fields and views of the nearby Organ Mountains. The Williams/Perry rammed earth home is

3,445 sq. ft. of heated area, 604 sq. ft. of portales, and an 852 sq. ft. garage. Along with all the typical features of an SCEB home, it produces about 80% of its electricity via a bank of photovoltaic solar panels on the roof.

Soledad Canyon maintains a warm and welcoming office at 949 S. Melendres St. within the Downtown area of Las Cruces. Call 575-527-9897 or visit them on-line at www.adobe-home.com

Viga ceiling with grape stake latillas in a new Soledad Canyon home.

17


Contractor Profiles ~

The change of occupation required some preparation. Ernesto enrolled in classes at Central New Mexico College for electrical, plumbing and AutoCAD. He attended a vault and dome workshop, led by Quentin Wilson. He studied with adobe vault builder Simon Swan in presidio, Texas. He trained under Associated General Contractors to become a certified brick mason, a 3 ½ year apprenticeship. His abilities with brick led to firebrick and then to Count Rumford fireplaces. He studied the Grubka, an efficient masonry stove of Russian design.

Ernesto Aragón of Adobe

Palaces

in Albuquerque, New Mexico Lic. # 94663 By an Adobe Builder staff reporter~

W

alking around the front of a red pickup that appears to have lost it’s battle with a stack of adobes, I hear the strains of a corrido from in back of the building site. There, under a shady, fall cottonwood sits one Ernesto AragÓn, conversing with his client. Laughter can be heard from the two as they gesture over a set of plans. The discussion has to do with Ernesto’s rendition of a Rumford fireplacethis one with a rounded Kiva-style firebox. In this languid autumn scene, the workaday rhythm of adobe laying is broken only by the occasional beat of the plaster mixer or an exclamation from the crew. There’s that timeless New Mexico quality. Suddenly I have a flashback to an earlier fall day- the Albuquerque valley in 1965 when I worked on a Dietz Farms adobe crew. The names of adoberos from that time swim by- Jim Schull, Nick Garcia, Leo Bartolucci, Ralph Roybal, Louie Padilla, Nat Kaplan, H.L. Cleff- the list goes on. Ernesto recalls names that connect the dots between his adobe decade and mine, such as Quentin Wilson of El Ritoanother key adobero who spans the years. Then there was Albuquerque’s “adobe Mayor”, Harry Kinney, who between his two terms became an adobe contractor and built several nice ones on the west bluffs. You have that sense of traditions being kept- and passed on. Local crafts folk, local materials, local character, local economy still perking along in spite of the worst recession on record- this has to say something about the uniqueness of the region. Does it operate on its own set of energies? Is it a kind of separate economy? Shades of Carlos Castaneda? Who can say? In any case, today, it’s got to be the somewhat jolly, energetic quality of Ernesto himself, combined with that air of substantial informality so characteristic on adobe sites~ a timeless quality indeed. I realize that Ernesto’s operation is in that true New Mexico character, often making adobes right on the site; utilizing the crew’s skills in sculpting, carving and plastering, so as to add that touch of artistry. A quarter century back, Ernesto cruised by adobe houses rather than built them. As a patrolman on the Village of Corrales Police Dept., he was fortunate:Corrales has a high percentage of adobe homes (even then his hobby), ranging from historical sites to hacienda-style B&Bs to custom solar adobes. While still a patrolman, he and wife Dolores built their first adobe. Dolores mixed mud, laid blocks and accompanied Ernest on viga gathering trips to Chimayó

18

At first, jobs were diverse. For example, some years ago, the Bureau of Indian Affairs had prescribed a poor fireplace design for Pojoaque Pueblo. The resulting fireplaces put out little radiant energy- and they smoked. Ernesto had to rebuild all twenty fireplaces at Pojoaque to complete that job. At Tingley Beach in Albuquerque, Ernesto built a quarter mile of stabilized, exposed adobe wall and several adobe entry pilasters at the Albuquerque Botanical Gardens. Ernesto Aragón and the Jémez. After retirement, Ernesto was still young enough to turn his hobby into a second career. In the mid-1990’s, Adobe Palaces began.

Masons are attracted to arches and if you turn an arch 360 degrees, it becomes a Below: Wrought iron railings in the Aragón residence are built on solid adobe starways that are several feet thick!


dome. Turrets can support domes and both remind us of castles. Ernesto likes to build castles and palaces in the residential scale. If this sounds fanciful, it is. One of his castle inspirations is Saint Michael’s Mount in England, with its stone balconies and turrets. In 2012, an ultimate palace project looms ahead. Ernesto’s client wants an 8000 sq. ft., two-story “palace adobe” on the Bluffs of Northwest Albuquerque. It will sport handcut stone windows, a marmolina finish and yes, adobe turrets (see rendering to right). Every adobe contractor has his symbol or signature, left somewhere on the structure. With Nick Garcia, it was a flower design or rosette, set into the plaster finish. With Terry Taggart, it was the way joinery was handled in his wood bond beams and how adobe walls were exposed on the interior. With Ernesto, the signature must be a dome, vault, turret or similar shaped form- even an horno will do! At a recent project on Sunset near Five Points (in Albuquerque), his 1934 sq. ft. adobe sports an entry dome. Ernest also likes wrought iron. Once, while watching a Mexican novela (soap opera), he spotted a wrought iron staircase, which inspired the staircase in his current home, the 4800 sq. ft. two-story adobe pictured on the previous page. Ernesto may have suffered a bit during a current project on Candelaria Road in Albuquerque (see photo to right), as it has no domes or vaults. But the handsome ceiling and adobe fireplace make up for it. That project adds 2700 sq. ft. to an already existing adobe. Ernesto notes that during better times, families used to upscale to larger homes in new locations. Today, they are staying put and expanding their existing homes. Ernesto is a member of The Earthbuilders Guild. Contact him at (505) 907-3773 or drop him an Email at ernestaragon1@gmail.com

THE EARTHBUILDERS' GUILD

Photo with stepladder above: Larger room in the 2,700 sq. ft. addition with Rumford fireplace roughed in. Photo to left: Same fireplace with a lime stucco finish. Photo with adobero on ladder: East wall of same addition in 14" thick adobe during construction. Photo to right: Upstairs bedroom with arches at the Aragón residence.

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REGIONAL BUILDERS and SUPPLIERS ADOBE BLOCK WORKS Design~Drafting~Adobe Facility Set-Up Jonathin Spinner ~ Experienced Adobero Southern, AZ and Baja California 480/449-0212 jon@adobeblockworks.com jespinner@gmail.com

Adobe Bóvedas & Vaults

Old World Craftsmanship with Joe Fait Scottsdale, AZ • jfboveda@cox.net 480/443-8477 • AZ ROC 198444 • 480/510-8478

ADOBE IN ACTION

505/310-3259

Promoting Economic & Community Development through affordable Adobe Home Building Santa Fe, NM www.adobeinaction.org Teg member

ADOBE INTERNATIONAL Manufacturers of Earth Press models II, III and V Milan, NM www.adobe-block.com adobe@7cities.net Since the 1970’s 505/287-3961 ~ 505/287-0103 cell

Adobe Palaces by Ernesto Aragón

Lic. 94663  Albuquerque, New Mexico  Member TEG Custom Adobe Homes– Domes– Arches–Traditional Crafts Ernestaragon1@gmail.com  505/907-3773

22 years of Customer Satisfaction Advanced Earthen Construction Technologies San Antonio, TX 210/633-3224 aectceb@yahoo.com www.aectceb.com

K. Ben Loescher, AIA | ICC | NCARB

Golem

Los Angeles, California TEG Member 760/820-5970 ben@g-o-l-e-m.com

Huston Rammed Earth Consulting Services based on three generations of Rammed Earth Construction Edgewood, New Mexico ~ hrammedearth@gmail.com hustonrammedearth.com ~ 505/281-9534 ~ TEG member

What is TEG? The Earthbuilders’ Guild

THE EARTHBUILDERS' GUILD

TEG points to the original medieval meaning of the term “guild” as an association of persons in the same craft or trade who act to uphold standards and protect the members. The Earthbuilders’ Guild is a 501c(6) corporation registered in New Mexico as a Businesspersons’ League representing those who earn their livings either wholly or partly through Earthen construction and related green applications. Visit TEG at www.theearthbuildersguild.com

SWSA CLASSES SPRING 2012

Adobes by

Lesile Oldar California Licensed since 1999 leslieoldar@yahoo.com TEG Member ~ SWSA grad

EarthCo Building Systems introduces the

MEGABLOCK Earth Process

Twice the speed at half the cost Ranger,TX  www.EarthCoMegablock.com  hamesg@gmail.com Gary Hames 817/715-9632

MRP Design and Construction

The Lizard King Custom Adobe Matteo Pacheco ~ Albuquerque GB98 ~ Member TEG 505/934-4298 mrplizardking@live.com

MUD & SUN CONSTRUCTION Selling & Installing all types of Solar Equipment  Carl Rudnick Lic. 14251 Tijeras, NM 

1.Rammed Earth Planning-Mar 31/Apr 1-Albuquerque 2.Adobe & CEB Planning Class-Apr 21/22-Albuquerque 3.Adobe and CEB Hands-on-May 5/6-Bosque, NM 4.Rammed Earth Hands-on-May 18/19/20-Bosque, NM 5.Vaults/Domes/Horno Hands-on-June 2/3-Bosque, NM Check out the details at www.adobebuilder.com We will also be building the HORNO in ADOBE BUILDER, Spring 2012 Look for an extensive article on Horno construction and use, a study of California’s adobe codes and notes on stabilizing Earth Blocks using Lime.

Sculptured Adobe Lic. No.053119 Albuquerque, New Mexico Fine exposed Adobe fireplaces & walls for 30 yrs. Paul Chávez 505/345-3079 or 269-5175

We make Compressed Earth Block machinery

505/281-2202 crudnick@thuntek.net Photovoltaics, Hot Water, Hot Air

Arid Land Consultants

New Mexico Earth Adobes

SOLEDAD CANYON EARTH BUILDERS

Supplying Contractors & Owner-builders since 1972 Located in the Albuquerque North Valley 505/898-1271 ~ Member TEG ~ Delivery Available www.newmexicoearth.com ~ Semi & Fully stabilized Adobes

Rammed Earth & Adobe in Southern New Mexico since 1985 NM Lic. 56340 ~ Las Cruces, NM ~ 575/-527-9897 pat@adobe-home.com ~ www.rammed-earth-homes.com

BIO-HAB, Inc

New Mexico Earth Works

Southwest Adobe Supply, Inc.

Over 35 years in the construction industry Todd Swanson ~ Durango, CO ~ 970/259-5985 biohab@gobrainstorm.net Adobe • Straw • Wood • Earth

Sean Kaltenbach - Custom Home Builder Cochiti, New Mexico  Lic. 368104  Member TEG Adobe and Compressed Earth Block sean@newmexicoearthworks.com 505/490-0238 www.newmexicoearthworks.com Earth Plasters~Lime Stuccos

Carl and Debra Clark Las Cruces, New Mexico ~ Member TEG Traditional Adobe & Compressed Earth Block 575/639-3085       cnclark@spinn.net

Historical Restoration in Adobe, Fired Adobe and Pioneer Building Techniques. Projects Regionwide Lic. 98-368022-5501 • 435/619-3476 Russell Bezette • La Verkin,UT • rjbezette@gmail.com

C.E. LAIRD Designer/Builder Extraordinary Adobe Homes since 1980 Alameda, NM Lic. 24621 by appointment for qualified projects

Celaird2@hotmail.com 505/898-6878

EARTH AND SUN CONSTRUCTION Ramming Earth Across the Southwest Gary Wee Las Cruces, NM GB-98 57934 575/644-5380  Member TEG www.earthandsun.com earth-sun@zianet.com

Earthspace Construction Company Claude Hayward Anton Chico, New Mexico Lic. 91397 ~ Consulting for your project ~ Member TEG Building with Adobe & Green Alternatives for 30 years 575/427-4202  chayward45@gmail.com

Pueblo Tierra, Inc.

Sustainable Energy & Building of New Mexico Jane Whitmire HERS Rater/NAHB Green Verifier v Member TEG 505/867-2643 v Placitas, New Mexico jane.sebnm@yahoo.com

RAINBOW ADOBE Southwest Texas’ Dependable Supplier of Quality Adobe Block

The Adobe Works Co.

