Rubberseal didn't start on a hardware-store shelf. It began as a commercial waterproofing company - spray-applied systems for foundations, roofs, and industrial structures where a failed seal isn't an option. Rubberseal Black brings that same contractor-tested protection to your projects. Black is our toughest, true-waterproof formula, curing into a single seamless, flexible rubber membrane - no seams for water to find - that bridges hairline cracks and stands up to constant water contact. It's the color we recommend for the most demanding, water-immersed jobs: ponds, pond liners, water gardens, fountains, and planters, plus below-grade waterproofing for foundations, basement walls, retaining walls, and footings. It also protects roofs (including RV and mobile-home roofs), gutters, downspouts, and concrete. Application is simple: water-based, low-VOC, non-toxic, and odorless, it rolls or brushes on cold - no mixing or torching. Apply between 50-95°F; the coating is flood-testable in about 24 hours and reaches full cure in roughly 72 hours at 70°F. One gallon covers approximately 32 sq. ft. at a full 40-mil waterproofing build, or up to 130-150 sq. ft. as a thinner protective coat, and it bonds to concrete, wood, metal, and most common building surfaces. Proudly made in the USA to a heavy-duty, true-waterproof standard.