BAMBOO WORKSHOP SPRING 2021 METHODOLOGY REPORT Dan Perenyi & Brandon Raettig
Materials Lab
Bamboo Bamboo Workshop Workshop SpringSpring 2021 2021 1
CONTENTS 3 SUMMARY 4 RESEARCH
Precedent Projects Joinery Techniques Notable Organizations
14
PROTOTYPING THE WORKSHOP KIT
Materials, and Tools Prototype Findings
16
BUILDING A BAMBOO PLANT STAND
Workshop Format Lashings
22 CONCLUSIONS
Bamboo Workshop Spring 2021 2
SUMMARY RESEARCHERS: Daniel Perenyi, Brandon Raettig INSTRUCTOR: Jen Wong SEMESTER: Spring 2021
This methodology report is meant to be a lasting compendium of the research, prototyping, and preparation that went into the Spring 2021 Bamboo Workshop. The workshop was a two-part event consisting of a presentation given by Ewe Jin Low, architect, bamboo educator, and founder of Ten Ten Design; and a hands-on workshop where participants learned bamboo joinery techniques and built a plant stand. The resources here are meant to serve as a jumping off point for someone who is interested in bamboo as a material. Detailed in the following pages are bamboo construction precedents, the process of prototyping, manufacturing, and building the plant stand, and conclusions, findings, and considerations for further bamboo workshops.
Ewe Jin Low
Carole Meckes’s Bamboo Farm
Bamboo Workshop Spring 2021 3
RESEARCH
PRECEDENT PROJECTS Precedent gathering coincided with the prototyping of joinery techniques from the beginning. Sources were gathered both locally and abroad in order to better understand contemporary trends in bamboo construction. Precedents are grouped into four different categories: traditional lashing, metal joinery, concrete embedded joints, and 3D printed joints.
CORD LASHING Son La Restaurant, VTM Architects Son La, Vietnam | 2014 Due to its remote location, local bamboo and stonework became the source material for this project. Once treated with mud and smoke, bamboo culms were roped together to express verticallity with a dense grouping of members at the ends to increase shear resistance. Beams-to-column and some beam-to-beam connections are made using the Mark II lashing. Further unidentified techniques are utilized for additional support.
Bamboo Pavilion, Penda Beijing, China | 2015 This modular system is designed only with bamboo and lashing cord. The culms are not pierced, leaving them unharmed for future use after installation. It is not fixed on the ground to facilitate disassembly and promote sustainability. The system is capable of infinitely expanding both vertically and horizontally, and the architects hope that it can be a resource for temporary housing in the instance of a natural disaster.
Bamboo Workshop Spring 2021 4
METAL JOINERY Bamboo Gateway, West Line Studio Chishui, Zunyi, Guizhou, China | 2008 Bamboo is utilized as a vertical shading device in this project. Steam-treated bamboo poles were fastened together end-to-end with a bolt in order to reach the desired height by the designers. Metal joints were also used to attach the bamboo cladding system back to the building.
Bamboo Structure, Pouya Khazaeli Parsa Ramsar, Iran | 2009 Starting as a student project, this structure is comprised of bamboo poles arrayed in a circular form. Conventional gas pipe t-connections were used without a fixed assembly at the base of the structure. For a team of three people, the shelter could be constructed from start to finish in no more than two days. This system allows for future disassembly and possible displacement by simply disconnecting the bamboo from the gas pipes.
Bamboo Workshop Spring 2021 5
CONCRETE EMBEDDED JOINT La Ceiba Dining Hall, Lucila Aguilar Arquitectos Chiapas, Mexico | 2016
La Ceiba Complex consists of housing, dining rooms, and workshop pavilions. Through their use of bamboo, the architects desired to “transmit a message in the region that industrial constructions can have another, more natural language.” In the dining space, bamboo central columns are comprised of sixteen culms that are embedded directly into a concrete base with no additional components.
Kontum Indochine Cafe, VTN Architects Kontum, Vietnam | 2013
This project combines many techniques of bamboo construction to create a very large open space. Steel tension rings are inserted into bamboo columns to add stiffness before they are embedded within the concrete foundation. The shape of the columns was inspired by the Vietnamese fishing basket, which has a wide opening that narrows towards the other end. In total, there are fifteen columns supporting the roof, giving inhabitants the feeling of being within a bamboo forest.
