Bamboo Questions and Answers
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Q: Can you explain what are the main ways of joining bamboo for building?

A: You can join bamboo several ways. Generally, the simpler the better. Always remember that bamboo is hollow, and any compression can compromise its integrity.

Through bolts, with wood or other inserts (to prevent crushing) works well. The best method is to fill the voids with cement, let cure, and tighten down. If the stress on the joint is not great, the through bolt alone can work with thick walled, timber bamboo.

Also, mortice and tenon joinery works with bamboo poles of complimentary diameters (the smaller diameter fits into the void diameter of the second). A bamboo branch or other insert keeps the joint together. This is not a rigid, strong joint, nor are others mentioned here. The best strategy for bamboo joinery is to triangulate. Triangles relieve the stress on a joint tremendously, and is just good building.

Wrapping bamboo with galvanized wire on the ends helps prevent the ends from splitting, and greatly increases strength and durability.

Birds-mouth joinery also is done- much work and skill is needed to pull this off- but it looks nice. There are several variations of all techniques mentioned here.

Q: Can you give me instuctions on how to make a bamboo hut?

A: Build it anyway you want, but use something else for the roof, and keep the bamboo away from rain, moisture, sun, and not touching the ground. Be creative-bamboo bends!

Q: Are there examples of reinforced bamboo construction and also ways of using bamboo for retaining walls?

A: I stumbled upon some research about bamboo reinforced concrete:  Bamboo Reinforcement in Portland Cement Concrete . I have seen woven bamboo containing rocks or rock walls. Generally, bamboo exposed to weather and wet conditions does not last long.

Q: I am making a walking cane and wonder how to bend the handle?

A: You need, fresh, suitable bamboo (diameter, age, species). Green bamboo is bendable; brown, cured, dead bamboo is not. Take a propane torch and gradually heat up the area to be bent. This is the same technique for bending PVC pipe. Gradual, all sides, large area is heated with the torch, being careful not to scorch it.When the bamboo becomes pliable, you will know it- it bends quite easily. Do not force it, rather, heat it up some more. Slightly overbend to the desired configuration as there will be some spring back (judgement call). Let it cool, and you got it.

Q: I would like to construct a bamboo screen to enclose the under-floor area of a newly built pole-house in Sydney, Australia. The area is bushfire prone and subject to white-ant/ termite problems. I intend to harvest about 60 culms and cure by standing for 3 weeks then immersing in salt water for anothter 3 weeks. I would then like to longitudinally split the culms for ease of mounting and weight saving, then gal-wire the material onto 2m high sections of gal-steel grid (ala concrete reinforcement mesh) If the mechanics of the above sound ok, I wondered about the flamability of the product when cured, and wether the cured material is tempting to termites. We have the house erected on gal-steel poles and I want to avoid offering the little buggers an easy route of ingress. Any advice will be greatly appreciated.

A: I will say you aussies got your act together. The plan sounds good. I would recommend that the culms be split first, before soaking, so that the salt water can penetrate the meat of the culms better. Salt preservation works. I assume you have low rainfall and/or a large overhang- best for keeping the salt from leaching out. Also, direct sun on bamboo will dry it.crack it, and grey it. The bamboo should not come in contact with the earth. Moisture will rot it, and, it is a nice unseen route for those buggers. If the bamboo starts, say, 6 inches above grade, any ants/termites traveling upward can be seen, and dealt with. Also, leave a gap where the bamboo meets the house as well- another visual window. Also, a cheap preservative, in addition to salt treatment, is used engine oi. I've seen it used, though I've not used this technique. It might keep the bamboo from drying out a bit. Bamboo has a high flash point- the temperature where it burst into flame. But, once burning, burns intensely. Salt treatment does reduce the flammability, though not completely.

Q: We have a good overhang so moisture is not so much of an issue, but we have really strong sun in the early part of the day. Would the culms be less susceptible to cracking and drying out if left un-split? There are pre-fab fencing products (gal wired bleached bamboo) that I am trying to emulate in a way. Will these crack too or is there a step I'm missing.

A: Actually, splitting the bamboo is the best thing you can do to prevent splitting. The eventual differential shrinkage that occurs with the drying process is inconsequential when the culms are already split. The splits can change their shape without the splitting if they were whole culms. Even pre-split culms may split more under direct sun, however. Love the splits- no problem!

