Rust-Oleum Roofing and Foundation Sealer is a non-fibered, spray-grade coating for roofs and foundation walls. This versatile formula can be used as a damp proofer on vertical surfaces to protect against moisture penetration in roofing or building applications. Rain resistant and can be coated or backfilled in only 2 hours and fully cured in 24 hours. Covers up to 50 square feet per gallon.