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Preservation of Bamboo
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Jo Scheer has been deeply involved in working with bamboo for about two decades, having lived in Rincon, Puerto Rico, where he built a home for his family with mainly bamboo components. He has been designing, building, and marketing a wide range of beautiful bamboo creations that can be seen at his website tropical-treehouse.com, where you can also find rental information on various accommodations in this tropical paradise. Jo has recently authored a book, How to Build with Bamboo, that outlines some 30 bamboo projects that elegantly demonstrate the beauty and functionality of bamboo. One of the more inventive of his designs is what he calls a "hooch", which is a small elevated abode made almost entirely of bamboo. The grounded footprint of this inverted pyramidal structure is roughly one square foot, since the entire weight is born on a small pedestal, while the room above is stabilized with guy wires. This hooch has been featured on TV and at conferences. With a background in science, Jo has been a teacher, technician, inventor, builder, contractor, sailor, agriculturist and artist, and thus is eminently qualified to field your questions about building or living with bamboo.

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 live in Sri Lanka and nobody is building with bamboo here which is a shame. My understanding is that bamboo likes shade, no rain etc. Here it is always raining and the sun is scorching one minute and then not !! OK So I still wanna try and build a bamboo treehouse which will be shaded in a jack tree. So we cut the bamboo and the pieces are 30ft in length...what do we do then? Do we need to boil them? If so, in salt water or chemicals, and for how long? Do we then leave it for some time? I was thinking of building a 12 ft long boiling half cylinder welded oil cans cut in half !! Once these are cured what further treatments can we put on the bamboo to prevent rain and sun damage, temperature fluctuations etc.

A: Make sure you cut older bamboo (over 5 years since sprouting)- it needs to lignify for strength and durability. Also, what is the species? Some species are better than others- starch content being the biggest factor (more starch-more attractive to bugs-termites, bamboo beetle.    

The best environmentally benign treatment is with borax solution- either pressure injected into the xylem and phloem, or taken up naturally with a bucket under a newly cut bamboo (left standing-in place)     Keep the bamboo out of the direct sun and rain as much as possible (borax is water soluble)- big overhang (the hooch design is good for this (http://www.tropical-treehouse.com ) Also, keep bamboo away from direct contact with soil - route for bugs - and moisture retention. Bamboo should be cured (dried, in the shade) for a while (months) before use, or use only stand cured bamboo (dead, and dried naturally). Or, if exposed and airy construction design, you may use green bamboo (still not recommended). I have heard of salt-water soaking as a treatment also. But, it does leach out, and salt attracts moisture.

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: 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 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: 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 cut down about 3000 bamboo shoots that the city said it had to go. Tomorrow a group of friends will help me move it. Now where is the question. Another friend said to submerge it underwater for a month than dry it standing, but for how long. Or could I just stand them in a metal silo which has a floor off the ground that breathes air. At one time it was used for drying grain. Now its just a silo. I live in Americus, Ga. so the moisture is going down, but inside is very dry from the weather. Does this sound in the right direction?

A: Ideally, you cut the bamboo and let them stay in the stand until they lose their leaves and start turning brown - in the process they lose starch content and water. Soaking in water also dissolves and leaches starch. Storing in the silo sounds like a good drying place - in the shade, with ventilation.

My next problem is not enough time to complete the process. So, they're sitting in our cow pasture. If you were to look at them, they lie on the the ground, 6' wide, 4' to 5' ft. tall, and 20' to 30' long. The leaves are falling off slowly. I have questions, (1) the little branches, do they break off easy or do I still have to cut them off with a shape knife. Or what is the easiest way? (2) If they are lying on the ground, like they are, will they still dry if I put a tarp over them until I can get to them. Will the bottom ones laying on the ground grow roots? or just rot closest to the ground? What do you think?

A: If you can raise the pile off the ground, it'd be better for drying. Lay some sacrificial bamboo 90 degrees to the pile. A tarp - to keep the bamboo in the shade, out of the rain, and dry is good. You may perhaps keep the ends open, for ventilation. Good that you kept the branches and leaves, they will facilitate the drying process, and use up food, ie, starch. The branches can be removed efficiently with a machete', or any sharp knife with some heft. An accurate swing from the underside of the branch works well. Cutting from the top may cause a strip of epidermis to peel away - not good.

Q: I'm looking to construct a free standing structure in the north east using Bamboo, what is the life cycle considering the harsh winter.

A: A few years. It will crack initially, then weather. If kept somewhat dry, it will remain structurally sound for a while. Wire bamboo ends to prevent cracking, and try to keep it out of direct sun and rain.

