Not quite sure which forum to post this in, but this at least involves insulation, so here goes.
I have a pre-fab fireplace that I have never used. Recently, I had a chimney sweep come out, and he checked it out. The one thing he pointed out was a gap that ran around three sides of the fireplace. His recommendation was to put insulation in the gaps, and then caulk over it with a fireplace caulk.
However, when I went to do this, I realized that the gap is quite large. At the top, it's over an inch in width. And being pretty much a novice with caulk, I have no idea how to caulk such a large opening.
Also, finally, I had some extra insulation that has been lying unused in my basement for the three years I have been here. Is any old insulation OK for these purposes, or how could I tell if this insulation is OK?
I'd love to have a fire for Xmas (in the fireplace, thank you), so your help would be greatly appreciated!!