Firestopping Wall Cable Penetrations

To prevent through-wall penetrations most effectively, a firestopping system should encompass a broad spectrum of capabilities that go beyond a store-bought device’s. For optimal protection, a professional cable contractor can install a network of advanced firestop solutions to create a cohesive system that encompasses the fire-rated wall, the actual penetration, the cables, and the cable tray or conduit that passes through the penetration.

In one current and widespread firestopping method, the cable tray is terminated at the wall while a conduit sleeve penetrates the wall, providing a home for cable paths and firestopping material. In a second method, the entire cable tray passes through a wall opening that gets filled with firestopping materials. Other common materials include semi-permanent firestop mortar and caulk, and manually applied putty sticks. More advanced firestopping products like firestop blocks and pillows utilize intumescent materials that expand to fill penetration voids when exposed to heat.

Unfortunately, even though they are effective firestopping materials, caulks and putties can be difficult to inspect after installation as they get sealed in behind an outer surface that appears code-compliant. And since most penetrations are not permanent, putties and caulks must be reapplied each time a structured cabling contractor adds or removes cables. Even pillows have their cons, as they too require reinstallation and are subject to tampering when doing so.

To ensure the most effective firestopping, an integral system that combines intumescent firestopping material with a through-wall penetration device is recommended. Compared to a cable tray, this system is easier for a cable contractor to install and inspect, is tamper-resistant, creates a smaller wall penetration, and maintains the fire rating of the wall without requiring additional firestop material. Plus, if more cables need to be added or removed, the through-wall penetration remains completely accessible without disturbing firestopping materials.

Like fire-rated poke-through devices, these through-wall penetration systems contain a pathway for cables and integral intumescent material. Here, a structured cabling contractor installs a firestop system consisting of a cover that houses a block of intumescent material with an opening for cables to pass through. A length of conduit carries the cables through the penetration to a similar cover and block of intumescent material on the opposite side of the wall. When there’s a fire, the intumescent material expands and creates a hard char that fills voids around the cables and blocks the fire’s path.

Technology for firestopping through-wall penetrations is constantly advancing, but one thing is clear: the most effective firestop system contains a combination of integral firestopping material and allows for the safe and simple addition or removal of cables. To fully meet building code requirements for your firestopping needs, CTS installs, inspects, and maintains a wide variety of advanced cabling solutions.

If you have questions about firestopping or structured cabling, or if you need a qualified cable contractor in Tucson and Phoenix, contact us online or call 877-685-2626 to speak with an expert at CTS.