432/364-2777 Alpine, Texas sbelardo1@yahoo.com DESIGNER ~ BUILDER of Fine Adobe Homes

Dimensional Timbers sawn from dry Engleman Spruce Vigas & Big Character Posts ~ Sawmill in Eagar, AZ bfishn@gmail.com Gary Kimball 480/882-2720

RAMMED EARTH

Sims General Building, Inc. Covering New Mexico, Texas and Southern Colorado

Simsgbinc@gmail.com

505/450-6333

www.Rammedearth.net ~ TEG member Michael & Mary Sims, Corrales, NM

Rick and Luke Catanach

Manufacturers of The AdobeMachine and The EarthBlender

Bernalillo, New Mexico Replication of historical Adobe work, Sash, Railings and Doors ~ Region wide since 1980 505/867-9267 rickcatanach@gmail.com

Seismic Design and Retrofit for Earthen structures FRED WEBSTER ASSOCIATES, INC. C.E. 28364 State of California © TEG Member FAWebster@aol.com Menlo Park, CA 650/321-6939 CIVIL/STRUCTURAL

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Member TEG

CEB & Rammed Earth in the 4 Corners for 15 years adobesdavila@frontiernet.net Antonio Davila  Bluff, UT  435/459-1545 References available for serious inquiries

EarthTek, Inc. www.adobemachine.com www.earthtek.us

 Uniquely New Mexico 

SAN TAN ADOBE COMPANY Manufacturing Quality Adobe for over 40 years  Queen Creek, AZ 928/231-2926 www.santanadobe.com santanadobecompany@gmail.com

Valle Escondido Organic Ranch

Traditional Adobe Bricks Delivery within 500 miles of Antonito, Colorado Demetrio and Olive Valdez 719/376-5873 Located at Conejos, Co. valdezgravel@aol.com

Wholesale Timber & Viga Jeff Gonzales ~ Bernalillo, New Mexico Rough Sawn Lumber ~ Vigas ~ Latillas ~ Corbels ~ Timber Trusses ~ Custom Carving & Metal Work ~ Design & Drafting Ucanblacksmith@yahoo.com • 505/867-1200

www.wholesaletimber.net

Winn DeLapp Custom Adobe Builder NM Licensed ~ Albuquerque, NM yogano@aol.com ~ 505/898-5818 Member TEG


HERS - continued from Page 13

Jane: Because at times, we need it. Third party verification and testing confirm that efficiency claims are accurate for code enforcement, government incentives, or home sales. Mark: I should say that the choices we have to qualify a home must be expanded and a common grading system needs to be established, coupled with actual building performance testing to simulate reality. The talk of comparing BTUs/sq. ft./hdd is a good common comparison if a building size factor is included. Embodied energy would also be a good factor to include when judging a home. HERS does not mention any passive solar contribution. How do you factor it in? Jane: The software used should include inputs to be used for passive solar designs. REMRate (one software used by HERS) does recognize the impact of passive solar, as mentioned above in respect to Plan 1870. The program requires standard window data including solar heat gain co-efficients, orientations and overhangs; adding thermal mass can have a dramatic (good) effect on the HERS index. Mark: It would seem that HERS cannot integrate thermal mass or temperature swing. Jane: There are some fairly detailed entries available for thermal mass in REMRate, used by many HERS raters. Mass walls in sunny or shaded rooms and floors all impact the HERS index. Temperature swing may be included via climate data. Mark: HERS leans designers away from Passive Solar. Your opinion? Jane: While the RESNET approved energy rating programs may not give as much credit as some would like, a properly designed passive solar structure with appropriate mass is absolutely recognized and rewarded by REMRate (which is the program I use). The software is updated regularly and continues to evolve. Mark: I must say that HERS cannot compute Trombe walls. Jane: At the time we evaluated plan 1870, I questioned whether the program fully calculated the benefits of the Trombe walls. Because 1870 has 7 Trombe walls, all transferring solar energy, we wanted to be sure that they were being recognized. I have queried my HERS contacts about this. Mark: HERS appears to lean designers

towards expensive equipment that requires government subsidies. Jane: I think that depends on the particular design in question. For example, the boiler in Plan 1870 is the most expensive piece of mechanical equipment in the home and you want it to be as efficient as possible. Qualified HERS raters have the software to work with designers to model the home before it is built. Thus, the boiler efficiency can be evaluated before purchase to see how it will affect total home energy use. I should add that as a third party, HERS raters act as outside resources confirming that a design will work. Inspections during construction and blower door and duct testing after construction will verify how well the design and ever important air sealing were carried out. Mark: REMRate may be a requirement for new, green building codes. Jane: Hopefully, I have illustrated above that REMRate is evolving through responsible updates. While most HERS raters use the REMRate software, it is not the only choice. Current versions of EnergyGauge, OptiMiser, and EnergyInsights software are also accredited by RESNET for HERS ratings. —————————————————— Joe: Arguments continue about whether HERS scores should be required towards obtaining a building permit, as is the case in Santa Fe. It is a real cost if you don’t need it. For example, if the builder is not interested in touting performance or being rebated for energy extras, then only a minimum energy code (see beginning of article) not requiring a third, paid party is needed.

HERS state a Passive Contribution to the energy analysis reports it provides. It very much states how effective PV is.” I feel that a bias does exist that sees PV as an “easy score upgrade” in some programs. This is likely due to unawareness on the part of some programmers about Passive Solar. Mark feels that if the Passive Solar Contribution is stated, then more people will be encouraged to use it. I agree. In the Southwest, the knowledgeable solar designer starts with passive solar as the basic design instrument. A note of clarification here: Mark Chalom is not anti-PV. He has designed many passive solar homes where electrical power is supplied by PV. I want to thank Jane Whitmire who has been a willing participant in this study. While not a programmer, she sits at the “user end” of the process and is in a position to add valuable feedback towards program improvement. She has been discerning and fair in this process. In summary, my question is not “When will Earth Builders catch up with out-of-region energy software, but when will out-ofregion energy software catch up with passive solar research scientifically proven by thermal engineers and builders thirty or more years ago? Let’s hope soon. — Joe Tibbets, editor * further details about Plan 1870 are available at www.adobebuilder.com

But, should you be a builder promoting energy saving features through third party verification, then paying for HERS work adds credibility. If you have purchased energy producing/saving materials that exceed minimums and you want to be reimbursed via tax credits or rebates, then the HERS cost is worthwhile, providing your score qualifies you. As is made visible by this article, HERS raters have a choice of software options, listed above by Jane. REMRate appears as increasingly “passive solar friendly”, but I cannot speak for other programs, nor can Jane, who has chosen to stick with REMRate. Jane mentions that RESNET is the governing body for HERS raters and RESNET has vetted and approved the other programs she mentions. Thus, questions as to their viability for passive solar should be directed to RESNET or the applicable software company. Mark strongly feels that the Passive Solar Contribution of a design must be stated by any program. He says, “I would like to see

Locating the south solar overhang cut-off on Plan 1870. The plywood triangle (removed later) sets the winter sun altitude from the window top at 35 degrees. The string rising from the bottom is the summer sun angle, set from the window bottom at 73 degrees. Where the two intersect is the cut-off point, often expressed as a fascia edge or end of a metal roof traveling above the large windows, including Trombe walls and French doors. These angles produce full, incoming sun during the winter and a shaded south wall during summer at this latitude and elevation.

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RAMMED EARTH NEWS Earth and Sun Construction has begun work on a spacious rammed earth home for Jerry Grence and family on their holdings within the Lincoln National Forest, near Capitán, New Mexico. The home is the largest rammed earth project currently underway in New Mexico. Jerry Grence and

Project architect Michael Sayre and owner Jerry Grence by a Kiva style Rumford, one of the 5 fireplaces Jerry is building at the Capitán home site.

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project architect Michael Sayre both attended the SWSA Count Rumford fireplace class last year. Jerry is building the home’s five fireplaces himself, as he works along with Earth & Sun contractor Gary Wee’s rammed earth crew. The 5,000 sq. ft. plus residence contains another 2,000 sq. feet of patio space, for over 7,000 sq. ft. of contiguous home.

cubic yards were poured for the exterior walls, with an additional 40 cubic yards supporting the interior walls. The home is laid out to command a panoramic view of legendary Sierra Blanca, a 12,000' high peak to the southwest of the site. Contact Earth & Sun at 575-644-5380 or on-line at www.earthandsun.com

The double-rammed earth walls are 9 and 12 feet tall and super-wide, with a 2” thick layer of insulation between the two walls. Gary has already used this technique in a rammed earth home that Earth & Sun built in Cortez, CO. a few years back. Thermally speaking, placing insulation between two earthen walls is very effective in both hot and cold climates and eliminates the need to attach insulation to the exterior of the walls, along with the necessary attachment costs. Never the less, the wide walls consumed a fair amount of foundation concrete. 145

A view of rammed earth form assemblies set up at Capitán with whalers and braces in place.


N

ot all of the thousands of adobes made annually at New Mexico Earth, are the standard 10 x 14 x 4 inch size, each weighing about 32 pounds. A popular smaller size is a miniature adobe measuring 1 ½ x 2 ½ x ¾ inches. It’s the key element in the Adobe Casita Kit, now available through this long established company, located near El Pueblo Road and North Edith in the Albuquerque North Valley. Kit developers, Helen and Mark Levine, believe that a fun, mini-hands-on experience can lead to the macro hands-on of building the real thing. They should know; their adobes have been a mainstay in the Albuquerque home building market for forty years. Says Helen, “ The kit attracts attention because of its handy size and inherent charm. Its value is in its ability to pull the family together to work with adobe.” The blocks supplied in the kit are authentic sun-dried adobes in miniature, complete with the traditional straw. The one room, flat roof Adobe Casita Kit also includes a number of traditional Southwestern adobe home components: mini-door and window lintels, mini-roof beams, powdered adobe mortar, a simple roof, and a Saltillo tile base to build on. There is built-in flexibility in the design, which allows builders to change door and window locations, encouraging exploration and creativity. This can lead to teaching drafting basics, as modelers sketch out the changes they want to try. “The kit helps teach the basics of adobe construction, and can help transform nebulous ideas into reality with a simple hands-on activity,” said Helen. “We also sell the miniature adobes separately, since architectural students often want to build larger models.”

The materials used are primarily from recycled and renewable resources: the beams and lintels are reclaimed from the

yard’s old mud hoes or are scraps from adobe form making, and the adobes are non stabilized earth. “We want the Casita Kit to illustrate how green adobe construction is. Whether full sized adobes or miniatures—there is nothing greener than dirt,” Mark said. The kit fits into a stout cardboard box, which can be shipped. “Most kit buyers prefer to pick them up on their way through Albuquerque,” said Helen. “That gives them the opportunity to see stacks of real adobes here at the yard.” So far, interest in the Adobe Casita Kit has been strongest among parents and teachers, who see it as a useful teaching tool. The instructions are aimed at builders eight years old and older—those younger may need assistance. To special order one for yourself or as a gift, call 505-898-1271 or Email Helen at he_Levine@msn.com New Mexico Earth is taking spring 2012 orders now for their regular sized adobes, both semi and fully stabilized. They retain some stock for winter deliveries.

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Southwest Solaradobe School students recycle terrones into a new patio wall in North Albuquerque.

Adobe’s Forgotten Cousin ~

Terrón by Joe M. Tibbets

A

Terrón El primo olvidado del Adobe.

translation by Angela Stassano

terrón is an earth block. But instead of being cast out of saturated mud like adobes, terrones are “cut” using special spades, from the moist, grassy vegas (meadows) along the Rio Grande. They are tougher than adobes. I remember throwing terrones off a parapet in Corrales, NM back in 1973. They just bounced, staying intact. They are cut from grassy soil, so the roots are part of the matrix. In this sense, they are somewhat akin to “soddies”, or the plowed, earth and grass strips used to build frontier-era earth homes in Nebaska. Some say there’s a natural stabilizer in the local terrones- aluminum silicate has been mentioned. It’s true that they erode very slowly, but I can’t verify if a naturally occurring chemical contributes to their integrity. Terrones are typically squarish on the ends (6” x 8” or 8” x 8”) and vary in length from 10” to 14”. When dry, they are laid in mud mortar like adobes. When green (still damp from being recently cut), no mud mortar is necessary. They are flexible and will “meld” into each other, making a nearly airtight wall. The practice of cutting terrones came to the New World from Spain during colonial times. Not every area of every region is suitable, since a river valley with moist meadows or irrigation is necessary. Terrón fields can regenerate, sometimes from the underground “pressure” exerted by a nearby river. That is, the terrón cutter may cut out of a particular pasture to a depth of six or eight inches. The field is thereby lowered. If the field is “self irrigated” due to the water pressure from a nearby river, the earth is pushed upwards. New grass will grow and sediments will build. After time and depending on climate cycles, the field can regain its lost elevation and may be ready for a new harvest of terrones. Until the early 1980’s, terrones were delivered to Albuquerque building sites at prices cheaper than adobes. Today, production is limited to Native American Pueblos along the Rio Grande. A traditional terrón cutter may still cut

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Estudiantes de Southwest Solaradobe School reciclan terrones en una nueva pared de patio en el Norte de Albuquerque.

Por: Joe Tibbets.

