Question: Regarding wall mounted heat shields - I have browsed your questions for a while and find nothing regarding my questionsorry if I missed it. I have long wondered whether or not using multiple heat shields is more effective in reducing clearance percentages than a single shield. For example If I install a sheet-metal shield spaced 1 in. from the back wall, and then placed another of the same or different material spaced one in. out from the first, would this effectively reduce the heat transfer by any amount that would make it worthwhile? Answer: Actually, it would. The older NFPA and other standards used to show this method. However, there is a problem....the stove pipe also has to be certain distances away from the wall. Additionally, many (most) newer stoves have built-in heat shields and reduced clearances even without materials on the wall. As a result, simply doubling up the wall heat shields often cannot save more than a few inches...which is why it is rare to see.