Cut these sheets to any size and shape you need to seal large openings in fire-resistant walls and floors. They’re often used to fill the space around pipes, conduit, and ducts. These sheets are tested to ASTM and UL standards for stopping the spread of smoke and flames. Made of steel, they have a firestop coating that expands when it’s heated. If the equipment passing through these panels melts or shrinks during a fire, this coating will fill the gaps.

Use shears to cut these panels to size, then fasten to your surface with No. 10 self-drilling sheet metal screws (not included). Fill any gaps around the sheet with fire-stop caulk (sold separately) for a tight seal. Once they’re installed, you can paint over them without losing fire protection.