Flex Seal Flood Spray is designed to help prevent damaging flood waters from entering people's homes and businesses. Should be used in combination with our other Flood Protection products. Use on all types of openings such as windows, doors, seams, garages, casings, thresholds, conduits, vents and ducts, key holes and more. Flex Seal Spray Flood Protection is UL Verified: No water penetration through 1/8 In. gaps at depths up to 3 Ft. for 14 days.