$66.99 Rmax 4x8 4 x 8-Foot X 1/2-Inch Foam Insulation Board at Sutherlands
Cellofoam 1-1/2 in. x 4 ft. x 8 ft. R-5.9 Polystyrene Foam Insulation Board-125755 - The Home Depot
Dural Durabase XPS 32 in. x 48 in. x 1/2 in. Foam Backer Board Underlayment (Package of 9 - 96 
