Sun Jan 15 10:31:32 CET 2012
build the roof of a house first, at ground level, and then, somehow, build the rest
of the house underneath it. Straw bale houses, with their forgiving nature,
somehow seem appropriate for this sort of thinking. I came up with several ideas
- jacking it up; flipping it over onto the built house; rolling it; 'pole vaulting' it, etc.
But in the end I concluded that, in fact, there is no real advantage in doing it at
all. It's no easier, it's no quicker, it's no cheaper, it's no better. But it was fun
scheming, and who knows, maybe I'll try it out one day.
I quite agree with you that load bearing structures make more sense in many
respects, rather than just in-filling a timber frame. But then timber frames have
their place, too. But I would worry about the spreading load in the lower courses
of bales. I'm pretty sure that the pressure within them will not be simple and
vertical, but will involve spread out sideways, too. A possible problem with this is
that if one starts to splay out, the surrounding bales will not have the rigid,
interlocking stability to support themselves like bricks (for example) would. A
single collapsing bale low down, in a key position like a corner, could end up
bringing the whole structure down. Remember that block of flats that collapsed in
London(?) in the 70s(?) - a low level structural failure brought them all down like
a pack of cards; they don't build towers like that any more.
20 metres is one hell of a four story building. Even allowing for a pitched roof,
this is still 12+ foot ceiling heights. There is going to be huge weight bearing
down on the lower bales, and keeping the all straight, level and even will be
absolutely imperative. Building from the top down will mean that you get to lay
the least stressed bales first, so your experience, ability and understanding of the
structure will increase as you get to the bits where that counts more.
Jacking it all up as you go - well of course they build some concrete tower blocks
that way, so it's a proven technology, it's certainly spectacular, may be quicker,
may be more fun, and who knows, may be more practical. Site insurance,
including public liability, may be a problem.
Rendering a storey at a time and then jacking? Things *will* move as you jack,
and without the rigidity and structural stability of 'traditional' materials (ie
reinforced concrete) cracks are a certainty. You would need a plan to deal with
high level repairs, and also for the periodic maintenance that lime or earth
As I said further up, I have absolutely no experience of strawbale building yet, so
I've absolutely no business in spoiling your party. If you can deal with the
challenges, what a fantastic thing to do.
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