I want to transform my attic space into a conditioned space by insulating the roof using some kind of foam.
My house was build in the late 30’s and my roof is covered with ceramic tiles resting on pine planks. The attic currently has two screened opening, one on each sides. This is not enough in the summer to cool the space with the help of an attic fan; in the winter the space is freezing.
I was thinking to apply foam on the attic ceiling in order to convert the attic space into a conditionned space.
So far, I had 3 contractors looking at the job:
- 2 contractors are planning to spray 4 inches of closed cell foam and
- 1 contractor is planning to spray 7 inches of open cell foam.
According to the last contractor, open cell foam from “Foam Tight Insulation” is better because:
- is a green product since it use water as spraying agent
- since it is not a water barrier, it will enable to see leaks coming from the roof.
I am now confuse because Fine Home Building magazine always preconize the use of Closed Cell Foam for attic ceiling. What do you think.
Also, is it a requirement to remove the old fiber glass insulation on the attic flooring after installation of the foam on the ceiling?
Thank you for your help.
Replies
Attic Insulation
I wish I knew the answers, but I don't. I want to do the same thing to my attic. MY house was built in 1998 and is located in South Carolina.
There are no simple, foolproof answers for insulating attic space. Even the applicable theory is a bit muddled, and there are almost always physical constraints that limit how much one can apply pure theory.
Toss a dart.
Hard to believe that
the open cell guy told you his product was better because you'd know if your roof is leaking. That's a really dumb sales pitch. Hopefully it goes without saying that you need to make absolutely certain that your roof is NOT leaking if you're going to insulate the rafters.
I would use closed cell foam. It will not allow condensation to form on the bottom of your roof sheathing, which is the risk in this situation. You probably need to drywall the attic after the foam is installed to reduce the fire hazard.