Traducción: Angela Stassano

U

n terrón es un bloque de tierra. Pero en lugar de haber sido moldeado de lodo o tierra saturada en forma de adobe, los terrones son cortados usando palas especiales, de las praderas o vegas húmedas y herbosas a lo largo del Río Grande. Son más resistentes que los adobes. Yo mismo recuerdo haber tirado terrones desde un parapeto en Corrales, Nuevo México en 1973. Simplemente rebotaban, manteniéndose intactos. Estos se cortan de suelos o prados herbosos, de manera que las raíces son parte de la matriz. En este sentido, son como emparentados, semejantes a “soddies”, o las bandas de tierra y grama aradas utilizadas para construir las casas de tierra de Nebraska durante la época de las fronteras. Algunos dicen que existe un estabilizador natural en los terrones locales, mencionándose silicato de aluminio. Es cierto que se erosionan muy lentamente, pero no puedo verificar si la ocurrencia de un químico natural contribuye a su integridad. Los terrones son típicamente casi cuadrados en sus extremos (6”x 8” ó de 8”x 8”) y varían en su longitud desde 10” hasta 14”. Una vez secos, son colocados con mortero de lodo igual que los adobes. Cuando están verdes (aún húmedos por haber sido cortados recientemente), no se requiere mortero de lodo. Son flexibles y se fundirán entre sí, haciendo una pared casi hermética o sellada. La práctica de cortar terrones llega al Nuevo Mundo procedente de España, durante la época colonial. No todas las áreas de todas las regiones son adecuadas, debido a que se necesita un valle con río y vegas húmedas o irrigadas. Los campos de terrones pueden regenerarse, algunas veces debido a la presión subterránea ejercida por un río cercano. Esto si, el cortador de terrón puede cortar de una pastura particular hasta


terrones, but likely for local use only. If you visit Isleta Pueblo, you will see that terrones are valued. But terrón cutting is rare today in New Mexico for several reasons. Cutting them was always a local enterprise, with the blocks available only in limited areas. Second, in a desert land, the verdant strips of green along the rivers are becoming precious as water supplies dwindle and environmental concerns grow. One cannot blame the Pueblos for stopping the export of their own soil to everywhere but home. Third, terrones don’t get much press. Builders almost never hear about them and if they do, they don’t understand them. Besides, adobes are in stock. There are probably thousands of standing terrón structures scattered along the Rio Grande, many still occupied as family houses, some as commercial buildings and some abandoned. They are treated as adobes code-wise, but still get attention because the blocks are often recycled. They have been mentioned in the New Mexico code for decades and are referred to at least once in the New Mexico 2009 code. Another area of the Américas that has a tradition of terrón are the countries of Uruguay and Argentina. An Adobe Builder reader, Frederico Villagrán of Santa Lucía, Uruguay, writes: “The gauchos (Uruguayan cowboys) were skilled builders of houses made of terrón. It was a large block of earth mixed with grass, which was cut directly from the earth with shovels. It was used freshly cut and was then smeared with mud by hand. Terrón is much more resistant to rain than ordinary adobe.” A New Mexico plasterer friend, Joe Gutierrez, referred to them as “hairy old men”, because of the grass content. He didn’t really like to plaster terrón walls,

una profundidad de seis ú ocho pulgadas. El campo es entonces así, rebajado. Si el campo es auto-irrigado, debido a la presión de agua de un río cercano la tierra es empujada hacia arriba. Nuevos pastos crecerán y se construirán sedimentos. Después de cierto tiempo y dependiendo de los ciclos climáticos, el campo puede recuperar su elevación perdida y podría estar listo para otra nueva cosecha de terrones. Hasta inicios de la década de 1980, los terrones eran enviados a los sitios de construcción de Albuquerque a precios menores que los de los adobes. Hoy día, su producción está limitada a los pueblos nativos americanos a lo largo del Río Grande. Un cortador tradicional de terrones puede aún cortar terrones, pero solo para uso local. Si Ud. visita Isleta Pueblo, verá lo valorados que son los terrones. Pero el cortado de terrones es muy raro hoy día en Nuevo México debido a diversas razones. Primero, su corte fue siempre un trabajo local, con los bloques disponibles solo en limitadas áreas. Segundo, en un terreno desierto, las bandas de cintas verdes de árboles a lo largo de los ríos se han convertido en preciosas a medida que disminuyen las fuentes de agua y crece la conciencia ambiental. No podemos culpar a los Pueblos por detener la exportación de su propio suelo a cualquier parte excepto a su casa. Tercero, los terrones no reciben mucha publicidad. Los constructores casi nunca han oído de ellos y si lo han hecho, no los entienden. Además, los adobes están siempre disponibles en ventas al por mayor. Existen probablemente miles de estructuras en pié de terrones diseminadas a lo largo del Río Grande, muchas aún siendo usadas como casas familiares, algunas como edificios comerciales y algunas abandonadas. Las mismas son tratadas como adobe en relación a los códigos pero aún llaman la atención debido a que los bloques son a menudo reciclados. Han sido mencionados en el código de Nuevo México por décadas y son referidos al menos una vez en el código Nuevo Méxicano 2009. Otra área del continente americano que tiene una tradición de terrón son los países de Uruguay y Argentina. Un lector de Adobe Builder, Federico Villagrán de Santa Lucía, Uruguay escribió: “Los gauchos (vaqueros uruguayos) fueron habilidosos constructores de casas hechas de terrón. Consistía en un bloque grande de tierra mezclada con pasto, que era cortado directamente de la tierra con palas. Se usaban recién cor-

Front view of the Linda Vista. Outward movement of the walls, due to no bond beam, had caused cracking at both corners. The floor level is shown by the built up terrones under the entrance. The floor was entirely of wood, with joists supported by the terrón walls on both sides. Vista frontal del Linda Vista. El movimiento hacia fuera de las paredes, debido a no tener viga solera, ha causado grietas en ambas esquinas. El nivel del piso se muestra por el apilado de terrones bajo la entrada. El piso era completamente de madera, con joist soportados por las paredes de terrón en ambos lados.

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because they are rough compared to adobe. They often have holes or pits that have to be filled with adobe mud before plaster is applied. Plasterers tend to quote higher prices to cover a terrón wall because of this added preparation. A good example of an abandoned terrón structure is (was) the Linda Vista Bar and Dance Hall, pictured here. It lived from the early 1930’s until the summer of 2004, about 70 years. The current owner knocked it down in 2004. While many older folks in the area lament its passing, it was the right thing to do. Why? Because, as with many depression era structures, it was built cheap. Foundations were non-existent or stone packed in mud. There was no bond beam up top to hold the walls together. As the inadequate foundation settled over the years, walls began to curve, leaning this way and that. Area seismic activity is not severe, but mild shakes have occurred every decade, affecting the integrity of the Linda Vista. Add to that the Santa Fe railway, with tracks just across the highway. Today, heavy, 100 car coal trains pass daily, as opposed to lightweight passenger trains of an earlier day. The structure eventually became a safety hazard. If the same terrones had gone into a building with good foundations and bond beam, the Linda Vista would still be building memories. However, the builder, one C. Silva, did the best with what he had at the time. And in those times, there was no code, and there was little money for building budgets. The good work of Mr. Silva is still remembered in the continued next page

View of southern exposure of the Linda Vista. Lintels were recycled railway timbers, banned today because of their creosote content (a carcinogenic safety hazard). Vista del lado sur expuesto del Linda Vista. Los cargadores o dinteles eran maderos reciclados de ferrocarriles (durmientes), hoy prohibidos debido a su contenido de cerosota (una amenaza carcinogénica).

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tados y luego eran embarrados con lodo a mano. El terrón es mucho más resistente a la lluvia que un adobe corriente”. Un amigo revocador de Nuevo México, Joe Gutiérrez, se refiere a ellos como los “viejitos peludos”, debido al pasto o grama que contienen. En realidad a él no le gusta revocar paredes de terrón, debido a que son rústicas comparadas a las de adobe. A menudo tienen huecos o agujeros que hay que llenar con lodo de adobe antes de aplicar el revoque. Los revocadores tienden a cobrar precios más altos para cubrir paredes de terrón debido a esta preparación adicional. Un buen ejemplo de una estructura abandonada de terrón es (fue) el Salón y Bar de Baile Linda Vista , aquí fotografiado. Duró desde inicios de la década de 1930 hasta el verano del 2004, cerca de 70 años. El dueño actual lo demolió en el 2004. A pesar de que muchos amigos veteranos lamentaron que esto ocurriera, fue lo correcto de hacer. ¿Por qué? Pues porque como muchas estructuras de la época de la depresión, fue pobremente construida. Los cimientos o no existían o eran de piedra empacada en lodo. No existía viga solera superior para mantener las paredes unidas. A medida que la cimentación inadecuada continúa próxima página

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The “look” of a terrón wall, laid up without mud mortar while the blocks were wet and showing how terrones “meld” into each other.

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Belén, New Mexico area. Adobe Builder hopes to do a piece on his existing structures in the future. Five years ago, Southwest Solaradobe School students had a chance to work with recycled terrones in North Albuquerque. Recycled from an adjacent ruin, interior designer Orana Simpson used them to build an enclosed patio on the front of her adobe residence. In this case, the dry terrones were laid up using a thick mud mortar. After five years of exposure to the weather, only a small amount of erosion has occurred, most likely from the unstabilized mud mortar and not the terrones themselves. At any point, Orana can always seal, mud plaster or stucco the wall. ✽

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El aspecto de una pared de terrón, erecta sin mortero de lodo mientras los bloques estaban aún húmedos, muestra como los terrones se funden entre sí.

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Northern exposure of the Linda Vista, showing settlement and warping problems of the walls, due to no bond beam and no foundation system. Vista del lado norte del Linda Vista, mostrando asentamiento y problemas de alabeo de paredes, debido a no tener viga solera ni sistema de cimentación.

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se asentaba al paso de los años, las paredes comenzaron a curvarse, inclinándose aquí y allá. Si bien la zona de actividad sísmica no es severa, pero sacudidas menores han ocurrido durante cada década, afectando la integridad de el Linda Vista. Sumado a ello el ferrocarril de Santa Fé, con rieles justo a través de la autopista. Hoy día, pesados trenes con 100 carros de carbón pasan diariamente, opuesto a lo que era el tránsito de trenes livianos de pasajeros que ocurría en tiempos anteriores. La estructura eventualmente se convirtió en una amenaza de seguridad. Si los mismos terrones hubieran sido colocados en una estructura con buenos cimientos y viga solera, el Linda Vista aún estaría construyendo recuerdos. Sin embargo, el constructor, el Sr. C. Silva, hizo lo mejor con lo que él tenía en aquella época. Y en esos tiempos, no existían códigos, y existía muy poco presupuesto para la construcción de edificios. El buen trabajo del Sr. Silva es aún recordado en Belén, en el área de Nuevo México. Adobe Builder espera hacer un artículo a futuro relacionado con sus aún existentes estructuras. Hace cinco años, estudiantes de Southwest Solaradobe School, tuvieron la oportunidad de trabajar con terrones reciclados en el Norte de Albuquerque. Reciclados de una ruina adyacente, la diseñadora de interiores Orana Simpson, los utilizó para construir un patio cerrado al frente de su residencia de adobe. En este caso, los terrones secos fueron colocados usando un mortero de lodo espeso. Después de estar cinco años expuestos al clima, solo ha ocurrido una pequeña cantidad de erosión, más bien relacionada al mortero de tierra que a los terrones mismos. De cualquier manera, en cualquier momento, Orana puede siempre sellar, revocar con lodo o estuco la pared. ✽

v Another wall in the Linda Vista Otro pared de La Linda Vista

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Limewash finish on the San Antonio church, Questa, New Mexico, during winter. A job by Peter Mold and Ed Crocker. Four coats of adobe plaster (render) on adobe walls rough cast with hawk and trowel. The last adobe coat finished with a wood float, followed by limewash. Acabado de pintura de cal en la Iglesia de San Antonio, Questa, New Mexico, durante invierno. Un trabajo de Peter Mold y Ed Crocker. Cuatro tapas ásperas de adobe repello sobre paredes de adobe, usando halcón y plano. La ultima tapa en adobe, usando plano de madero, seguido de pintura de cal. Foto de/by Peter Mold

Limewash: Compatible Coverings For Masonry and Stucco

PINTURA DE CAL: RECUBRIMIENTO COMPATIBLE PARA MAMPOSTERÍA Y ESTUCO* *©Derechos de Autor NLA (Grupo de Constructores con Cal) Building Lime Group

Copyright ©National Lime Association, Building Lime Group; reprinted with permission, all rights reserved.

