GBs Fire-Gard Fire blocking Foam Sealant is a ready to use polyurethane expanding foam designed to block and prevent the spread of flames and smoke in residential Type V and non-rated commercial construction. The foam expands up to 200% during application to effectively fill, insulate, and seal the space around wires, vents, pipes, ducts, and other mechanical items that penetrate top sill plates and similar openings. With a wide range of applications in electrical, HVAC and plumbing, the Fire-Gard Foam Sealant has been tested as an effective barrier against flames, smoke and toxic gases in single family, non-rated construction. The foam also acts as a draft stop preventing air infiltration in certain areas to help insulate and improve energy efficiency.