Q: Greetings from rainy and sunny Costa Rica. Very soon I am going to move into my new home---a treehouse built mainly with Bamboo. The roof is completely made of Bamboo and my concern is how to protect it from rain and sun. Do you have any advice?

A: Nice work on doing the bamboo treehouse. I just build a bamboo treehouse in Costa Rica also- in Dominical. We used galvanized roofing- it works. An all bamboo roof? How did you do it? Spanish tile arrangement? I have used elastomeric roofing compound on my plywood roofs- works great. I have not used it for bamboo, or, spanish tile bamboo, but I think it would work. Waterproof, elastic, and re-coatable.  Any pictures? You can see mine on my website (tropical-treehouse.com) check it out.

Q: The architect who build my house is Martin Coto. He used bamboo poles, split them in half and placed the upper halfs above the meeting points of the lower halfs......well my English isn't that good, so I will take a few pictures and email them to you. This elastomeric stuff sounds to me like Sci-Fi and the words "waterproof", "elastic" and "re-coatable" strung a chord inside.......any idea how to get it down here in paradise?

A: Martin is a master, no? Yes, the arrangement you describe is as I thought, spanish tile bamboo. I think the elastomeric would work very well. As for where it is available in C.R., I have not a clue. Pretty common in the big chain building stores, and chain paint stores.

C: The normal progression with Bamboo is: First year it sleeps. Second year it feeds. Third year it LEAPS!.

C: I saw a new "hardwood" floor made of bamboo in Calif a couple of years ago. It was beautiful, and was claimed to be harder and more durable than the usual hardwood flooring such as oak. I've since heard that many different building materials are being made from bamboo, including doors, door facings, cabinets, etc.

There are two type of bamboo floors. The first type is the horizonal cut and leaves broad stripes with large joint marks. The second is the vertical cut which leaves a narrow grain. Both types can be blond, which is harder, or steamed which creates a darker color but is a little softer. We installed a vertical cut steamed version last year and really enjoy it. Easy to care for, and shows no sign of wear from the dog romping over it. Just make sure you get the 9/16 inch thick tongue and grove verson. Can be glued or nailed down.

Q: I need to know whether Bamboo is approved to be used instead of Steel for concrete buildings in Connecticut, Florida and other states. I have a developer am encouraging to use but need to know the building codes and whether you know how far the towns have gone in approving them. Especially now that the price of steel has risen so high.

A: Bamboo has not, as yet, been approved as a wood substitute, or as a concrete reinforcer in the US. Some bamboo kit buildings have been approved in Hawaii- but only made from a specific species grown in Viet Nam. There is currently an effort to get bamboo approved for building under the UBC regulations, but it has yet to be completed.

Q: Do you know of any bamboo product for exterior siding? I live in a cool, rainy climate in Portland, OR.

A: Bamboo needs to be treated with severe chemicals before it is ever ready for exterior siding. Bamboo likes it in the shade, away from rain, away from direct sun, away from moisture. Cedar, maybe.

Q: I am planning to make a large home in the Big Bend desert region of Texas. I plan to use Rammed Earth construction. I am thinking about growing bamboo (nigra henon probably) on my property. And harvesting and using this for the roof, this means that if any bamboo rots, I'll have a continuing supply at hand. I know that bamboo is specifically not supposed to be used for roofs, but I had a thought. I read about the "spanish tile" bamboo roof that you suggested using elastomeric roofing compound to waterproof. I was wondering, since this is going to be a rammed earth home and the look would fit, if I could simply cover the top of the split bamboo poles with several layers of thick plastic and then cover it with a light layer of dirt to both hold the plastic down, and cover it from sight. To me, this seems as if it would hold out all moisture from rotting the bamboo poles (since it will be the desert as well). If you see a problem with this idea, please let me know, as well as any suggestions that you might have. Like if whole poles as opposed to split "spanish tile" poles might be better.

A: Interesting question, and an interesting concept. The Spanish tile bamboo arrangement is a good design, if fitted properly. Therein lies the rub - fiting bamboo is more than art- but doable. My problem was too shallow of a pitch, leaf debris tended to clog up the channels, then the rats started making nests..... So, a steep pitch at the very least.     The finished interior (overlapping bamboo) looks not so bad. Less work, and less fitting, but still artsy, you could weave the bamboo into a rigid (or at least tight) roof framework. A gable roof would be easy, a hip roof- doable, a shed roof easiest. The interior, exposed surface wouldn't look so great- plastic bulging out of the sparse weave).     The whole bamboo is a good alternative- no splitting, and a nice looking interior. With the earth roof, and the moderated interior climate, the bamboo should have a minimum of cracking. Good curing techniques would help a lot.