Peter Mold 1 & Richard Godbey 2 Abstract

Limewash is a versatile, accommodating, and robust surface covering that is compatible with a variety of building surfaces. It is maintainable, beautiful, stable, and long lasting. It is an aesthetic statement to many cultures, from the white houses of Greece, to earth tones of the Southwest United States. This paper takes an on-site look at the practical aspects of limewashing on a wide variety of substrates and in a wide range of climates, including:

Resumen La pintura de cal es un recubrimiento robusto, versátil y adaptable que es compatible con una variedad de superficies en la construcción. Se puede conservar, es hermosa, estable y duradera. Es una expresión artística en muchas culturas, desde las casas blancas de Grecia, hasta los tonos tierra del Suroeste de los Estados Unidos. Este resumen toma los aspectos prácticos de la pintura de cal aplicada a una amplia variedad de sustratos y en una amplia extensión de climas, incluyendo: • Tipos de sustratos compatibles • Preparación del sustrato para la pintura de cal • Uso de pigmentos y aditivos • Aplicación de técnicas en diferentes sustratos • Aplicación de técnicas en diferentes climas; y • Mantenimiento

• Types of compatible substrates; • Preparation of the substrate for lime washing; • Use of pigments and additives; • Application techniques on different substrates; • Application techniques in different climates; and • Maintenance. The authors combine their experiences from both the science of lime and the practical application of lime, stone, and earth construction in Europe, America, and Australia—from lime plastering the Globe Theatre in London, England to lime washing modern three-coat stucco in Las Vegas, Nevada. P. Mold, Worker in Lime, Stone and Earth, UK & USA, peter_mold@yahoo.co.uk 2 R. Godbey, Chemist, rjgodbey@msn.com 1

Los autores combinan el conocimiento científico sobre la cal con su experiencia y la aplicación práctica de la cal, la piedra y la tierra en la construcción en Europa, América y Australia – desde los acabados con cal del Teatro Globe en Londres, Inglaterra, hasta la pintura de un moderno estuco de tres capas en La Vegas, Nevada. Los puntos de vista presentados en este artículo son exclusivos de los autores. P. Mold, Trabajador con Cal, Piedra y Tierra, Reino Unido y Estados Unidos, peter_mold@yahoo.co.uk 2 R. Godbey, Químico, Estados Unidos, rjgodbey@msn.com 1

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Keywords

Limewash, Lime

Introduction

Limewash is an effective surface covering for a wide range of water-absorptive surfaces. Limewash is vapour-permeable and allows a building to “breathe.” Limewash is robust and, in the proper number of coats, may consolidate and improve the condition of the underlying substrate. Limewash is stable and long lasting. Limewash is beautiful in either its brilliant white, non-pigmented native state, or when pigmented with compatible oxides to complement architectural colour schemes. Limewash has always been, and remains, a most effective way to protect, maintain and beautify the surface of historically-significant structures. Additionally, limewash can be an effective and innovative method to finish more modern surfaces. Limewash is materially inexpensive and well suited to professional or do-it-yourself application. Surface preparation for sound, previously limewashed surfaces is straightforward, generally only requiring a washdown with water to remove accumulated dirt and growth, or with a mixture of diluted vinegar to remove scale. By taking an on-site look at limewashing, we hope to give a broad outline of its practical use and its advantages, limitations and qualities. By doing so, we hope to take the mystery out of limewash and advocate its return to commonplace use.

Using limewash: a general background The substrate

The success of limewash application is dependent upon the quality of the surface, or substrate, to which it is applied. There are 3 major factors associated with the substrate: 1) mechanical key, 2) absorbency, and 3) chemical compatibility.

Mechanical Key

A coarsely-textured surface provides the skeleton for a series of repeated thin coats of limewash that can build up to thicker and thicker depths with minimal or little cracking. Examples of coarsely textured surfaces include stone, brick, adobe and concrete block, as well as clay, lime- and cement based mortars and renders. . For new render, we may design the render mix with mechanical keying in mind. For example, using clay, lime or cement-based renders mixed with angular and coarser, well-graded sand (having sand grains of many different sizes) may improve the mechanical keying of subsequent thin coats of limewash. Additionally, the use of wood floats during the render finishing stage can also increase the texture of the surface. Smooth surfaces may be limewashed; however, they can often benefit from a “roughening-up” using fine-to-medium abrasives, steel wool, or simply wire brushing, as the job allows. Examples of smooth surfaces include hard-trowelled renders and plasters, dense stones, timber, rusted steel, and glass.

Absorbency

Limewash needs an absorptive surface so it can penetrate into the substrate and exploit the potential for mechanical keying. The common test for absorbency is to apply water and observe whether the moisture is absorbed or not. If the moisture is absorbed by the substrate, the surface is a good candidate for limewashing. If, however, the wall has been treated with a non-absorbent material (e.g. paint), the only real way to overcome this problem is to remove all of the non-absorbent material. Limewash is only as good as the substrate to which it is applied.

Chemical Compatibility

Whereas we may mechanically change or enhance a substrate to be more limewash-friendly, we cannot necessarily change the substrate’s chemical compatibility. The lime in limewash is applied as a very thin slurry suspended in water. Safe use of limewash can generally be expected on traditional materials such as lime, stone, soft brick, plaster, stucco, render and earth. Likewise, limewash can adhere to and be compatible with glass, but not plastic. Limewash will adhere to a rusty corrugated tin roof, but not the areas in which the tin has been treated.

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La Asociación Nacional de la Cal (NLA, Nacional Lime Association) y el Grupo de Constructores con Cal no se hacen responsables de error alguno, omisiones o cualquier otra limitante en el contenido de este resumen o por cualquier producto, servicio o método presentado. Este artículo va dirigido al personal profesional competente que pueda evaluar el significado y las limitaciones de la información aquí presentada y quien acepte total responsabilidad de la aplicación de esta información. NLA y el Grupo de Constructores con Cal no tiene la intención de infringir en patente alguna o cualquier otra propiedad intelectual con derechos o inducir a tercero a hacerlo, por lo tanto, todo aquel que utilice este documento se hará responsable de determinar si los métodos, técnicas o tecnologías aquí descritos están protegidos por patentes o cualquier otra restricción legal. Palabras Clave

Pintura de Cal, Cal Introducción

La pintura de cal es un recubrimiento muy efectivo para una gran variedad de superficies absorbentes. La pintura de cal es permeable al vapor y permite que la construcción “respire”. La pintura de cal es robusta, y aplicada en la cantidad apropiada de capas, puede consolidar y mejorar la condición del sustrato inferior. La pintura de cal es estable y duradera. La pintura de cal es hermosa ya sea en su estado natural blanco y brillante sin pigmentos, o cuando se le ha pigmentado con óxidos compatibles que complementan los esquemas de color arquitectónicos. La pintura de cal siempre ha sido y será el modo más eficaz de proteger, mantener y embellecer la superficie de estructuras históricamente importantes. Adicionalmente, la pintura de cal puede ser un método efectivo e innovador para los acabados de superficies más modernas. La pintura de cal es muy económica y se adapta muy bien a aplicaciones profesionales o para quien prefiera el “hágalo usted mismo”. La preparación de una superficie previamente blanqueada con cal es directa y rápida y generalmente sólo se requiere de un lavado con agua para remover el polvo acumulado, o de una mezcla de vinagre diluido para remover el sarro. Estudiando la pintura de cal directamente en su campo de aplicación, esperamos dar una idea más amplia de su uso práctico y de sus ventajas, limitaciones y cualidades. Y al hacerlo, queremos esclarecer sus misterios y defender su lugar de regreso al uso común. El uso de la Pintura de Cal: antecedentes El Sustrato

El éxito de una aplicación de pintura de cal depende de la calidad de la superficie, o sustrato, sobre la cual es aplicada. Existen 3 factores importantes asociados con el sustrato: 1) la adherencia mecánica, 2) la absorción, y 3) la compatibilidad química. Adherencia mecánica

Una superficie rugosa nos da el armazón para una serie de aplicaciones repetidas de capas finas de pintura de cal que pueden ir construyendo un fondo más y más grueso con muy pocas grietas. Los ejemplos de superficies rugosas incluyen piedra, ladrillos, adobes, y bloques de concreto, así como arcilla, morteros a base de cal-y-cemento y acabados. Para acabados modernos, se puede diseñar la mezcla del acabado planeando que éste tenga adherencia. Por ejemplo, al usar acabados con base de arcilla, cal o cemento y mezclarlos con arenas angulosas, más gruesas y bien calibradas (que tengan granos de arena de diferentes tamaños) se puede mejorar la adherencia de las capas de pintura de cal que se aplicarán una tras otra. Adicionalmente, el uso de flotas ó llanas de madera, al estar aplicando la última etapa del acabado, puede también aumentar la textura de la superficie. Las superficies muy lisas también pueden ser blanqueadas con cal; sin embargo a menudo se favorecen cuando se logra un poco de aspereza usando abrasivos de medianos a suaves, lana de acero, o simplemente con un cepillado con alambre, según lo permita la situación. Ejemplos de acabados muy lisos incluyen acabados pulidos con llana, piedras muy densas, madera, acero enmohecido y vidrio. Absorbencia

La pintura de cal necesita una superficie absorbente para que pueda penetrar al sustrato y explotar el potencial de su adherencia. La prueba más común para conocer la absorción es aplicar agua y observar si se absorbe la humedad. Si la humedad es absorbida por el sustrato, se puede considerar que la superficie es un buen candidato para la pintura de cal. Si por el contrario, la superficie ha sido tratada con algún material no absorbente (Por ejemplo: Pintura) la


única manera de remediar esta situación es retirar todo el material no absorbente. La pintura de cal tendrá tan buen resultado como bueno sea el sustrato al que se aplique. Compatibilidad Química

Así como podemos cambiar mecánicamente un sustrato o mejorarlo para que sea más propicio para aplicar la pintura de cal, no podemos cambiar la compatibilidad química de éste de ningún modo. La cal en la pintura de cal es aplicada como una lechada muy fina suspendida en agua. El uso seguro de la cal es generalmente encontrado en materiales tradicionales como cal, piedra, ladrillo suave, emplaste, estuco, recubrimientos y tierra. De la misma manera, la pintura de cal puede adherir y ser compatible con vidrio pero no plástico. La pintura de cal puede adherir a un techo de lámina corrugada, pero no a las áreas de la lámina que han sido tratadas. La pintura de cal no es compatible con pinturas u otros materiales sensibles a un alto pH de 12 o más. Si existe la duda sobre la compatibilidad, siempre es mejor hacer pruebas sobre paneles del material a utilizar, o contactar al fabricante del sustrato y preguntar cómo se comportan las propiedades del material al ser expuesto a un alto pH en una solución de agua y/o medio ambiente de humedad durante la aplicación y durante periodos de humedad relativamente alta, los dos al mismo tiempo (i.e. lluvia). Los morteros y acabados a base de cemento y cal tienen altos valores de pH en presencia de humedad. Esta naturaleza alcalina es compatible con la pintura de cal. Con respecto a lo idóneo con el uso de la pintura de cal, hay una diferencia entre un acabado de cemento que ha sido aplicado a mano y el concreto. En particular, el concreto aplicado con molde (y de igual manera cualquier superficie muy pulida con llana), habrá desarrollado una capa dura y resbalosa, que será menos absorbente, y por lo tanto, más difícil de pintar con cal. Por ejemplo, en el desierto del Suroeste de los Estados Unidos, los recubrimientos tradicionales (estuco) hechos a base de cal y cemento tienen generalmente una textura áspera y porosa ideal para la pintura de cal. Por el contrario, las paredes de concreto muy lisas pueden resultar muy difíciles de pintar con cal. Como mezclar y aplicar la cal Peter Mold working with his limewash brush. Peter Mold, trabajando con su brocha para pintura de cal.

Limewash is not compatible with paints or other materials sensitive to high pH of 12 or more. If in doubt about compatibility, it is always best to try out some test panels on the material under consideration, or to contact the substrate manufacturer and inquire about the material’s properties when exposed to high pH in a solution of water and/or moist environments during both application and during periods of high relative humidity (i.e. rain). Cement- and lime-based mortars and renders have high values of pH in the presence of moisture. This alkaline nature is compatible with limewash. Regarding “limewash suitability”, there is a difference between hand-applied cement render and concrete. In particular, cast concrete (and indeed any hard-trowelled or polished surface) will have developed a surface glaze, or laitance, which is less absorbent and, therefore, more difficult to limewash. For example, in the U.S. desert Southwest, traditional plaster renders (stucco) based on lime and cement are commonly coarsely textured, porous and ideal for limewash. Contrary to this, smooth tilt-up concrete walls may prove more difficult to limewash.

