Hi,

I'd like to insulate one of my (unfinished) basement walls. The problem is
this: running parallel to the wall (near the ceiling) is a furnace duct, and
the space between said wall and said duct is approx. 3 inches (a bit less in
spots). I was thinking of insulating with 1.5'' of foam insulation with
1/2'' gypsum board covering, but anyone have a thought as to whether or not
this would be hazardous? The duct is approx. 12" high, so the other option
would be to just skip the upper 12" of wall and insulate below..

Many thanks,
Jim