Q: For some time now I have been trying to find out if boat cabins were/are ever fited out in bamboo. I'm traveling all over the world and want to see countries were they do this. Not only because it is interesting but because I'm very interested in getting a boat built out of modern materials (most likley steel or aluminium) and taking it to some country were labour is cheap and going directly to someone skilled enough to do the job. Is this a stupid idea? If not why can't I find any info on the web? No doubt I'm not the first person to think of this. I do wonder if maybe once upon a time it wasn't a good idea because boats would have been damp or wet. But it seems strange that no one does it today.

A: As a sailor for many years, I completely re-fitted the cabin of my sloop with bamboo trim and light fixtures. It worked fine, and looked great. A friend of mine had a custom chinese junk that had many bamboo appointments. As for where you might find qualified, cheap labor to install a bamboo interior in a boat. Good question. Most skilled boat carpenters are wood. Asia may have some bamboo artisans that would take up the task. Viet Nam is developing a decent bamboo industry, and China's bamboo industry is well established. Also, the islands of SE Asia are very bamboo oriented: Java, Indonesia, Phillipines. If you look, you will find.

Q: If it's not to much trouble could you show me any photos? I have just spent a few weeks in Vietnam, but looking hard wasn't really an option. I asked a few people and no one seemed to have a clue. I will be going back in a few months to stay with a Vietnamese girl I met there. Hopefully I may be able to get her to do some research for me. And when I'm there she will help me get past the very large and frustrating language barrier. But I still have quite a big problem in knowing were to start looking. Do you have any advice as to what part of the country I should start? Or any advice generally (at this moment I know nothing about bamboo)

A: There is a company in Hawaii:   http://www.bambootechnologies.com/index.htm   They have complete bamboo houses pre-fabricated in Viet Nam. They are made, put together, then taken apart and shipped to Hawaii - where they are approved by the building code (not a small feat). I do not know where in Viet Nam is the factory, but you could contact them for information. I have a long ago friend who opened a bar in Hanoi- if you ever get that far North - and spent some time in that country- though not as a voluntary tourist (70-71) I was based in Chu Lai.

Q: I purchased a 5" diameter 10' pole of Moso bamboo grown in China. It is slighty green shaded but mostly yellow so it is fairly freshly cut. The smaller end was split but I'm using 3' of the 5" end still entact. What can I do to best maintain pole and prevent splitting? I am using it indoors and reside in subtropical southern California.

A: The bamboo will need to dry out, but slowly. Even so, the cracks will progress unless measures are taken. Cutting the remaining, unsplit bamboo from the split end will stop the progression. Also, you could wrap a few turns of wire around the ends to prevent a split from developing. A slow curing is best. Keep it in the shade, away from extreme changes in temperature. Allow air around it, store it vertical or well supported horizontally.

Q: I am building a 45'x22.5' building and want to put a bamboo roof that will support straw bale for insulation. I am not worried about water since their will be a canopy covering the top. I am thinking that if I ran cable lengthwise, I could weave the bamboo over the 22 ft span. Do you think that would be strong enough to support the straw? Would that even work...I am open to any advice.

A: Radical design. The cable and woven bamboo may be strong enough to support strawbale, but it would surely sag. But, if that is okay, then it might work. You will need to use good judgement on cable spacing and bamboo weaving. I think there are no structural tables that cover this design strategy.

Q: Do you have to dry out the bamboo before building something such as a tiki bar?

A: It is always best to dry out bamboo before using...slowly, uniformly, to prevent cracking. Even then the bamboo may crack, being exposed to whatever conditions. If you use green bamboo, use it as splits; it will not split more, and it is easier to bend. As it dries out, it will relax a bit to the contortion it is fitted. Depending on where you live, the bamboo may be more susceptible to insects if used green (the tropics).

Q: I am having a really hard time finding answers and instruction how to dry out the bamboo that is growing on my land. I would love to be able to build some of the following: trellis, small furniture, decortive walling, plant holders, a bar for my pool deck, etc.

