Bamboo

[camarko]

Hi all-
I'm new here, and was just throwing some ideas around until I can logistically get myself out to take the course. Alternative building materials have always interested me, especially bamboo (the strength and ease of renewability is pretty cool!). I haven't been able to find all the info I'd like out there, and was wondering if anyone here had any experience working with it.
From what I've read, the r-value of bamboo is anywhere between 0.7 to 1.0 which isn't all that far off from a softwood log (does that sound right?). Does anyone know the feasability of constructing a butt and pass home from bamboo? The larger poles can be up to 7" in diiameter, which isn't too bad. Maybe something with a double envelope construction?
Right now its all just hypothetical, just wondering what you guys thought!

Marko

[loghousenut]

Marko, Although there are varieties of bamboo that are referred to as "tree bamboo", I must simply respond that our primary interest on this forum is building with logs.

http://i157.photobucket.com/albums/t55/loghousenut/P1000686.jpg

There are few alternatives hAHAhahahaa.

[ramblinman502]

heya n welcome.
i dig bamboo too. ive seen some cool weekend getaways made from it. im pretty sure BNP wouldnt work. at least not the way we do it.

[camarko]

Can I ask why you think it wouldn't work? Things that come to my mind, would be concerns over the bamboo splitting when driving rebar through it (I would think everything would have to be predrilled to make it work), low r-value for each bamboo 'log', compression strength of bamboo... What were you thinking of? While eventually I aim to build a log cabin of real logs, I just love the idea that I could potentially plant a grove of bamboo (Moso can be grown here in the US), and in three years, have 7" diameter logs!

Thanks!

[rreidnauer]

I think Ramblinman's concern (as well as my own) would be the hollow cavity of bamboo, and the way the rebar wouldn't be doing what it does in a solid log. Another worry in my opinion, would be compression issues. Not so much the compression strength of individual logs, but a "rollout" tendency from the weight of the rest of the structure above it. I could envision the wall bowing/buckling, causing an axial loading or twisting to the bamboo via the rebar, causing the bamboo to split and ultimately fail.
Now, that said, it doesn't mean your out of luck. You simply need to modify the design to meet the limitations of the building material. I'd recommend a bamboo post & beam type construction with bamboo in-filling. Or, if you really like the butt & pass look, build a non-structural envelope of B&P around the structural P&B.
Wadaya think?

[BarstowRat]

I think that everyone has pointed out alot of very legitimate problems with the build, such as splitting from rebar and rolling. I do knoe that bamboo is incredibly strong as they use bamboo instead of steel for scaffolding in many parts of Asia, and I don't believe there is as much shrinkage as with common trees. So how do we secure the bamboo without causing any splitting or rolling? Tightly pinned rebar would most certainly cause splitting, but how about 'loose' rebar extending the entire height of the wall, like in a brick wall. Or perhaps adding a few vertical columns of bamboo every ten feet or, one inside and one outside, and in the corners sandwiching it together with lashing all the way up. I think that would be more then secure and also add to the "tribal" look that a bamboo cabin would have. Just a thought.
Joshua

[edkemper]

Our logs are pinned by rebar. Exactly how would you do the same with bamboo? Pre-drilling would make the rebar go through without it splitting but how would that hold (pin) the bamboo, one to the other? I've never seen Bamboo "logs." Perhaps I'm missing something.

[ramblinman502]

ya might get away with butt n pass bamboo that was tied together. but ya better live in a very warm climate cuz im pretty sure you wont be able to chink bamboo. it will move too much no matter what ya do. it might make for a cool island castaway hutt. but a house..im not so sure it would work. but then again i love when im proven wrong.
sides..we all want you to join us on the dark side. : )

[StressMan79]

I stayed in a bamboo hut in N. Thailand one time. It was cold at night!
However, say you could address all the issues, and bamboo had an R of 1/inch. Then you could have at most a wall of R 7, with little thermal mass, I know of few places this would pass energy code.
DISCLAIMER: I don't know of a singe thing I am more opposed to that telling me how I have to house my family, That is, I think code enforcement should be nonexistant, other than for commercial buildings, or professional builders, However, there are parts that are a good idea. R7 (at best) is FAR to small in any climate that requires heating or cooling.
However, if you are dead set, you'd have to build a double envelope to get the required thermal efficiency.