For years I have been dreaming about building my own cob house but the piece of land I have acquired is on a slope so instead of a large investment in retaining walls my alternative is to build on stilts, this also means that I do not have to disturb the land too much. As this is in quite a warm area I do not have to have very thick walls but I am concerned about the weight of the walls on a raised structure. In my mind Straw Light Clay cannot be heavier than logs, is there any advice on the weight of SLC and if it is suitable for walls on stilts instead of wooden walls?
We built a timber frame cabin infilled with SLC on piers. Here is the blog post about it.
Per international residential code the design load for SLC is 40 lbs per cubic foot (640 kg per cubic meter). In practice the weight of SLC can vary from 10 - 50 lb per cubic foot (160 to 801 kg per cubic meter) per Essential Straw Light Clay by Lydia Doleman depending on straw to clay ratios and how tightly packed the wall is.
The higher range seems a little extreme. At 40 lbs per cubic foot you would lose a lot of the insulative value of SLC walls. For my load calculations I went with 15 lbs per cubic foot and then overbuilt my piers just to be safe.
I highly recommend getting a copy of the book I mentioned above.