Foam & Fill® Large gaps & cracks expanding polyurethane sealant is quick and easy-to-use. It expands to fill holes, cracks, gaps and voids around windows, doors, pipes, outlets, vents and foundations. This insulating foam forms an air-tight, waterproof bond and seals out drafts, moisture and pests. Cured foam can be sanded, painted or stained. Contains no HCFCs or CFCs so it is safe for the environment.