[Strawbale] Load Bearing Multi-storey Straw Bale Tower House Castle

Rene Dalmeijer rened at cistron...
Tue Jul 29 16:34:48 CEST 2003


I have few suggestions to make:

1) Build the two bottom stories with jumbo bales. They will easily take the 
load. Build the other two either with normal bales or even  wood on the top 

2) I suggest you make an architectural detail at each floor break to keep 
rain off the walls. (like a 500-600mm skirt use thin slate to keep it light 
but authentic) An alternative is to let successive floors jut out over the 
previous. Both solutions offer easy access to the necessary jack lifting 

3) Don't discount the weight of plaster it is huge. We made a 2m^2 SB 
plastered sample it weighed in including frame at almost 400kg. ie at 20m 
high this means 4000kg per meter wall length without any other structure. 
It is quite a weight but doable.

4) I suggest you build a story at a time and then jack it up, which can be 
done in stages. As SB is much more forgiving then most other building 
materials you don't need super precision.

5) I also suggest you use some method to keep the walls as flat as possible 
thus reducing the amount of stucco needed. (you also need good tight bales 
which also require less settling)

6) Make sure all bearing portions are symmetrically placed otherwise the 
building is sure to slowy become lopsided.

7) I am very wary of the battlements. We all know what to what grief the 
Sante Fe style leads to in SB construction it is asking for trouble. The 
parapets are a sure source of leeks. If you have to make the battlements, 
fake them ie not SB and with the roof going all the way out to and 
including the previously suggested rain skirt.

Besides the structural measures I didn't do any calculations. I think 
probably point 2 is the most important measure you should take. Keeping 
rain off the walls is essential for longevity.

At 07:36 AM 7/29/03, you wrote:
>Subject: [Strawbale] Load Bearing Multi-storey Straw Bale Tower House Castle
>Reply-To: strawbale at amper....muni.cz
>Four Storey Straw Bale Tower House Castle at The Free Energy Centre,
>Kildonan Farm, Isle of Arran, Scotland
>Has anyone any experience of building multi storey straw bale buildings?
>We want to build a four-storey tower house castle. This would be in the
>style of the traditional Scottish four storey tower house castle. It would
>be about twenty metres in height and include a conventional pitched roof and
>simulated battlements. The aim is to use load bearing straw bale
>construction methods. We have spoken to the local authority planning
>department and building control and their response was encouraging.

Rene Dalmeijer

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