I had done some open cell foam in my attic and it took years for the off gassing to subside. I am wondering if I have the insulation company install closed cell foam whether there will still be offgassing and how long it will last. Any feed back from anyone who has had closed cell foam installed would be most welcome. I have 2x4 walls and they have proposed only putting in 3" of closed cell foam to replace fiberglass insulation.