$60.99 Plywood, Fire-Rated Fir, 4' x 8' x 3/4 (18.5 mm) - Copp's Buildall
Columbia Forest Products 1/2 in. x 4 ft. x 8 ft. PureBond Birch Plywood-833185 - The Home Depot
Fire Retardant Plywood 4 X 8 X 1/2 Exterior Rated (72/Pallet) GNSPLYWOODFR GNSPLYWOODFR - Gas 
.jpg "Fire Retardant Coatings, Fire & Flame Retardant Treatments")
