Silicone Firestop Joint Spray
This information reflects our best understanding of product composition in 2022.
Elastomeric firestop joint sprays are used as passive fire protection to prevent the spread of water, flames, smoke, and hot gasses through joint openings in horizontal and vertical surfaces, and are sprayed over other firestopping backing...
Elastomeric firestop joint sprays are used as passive fire protection to prevent the spread of water, flames, smoke, and hot gasses through joint openings in horizontal and vertical surfaces, and are sprayed over other firestopping backing materials. Products may take one to two weeks to cure, though some products are available that cure in several hours to a day. Elastomeric firestop joint sprays are based on a variety of chemistries including silicone, acrylic, or hybrid technologies that incorporate polyurethanes or modified polyethers. This Common Product describes a single-component neutral curing silicone firestop joint spray that can be used on curtainwall joints, wall-to-floor transition joints, wall-to-wall control joints, and floor-to-floor control joints. In addition to firestopping, these products also protect against water damage.
Silicone firestop joint sprays are formulated similar to other types of neutral curing, room temperature vulcanizing (RTV) silicone sealants. They incorporate an oxime crosslinking system that cures when exposed to atmospheric moisture, releasing butanone oxime, a suspected carcinogen, as a condensation byproduct. They can also contain inorganic flame retardants and antimicrobial pesticide preservatives, though these were not identified as common.