How effective is Fastout CS Foam in walls with fiberglass insulation?
Is there enough room to expand
That all depends on how dense the fiberglass insulation is in your wall void. The foam can only enter space that is available. If they used a dense insulation that is packed in your wall void, then the product will not have much room to expand into. There is no way to really know until you try to foam a void and see how far it goes. If there is no room the product will squirt back out of the hole you are treating through from the pressure.
Answer last updated on: 05/09/2011