Which statement is true regarding putty pads?

Putty pads are indeed classified as intumescent materials, which means they expand when exposed to heat. This characteristic enables them to effectively seal openings and joints in fire-rated wall assemblies during a fire, thereby helping to slow the spread of smoke and flames. The intumescent property allows putty pads to fill gaps that may form as building materials expand and contract due to heat.

This functionality is critical in firestop applications, as it ensures that these materials perform competently to maintain the fire-resistance rating of the assembly. The expansion helps to maintain an effective barrier, even as conditions change, showcasing the importance of their use in passive fire protection systems.