Q: I live near Cancun Mexico. Humid, rainy, sunny. I'm building and would like to make the fence (wooden beams, then horizontal wooden beams, and then bamboo nailed to the beams without touching the ground); floor (laying bamboo then pouring a concrete on it). I found out where there is bamboo in a friend's place so I can cut it. Should I use it green as it would be almost close to impossible to arrange for a curing place? I'm not to much into aesthetics as I'm into functionality and practicality. Could I use them green, then rub motor oil on them?

A: I have seen people do that, ie, motor oil preservative. Doesn't look good, but the bugs do not eat it, for sure. So, use it green, it will cure in place- airy. The reinforcement of concrete with bamboo is a technical endeavor. Much research has been done on the best way. You should investigate via the internet- lots of information available.

Q: Is there any way I can preserve bamboo with its original green color for at least a few years by sealing it?

A: In a word, no. The green is chlorophyll- live, it breaks down rapidly with death of the tissue.

Q: My husband and I have purchased cleared and rainforest land on a Panamanian island and are in the process of building our totally Earth-friendly and sustainable, toxin-free home. We would like to utilize the bamboo that we have already established on our property. This would be for interior trim, windows, kitchen and bathroom cabinets, headboards, various furniture pieces, as well as some outdoor structures. I guess the most pressing issue is how to construct the counters and windows (the windows have to be accord ian style (double, 2 panes each side, opening inward), due to the way we designed the house for maximum air flow). PLEASE give us some ideas. We REALLY want to do this right, and make it look REALLY good, so others can be inspired to make more sound ecological choices.

A: Great project. Not knowing the species of bamboo you have planted makes any design recommendations difficult. However, one rule of thumb- harvest bamboo that is at least 5 years old- for maximum strength and durability. Also, cure the bamboo in the shade for two months after cutting the bamboo, and allowing the leaves to transpire the moisture out of the culm. Split, woven bamboo is a good strategy as it dries out quickly. Whole culms can trap moisture inside-causing rot. If shielded from rain and sun, the bamboo will last a very long time.

What about salt-water curing? Would you recommend that?

Salt water curing does work. The starches are water soluble, and leach out. How long to soak them- I do not know. Too long may adversely affect the surface. The common bamboo, B. vulgaris, is widely planted, though its' high starch content makes it not so great. With good curing, stand curing (leaving the cut culm in the stand for a month), they can be used.

Q: I am wanting to built a noise reduction barrier wall out of bamboo (long 8 ft stalks from ceiling to floor). I love the green natural colors and want to preserve the color. Can I nail them straight up without drying them first (fresh from harvest), and what is the best "natural" way to keep them green (some have said spray paint or polyurethane).

A: The bamboo should be harvested from the inner part of the stand, trying to harvest 5 year old culms- strongest, best. They then should be left in the stand to cure- use up any remaining starch and water- about 1 month. They are then collected, cleaned, and used.

Every attempt I have seen to color bamboo, usually green, looks totally artificial- not natural. Polyurethane will not stick to the smooth skin of bamboo, and peels away as the bamboo contracts and expands with the weather/humidity. The natural, light tan/cured bamboo looks nice with a light coating of furniture polish. Oil tends to collect dirt. Or a 50-50 combo of linseed oil & beeswax works nice.

Q: I'm trying to get some huge window shutters installed.The frame is made out of mild steel and we were planning to use whole round bamboo, about 2" diameter, with about 1" spacing inside the frame fit horizontally. These frames will be placed on the first floor of a building. What kind of treatment should I do to make sure the bamboo can bear the weather. I'm located in India and its usually hot. During monsoon it rains a lot and winters are cold. The frames are placed on the exterior and do not have any over hang that would protect them from rain or sunshine.

A: The bamboo will likely split, then rot, especially horizontally mounted. Better to use split, vertically mounted, but they will still weather and deteriorate without protection from sun and rain.

Q: I am using some old-growth bamboo that I cut here in the southern United States (Tennessee), and I'm not sure which variety or sub-species it is, but the pieces I have are about 3 inches in diameter. I am not using it to build with, but do plan to make a stand for my hammer dulcimer music instrument, which weighs about 15-20 pounds. Not a heavy weight, I know, but for aesthetics I would rather the bamboo not split on me. In addition to wrapping the ends with wire as you suggest, would you recommend any kind of oil or such treatment that might prevent splitting? I was thinking of maybe saturating the bamboo with linseed oil (I have plenty of the stuff) if that would tend to prevent it from splitting.

A: I know of no treatment that prevents cracking. However, cracking is due to drying out, so, anything that keeps the fibers from drying out, would help, I think. Linseed oil applied or infused into the interior of the bamboo, while knocking out the internodes, would work best. The outer skin is pretty impermeable. Another technique is to do a sacrificial crack, easing the tension, on the side that you do not see in your stand, or whatever.

