is used in exterior walls between wall studs. Sprayed in before any painting or texturing done on those walls. A small hole is drilled between each exterior wall stud about the size of a silver dollar and each section is filled up with this foam. The foam is not under as much pressure at all. So, it won't bow or add pressure to the drywall walls. It fills up to the hole and then the spicket is applied to the next hole. Then the hole is plugged up and drywalled in.
Ideally, this is done on new construction, BUT, the article stated its done on older homes also. Remember, you may have over 500 holes in the walls between each and every stud. Existing homes this may really create a nightmare especially were wall papering is located.
The R factor is ungodly, I forgot what it is exactly, but its over 24.
DO NOT confuse this product with the $#%^ that is sold in a can at home centers. This stuff in the can is under so much pressure that I am sure it would blow out a drywall wall.
If you want more information on this company, let me know and I will research it and find out for you.