Versatile fire barrier systems for telephone cable

Fire barriers prevent smoke and fire spread along and between cables, through walls and floors, and protect critical conductors and equipment from heat. New flexible intrumescent materials expand up to 10 times when heated, are versatile and easy to install in sealing fire rated floor and wall penetrations. Telephone cables have large insulator/metal ratios and may have slack or oval jacketing, making older limited expansion materials ineffective. Strict design for specific cables and cable densities is obsoleted; reactive foaming chemicals are not needed for an effective seal. Fire expanding hydrated silicate particles are incorporated in a neoprene matrix yielding environmental protection for tough, flexible board, sheet, tape, caulk, putty, and foam rubber products. Penetration kits from these materials have been underwriter tested. Their UL ratings are compared with rubber blocks, foaming resins, and compressed washer devices. Traditional telecraft skills and tools install and adapt the new material to many cable types. Ease, simplicity, speed, and sureness of installation entry, and reentry/reseal are related to the fire hazard window of cable, fiber, or coax additions.