A: Some basic principles of harvesting and curing are:    

1. Harvest only poles that are mature- at least 5 years old.    

2. Store in an open air rack -in the shade. You might want to rotate occasionally.    

3. Cure for a few months, until completely dry, before use.    

4. Stand cured bamboo, those that die and dried out while still in the stand, can be used immediately.    

5. A light scrubbing with a dish scrubber will bring back the luster of the skin, and remove any lichens, etc.    

6. Bamboo will split, especially the larger diameter pieces. You can wrap wire around the ends to prevent this, or, pre-split the bamboo to relieve the stress and prevent further splitting.    

7. You can oil or wax the bamboo for a nice sheen, and it is good for protection from the elements.

Q: I am about to build my dream home in Rodrigues Island (Mauritius). It's taken me 43 years to reach my goal and I want to do it right. Are there some golden rules and advice you could give me. Rodrigues is in a cyclonic region...and we have severe water shortage and building materials are very expensive. I can access a lot of bamboo on the Island. How could I use bamboo in my construction?

A: Do your research. There are lots of books out there on bamboo construction. Bamboo- the Gift of the Gods , by Oscar Hidalgo is one of the best. Otherwise, no big overhangs, build with open walls, windows, to reduce windage. Anchor bamboo with cement footers, but do not sink the bamboo into the cement- use rebar sticking up out of the footings, then attach the rebar to the bamboo (with cement/through bolts). Do not allow the bamboo to come into contact with the wet earth- it will rot. Protect the bamboo from exposure to direct sun/rain/prolonged moisture- it will deteriorate.

It is best to treat all bamboo components with Borax, infusing the culms with a pressure treatment, the Boucherie method, works best- but is a bit of an effort. Taking fresh cut bamboo and allow them to sit in a bucket of borax solution, still upright, works well (the natural uptake of water through capillary action with get the borax in the tissues.    

Always triangulate structural components. The style is up to you. Check out traditional buildings in your area.

Q: I am a senior in college studying architecture. I am designing a bamboo home in one of my upper division classes and am wondering if there is any specific length/span used. What I am trying to get at is what size grid should I use when designing (ex. for wood you would use increments of 4' and for steel 10' to generalize it)?

A: The current ongoing effort to establish building standards, ie, strength, deflection, spans, etc., has a very difficult task before it. Though tests can be devised and some ballpark strengths can be elucidated, bamboo is not standard. Its strength varies with species, diameter, node spacing, wall thickness, which section of the culm the piece is from (upper culm vs lower culm), and age. The one place where bamboo has been approved for building, and standards have been established, is Hawaii- and that is only for one species of bamboo.    

Also, the deflection standards for the building industry, is very strict. Bamboo, though very strong and resilient, even with large deflections, would have to be used way beyond what is necessary to keep deflections within limits (people do not want to feel movement in their dwellings, and the standards reflect that. If a dwelling were less than 120 square feet, you could build a bamboo structure more in line with the material- flexible, resilient, and strong.    

When building an all bamboo hooch in Costa Rica last year, we tested the floor joist spacing (5-6" bamboo) with the flooring being bamboo "esterilla"- multiple split bamboo that is folded out as a board. Though thin, it was very strong- and flexible. I think our spacing ended up to be 16" o.c.- similar to normal wood flooring layout. So, a specific grid layout would be similar to wood. Always triangulate, keeping joinery components at two (trying to join three pieces of bamboo is difficult, weaker)    

Long lengths of bamboo, with tapering diameter, can be incorporated as vertical members also, up to about 24'.

Q: I interested in the engineered bamboo floors, e.g. horizontal, vertical, strand-woven. Are you aware of any durability/maintenance issues with these products compared to standard timber floors.

A: I have heard that the quality of various types of bamboo floors varies quite a bit, depending on the manufacturer. Many bamboo manufacturing enterprises have popped up recently, with concomitant idiosyncratic/proprietary methods. Some are better than others. You should check out the track record of a possible source. A reputable dealer in the US is a good sign.     The advantage of bamboo floors, besides the renewability and beauty attributes, is that they are purported to be harder than oak or maple, as well having a more stable temperature/dimensional stability.    

Two issues: The bamboo floor may darken with time. If this is fine, okay. Just beware of that possibility. I heard one testimonial that catastrophic impacts, ie, dropping a sharp edges, heavy object on the floor, may cause a dent, yes, but it may bend the fibers such that they may protrude from the floor. Basically, a rough spot that may require sanding or re-finishing. This is just one report and I have not heard anything like that before. Considering the damage would occur with a conventional floor, it may not be a big deal.