Precompressed foam sealants are polyurethane foams impregnated with acrylic or bitumen compounds, delivered compressed on rolls or in sticks. Once placed in the joint they recover over minutes to hours and press against the joint faces, sealing out water and air while accommodating movement. Some come with a factory-applied silicone face. Joint width must stay within the product's range.
Expansion joint's three inches, so it's the precompressed foam with the silicone face, not a wet seal.
Also heard as
- expanding foam tape
- impregnated foam
- precompressed foam tape
Related terms
Expansion joint
A designed gap between building elements that lets them move with temperature, settlement and load without cracking.
Two-stage joint
A joint with an outer rain seal and an inner air seal separated by a drained cavity.
Movement capability
How far a sealant can stretch and compress, as a percentage of joint width, while keeping its seal.
Silicone
A sealant with a silicon-oxygen backbone, prized for UV resistance and high movement capability.