Bamboo Workshop Spring 2021 6
3-D PRINT JOINERY Bamboo Pavilion, Bezalel Academy Jerusalem, Israel | 2017 3-D printed joints solved the question of flexibility in this pavilion. The designers created a unique joint for the splicing of bamboo poles and vertical and horizontal member joints. The 3-D printed components were designed to allow for a specific pole radius while simulating traditional lashing techniques.
Digital Bamboo Pavilion, ETH Zurich Zurich, Switzerland | 2019 The pavilion utilized 3-D printing in both its cladding and joints. The member connections were printed in stainless steel guided by a digital optimization process. Shading panels were fabricated with 3-D printed recyclable UV resistant thermoplastic over Lycra textile, giving it stability and flexibility.
Bamboo Workshop Spring 2021 7
JOINERY TECHNIQUES
Cord Lashing Cord lashing is the oldest bamboo construction technique, and it continues to be utilized in the twenty-first century. The cord used in the lashings can be made from natural fibers or synthetic materials, such as rubber. Wax coatings are also common, as they add extra friction to the knots. Despite its long history, cord lashing comes with many limitations. Compared with other joinery techniques, it is much less durable. Additionally, this method is heavily dependent on the physical characteristics of each bamboo culm. For example, it is recommended to make joints near the nodes of the bamboo; this can be difficult to do at large scales because of bamboo’s inherent irregularity. On the other hand, the accessibility of this technique, in terms of affordability and construction, as well as its temporal qualities make it very successful when used in installations and smaller projects. Because the culms are not being damaged, they can easily be reused in future projects.
Bamboo Workshop Spring 2021 8
JOINERY TECHNIQUES Metal Fasteners Metal joinery is a newer trend to emerge in the bamboo construction industry, but it quickly gained widespread popularity due to its reliability. Where traditional cord lashing is dependent on the location of nodes, metal fasteners may be installed anywhere along the length of a culm. Fasteners do the job of adding an artificial strength to the bamboo that is impossible with lashing cord. Additionally, the use of a prefabricated metal joint means that construction times are drastically diminished. Workers that are trained in steel and timber construction are already knowledgeable in traditional fasteners, making it easier to find skilled labor; because traditional lashing requires more training, the use of metal makes more sense from a financial standpoint. Despite metals contributions to the bamboo construction industry, it does present some drawbacks. Culms that are pierced by fasteners are less easily reused, meaning the generation of waste is a bit higher. Furthermore, the joints are not as aesthetically pleasing, making them less desirable to many architects and clients.
Bamboo Workshop Spring 2021 9
JOINERY TECHNIQUES Concrete Embedded Joints When maximum stability is desired, bamboo culms may be embedded within concrete footings or foundations in order to permanently unify the structural systems. While the seamless joint between the concrete and columns can be pleasing to the eye, this method requires more maintenance in order to retain stability. Because concrete absorbs lots of moisture, the bamboo is susceptible to rot. Once the culm decays, there is no way to restore it back to health without completely replacing it. This is not only difficult but costly. Reuse and recycling of these columns is also difficult due to the concrete that is infilled inside the polls. From an environmental standpoint, this is a less desirable option.
Bamboo Workshop Spring 2021 10
JOINERY TECHNIQUES 3D Printing As digital technology and fabrication becomes more accessible, new possibilities emerge. The twentyfirst century’s answer to bamboo construction is the 3D printed joint. Using flexible mediums to allow for maximum tolerance, printed fasteners push the boundaries for mass customization and formal optimization. Many joints aim to mimic the pleasing aesthetic of traditional cord lashing, making them even more desirable for architects and clients. Depending on the project, they are capable of making both permanent and temporary connections between culms. Additionally, the bamboo may not be damaged by incision, making reuse very easy. However, due to the precision of the medium, matching diameters to unpredictable bamboo columns can be quite challenging.
Bamboo Workshop Spring 2021 11
NOTABLE ORGANIZATIONS
As we began researching potential guest lecturers, we discovered these three organizations, each possessing their own unique perspective on Bamboo. We maintained direct contact during development.
Better Bamboo Buildings is an online blog created during the Covid-19 pandemic by Ewe Jin Low. In order to continue educating people about bamboo during the lockdown, he established this communication hub that holds virtual courses and workshops. IBUKU is a team of innovative designers that focuses on bamboo construction. Founded in Bali, Indonesia, by Elora Hardy, her team has built over sixty bamboo structures over the past ten years. They believe in the possibilities of sustainable architecture and hope to push the boundaries as they continue to expand in the new decade. Ewe Jin Low was a member of their team near the start of his bamboo journey. Carole Meckes is the President of the Texas Bamboo Society and the founder of Bamboo Branch, an Austin-based bamboo grove. Through her life-long dedication to the material, she strives to aide in both the promotion and research of bamboo.
