My rental apartment has a fireplace, which we use often. This fireplace lacks a glass door. On nights when we have used the fireplace, we leave the flue open until the morning, and when we get up, the entire level is freezing. As it's a rental, I can't just install a glass door myself.
I bought this fireplace cover, but I find that it only helps so much. I am thinking of building a supplemental heat barrier, with the following layers (from closest to furthest from fire):
- radiant foil barrier
- fiberglass insulation (no vapor retardants)
I would cut the fiberglass to the size of the plywood, then take a slightly larger piece of foil and wrap it around, then tack and tape it in place. I would lean this over the fire retardant fireplace cover that I already have.
Would this be safe? My concern is that, if an ember managed to rekindle, I wouldn't want to create a fire hazard. One possibility is to use a spray-on fire retardant, or just to wrap the entire piece of plywood in foil before attaching the fiberglass and outer foil layers.
Alternatively, and preferably, is there a commercially available product I could use instead?