3M™ Fire Barrier Water Tight Sealant 3000 WT provides up to 4-hour fire protection in tested and listed systems. It is a gun-grade, intumescent, silicone, elastomeric sealant that cures upon exposure to the atmosphere to form a monolithic flexible firestop seal. Properly installed, this sealant helps control the spread of fire, smoke and noxious gasses before, during and after exposure to fire and exhibits good adhesion to a full range of construction substrates.