Bamboo U
Carole Meckes
IBUKU
Bamboo Workshop Spring 2021 12
MATERIAL SOURCING All of the bamboo that was used during the prototyping phase as well as the workshop kits was sourced from Bamboo Branch. The local bamboo grove is owned and operated by Carole Meckes, president of the Texas Bamboo Society. She and her husband purchased the property where Bamboo Branch is presently located back in the 1990s. She has been devoted to the material for most of her life. The Materials Lab team was involved in every step of the bamboo cultivation process. Once the team arrived, we descended the steep slope of the property. First, we uprooted the most mature culms, which had a more tan finish compared to the younger, green bamboo. This could be achieved by either pulling the culm directly out of the ground or sawing the pole just above the roots. Once removed from the soil, we clipped off all of the branches that spanned the length of the bamboo. Next, all the culms were hauled up the hillside, where they were sorted based on diameter and cut to lengths of no more than twelve feet. Finally, they were placed in the truck and driven to campus.
Bamboo Workshop Spring 2021 13
PROTOTYPING THE WORKSHOP KIT Constructing the Bamboo Workshop kits for participants involved a large amount of prototyping. Bamboo presents a few unique constraints when mass producing. The two main constraints for the kits were reconciling that bamboo is uneven and can be prone to cracking. After researching different types of bamboo joinery, we opted to investigate joins that involved using cord to lash pieces together. As for the form of the work, we discussed and experimented with building an easel, small stool, plant stand, phone stand, and phone amplifier. We prioritized objects that would allow participants to learn a variety of concepts and techniques regarding bamboo construction. Ultimately, the plant stand was the object that would enable participants to experiment and try the most techniques, and be producible in a 50-kit production run. The plant stand allows for a diversity of knots and joinery techniques without the need for too much special equipment or prior knowledge.
TOOLS USED Miter Saw: Cutting bamboo poles to length Drill Press: Creating holes for dowels Spindle Sander: Sanding pole ends for fish mouth lashings Band Saw: Cutting dowel rods to length.
Plant Stand Prototype
Diagonal Fish Mouth Joint Prototype
Easel Prototype
Bamboo Workshop Spring 2021 14
PROTOTYPE FINDINGS The strongest joints were ones that utilized dowel rods, such as the peg mount joint (a). However, the more holes that are drilled for dowels, the more likely the bamboo will crack (d) and the more likely the bamboo will twist (f) if the holes do not align perfectly. Furthermore, because bamboo has a fluctuating diameter, using a standard drill press does not always accommodate for smaller or larger bamboo connecting pieces, when using the pieces as dowels. More complicated joinery, such as carving or sanding the end joints, was typically stronger (c), but more difficult to mass produce. The spindle sander (e) allowed us to sand down the connecting pieces for a better fit against the plant stand uprights. Cord lashing techniques, while sometimes difficult to learn, were most effective for mass production, since they require less cutting and shaping of each bamboo piece. Many bamboo artisans do use special knives that help more easily cut complex joints. One could complete most of the more complex joints with a Japanese Hand Saw and a drill. Using smaller end pieces of bamboo as dowels to connect the plant stand uprights were effective for adding lateral stabilization to the prototypes, but hard to mass produce (b). Each dowel needs to be cut to size so that it reaches fully to the back end of the upright.
f. Bamboo twisting.
e. Spindle Sander
a. Peg Mount Lash.
b. Dowel Joint.
c. Two-ear Joint.
d.. Bamboo splitting.
Bamboo Workshop Spring 2021 15
BUILDING THE BAMBOO PLANT STAND Participants were given a kit of bamboo parts to build a plant stand. During the workshop, the Square Knot, Clove Hitch, Peg Mount, Fish Mouth, and Mark II lashings were taught. A series of videos explaining each lashing type were produced using Premier Pro. During the workshop, one researcher talked over each video at half speed, while another researcher build the stand along with the workshop participants. The YouTube instructional videos for each knot can be found here: https://youtube. com/playlist?list=PLUty_n0rTirG71njuauIHdPNxmH7dlST0.