Mixing and applying limewash Sources of lime

The raw material for limewash may be available in one of three forms, depending on geographic location. The first form, quicklime, is calcium oxide, which is different than hydrated lime (calcium hydroxide). To make limewash from quicklime, the quicklime must first be carefully slaked (by adding water) in the approximate ratio of 8 gallons of water to 38 pounds of quicklime. Slaking converts the oxide to a hydroxide (National Lime Association, 1955). Manufacturer’s instructions and safety precautions should always be followed before attempting to slake quicklime. Additional guidance is available from ASTM International in their standard, ASTM C 5-03, Specifications for Quicklime for Structural Purposes (ASTM, 2003). Slaking quicklime is hazardous and can cause severe bodily harm if proper safety precautions aren’t followed. The chemical re-

Fuentes de Cal

La materia prima para la pintura de cal puede ser encontrada en alguna de sus tres formas, dependiendo de la localización geográfica. La primera forma, la cal viva, es óxido de calcio, que es diferente a la cal hidratada (hidróxido de calcio). Para hacer pintura de cal con cal viva, la cal tiene que ser cuidadosamente hidratada (añadiendo agua) a razón de 8 galones de agua aproximadamente a 38 libras de cal viva . La hidratación convertirá el óxido en hidróxido (Asociación Nacional de la Cal, 1955). Las instrucciones del fabricante y las precauciones de seguridad deben de ser observadas al intentar hidratar la cal. Existe asistencia adicional en ASTM Internacional y sus estándares, ASTM C 5-03, Especificaciones para Cal Viva en Usos Estructurales (ASTM, 2003). Hidratar cal viva es peligroso y puede causar daños severos al cuerpo si no se siguen estrictamente las precauciones de seguridad. La reacción química es exotérmica (genera gran cantidad de calor) y el hidróxido que resulta es muy básico (tiene un alto pH) que puede causar quemaduras químicas en la piel, ojos, y otros tejidos. Una vez hidratada, esta “masilla” de cal se deja madurar por un periodo de tiempo. Este periodo puede durar de un día a varios meses, dependiendo de la calidad de la cal viva. Durante este periodo de maduración, el tamaño de las partículas de los granos individuales de cal continúan achicándose (Hansen, et.al, 1999). De cualquier manera, al final de esta etapa de maduración, se acostumbra colar la masilla con una malla fina para quitar cualquier residuo de crudos u otras impurezas. La segunda forma de cal que puede encontrarse es masilla de cal. La masilla de cal es el producto final de la cal viva hidratada. (La masilla de cal también se puede hacer con polvo de cal hidratada, añadiendo agua simplemente. Este proceso puede extender la vida de la cal almacenada, y en el caso de cal hidratada muy pura, puede incrementar la plasticidad del mortero de cal). La masilla de cal es por lo general una pasta gruesa que contiene aproximadamente 50% de cal y 50% de agua. Estos porcentajes pueden variar dependiendo del productor, pero la masilla de cal siempre se vende en forma de líquido. Igual que la cal que ha sido hidratada, la masilla de cal puede haber pasado por un periodo de maduración para reducir el tamaño de las partículas. Puede haber sido precolada o tendrá que ser colada con malla fina. Un guía general para la masilla de cal que se vende comercialmente puede ser encontrado en ASTM C 1489-01 Especificaciones Estándar para la Masilla de Cal en Procesos Estructurales. (ASTM, 2001).

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action is exothermic (generates tremendous heat) and the resulting hydroxide is very basic (has a high pH) that can cause chemical burns to skin, eyes, and other tissue. Once slaked, the resulting putty is often left to age for some period of time. This period of time may last from 1 day to several months, depending on the quality of the quicklime. During this period of aging, the particle sizes of the individual grains of lime continue to decrease (Hansen, et.al, 1999). Regardless, at the end of the aging process, the putty is customarily sieved through a fine screen to remove any leftover grit and other impurities. The second form of lime that may be available is lime putty. Lime putty is the end product of slaked quicklime. (Lime putty can also be made from hydrated lime powder, simply by adding water. This can both extend storage life of the lime and, in the case of hydrated high-calcium lime, may increase workability of the lime mortar.) Lime putty is often a thick lime paste that is approximately 50% lime and 50% water. This ratio may be slightly different depending on the manufacturer, but lime putty is always sold in a wet condition. Like lime that has been slaked, lime putty may have undergone a period of aging to reduce the particle size. It may have been pre-screened or it may need to be screened. A good general guide to lime putty that is sold commercially may be found in ASTM C1489-01 Standard Specification for Lime Putty for Structural Purposes (ASTM, 2001). The third commonly available form of lime is hydrated lime. Hydrated lime is generally sold in bags as a dry powder. Hydrated lime is made by adding just enough water to quicklime to satisfy the water demand of the chemical reaction that converts the calcium oxide (quicklime) into calcium hydroxide (hydrated lime). In many parts of the world, hydrated lime is made from limestone with a very high calcium content (95%+) and is known as high-calcium lime. Uniquely in the United States, hydrated lime for building construction applications is made from dolomite (magnesium-containing limestone and is slaked in pressure hydrators or by secondary steam processing that results in a lime of the very finest particle size. This lime is ready for immediate use and is so special that it is given an ASTM designation of Type S, Special Hydrated Lime. High-calcium hydrated lime in the U.S. may be designated as Type N, for Normal Hydrated Lime, and will require a soaking period of at least 24 hours in water prior to use. Two ASTM standards, C 206-03, Standard Specification for Finishing Hydrated Lime and C 20704, Standard Specification for Hydrated Lime for Masonry Purposes, provide good guidance on the specification of hydrated lime (ASTM C 206-03, 2003; ASTM C 207-04,2004).

Making limewash

In general, limewash may be made from lime putty or hydrated lime by the addition of water to make a slurry with the consistency of whole milk. In terms of solids (lime) content, this works out to be a mixture that is approximately 15 to 20% lime and 80 to 85% water (one gallon of water, at 20 °C weighs 8.33 lbs.). For example, in our experience, using a 50 lb. bag of hydrated lime and 30.5 gallons of water gives the approximately correct ratio for a 20:80 mixture based on the weights of lime and water. Thinner slurry, for a 15:85 mixture, would require a 50 lb. bag of hydrated lime and 40.5 gallons of water. Lime putty already contains an excess of water and, therefore, an allowance must be made for adding just enough water to lime putty to achieve the above-mentioned solids contents. Water accounts for approximately 50% of a lime putty and, therefore, each pound of lime putty may only contain ½ lb. of lime. When mixing by weight, more lime putty and less water would have to be added to achieve the whole milk-like ratios. For example, 100 pounds of lime putty contains 50 lbs of lime and 50 lbs of water. To achieve a 20:80 mix with lime putty, 100 pounds of lime putty should be added to approximately 24 gallons of water. (The water that is already in the lime putty displaces approximately 6.1 gallons of water needed for the proper ratio.) The above designs are only approximations. Each lime that is encountered may have slightly different water demands and experimentation

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La tercera forma más común de la cal es cal hidratada. La cal hidratada se vende habitualmente en sacos de polvo seco. La cal hidratada se fabrica al añadir agua suficiente a la cal viva para satisfacer la demanda de agua de la reacción química que convierte el óxido de calcio (cal viva) en hidróxido de calcio (cal hidratada). En muchas partes del mundo, la cal hidratada se obtiene de la piedra caliza con un alto contenido en calcio (95%+) y es conocida como cal rica en calcio. En los Estados Unidos únicamente, la cal hidratada para aplicar en la construcción se produce a partir de la dolomita (piedra caliza que contiene magnesio) y es hidratada en hidratadoras a presión o por procesos de vapor secundario que da una cal con partículas de tamaño muy fino. Esta cal se puede usar de inmediato y es tan especial que ASTM la ha designado con un Tipo S, (Special Hydrated Lime) Cal Hidratada Especial. Cal hidratada con alto contenido en Calcio en los Estados Unidos puede ser designada como Tipo N, o (Normal Hydrated Lime) Cal Normal Hidratada, y requerirá un periodo de hidratación en agua de al menos 24 horas antes de usarse. Dos estándares de ASTM, C 206-03 Especificaciones Estándar para Acabados con Cal Hidratada, y C 207-04, Especificaciones Estándar para Mampostería con Cal Hidratada, proveen buenos consejos para las especificaciones de la cal hidratada (ASTM C 206-03; ASTM C 207-04, 2004). Elaboración de la Pintura de Cal

En general la pintura de cal se puede elaborar con masilla de cal o cal hidratada añadiendo agua para lograr una mezcla con la consistencia de leche entera. En términos del contenido de sólidos (cal), esta mezcla contiene aproximadamente de 15 a 20% de cal y entre 80 y 85% de agua (un galón de agua, a 20º C pesa 8.33 lbs.). Por ejemplo, en nuestra experiencia, usando un saco de 50 lbs. de cal hidratada y 30.5 galones de agua nos da aproximadamente una correcta relación para una mezcla de 20:80 basada en el peso de la cal y el agua. Una mezcla más fina de proporción 15:85 necesitaría un saco de 50 lbs. de cal hidratada y 40.5 galones de agua. La masilla de cal ya contiene un exceso de agua y, por lo tanto, se debe dar un margen suficiente para añadir la cantidad suficiente de agua a la masilla y lograr los contenidos de sólidos mencionados arriba. El agua representa el 50% aproximadamente de la masilla de cal y, por lo tanto, cada libra de masilla de cal, puede contener solamente ½ libra de cal. Al mezclar por peso, más masilla de cal y menos agua tendrán que ser añadidos para alcanzar la proporción de la leche entera. Por ejemplo, 100 libras de masilla de cal contienen 50 libras de cal y 50 libras de agua. Para lograr la mezcla 20:80 con masilla de cal, 100 libras de masilla de cal deben de ser añadidas a aproximadamente 24 galones de agua. (El agua que ya está contenida en la masilla de cal desplaza aproximadamente 6.1 galones del agua necesaria para la proporción adecuada.) Las fórmulas mencionadas arriba son sólo aproximaciones. Cada tipo de cal utilizada puede tener diferentes requerimientos de agua y será necesario experimentar para encontrar la cantidad exacta de agua que el tipo de cal utilizado necesitará. La pintura de cal puede ser mezclada a mano con la ayuda de un motor de taladro inalámbrico de pilas en el cual un agitador con paletas de brazos largos se ha insertado. Aunque es posible mezclar a mano, el uso de herramientas eléctricas acelera el proceso. La pintura de cal debe ser mezclada durante un tiempo suficiente para asegurarse de que toda la cal esté en suspensión. Resulta benéfico hacer una buena cantidad de pintura de cal en un gran contenedor y transferirla después a contenedores fácilmente transportables. Por ejemplo, un bote de basura de plástico de 32 galones es un buen contenedor para un saco completo de cal hidratada con 30.5 galones de agua. De este contenedor, la pintura de cal puede ser transferida a contenedores de 5 galones (o más pequeños) para trabajar. NOTA: La pintura de cal puede dañar la piel, los ojos y otros tejidos. Las recomendaciones de los productores de cal con respecto a la seguridad deben de ser observadas. Aplicación de la Pintura de Cal

La importancia de mezclar la pintura de cal hasta obtener una mezcla delgada, con consistencia de leche entera, es fundamental. La pintura de cal demasiado gruesa puede parecer que cubre mejor al principio, pero se agrietará al secar, en especial en los huecos de los sustratos con textura más rugosa. Como cualquier recubrimiento de buena calidad, muchas capas aplicadas con material fino y delgado formarán un acabado superior y mucho más duradero que pocas capas gruesas. No se sienta tentado de hacer más espesa la mezcla. La pintura de cal es un producto muy bueno para trabajar, fácil de aplicar y muy eficaz cuando se logra la consistencia lechosa.


may be required to find the exact amount of water to add to the lime that is used. Limewash may be physically mixed by the aide of an electric or battery operated drill motor in which a long-stemmed paddle stirrer has been chucked. While it is possible to mix by hand, the use of power tools speeds the process. Limewash should be mixed long enough to assure that all the lime is in suspension. Making one large batch of limewash in a larger container and then transferring the limewash into more easily transported containers for application is beneficial. For example, a 32gallon plastic rubbish bin (trash can) is a good container for a whole 50 lb. bag of hydrated lime mixed with 30.5 gallons of water. From this container, the limewash can be transferred into 5-gallon (or smaller) containers for work. NOTE: Limewash can damage skin, eyes, and other tissue. The lime manufacturer’s recommendations regarding safety and health should be followed.

Application of limewash

The importance of mixing limewash to a thin, whole milk-like consistency cannot be overemphasized. Limewash made too thick may appear to cover better when first applied, but will surely crack and craze upon drying, especially in the recesses of rougher-textured substrates. Like any fine-quality surface coating, many applied layers of thinned material build up a superior and, hence, more durable finish than fewer and thicker coats. Do not be tempted to thicken the mix. As a milk, limewash is superbly workable, easy to apply and very effective. Practically speaking, when transferring limewash from the mixing vessel to the more manageable application containers (say from a 32-gallon mixing drum to a 5-gallon pail), the mix should be given a quick stir with the drill motor. This keeps the solids in suspension and makes the most of the previous efforts. During the transfer, pouring the transferred limewash through a 30 mesh (0.600 mm. openings) sieve, or similarly sized window screen, into the application container has been found to be advantageous. A good way of doing this is to use the lid of the 5-gallon bucket from which a circle has been cut to fit the screen, and then pouring through it. This method allows both hands to be used for scooping limewash out of the larger container with another 5-gallon bucket especially set aside for that purpose. Between uses, storing limewash in the mixing container for indefinite periods of time is possible as long as a lid is kept on the container to minimize evaporation of the water. (The thin layer of crystalline material or “scum” that forms on top of limewash stored for a period of time [even overnight] is pure calcium or calcium/magnesium carbonate. This layer is harmless and easily mixed back into the limewash upon the next stirring prior to further use.) Depending on location, traditional limewash brushes may or may not be available. Limewash brushes are a matter of personal preference, but a brush with soft- to medium-stiff bristles that will hold limewash should be sought. Some countries have a good selection of limewash brushes that are commonly available at building supply or hardware stores (i.e. Greece), but in a pinch, a 4-inch to 6-inch ordinary paintbrush will work. Other brushes may be acquired by research on brush manufacturers via the Internet. There is no generally-accepted individual limewash brush for all application situations and different brushes may be experimented with to find one that suits the applicator best. Common stiff-bristled scrubtype brushes should be avoided since they just don’t pick up and transfer the amount of limewash necessary for a good job. Limewash can also be applied with a spray-type apparatus (e.g. a handpumped garden or insect type sprayer or a pneumatic or airless sprayer). When applying by sprayer, however, the limewash should be prescreened to avoid plugging the nozzle. Nevertheless, we do not recommend the use of sprayers because sprayers make it very difficult to properly work the limewash into the substrate and the work has to be gone over again with a brush to smooth things out. (Additionally, even with prescreening, there are inevitable nozzle plug-ups and extra time will be spent cleaning the nozzle.) For us, using a sprayer just adds one unnecessary step and increases the time needed to put on the limewash.

