ROOF COATINGS ARE SOLVENT-FREE HSS 535 and HSS 540 R2R from West Development Group are one-component, moisture-curing silicone rubber roof coatings designed for use on sprayed-in-place polyurethane foam. Neither coating releases solvents into the air, and HSS 540 contains 20 percent recycled EPDM material, which strengthens the coating’s physical properties and helps keep old roofing material out of landfills. (866) 924-4585 /