Fireblocking uses approved materials to break up small concealed spaces and slow fire spread, but carries no formal fire-resistance rating. Firestopping is a listed system tested to UL 1479 or ASTM E814 that seals a penetration through a fire-resistance-rated wall or floor and restores its rating. Where you need the latter, our firestop range covers foams, sealants, blocks, and plugs.