Spray foam sealants are used to fill large gaps around pipe, door and window frames, and more. The foam is applied directly from the container and expands to fill the gap when sprayed. It has a soft, spongy texture when dry, which allows the foam to be trimmed flush with the surrounding surface. Spray foam sealants don't flex and change shape when they're dry, so they shouldn't be used where the gap is expected to move or change size.