I want to seal the damper of my fireplace, which I never use. I thought it
was a narrow opening that I could easily stuff some insulation. However,
the damper is about 2' wide, and above it is a large chamber. Only further
up the chimney does it taper down to the square terracotta tube. The tube
is no more than 12"x12".
Since I can't really insulation from right above the damper, would I gain
much by stuffing insulation at the top of the chimney? The chimney is
capped of with a metal cap, which should keep the insulation dry, except in
a blowing rain.