On Jun 9, 5:43*pm, " wrote:
On Jun 9, 5:01 pm, JIMMIE wrote:

This past winter I found I had a cold wall in my home around my
chimney. I want to replace the fiberglass insulation in that wall
with spray in closed cell foam. I dont want to open up the sheetrock.
It would be much easier to pull off the siding and spray it in from
the outside. Would this be problematic?

Jimmie

use care insulating around chimneys. a camera inspection is a
excellent idea.

spray foam is very flammable

Not all spray foam is flammable. There are a number of them out there
that don't support combustion - you remove the flame and the foam
won't burn any more.

To the OP: It is pretty common in these parts to insulate from the
outside as you're planning to do. If you can easily pull some of the
siding (you didn't say what type of siding), then it's certainly worth
looking into. Be aware that code calls out a 2" spacing around the
chimney, and that by adding insulation the requirement for that
spacing is even more important. You mentioned a gas log in a
subsequent post, and that helps matter as the heat produced won't be
as great as a roaring wood fire.

The camera inspection is a very good idea. Unless you can verify that
the stud bays are completely sealed, and the foam won't expand beyond
the stud bays, it's probably a bad idea to spray foam into a wall at a
chimney.

R