STI SIL305 Silicone Firestop Sealant is a one-part,neutral-curing silicone sealant exhibiting superior performance in places where sealing openings in walls and floors are needed to control the spread of fire, smoke, toxic gasses, and water during fire conditions.

STI SIL305 Silicone Firestop Sealant reacts with atmospheric moisture to form a high-strength, durable seal that will adhere to most building substrates without the use of primers. SpecSeal products do not contain asbestos or PCBs.

STI SIL305 Silicone Firestop Sealant is designed for use in firestop systems for through penetrations and joints. This product excels in places where greater water resistance is required. Systems have been tested for Class 1 W Ratings per UL1479.

STI SIL305 Silicone Firestop Sealant is available in non-sag (SIL300) and self-leveling (SIL300SL) grades and may also be used to seal vertical and horizontal joints between metals, masonry, concrete, and other common construction materials. STI Series SIL Silicone Firestop Sealant is specially designed for use in static or dynamic joints. The low modulus characteristic minimizes strain on the substrate surface and the elastomeric quality allows excellent recovery from extension and compression cycling.

This product can expose you to chemicals including Carbon Black, which is known to the State of California to cause Cancer & Reproductive Harm.