[Cob] strawbale, geodesic domes, and igloos

[Jane Mondrup]

Jonathan wrote:

> Actually, I have been wondering if igloo style roofing couldn't be done
> with straw bale.  Cut the straw bales to the right size and shape, and
> stack them up in a spiral to form a dome roof.  Great insulation.  Any
> thoughts?
> 
> Doesn't even need to be igloo style, we could make straw bales in
> triangular shapes inspired by geodesic domes.  I think some folks have
> reduced a geodesic dome to three different sizes and shapes of triangle;
> we'd just need a custom baler to bale the hay.
> 
An organic building company in Demark are experimenting with straw bale domes. Their webside is:

http://www.bsbhuse.dk/index_halm_uk.html

They have built domes of mussel shells as well. Denmark has a large production of canned mussels, so mussel shells are plenty and cheap - almost all organic builders here use them for foundations, and sometimes for roof covering. I don't remember to have seen mussels mentioned in any books or websides from outside Denmark. Other places must have a similar industry. 

Straw bale houses are far the most common type of organic houses in Denmark, because of the good insulation, which is needed in our relatively cool climate. But the climate is wet too, and it is not unheard of that the bales contract water and rot from the inside. This is one of the reasons that we are going to build a cob house instead, with double walls and extra insulation to overcome any heat loss problems.

But what I really wanted to say about straw bale is: it is possible to insulate your roof with straw bales. Another couple in the community where we live are building a straw bale house, and have a layer of bales between the roof and the ceiling, covered with clay to reduce flamability.  This way you can exploit the insulation property of the straw bales in the roof, but of course it makes your roof quite heavy.

Jane