Tim, thanks for your input on this, I've been following your blog/site for quite some time now wink

The light clay/shavings/straw is something I'm considering for two thermal walls I'm building but am also interested in using this technique for the 2x4 curtain walls on our frame. The walls are already insulated with 5.5" of exterior polyiso (yes I know...way too foamy, but at the time it was the only manageable way to enclose the frame for me). Now it's time to put a natural "buffer" zone. With polyiso being impermeable, do you think the slip technique can still be used and allowed to wet/dry to inside only?

there's a thin line between hobby and mental illness