What characterizes ablative materials in firestop systems?

Ablative materials in firestop systems are specifically designed to operate by burning away when exposed to high temperatures during a fire. This process is intentional; as the material burns, it forms a protective char that helps to insulate and protect the underlying structure or the combustible materials surrounding it. The ablative action contributes to slowing the transfer of heat and gases, thereby maintaining the integrity of the fire barrier for a longer duration.

In contrast, other characteristics like quick curing, being unaffected by heat, or being solid and unyielding do not accurately describe ablative materials. These materials must undergo a chemical change when exposed to fire, which is critical to their functionality in protecting structures during a fire event. This unique feature is what distinguishes ablative materials from other types of firestop products that may behave differently under fire conditions.