Firestop products, when installed in accordance with a listed firestop system, help stop the spread of smoke and fire. Contractors use these materials in fire-rated floor and wall assemblies to prevent smoke and fire spread through mechanical, electrical, and plumbing penetrations. That’s why intumescent systems have become such an essential part of firestopping.
What are Intumescent Products?
Intumescent products expand when exposed to very high temperatures. Some products can expand by a factor of 100, creating an insulator that prevents fires from spreading through openings. Some Intumescent coating products can also react to heat by forming a char layer that protects the substrate from heat damage.
Critical Fire Protection for PVC
Ryan D. Fenstermaker, a 3M firestop consultant and account executive for the Northeast territory, works with 3M’s intumescent products every day. He’s seen how innovations in firestopping have created more flexibility in other areas. “Thirty years ago, the majority buildings had plumbing systems made of copper, steel, and iron,” he notes. “These non-combustible pipes needed only a small bead of sealant to satisfy fire codes. Over time, experts developed new technologies for these systems. Today new materials have made installing plumbing and building systems easier. Whether it’s PVC, CPVC, or PEX, these options provide distinct advantages for the installing contractors. Oftentimes, they cost less and can be easier and faster to install. There is a long list of benefits, but these systems are composed entirely of combustible pipes.”
From a firestopping standpoint, combustible materials presented new challenges. “A fire can quickly soften many of these products,” Fenstermaker explains. “They can melt and burn away quickly. That means it’s easier for fire to extend from room to room or floor to floor if they are not properly firestopped.”
3000 WT for Use With Large-Diameter Pipes
3M has developed lines of sealant products and intumescent articles and devices that address the challenges of combustible penetrants. “3M’s intumescent caulking products are used for penetration firestopping,” he adds, “to address the challenges presented by having mechanical, electrical, and plumbing penetrations in walls and floors. For example, 3M has a product called 3000 WT, which stands for watertight. It is a silicone-based intumescent product, which is unique to the industry.” He adds that 3M’s 3000 WT can be used with large-diameter combustible pipes, and since it’s siliconized, it also offers watertight protection.
Tuck-In Wrap Intumescent Strips
“3M also manufactures Fire Barrier Tuck-In Wrap Strips, which are flexible intumescent strips,” he notes. “Tuck-In Wrap Strips start out as an eight-foot roll, and contractors can cut them to size to wrap around combustible pipes. For example, they are useful if you have a six-inch PVC roof drain. 3M Wrap Strips can be used to wrap around these larger pipes in layers. This product offers a cost-effective and space-saving solution for the installing contractor.”

Moldable Putty Pads
Putty pads are another 3M innovation. Fenstermaker explains, “3M Fire Barrier Moldable Putty Pads MPP+ are pliable intumescent firestop materials designed for wall openings and through penetrations, and they allow for adhesion to a wide range of construction materials.” He adds, “For example, when electricians install electrical boxes in a fire-rated wall, code often requires they be protected. Contractors can achieve this by encapsulating the box with a very thin profile, 3M Moldable Putty Pad.”
Cast-In Intumescent Devices
Fenstermaker goes on to explain that 3M Fire Barrier Cast-In Devices for Metallic or Non-Metallic Pipes are a solution that not only satisfies code but can also create convenience. “Fire Barrier Cast-In Devices get fastened down to the concrete floor form,” he notes, “before the concrete is poured. And intumescent materials are within that device, located in the base closest to the underside of the floor. Then, concrete is poured around them, and these sleeves make it possible for a contractor to pass their pipe through with firestopping already built in. There’s no need to come back and core drill or firestop with caulking, so this is an advantage for the contractor.”

Composite Sheets CS-195+
For situations that require large format intumescence, 3M offers Fire Barrier Composite Sheet CS-195+ in five sizes. “This is a large format sheet that is less than a half-inch thick,” Fenstermaker reports. “It’s appropriate for really large mechanical penetrations through walls and floors. For example, we were working on Tower One on the Trade Center, and a bank of electrical risers went from the basement to the roof. So we put down Fire Barrier Composite Sheets, drilled through them where the conduits passed through, and provided a cost-effective way to firestop a large, complex opening.

Meets the Most Rigorous Fire Codes
While most people in the New York construction industry are well aware of firestopping materials, some professionals don’t know that many 3M products are manufactured to meet very specific site needs. 3M products are rigorously tested to meet New York City requirements and also comply with the International Building Code (IBC). Fenstermaker emphasizes that not all firestop products are intumescent, and just because products are red in color, typical of some firestop materials, doesn’t mean they can be used for ANY condition. “Contractors must be careful to ensure fire stopping products are appropriate for the application. 3M representatives like myself are always available to help confirm our customers are using the correct product in the appropriate system.”
3M and Metro Solve Customer Challenges
Metro Interior Distributors works closely with 3M and carries a wide range of 3M firestop products.
Contact us today to learn more about all the firestopping solutions Metro offers, contact us today. We stock a wide variety of 3M products and can set up consultations upon request.
Want to Learn More?
To learn more about all the firestopping solutions Metro offers, contact us today. We stock a wide variety of 3M products and can set up consultations when needed.
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