Q: How long does well preserved bamboo last? Its for building construction.

A: Well preserved bamboo can last over 100 years (bamboo used for coffee drying sheds in Columbia). If sheltered from rain and direct sun, it can last a very long time. However, if not protected, and subjected to harsh environmental damage, it will quickly deteriorate. It all depends...

What is the preservation method that lasts it this long? How long does a borax treatment last? Do you know any other environmental friendly treatments that lasts for a long time?

In essence, the coffee drying sheds that I was referring to had no preservation treatment. The key to their longevity is design - large overhangs, no contact with the ground, maintenance, no exposure to direct sun and rain.
The borax treatment is a very good, environmentally friendly method of treatment. But, remember, borax is water soluble - it will leach out with continued exposure to rain, losing its effectiveness. Some people use old engine oil as a treatment. Effective, but not very nice.

As long as the borax does not leach out, its effect lasts forever. Practically speaking, however, I would expect some leaching or migration with variations in relative humidity, dew point events, etc - purely conjecture.

Q: Since bamboo won't last with the Utah weather, is is feasible to remove the bamboo panels each winter, as they are installed with screws to the frames. Also what material should be used for the framing so it can be permanent thoughout the coming years.

A: I would guess you are talking of bamboo panels on an outdoor fence. The framing should be treated wood - painted so it does not leach, or otherwise sealed. You could design it such that the bamboo panels are easily removable. It would increase the life tremendously, I would think.

Q: I'm currently a degree 1st year student in university.. I'm designing a bamboo house in my project. I would like to know how to maintain a bamboo house? How is each part of the design prone to breakdown? How frequent to maintain each part of the design?

A: Bamboo is a natural material-prone to rot due to wetness, bugs (termites, pollilla bug), discoloration due to sun fading, and migration of silica to surface (making it white.) The key is to minimize these effects through good design. Oil or wax treatment is a good preventive treatment, as well as borax pre-treatment.

Q: Every one seems to be trying to beat the curing process, and so am I if possible. I plan to build a tiki hut with a bar by my pool; it will not have a lot of direct sunlight. I plan to split green bamboo and mount the halves vertically to my hut without it coming in contact with the ground, would this work?

A: Stand curing, leaving the culm in the stand after cutting, for a month or two, is a simple method to reduce starch content and water content. Also, cutting older culms ( like 5 years old or so) makes for stronger culms and lower starch content. Good to keep it out of the sun, away from rain, and away from soil. Green culms, after splitting, may contort a bit, curling up, twisting, etc.

Q: I am drying 2-3 inch bamboo in my garage, some are 10 foot tall. I started cutting bamboo in Feb. from a guy who wants most of the bamboo gone. Most of the bamboo are over 10 years old. In the garage they are laid vertically and on concrete. I've read numerous ways of drying the bamboo, air drying is the way I have chosen. So any advice to slow down the drying process?

A: If you want to slow the drying process, to prevent uneven drying and cracking, I suppose increasing the relative humidity with daily spraying or humidifier. Also, turn the bamboo periodically to keep things even.

Q: I would like to use bamboo roofing (instead of hardwood singles) and terra cotta ties. We live in hurricane prone tropical zone (Kakinada, Andhra Pradesh, India). Please suggest to me what treatment for termites, waterproofing and fire proofing I need to do.

A: Bamboo cannot be made fireproof, and a treatment of borax infusion will prevent bugs- as long as the bamboo stays dry. India has a tradition of bamboo building, check out other examples to duplicate.

Q: If I were to build an underwater structure (not large, ten feet tall max) out of bamboo without treating the bamboo, how long do you think the structure would maintain integrity (keeping in mind it will be completely submerged for the entire duration)?

A: Bamboo, untreated will last maybe a year. Very quickly devoured by organisms/rot. In the islands, they make fish cages out of bamboo. However, to make them last, they are removed from the water and completely dried out.
Common treatment for bamboo is borax. Unfortunately, it is totally water soluble and quickly leached out.

Q: I have grown fond of the idea of working with bamboo: craft, home decorations, construction design, etc but I don't know were to start. I know there's local bamboo growing here, but don't know if it's the adequate type of bamboo for working with it.

A: The local bamboo is Bambusa vulgaris. Very nice bamboo, but use older culms (5 years) , and cure it properly, or use bamboo already dead in the stand (stand cured). Experiment, do your research.

Q: I just received a bamboo cup that was freshly cut as a few days ago. What should I do next? Leave it out to dry? Or should I apply a bees wax or oil to preserve it?

A: Yes, apply the beeswax/oil- it will slow the drying out and prevent cracks. Freshly cut? Still green? Not good. Keep it out of the sun. A long slow drying and curing is better than quick.

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