FLEX SEAL? is actually liquid rubber in a can! It sprays out as a thick liquid, seeps into cracks and holes and dries to a watertight, flexible, rubberized coating. Flex Seal coats, seals, protects and Stops Leaks Fast! Perfect for: roof repair, weatherizing your home, gutters, foundation and concrete waterproofing, indoor and outdoor projects, pools, RV, motorhome, car and boat, bathroom fixes, furniture, and so much more! Works on: wood, metal, tile, masonry, fabric, glass, plastic, porcelain, dry wall, cement, some vinyl's and more.