USA Insulation
USA Insulation advertises R20 wall insulation. Don't believe it!
As a certified energy auditor who has extensivly studied the subject, I can assure you that there is no insulation that will provide an R-20 insulation value in a 2 x 4 wall cavity. The best faom available is polyurethane which can achieve up to a value of R-6 per inch, but that is not the kind of ...