Clove Hitch + Peg Mount
Fish Mouth
Mark II
MATERIALS Bamboo: Bought locally through Carole Meckes, owner of Bamboo Branch and head of the Texas Bamboo Society. 2mm Waxed Cotton Cord: Fire Mountain Gems Sugru: Amazon Paperclip: Amazon 1/4” Dia. Dowel Rods: Amazon 6” Terracotta Pot & Saucer: Home Depot
Bamboo Workshop Spring 2021 16
LASHINGS Square Knot Used to finish off each knot. Good for connecting two pieces together.
1. Right side goes over the left side.
2. And then under and over the left side.
Detail of knot while loose.
4. Tighten Knot
3. Left side goes over then under and over the right side.
Bamboo Workshop Spring 2021 17
LASHINGS Clove Hitch Secures the rope on the dowel rod before starting the Peg Mount Lash.
1. Left side is under, right side is over cross member.
2. Cross left side over and to the right of the cross member and right string.
3. Pull under and to the right of right string. Hold string along member with finger.
4. Thread string through the hole created from Step 3.
Close up of loosened knot.
5. Tighten knot.
Bamboo Workshop Spring 2021 18
LASHINGS Peg Mount Tightens a cross member into a hole using a dowel for leverage and stability.
1. Start with Clove Hitch Knot. Right and left side sit under the peg.
2. Cross right and left string around leg member.
3. Cross string over the top of the dowel and then thread back over the leg member.
4. Do the same to the opposite side.
5. Repeat on each side three times.
6. Tightening. Pull the right and left side upwards in between the dowel and leg member.
7. Cross right and left over the horizontal member.
8. Cross again on bottom of member. Cross back over the top like in Step 7.
8. Tighten and finish off knot with a square knot.
Bamboo Workshop Spring 2021 19
LASHINGS Mark II Excellent way to secure two pieces at a right angle without any cuts required.
1. Right and left strands are same length. Cross over top member
2. Cross right and left under bottom member
3. Pull right and left over top member
4. Cross right and left under bottom member. Repeat 1-4 2 times.
5. Frapping (tightening) the knot. Cross right and left over bottom member.
6. Pull right and left under top member..
7. Cross right and left over bottom member. Repeat 2 times. Tighten as you go.
8. Finish off the knot with a square knot.
9. Finished knot.
Bamboo Workshop Spring 2021 20
LASHINGS Fish Mouth Secures a cross-member to an upright using a hole in the cross member and a notch at the joining site.
1. Using the paperclip as a needle to thread the string through the hole.
2. Thread 8” portion again through the hole.
3. Thread 8” portion again through the hole. Switch the paperclip to the other side.
4. Thread long side of string around the vertical member and through the hole the shorter end sticks out from.
5. Repeat twice. Tighten as you go.
Close up of knot before finalizing.
6. Pull long and short ends up and cross over and then under the horizontal member.
7. Tighten and finish off with square knot.
Finished knot.
Bamboo Workshop Spring 2021 21
CONCLUSIONS Future workshops involving bamboo could explore more of the various joints that could be used for connecting bamboo. 3D Printing may be one way to better connect pieces of different diameters. Metal and non-metal hardware can be used to join bamboo, and this may be quicker to assemble and fabricate for multiple kits. There are many more ways to explore bamboo as a material. The exterior of bamboo can be stripped off and used as a rope to tie other bamboo pieces together, similar to the use of rattan. The fibers can also be woven into baskets and other shapes. Bamboo can also split and flattened into sheets. Future work with bamboo should consider the planar dimension of flattened bamboo strips of exterior bamboo. Working with bamboo can require a large amount of skill and practice. Because bamboo is a nonstandardized material, there are variations associated with each piece that can be hard to identify. Some pieces of bamboo split more easily, when other seemingly similar pieces hold together under the same stress. Certain fungi and structural problems with bamboo can be subtle. In future workshops with bamboo, having someone identify prime pieces of bamboo may improve the overall quality of the finished product. The drill press, while effective in drilling holes quickly, can potentially cause cracking in the bamboo. It’s important to use a piece of wood as a backing piece when drilling holes, in order to mitigate the potential splitting of bamboo fibers that can cause cracks. Cross-stabilizing vertical bamboo pieces may be a more efficient way to build a plant stand with less pieces of bamboo. Future researchers should investigate knots and joints that join vertical bamboo members diagonally.
Bamboo Workshop Spring 2021 22
