3M™ Fire Block Foam FB-Foam is a fireblock and draftstop used to help seal, fill, insulate and bond for non-rated residential and commercial construction. This foam-in-place fireblock is heat-resistant (up to 240 °F / 115 °C) and meets ASTM E84 (modified) Class 1 for smoke spread and flame development. It is ready-to-use and tack-free in approximately 5 minutes.

Designed as a durable fireblock and draftstop, 3M™ Fire Block Foam FB-Foam seals, fills, insulates and bonds in non-rated residential and commercial construction. It resists the free passage of flame, smoke, and combustion by-products within concealed floor, ceiling, or wall cavities — helping restrict the movement of air, fire, and smoke. This foam expands up to 200% in volume to effectively seal penetrations and gaps.

3M™ Fire Block Foam FB-Foam has been evaluated by UL (report ER9700-01) and complies with the International Building Code (IBC) and International Residential Code (IRC). With an R-Value of 4–5 per inch, minimal shrinkage, and a sag-resistant formula, this foam ensures long-lasting performance. It bonds to concrete, brick, metals, wood, plastic, and cable jacketing.