Hablando en términos prácticos, al transferir la pintura de cal del contenedor en dónde fue mezclada a los contenedores más manejables para su aplicación (digamos de un tambor de 32 galones a una cubeta de 5 galones), se debe dar una batida a la mezcla con el taladro y las paletas. Esto mantiene los sólidos en suspensión y se aprovecha el esfuerzo anterior. Al cambiarla, también es recomendable pasar la mezcla por una malla 30 (orificios de 0.600mm), o un tamiz de igual tamaño. Una manera fácil de hacer esto es recortar el círculo de la tapa de la cubeta de 5 galones e insertar en él el tamiz o la malla, y verter la mezcla por ahí. Este método permite tener las dos manos libres para tomar la pintura del contenedor grande con otra cubeta de 5 galones dejada a un lado para este propósito. Entre jornada y jornada, la mezcla puede ser almacenada en el contenedor original por periodos indefinidos de tiempo, siempre y cuando se le coloque una tapa para minimizar la evaporación del agua. (La capa fina de materia transparente que se forma en la superficie de la pintura almacenada por un cierto periodo de tiempo – aunque sea una noche – es calcio puro o carbonato de calcio/magnesio. Esta capa es inofensiva y se puede integrar a la mezcla de nuevo al batir la pintura antes de volver a empezar.) Dependiendo de la localización, las brochas tradicionales para pintura de cal pueden ser adquiridas o no. Las brochas especiales para la pintura de cal son cuestión de preferencia personal, pero se debe considerar el obtener una brocha con cerdas de suaves a medianas que puedan retener la mezcla. Algunos países tienen una buena selección de brochas para pintura de cal fácilmente localizables y a la venta en las tiendas de material para construcción o tlapalerías (por ejemplo Grecia); en una emergencia, una brocha ordinaria para pintura de 4 a 6 pulgadas servirá. Otras brochas pueden ser adquiridas por Internet localizando a los fabricantes especializados en brochas. No existe una brocha para pintura de cal comúnmente aceptada para todo tipo de situaciones y aplicaciones y diferentes brochas deben de ser experimentadas hasta encontrar la que mejor conviene. Las brochas comunes con cerdas duras para raspar deben de ser evitadas ya que sencillamente no agarran la pintura y no transfieren suficiente cantidad de pintura de cal para un buen trabajo. La pintura de cal también puede ser aplicada con un aparato tipo rociador (por ejemplo una bomba de mano para jardín o bomba de insectos o un rociador sin aire o para neumáticos). Si se va a utilizar un rociador, se debe colar la mezcla para no obstruir el rociador. Sin embargo no recomendamos el uso de rociadores porque es muy difícil lograr que la pintura penetre adecuadamente en el sustrato y habrá que regresar a pasar la brocha para emparejar el acabado. (Adicionalmente, aún habiendo colado la mezcla antes de empezar, habrá partículas que taparán la manguera y se tendrá que tomar tiempo extra para limpiarla.) Para nosotros, el usar un rociador sólo incrementa un paso innecesario y el tiempo que se necesitará para aplicar la pintura de cal. Cuando se empieza a aplicar la pintura de cal, ésta se ve transparente. Pero al secar, la cal se opaca. Al aplicar capas adicionales, el poder de cubrir y la belleza del tratamiento comienzan a resaltar. Mantenga la mezcla agitada al estarla aplicando con la brocha. Al aplicarla con la brocha haga movimientos para levantarla y girarla dentro de la cubeta para que quede suspendida. Trabaje con patrones que le aseguren un cubrimiento total. Marque la última posición en la pared usando la mano libre para apuntar hacia la siguiente área a pintar. Aplique la pintura de cal libremente trabajándola hacia el interior de la superficie con brochazos en todas direcciones (hacia arriba, hacia abajo y diagonalmente) La pintura va a salpicar y caer fuera de la brocha ensuciando el área. Ropa vieja y protección debe utilizarse en las áreas que no serán pintadas. En paredes altas, es mejor usar andamios que escaleras, ya que tienen muchas ventajas para la seguridad y eficiencia durante la aplicación. En algunos casos, el uso de una extensión para la brocha puede ayudar a alcanzar algunas áreas muy difíciles. El clima y otras consideraciones para la aplicación de la pintura de cal

Al trabajar con cal en una amplia gama de climas puede empujar a sus límites las técnicas de aplicación. Desde el impredecible clima del Atlántico del suroeste de Inglaterra, hasta el clima desértico del oeste de Australia y los altos desiertos del suroeste de Estados Unidos, la protección y la “carbonatación” tienen que ser considerados. Los dos están ligados y son necesarios para asegurar la más alta durabilidad y belleza. De manera muy amplia, la “carbonatación” de la cal incluye la alteración química del hidróxido para convertirlo otra vez en carbonato. (Figura 1). (El dióxido de carbono, disuelto en agua, es uno de los componentes clave para la transformación del hidróxido químico al mineral de carbonato que antes fue. Al momento de pintar, favorecer la “carbonatación” se logra mejor si se tienen ciclos mojados/secos. En climas en dónde naturalmente se tienen estos ciclos mojados y secos, como en la costa de Atlántico, la naturaleza hace

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When limewash is first applied, it is translucent. But as it dries, limewash becomes opaque. As additional coats are applied, the hiding power and full beauty of the treatment becomes apparent. Keep the mix stirred while applying limewash with the brush. During application with the brush, use a scooping and swirling motion in the pail to keep the mix suspended. Work in patterns that assure full coverage. Mark the last position on the wall by using a free hand to point to the next area to be covered. Apply the limewash liberally and work it into the surface with strokes in many directions (up,down, and diagonal). Expect the limewash to splatter off of the brush and be rather messy. Drop clothes and masking should be used for areas that will not be covered by limewash. On high walls, scaffolding, as opposed to ladders, provide advantages for both comfort and efficiency during application. In some cases, use of a longer handle for the brush may help reach those otherwise hard-to-get-at areas.

algo del trabajo por nosotros (en efecto, la necesidad hace que a veces trabajemos en la neblina y la lluvia!). En climas más secos, el objetivo es mojar ligeramente la superficie pintada entre aplicaciones – y aún durante las aplicaciones. Aún si la pintura no debe ser aplicada en una superficie tan mojada en dónde sea visible el “brillo” del agua, una superficie húmeda en un clima seco es necesario y benéfico. Añádale altura y una atmósfera enrarecida y el secado puede ser muy rápido. El tiempo y los contratos de trabajo tienen sus exigencias, pero las superficies exteriores deben de ser pintadas fuera de las horas pico de los climas locales; para evitar los momentos en que hiela o cuándo las temperaturas son demasiado calientes (40º C+). De ser posible, hay que trabajar del lado de la sombra del edificio para evitar que el sol seque la superficie demasiado rápido. En algunos climas, la primavera y el otoño son mejores para pintar con cal, el invierno y el verano lo pueden ser en otras latitudes. Para extender la estación de la pintura de cal, se puede instalar una protección para crear un micro clima cerca del edificio. Esto resulta muy útil en climas impredecibles y ofrece protección en los extremosos.

Climate and other considerations for application of limewash

Belleza

Working with lime in a wide range of climates can push the limits of application. From the unpredictable Atlantic climate of Southwest England, to the hot desert climate of Western Australia and the high desert of the Southwest U.S.A., protection and carbonation need to be considered. The two are linked and necessary to ensure the highest quality of durability and beauty. Very broadly, the carbonation of lime involves the chemical alteration of the hydroxide back into a carbonate (Figure 1).

La pintura de cal tiene una belleza única, es increíblemente brillante y le da una profundidad al color que lo hace brillar. Es impresionantemente brillante en la noche y puede iluminar los cuartos más obscuros o los más sombreados patios. En la costa del Atlántico, los faros están pintados en blanco con cal como recuerdos vivos, tal como la señalización cotidiana para los embarcaderos.Ya sea usada en piedra y casas de tierra, catedrales y muros de piedra seca, o palacios y graneros en el campo, la pintura de cal ha pasado la prueba del tiempo y ha protegido y decorado las estructuras del mundo.

Figure 1. The lime cycle: from stone, to lime, to stone. Figura 2. El ciclo de cal: de piedra, a cal, a piedra

Setting (carbonation) Fijación (cabonación)

Calcum Hydroxide Ca(OH)2 Hidróxido de Calcio Ca(OH)2

Limestone (calcium carbonate) CaCO3 Piedra caliza (cabonato de calcio) CaCO3

The Lime Cycle

Hydration (slaking) Hidratación

Carbon dioxide, dissolved in water, is one of the key components of the transformation from a chemical hydroxide back into a mineral of carbonate. On site, encouragement of carbonation is best achieved under conditions of wet/dry cycles. In climates with naturally-occurring cycles of wetting and drying, such as the Atlantic coastline, nature does some of the work for us (indeed, necessity sometimes forces us to work in the fog and rain!). In drier climates, the focus is on lightly wetting down the limewash between - and even during - applications. While the limewash should not be applied to a surface so soaked that a “sheen” of water is visible, a damp surface in a dry climate is both necessary and beneficial. Add altitude and a rarified atmosphere, and drying can be very rapid. Time and work contracts do have their own momentum, but exterior surfaces should be worked outside the extreme times of any local climate; both avoiding times when frost is possible and times when tem-

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el Ciclo de Cal

Burning (calcination) Calcinación

Calcum Oxide (quicklime) CaO Oxido de Calcio (cal viva) CaO

¿Que le da a la cal estas maravillosas cualidades? La hermosa luminosidad de una superficie pintada con cal se debe principalmente al reflejo y la refracción de la luz. El brillo intenso de la pintura no pigmentada se debe en gran parte al reflejo de luz que llega de regreso a los ojos del que la ve. Una cualidad más sutil pero también asombrosa, es la refracción o inclinación de la luz a través de los cristales de calcita (el mineral de carbonato que se forma en el proceso de “carbonatación”). La luz refractada a través de la calcita se divide en dos rayos, uno rápido y otro lento, y el efecto visual es un desdoblamiento de la luz emitida por el cristal. La intensidad de la luz misma no cambia, pero al ser compuesta por millones de microscópicos cristales de calcita aumentando al tiempo que la superficie continúa su proceso de “carbonatación”, el efecto es el de una superficie que se ve brillante y vibra con una textura interna sutil con variaciones. Este efecto moteado le da profundidad y capta el interés del que la ve. Pigmentos

Por el hecho de que la pintura de cal tiene un alto pH, muchos pigmentos de


peratures may be too hot (40°C+). When possible, work on the shaded side of the building to avoid a too-quick drying from the full sun. In some climates, the spring and fall may be well suited to limewashing, as summer or winter may be in others. To extend a limewash season, sheeting protection can be installed to create a microclimate next to the building. This is always useful in unpredictable climates and can offer some protection in extremes.

Beauty

Limewash is uniquely beautiful, incredibly bright and gives off such a depth of colour that it appears to shine. It is impressively vibrant at night and can lighten up the darkest of interior rooms or heavily shaded courtyards. On the Atlantic coast, lighthouses have been limewashed white in living memory, as have day marks for shipping. Whether used on stone and earth houses, cathedrals and dry stone walls, or palaces and field barns, limewash has stood the test of time and has protected and decorated the structures of the world. So what gives limewash these wonderful qualities? The beautiful luminosity of a limewashed surface is due primarily to the reflection and refraction of light. The intense brightness of non-pigmented limewash is largely due to the reflection of light back into the viewer’s eyes. A more subtle, but startling quality, is the refraction or bending of light through crystals of calcite (the carbonate mineral that forms through the process of carbonation). Light refracted through calcite splits into two rays, one fast, one slow, and the visual effect is a doubling or twinning of the light emitted by the crystal. The intensity of the light itself is not changed, but when compounded by millions of microscopically small calcite crystals increasing over time as the surface continues to carbonate, the effect is a surface that appears bright and vibrant with subtle internal texture and variance. This mottled effect provides depth and interest to the viewer.

