I don’t use my open (rectangular) fireplace. I’m sure there is a lot of heat being wasted even though the flue is closed, as they leak air and provide no insulation.
I’d just like to safely fit in some sort of cover to close it up… perhaps rigid foamboard (plus cement board?) with a decent R rating. I’d also like to make it attractive or at least not ugly.
Any recommendations? Anyone done this successfully?
I couldn’t find any marketed product on-line.