[Carl]

Good start! I didn't use the thermalite for anything structural, so it'll be interesting to see how you get on. You'll need to protect the thermalite from water, because it soaks water up like a sponge, and won't do any insulating if it's wet. I presume the brick skin will keep most of the rain off.

I've not used it, but from reading other posts here I've heard it can take the vermicucrete a while to harden?