A thin one-part composite system designed to firestop blank openings and larger penetrations such as cable trays and conduit and HVAC ductwork through rated construction. Firestop tested for up to 4 hours in accordance with ASTM E 814 (UL 1479) Intumesces (expands with heat) to form a hard char that tightly seals penetrations against flameRead more about 3M – Fire Barrier Composite Sheet CS-195+[…]