Pigments

Because limewash has a high pH, many organically-based pigments are destroyed and incapable of being used to impart colour to the mix. If an organic pigment is desired to be used, the manufacturer should be contacted to assure compatibility in high pH (approximately 12 to 13). Oxidebased pigments (e.g. iron oxide) are both alkaline pH compatible and available in a wide range of colours (e.g. yellow, red, brown, tan, green, pink, blue, etc.). A good source of compatible oxides is available where pigments for masonry mortar are sold. If a pigment is deemed compatible with masonry mortar (ASTM C 979-99,1999), it is a good candidate for coloring limewash. Pigmented limewash is best mixed to subtle and pale pastel shades. Darker colors are possible, but may overwhelm the very nature of limewash, a bright and light material. Care should be taken to avoid adding too much pigment to limewash (e.g. more than 5% or so of the mix) because, in our experience, the pigment will tend to fall out of suspension and it will be difficult to achieve uniform colour. Regardless of pigment choice, the first few coats for a pigment-colored job should be made with unadulterated limewash. These first few coats of white provide the base and the proper adhesion to the substrate for the following colored coats. The pigmented coats should go on thinly to build up the colour that is expected. When wet, the pigmented limewash will look darker than when it dries on the wall. The best way to achieve the desired result is to make some test panels on a section of substrate that has been limewashed white. Experimentation is the best way to achieve the desired look and can be accomplished quickly with a little planning beforehand. For example, say that a yellow pigment has been chosen for the project; a pastel shade that complements the fenestration and trim. Using a gallon of wash from the storage container, add ¼ gram of pigment, mix it up and apply it to a 1 sq.ft. area of test panel. While that experiment dries, add 1/4 gram more pigment to the same gallon of test material and apply it to a separate 1 sq.ft. area. Proceed in this stepwise fashion until the result is satisfactory. Using the best test panel as a touchstone, mix up another gallon of that mix design and apply a second coat to the touchstone test panel to see how the colour stabilizes. Does the panel darken too

base orgánica son destruidos y no pueden ser usados para darle color a la mezcla. Si se desea utilizar un pigmento orgánico, el productor debe de ser contactado para asegurar la compatibilidad con el alto pH de la cal (aproximadamente de 12 a 13). Los pigmentos con una base de óxidos (por ejemplo: óxido de hierro), son compatibles con el pH alcalino y existen en una amplia gama de colores (por ejemplo: amarillo, rojo, café, canela, verde, rosa, azul, etc.). Una buena fuente de óxidos compatibles está disponible en el mismo lugar en dónde se venden los morteros para albañilería. Si un pigmento tiene la reputación de ser compatible con el mortero común (ASTM C 979-99, 1999), es un buen candidato para pigmento de pintura de cal. La pintura de cal se mezcla mejor con tonos pastel claros y sutiles. También es posible obtener tonos más obscuros, pero pueden abrumar la naturaleza de la pintura de cal que es un material claro y brillante. Se debe de tener cuidado de no añadir demasiado pigmento a la mezcla (por ejemplo más de 5% o algo así de la mezcla) porque, según nuestra experiencia, el pigmento se separará de la suspensión y será difícil lograr un color uniforme. Sin importar que color se haya escogido, las primeras capas de un rabajo con pintura de cal con pigmento deben de ser realizadas con pintura sin adulterar. Estas primeras capas blancas proporcionan la base y la adhesión al sustrato necesarias para las subsecuentes capas con color. Estast capas con color deben de ser pintadas muy delgadas para construir el color que se espera. Cuando aún está mojado, el color de la pintura de cal se verá más oscuro sobre la pared pintada que cuando se seca. La mejor manera de lograr el resultado deseado es hacer tramos de prueba en una sección del sustrato que ya fue pintado con la pintura blanca. La experimentación es la mejor manera de lograr el acabado deseado y puede ser logrado con un poco de planeación. Por ejemplo, supongamos que se escogió un pigmento amarillo para el proyecto; un tono pastel que complementa las ventanas y ribetes. Tome un galón de base blanca en un contenedor, añádale ¼ de gramo de pigmento, mézclelo y aplíquelo a una porción de 1 pié cuadrado de su área de prueba. Mientras este experimento se seca, añada ¼ de gramo más al mismo galón de material de prueba y aplíquelo a otro pié cuadrado de área de prueba. Proceda de esta manera hasta que el resultado sea satisfactorio. Escoja la mejor área de prueba, mezcle otro galón de ésta misma prueba y aplique una segunda capa al pié cuadrado de esta área escogida para ver como se estabiliza el color. ¿Se oscureció mucho el color o quedó equilibrado? Si está muy oscuro (o le falta más color) regrese al área de prueba anterior (o la siguiente en su línea de pruebas), pruebe con una segunda capa de ésa mezcla. ¿Es este el resultado que buscaba? Si así es, aplique una tercera capa en ésa área y decida si alcanza el efecto deseado. Una vez que el resultado se ha logrado, calcule la cantidad de pigmento que necesitará para el área a pintar. Por ejemplo, si ¼ de gramo de pigmento añadido a 1 galón de pintura de cal produjo el resultado deseado, añada 1 y ¼ de gramos de pigmento a 5 galones de pintura de cal blanca, etc. Aditivos

Los aditivos son algunas veces aconsejados para áreas de la estructura que están expuestas a climas extremosos y en dónde el agua que cae de la lluvia tiene la tendencia de erosionar la superficie (por ejemplo, parapetos, zonas dónde salpica el agua al caer al piso, áreas en dónde pegan los rociadores, etc.) Mientras que hay argumentos a favor y en contra de los aditivos en la pintura de cal en este tipo de áreas, conviene a veces echar un vistazo a la estructura en su conjunto y buscar métodos para prevenir el daño causado por el agua (por ejemplo, lámina metálica inoxidable encima de los pretiles, cunetas para minimizar el goteo de los aleros, reposicionar los rociadores, etc.) Sin embargo, cuando se opta por los aditivos, éstos varían de los muy comunes a los regionales. Los comunes incluyen aceite de linaza, sebo y caseína. Los aditivos regionales incluyen la baba del nopal, alumbre, sangre animal, orina, sal, formaldehído, y una gama de otros menjurjes. Creemos que el uso de algún aditivo sólo debe de ser tomado en cuenta cuando otras opciones de protección han sido eliminadas. Tenga en cuenta que en áreas en dónde se usaron aditivos, aplicaciones de mantenimiento adicional con aditivos serán necesarias. En general esto se debe a que la pintura de cal sin aditivos no tendrá la misma adherencia sobre aquella que ya ha sido adulterada con aditivos o el sustrato que ha sido tratado con aditivos. Los aditivos pueden afectar la porosidad y la permeabilidad de la pintura de cal; también su tolerancia a los rayos UV, afectarán la superficie de la capa exterior y en general su capacidad de manejo al aplicarla. Por lo tanto, los aditivos pueden afectar la adhesión de la pintura al sustrato. Hay que considerar un balance antes de escoger añadir aditivos. Como con los pigmentos, las pri-

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much or is it just right? If it is too dark (or not dark enough) then go back to the previous (or the next “one-up”) panel, try a second coat of that mix design. Is this the result you wanted? If so, apply a third coat to that panel and decide if it yields the desired effect. Once the desired result is achieved, scale up the weight of the pigment to the required batch size. For example, if 1/4-gram pigment addition to 1 gallon of limewash produced the desired result, add 1 and 1/4 grams of pigment to 5 gallons of limewash, etc.

Additives

Additives are sometimes advocated for areas of the structure that are exposed to extremes of the weather and where water falling as rain has the tendency to erode the surface (e.g. parapets, splash zones near the ground, areas hit by sprinklers, etc.) While there are arguments for and against the use of additives in limewash in these types of areas, it is sometimes best to look at the overall structure for methods to prevent the damage caused by running water (e.g. flashing on top of parapets, gutters to minimize eave drip, re-positioning of sprinkler heads, etc). However, when additives are preferred, they can range from the common to the regional. Common additives include linseed oil, tallow, and casein. Regional additives include mucilage from the Nopal Cactus, Alum, animal blood, urine, salt, formaldehyde, and a host of other concoctions. We believe that the use of additives should only be considered when other options of protection have been eliminated. Be aware that in areas where additives have been used, additional maintenance applications will require the use of additives as well. In general, this is because raw limewash will not adhere well to limewash or substrates adulterated with an additive. Additives to limewash can affect the limewash porosity and permeability, its tolerance to UV light, the surface skin behaviour and the general workability of limewash in application. Therefore, additives can affect the adhesion of limewash to the substrate. There is a balance to consider before choosing additives. As with pigments, the first few limewash coats need to be applied additive-free to provide the base and the proper adhesion to the substrate. The final coats may then be adulterated with the additive as desired.

The right number of coats

The biggest question people have regarding limewash is how many coats it will require to cover the surface. Again, properly-applied limewash must go on in a number of thin coats. As a protective and beautifying surface coating, limewash must adhere and “key” into the substrate. When put on thin and built-up, the various layers undergo more rapid partial carbonation during each period of wetting and drying, both prior to and during the application of the next coat. The end result is a surface that does not chalk when rubbed with the hand or other object. Properly applied and given a little time, limewashed surfaces will not chalk. For example, Pete Mold repaired an eroded Cob barn (Moortown Farm, Dartmoor, England-a wet upland region with more than 39 inches annual precipitation) eight years ago (1996) using lime mortar and 3 to 4 coats of limewash. Without additives, there is no chalking and the limewash has remained in serviceable condition without recoating. Likewise, the erosion has ceased. As another example, a 6-year old rammed-earth limewash project remains trouble free in the extreme climate of Western Australia. In terms of coverage, at least 3 to 5 coats of un-pigmented limewash can be expected for a typical rough-textured absorbent substrate. If the job is to be pigmented, expect to apply at least two more coats to achieve an even coverage of colour. Remember one very important point: all future work to maintain the original protection and beauty will only require an occasional freshening-up with very little preparation effort: a penny-saved and a pound earned!

Limewash: a case study

In 2004, Peter Mold was contracted to limewash a laboratory building in Henderson, Nevada, in the heart of the Mojave Desert. The laboratory building was a combination of 1960’s era wood frame/cement-lime stucco

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meras capas de pintura de cal tienen que ser aplicadas sin aditivo para que se haga una capa segura que proporcione la adhesión adecuada al sustrato. Las capas finales pueden ser adulteradas entonces con el aditivo deseado. El número ideal de capas

La pregunta más importante que la gente tiene con respecto a la pintura de cal es cuántas capas se necesitarán para cubrir la superficie. Una vez más, una correcta aplicación de pintura de cal debe de ir en un cierto número de capas delgadas. Como protección y embellecedor de una superficie, la pintura de cal debe adherir y sellar en el sustrato. Cuándo son puestas muy finas y de manera que se vayan añadiendo unas a otras, las capas experimentan una más rápida “carbonatación” parcial en cada periodo de mojado y secado, antes y después de la aplicación de la siguiente capa. El resultado final es una superficie que no se despinta cuando se le talla con la mano o cualquier otro objeto. Aplicada correctamente y cuándo se le da un tiempo, las superficies de pintura de cal no se despintan. Por ejemplo, Peter Mold reparó un erosionado granero de mazorcas (Moortown Farm, Dartmoor, Inglaterra, una región muy húmeda del norte, con más de 39 pulgadas de precipitación al año) hace 8 años (1966) utilizando mortero de cal y de 3 a 4 capas de pintura de cal. Sin aditivos, la pintura no se cae y permanece en buen estado sin tener que repintar. También frenó la erosión. Otro ejemplo, un proyecto de tierra apisonada pintado con cal hace 6 años en el extremoso clima de Australia occidental permanece sin problemas. En términos de cobertura, al menos de 3 a 5 capas de pintura no pigmentada son necesarias para un típico sustrato rugoso y absorbente. Si el trabajo exige pigmentar, prepárese para aplicar al menos 2 capas extras para lograr una cobertura de color uniforme. Recuerde un punto muy importante, en el futuro para mantener la protección y la belleza original sólo necesitará un ligero y ocasional retoque con muy poco esfuerzo de preparación: un penique ahorrado y una libra ganada. La pintura de cal: caso de estudio

En 2004, Peter Mold fue contratado para pintar un laboratorio en Henderson, Nevada, en el corazón del desierto Mojave. El edificio del laboratorio era una combinación de molduras de madera/estuco de cemento y cal de los años 1960, y concreto muy finamente acabado colado en sitio de los años 1940 con una pared de 10 pies (3 m) de altura sobre el nivel de la calle. El laboratorio está localizado en un complejo industrial y el estuco había sido pintado color café claro por los años de proximidad a una fábrica de manganeso. El estuco mantenía íntegramente su color y nunca había sido pintado. El concreto había sido pintado unos años atrás y se encontraba en lamentables condiciones. El clima del Mojave se posiciona en segundo lugar después del Sahara en cuanto a la resequedad y calor. Debido a las limitaciones de tiempo, el trabajo empezó justo al final de la mejor estación para la pintura de cal, la primavera, y el comienzo de la peor estación, el verano, Las temperaturas en el día ya estaban alcanzando los 100º F (38º C), pero las noches bajaban a un muy agradable 70º F (21º C). Los vientos, durante el tiempo del contrato eran generalmente inestables y en ráfagas que alcanzaban las 25 millas por hora (40 km/h). No hubo lluvia durante el tiempo que duró el proyecto. Se determinó que un limpiador a presión y en órbitas era lo más eficaz para limpiar la tierra y la mugre del estuco, así como (de una manera más concentrada) quitar (hacer explotar) la pintura del concreto (cuidado: los limpiadores a presión pueden no ser compatibles con algunas superficies históricas más suaves). El estuco se lavó bien, pero las manchas de manganeso no se quitaron. El estuco estaba quebrado en algunas áreas dañadas de los marcos de madera, (en dónde un vehículo había retrocedido hacia una esquina del edificio) abarcando ¼ de pulgada a lo ancho y extendiéndose en profundidad hacia la malla de alambre de soporte más abajo. Aunque menor en términos de su importancia estructural, grietas superficiales y delgadas eran evidentes en algunas áreas de la instalación original. El estuco tenía algunas áreas que necesitaban reparación usando mortero de cemento y cal igualando la textura del estuco pesado en forma de pegamento. El concreto era mucho más desafiante, ya que requería casi una semana completa de esfuerzo, pero se limpió con éxito. Tenía serias grietas superficiales en ciertas áreas, y también algunas áreas que necesitaban reparación dónde las varillas del interior se habían oxidado, y el material de la superficie se había expandido y había reventado. Sin embargo, después de reducir la capa con brillo de la superficie lavándola a presión, el concreto, aunque liso, resultó suficientemente poroso y permeable para continuar.


