Recently I had a home energy audit done. The auditor said there was quite a bit of air leakage where the furnace stack (a round sheet metal stack) comes into the attic. He said I should seal the by-pass in the attic and "thought" expandable foam would be OK. Anyone know if this could be a fire hazard?
He also pointed out that the furnace stack is not insulated and is giving off a good deal of heat in the attic - which is evident by the size of the icicles hanging from my eaves. Is there any safe way to insulate a metal furnace stack? Keep in mind - this is a crawl-space sized attic. I've been up there before and it is very hard to move around in. Thanks!