My concern would be that the steam coming in contact with the wood could cause a mildew problem. Also, a pad should be used so the wool doesn't flatten and defeat the purpose of the wool mat. Perhaps you should consider a waterproof heat proof cover on the board (plywood) and then a padding before applying the wool. I have an afterthought what is the plywood treated with? You would be heating that and breathing it.
Last edited by RedGarnet222; 02-04-2020 at 11:41 AM.
Reason: addition