Chris, 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 floor.
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 structure.
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@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