and 1940’s smooth-finished cast-in-place concrete with a 10-foot (3 m) wall height above grade level. The laboratory building is located in an industrial complex and the stucco had been stained light brown from years of proximity to a manganese-producing facility. The stucco was integrally colored and had never been painted. The concrete had been painted several years before and was in poor, flaking condition. The climate of the Mojave is second only to the Sahara in terms of dryness and heat. Because of time constraints, work began right at the end of the most optimal limewashing season, spring, and the beginning of the least desirable season, summer. Daytime temperatures were already reaching 100 F° (38°C), but the evenings were cooling off to a pleasant 70 F° (21°C). Winds during the time of the contract were generally unsettled and gusty up to 25 mph (40 kph). There was no precipitation during the time of the work. An orbital pressure washer was determined to be most effective for cleaning dirt and grime from the stucco, as well as (in a more concentrated fashion) removing (blasting) paint from the concrete (caution: pressure washers may not be compatible with some soft historic surfaces). The stucco cleaned up well, but the manganese stains remained. Stucco cracks in some minor structurally damaged areas of the wood frame section (where a vehicle had backed into a corner of the building) approached ¼” in width and extended in depth to the support lath below. Although minor in terms of structural importance, extensive surface hairline crazing and cracking was also evident in some areas of the original installation. The stucco had a few areas that required a parging repair using cement-lime mortar to a similar heavy lace stucco texture.

Después de limpiar y reparar, se mezcló una buena cantidad de pintura de cal en un bote de basura de 32 galones logrando una consistencia lechosa al usar un saco de 50 libras de cal hidratada tipo S con 30 galones de agua. Áreas de prueba fueron completadas en cada una de las diferentes superficies para determinar la compatibilidad, la absorbencia, la cobertura de grietas y la mejor brocha para cada superficie. Pequeñas áreas experimentales de pintura de cal pigmentada fueron pintadas adicionalmente para la aprobación del dueño del edificio. La capa inicial en ambos materiales se absorbió bastante bien y el estuco se pudo trabajar con facilidad. En total, con 5 capas de pintura de cal natural, seguidas de 2 capas de pintura de cal pigmentada se cubrió la porción de estuco que el dueño quería pintar con color. Para el frente del edificio, el dueño decidió que la pintura de cal se dejara sin pigmentar y un total de 7 capas de pintura cubrieron esta sección. El resultado fue una muy impresionante consolidación de las grietas superficiales llegando a llenar las grietas más grandes de ¼ de pulgada. El concreto resultó más difícil debido a la absorción dispareja, pero insistiendo lo logramos con 13 capas. El concreto también se coloreó, pero nunca alcanzó el mismo nivel de cobertura sólida que tuvimos con el estuco. En total, en este trabajo se usaron 250 galones de pintura de cal. Las áreas más altas del edificio se trabajaron colocando andamios, lo que permitió una aplicación mucho más eficiente de la pintura evitando subir y bajar constantemente por las escaleras. El total del trabajo nos tomó un mes completo de principio a fin, incluyendo la limpieza, reparación, experimentación y pintado. Este agrietado, sucio y viejo edificio se renovó. (Figura 2)

The concrete was more challenging, requiring nearly a week’s worth of effort, but was successfully cleaned. The concrete had severe surface crazing in some areas, and also some areas needing a parging repair where the underlying structural steel rebar had corroded, expanded and “popped” off some surface material. However, after reducing the surface laitance by pressure washing, the concrete, though smooth, proved porous and permeable enough to continue. Following cleaning and repair, a fresh batch of limewash was mixed up in a 32-gallon plastic rubbish bin (trash can) to a milk-like consistency using one 50 lb bag of Type S hydrated lime to 30 gallons of water. Test patches were completed on each surface to determine compatibility, absorbency, crack coverage and the best brush for each surface. Additional experimental patches of pigmented limewash were applied for the building owner’s approval. The initial coat on both materials was absorbed well and the stucco turned out to be quite easy to work with. All told, 5 coats of un-pigmented limewash, followed by two coats of pigmented limewash, covered that portion of the stucco wall that the owner wanted colored. For the front of the building, the owner decided that the limewash should be left unpigmented and a full 7 coats covered that section. The result was a very impressive consolidation of the surface cracks and filling of the larger, ¼” cracks. The concrete was more difficult because of uneven absorption, but by sticking at it, 13 coats finished the job. The concrete was pigmented as well, but never reached the same level of solid coverage as did the stucco. In all, the job required over 250 gallons of limewash. The tall areas of the building were worked from scaffolding, which allowed a more efficient application of material by avoiding many repeated trips up and down ladders. The entire job took one month to complete from start to finish, including cleaning, repair, experimentation and limewashing. The ragged, stained, and dirty building has been refreshed. (Figure 2) The most challenging aspect of this job was the climate. With daytime temperatures exceeding 100 F°, the limewash would flash dry and was impossible to keep constantly wet. Up until this job, Peter Mold had always been concerned with keeping things wet down and damp. Here, the Mojave Desert gave him no choice. What he learned from this job on these substrates was that frequent cycles of wetting and drying improve the rate of carbonation and that it is all right for a limewash to dry out between the cycles. He wet this system down at least 4 to 5 times a day in those areas that he had covered previ-

Figure 2. Front laboratory limewash, not pigmented. Figura 2. Frente del laboratorio pintado con cal, sin pigmentar.

El aspecto más desafiante de esta obra fue el clima. Con temperaturas que excedían los 100º F, la pintura de cal se secaba en un instante y era imposible mantenerla mojada constantemente. Hasta antes de empezar este trabajo, Peter Mold siempre se había preocupado en mantener las superficies mojadas y húmedas. En este caso, el Desierto del Mojave, no se lo permitió. Lo que aprendió en esta obra con estos sustratos fue que ciclos frecuentes de mojar y secar mejoran la velocidad de “carbonatación” y que no importa que la pintura de cal se seque entre cada ciclo. Humedeció las paredes por lo menos 4 o 5 veces al día en esas áreas que había cubierto previamente, pero dejó que el sistema se secará naturalmente en la noche y se secara rápidamente en el día. Esto cambió su manera de pensar acerca de la pintura de cal en el sol del desierto. No solamente es posible hacerlo sin protección contra el sol, se logró uno de los acabados más duraderos que él ha visto. Los dueños del edificio dicen que no ha habido erosión después de las lluvias de verano y que la superficie no se despinta. La obra fue un éxito total. Conclusión

Hoy por hoy, la pintura de cal sigue siendo un material comprobado, versátil y hermoso para proteger y mantener una amplia gama de superficies de construcción. Es barato, fácil de aplicar y duradero. Se puede pigmentar con una variedad de colores o mantenerse blanco. Puede consolidar benéficamente las superficies dañadas. Es permeable al vapor y permite que la construcción respire del interior hacia el exterior. La “carbonatación” de la superficie al paso del tiempo y sobretodo si fue promovida durante la aplicación con ciclos de

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ously, but he let the system dry out overnight and flash-dry during the day. This has changed his mind regarding limewashing in the desert sun. Not only is it possible without shade protection; it has given one of the most durable finishes he has ever seen. The building owners say that there has been no erosion after the summer rainy season, and the surface does not chalk at all. The job was a complete success.

Conclusion

Today, limewash remains a proven, versatile and beautiful material to protect and maintain a wide range of building surfaces. It is materially inexpensive, easy to apply, and durable. Limewash can be pigmented to a variety of colors or be left pure white. Limewash can beneficially consolidate damaged substrates. Limewash is vapour-permeable, allowing a building to breathe from the inside to the outside. Carbonation of the surface over time, and encouraged during application by cycles of wetting and drying, increases the beauty and durability of the limewashed surface. We hope that this paper, which combined the experience of application and science, will encourage more people to consider the use of limewash on their next project, whether it is for protection and beautification of a historic structure, or as a compatible and beneficial application to a more modern surface.

Acknowledgements

The authors wish to acknowledge and thank Margaret Thomson of Chemical Lime Company (Nevada, USA) and Bruce Induni (UK) for their thoughts, encouragement and collaboration regarding the traditional and non-traditional use of limewash. Additionally, the authors wish to thank the peer reviewers for their thoughts and suggestions to make this a stronger paper.

References

ASTM C5-03, 2003, Specifications for Quicklime for Structural Purposes, ASTM International, Conshohocken, PA, USA. ASTM C206-03, 2003, Standard Specification for Finishing Hydrated Lime, ASTM International, Conshohocken, PA, USA. ASTM C207-04, 2004, Standard Specification for Hydrated Lime for Masonry Purposes, ASTM International, Conshohocken, PA, USA. ASTM C979-99, 1999, Standard Specification for Pigments for Integrally Colored Concrete, ASTM International, Conshohocken, PA, USA.

mojado y secado repetidos, aumenta la belleza y la durabilidad de la superficie pintada con cal. Esperamos que este resumen, que combinó la experiencia de la aplicación y la ciencia, animará a más gente a usar esta pintura en sus futuros proyectos, ya sea para proteger y embellecer monumentos históricos, o como una aplicación compatible y recomendable en una superficie más moderna. Reconocimientos

Los autores quieren reconocer y agradecer a Margaret Thomson de la compañía “Chemical Lime Company” (Nevada, Estado Unidos) y a Bruce Induni (Reino Unido) por sus pensamientos, estímulos y colaboración con respecto al uso tradicional y no tradicional de la pintura de cal. Los autores también quieren agradecer a los compañeros que revisaron el escrito y dieron sus sugerencias e ideas para hacer de éste un documento más sólido. Referencias

ASTM C5-03, 2003, Especificaciones para la Cal Viva en Usos Estructurales, ASTM Internacional, Conshohocken, PA, Estados Unidos. ASTM C206-03, 2003, Especificaciones Estándar para Acabados con Cal Hidratada, ASTM Internacional, Conshohocken, PA, Estados Unidos. ASTM C207-04, 2004, Especificaciones Estándar para Cal Hidratada en Mampostería, ASTM Internacional, Conshohocken, PA, Estados Unidos. ASTM C979-99, 1999, Especificaciones Estándar para Pigmentos en Concreto Integrado con Color, ASTM Internacional, Conshohocken, PA, Estados Unidos. ASTM C1489-01, 2001, Especificaciones Estándar para Masilla de cal en Objetivos Estructurales, ASTM Internacional, Coshohocken, PA, Estados Unidos. Hansen, et.al. 1999, Los Efectos del Envejecimiento de la Masilla de Cal, Taller Internacional RILEM sobre Morteros Históricos: Características y Pruebas, Paisley, Escocia, P. Bartos, Cl Groot y J. J. Hughes, ed. 197-205. Asociación Nacional de la Cal, 1955, Mezclas Blancas y Pinturas Frías al Agua, Boletín Nº. 304-G, Arlington, Virginia, Estados Unidos, fuera de circulación. ✫

ASTM C1489-01, 2001, Standard Specification for Lime Putty for Structural Purposes, ASTM International, Conshohocken, PA, USA. Hansen, et.al. 1999, Effects of Ageing on Lime Putty, International RILEM Workshop on Historic Mortars: Characteristics and Tests, Paisley, Scotland, P. Bartos, C. Groot and J.J. Hughes, eds. 197-205. National Lime Association, 1955, Whitewash and Cold Water Paints, Bulletin No. 304-G, Arlington, Virginia, U.S.A. No longer in print. © Copyright NLA Building Lime Group 2005 The views presented in this paper are solely those of the authors. The National Lime Association (NLA) and the Building Lime Group assume no liability or responsibility for any errors, omissions, or other limitations in this paper or for any products, services, or methods presented. This paper is intended for use by professional personnel competent to evaluate the significance and limitations of the information provided and who will accept full responsibility for the application of this information. NLA and the Building Lime Group do not intend to infringe on any patent or other intellectual property right or induce any other party to do so, and thus users of this document are responsible for determining whether any method, technique, or technology described herein is protected by patent or other legal restriction. ✫

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An example of a type S hydrated, Dolomitic lime, in a 50 lb. bag, as sold in the Southwestern USA. Un ejemplo de un 'S' clase de cal hidratada, tipo Dolomítica en un bolsa de 22.5 Kg, como se venden en el región Suroeste de Los EE UU.

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