Re: [Strawbale] Green roofs on strawbale buildings

My own experience of placing a green roof on top of straw bale construction is that it can cause huge problems. We have a building which was put together in Teruel Spain and consists of two rectangular units broken up into various smaller rooms but both about 100 metres square each. This was originally designed as a load bearing construction with no wooden supporting structure. The weight distribution caused the main problem and this was accentuated by the difficulty of achieving perfect leveling of the straw bales in the first instance. The placing of the roof (very large pre fabricated 3 ply panels) and the subsequent impact of the weight led to the walls bulging and moving. This in itself led to water ingress as the panels had moved slightly causing further problems. We only managed to resolve this by adding a wooden frame throughout the structure to level and support the roof. Our roof is flat although obviously we have an incline built onto it, it our case we used small clay balls (arlita) but maybe more of an incline would have helped. Essentially I would not recommend the green roof on a large building unless you are only using straw bale as an infill.

On 13 September 2010 16:30, zac solomons <zac.solomons@gmail.com> wrote:

Hello all

I am considering putting a green roof on my next straw bale building. I have heard of several people doing this, but am struggling to find good info about how to do it. I have built two smallish loadbearing sb buildings so far, both with lightweight roofs. My next project is an outdoor kitchen for a school and i am a bit nervous about putting a big heavy roof on it. Due to budget constraints i would prefer not to involve an architect. It will be a simple one storey box but i am worried about calculating loads. If there is no point loading, can strawbale walls simply be relied upon to hold up an extensive green roof? Is there any structural info for strawbale walls available?

I'm also looking for a good guide to installing a green roof: how to build an effective drainage system, best plants and substrates etc

Hope someone can help

All the best

Zac

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