Performanc@.ratedl-ioists may usher in a new era of home building

FVERY SO often advancements in l-ltechnology and market conditions combine to foster new product developments that trigger a revolutionary shift in the home building industry. History records such events and, ultimately, acceptance by builders, consumer demand and time determine whether they succeed.

Currently, economic and environmental forces are driving engineered wood products into the arms of a new generation of builders. In return, growth in new building systems and construction methods are increasing the need for product performance reviews, effective quality assurance programs and marketplace education about the correct specification and use ofthese new building products.

To that end, APA-The Engineered Wood Association is introducing a new performance standard for wood I-joists in residential floor applications that will make the product easier to buy, specify and use.

Builders and specifiers now have to sort through a maze of manuals and manufacturer specs to select the right product for the right application. But the new performance standard -known as APA PRI-4OOwill allow builders to easily select and use Ijoists from member manufacturers with common load/span tables, installation instructions and engineering design values.

APA PRI-400 increases availability through multiple suppliers and streamlines installation with uniform rules and guidelines. Under the performance standard, I-joist depths, load/span tables, installation details and hole charts will be standard among the APA EWS manufacturers.

Span ratings will be stamped right on the product making it easier for builders and remodelers to install them properly and more visible for code officials to inspect.

The stamp will reduce the need for an engineer's approval for uniformly loaded applications which should help reduce some of the unnecessary costs associated with using I-joists. Additionally, the universal span ratings allow builders the freedom to use I-joists from different manufacturers having the same joist designation in the same floor system.

Wood I-joists are made by a grow- ing number of companies and each product varies a little from its competition. Differences include widths, standard lengths, and materials used in web and flange. APA PRI-400 recognizes the differences in manufacturing of the product and prescribes a performance criteria that all products must meet in order to qualify to become an APA Performance Rated I-joist. The result is a product that builders can feel comfortable using knowing it will perform in application.

Why I's?

The objectives for developing the I-joist performance standard are clear: o Simplify specification and use o Create a level playing field of performance o Lower costs o Assure product quality

Story at a Glance

New performance standard makes l-joists easier to buy, specify and use ... engineered product use should rise as costs decrease.

The standard assures specifiers and builders will receive a performancerated, quality-assured I-joist product that is simply smarter. APA PRI's provide consistent performance for the most demanding residential applications.

To simplify I-joist use and specification, APA, through technical research, product tests and performance reviews, established standard depths, load/span tables, installation details, hole charts and trademarks.

Performance Rated I-joists are available in four depths (see chart below).

Corresponding load/span tables provide for sawn or laminated veneer lumber flanges and OSB or plywood webs. The tables also allow for simple and multiple spans and recognize composite glued-nailed construction.

Standard installation details include end and interior bearings, framing for openings, transfer of concentrated loads, cantilever considerations and rim board provisions. In addition. APA Performance Rated Ijoists have standard hole charts developed from traditional tables that permit round or rectangular cuts.

The performance standard is based on today's end-use requirements and is designed to ensure life/safety and performance of the structure. APA analysis of the wood I-joist industry shows that most wood I-joists look the same and perform the same. APA PRI-400 takes this to the next level by standardizing these products under one specification. Performance Rated I-joists will ensure that no matter who manufactures the product it will perform to the stamp's recommendations.

In general, this performance standard allows products to meet a certain end-use criteria without prescribing the manufacturing technology required to qualify.

Builders United

Most builders celebrate the idea of a performance standard. More than 90Vo of homebuilders responding to a recent survey by APA and the Oregon State University Department of Forestry said they favor an industry performance standard for wood Ijoists in residential floors.

Builders said they would prefer a new standard that will allow them to use more I-joists in more applications-with less trouble and less confusion. Over 2,500 builders throughout the U.S. were queried and cited numerous reasons for supporting the industry effort. Greater product availability, uniform quality control and simplified engineering were the most common responses in support of the performance standard. And since the performance standard allows for multiple I-joist types, it will provide the options required by builders.

With less traditional lumber available for wood products, producers have had to improve existing methods and invent new ways to make more with less, and with alternative wood fiber resources. That necessity, in turn, has given rise to innovations and manufacturing technology that is changing the industry.

As glued engineered wood products, APA PRI's offer greater dimensional stability, higher strength, increased structural reliability and a lower tendency to check or split like solid sawn lumber.

A Historv Of Performince

Wood l-joists are among a number of "smart" engineered wood products championed by APA and its related corporation, EWS. The association has a long history of representing quality manufacturers of structural wood panels and glulam timber. APA, which pioneered the concept of performance rated structural wood panels in the early 1980s, provides a wide array of educational and field support services for engineered wood product users and specifiers worldwide.

APA trademarked Performance

Rated I-joists will be subject to APA's proven quality assurance program, which has expanded to include a host of engineered wood products including glulam beams and laminated veneer lumber.

The I-joist quality assurance program consists of a vigorous series of tests designed to assist manufacturers in maintaining consistent high quality.

APA's technical and field staff are working closely with code officials and building designers to secure recognition of the new APA standard. Simplifying the use and specification of I-joists will reduce the need for costly technical support.

But when support is needed, APA and its producing members will offer assistance from on-staff engineers and technical experts.

APA predicts the use of wood Ijoist in residential construction to increase significantly as national forest harvest constraints continue to affect the supply of high quality wide dimension lumber, as builders and specifiers become more familiar with the product's performance advantages, and as more manufacturers join the APA EWS l-joist program. Current producers include Willamette Industries, Georgia-Pacific and Standard Structures.