Firestop Products Explained for Non-Engineers
Firestop products can seem complicated if you don't regularly work in construction or fire protection. Sealants, putty, collars, pillows,wraps, and other products all have different applications, but they share the same basic purpose: helping maintain the fire resistance ofwalls, floors, and other building assemblies when openings or gaps are present.
Think of a fire-rated wall as a protective barrier. When a contractor cuts a hole through that wall for a cable, pipe, conduit, or anotherbuilding service, the opening can compromise the barrier. A properly designed and installed firestop system protects these penetrations andhelps limit the spread of fire, smoke, and hot gases.
What Exactly Is Firestopping?
Firestopping is a form of passive fire protection. Unlike a sprinkler or fire extinguisher that actively addresses a fire, firestop systems arebuilt into the structure and are intended to help contain fire and smoke within designated areas.
This concept is known as compartmentation. Fire-rated walls, floors, barriers, partitions, and other assemblies divide a building intosections. Firestopping helps maintain that protection where penetrations, joints, or other openings interrupt those assemblies. The bestfirestop product depends on what is creating the opening and how the underlying wall or floor is constructed.
Firestop Sealants
Firestop sealant is one of the most recognizable firestop products. It can be installed around certain pipes, cables, conduits, and otherpenetrations or used as part of particular joint systems. Depending on the product, sealants may be silicone, acrylic, or another specializedformulation. While firestop sealant may look similar to ordinary caulk, it shouldn't be treated like one. This specific sealant is used as onecomponent of a tested firestop system with defined installation requirements.
Firestop Putty
Firestop putty is a moldable material that can be shaped around certain penetrations. Its flexibility can make it useful for electricalapplications and locations where cables or other components may need to be changed. Putty pads and similar products may also be used inspecific applications involving electrical boxes or other membrane penetrations. The exact product and installation depend on the testedsystem being used. UL Solutions identifies both through-penetrations and membrane penetrations as applications that require appropriateprotection in fire-resistance-rated construction.
Firestop Collars
Plastic pipes create a unique challenge during a fire because the pipe can soften, melt, or burn away, potentially leaving an opening throughthe wall or floor. Firestop collars are designed for specific combustible-pipe applications. They typically incorporate an intumescentmaterial that reacts to elevated heat and expands, helping close the opening as the pipe changes during a fire. The type and size of pipe,wall or floor construction, and other installation details determine which collar and firestop system are appropriate.
Firestop Wraps
Firestop wraps or wrap strips also use specialized materials and can be installed around certain penetrants, including combustible pipes, aspart of a tested system. Like collars, the wrap is selected based on factors such as the penetrating material, pipe diameter, opening size, andtype of wall or floor. A wrap that's appropriate for one penetration isn't automatically appropriate for another.
Firestop Pillows and Blocks
Firestop pillows and blocks are often useful for larger openings or areas containing multiple cables. One major advantage is accessibility. Depending on the system, individual components may be removed when cables need to be added or changed and then properly reinstalled.This can make certain systems particularly useful in telecommunications, data, and electrical environments where penetrations change overtime.
Firestop Joint Systems
Not every opening is created by a pipe or cable. Buildings naturally contain joints where walls, floors, ceilings, and other structuralelements meet. Some of these joints are intended to accommodate building movement. Firestop joint systems are designed to protect thesegaps while addressing the movement required by the assembly.
The Most Important Concept: It's a System
This is where firestopping can become confusing. A firestop product isn't necessarily fire-rated by itself for every application. Firestoppingrelies on tested systems that combine several elements, such as:
- The wall or floor construction
- The penetrating item, such as a cable, pipe, or conduit
- The opening dimensions and configuration
- The specified firestop materials
- The installation method
The Firestop Contractors International Association describes a penetration firestop system in terms of three fundamental elements: the flooror wall assembly, the penetrating item, and the firestopping products. These systems are evaluated using specified testing standards. Thatmeans you shouldn't simply choose a tube of firestop sealant because it fits the hole. The entire installation needs to match an appropriatetested or listed system.
Why Proper Installation Matters
Even the correct firestop product can fail to provide its intended performance if it's installed incorrectly. Details such as opening size,material depth, backing material, penetrant type, and surrounding construction can all matter. UL Solutions tests and certifies firestopsystems to established performance standards, with fire-resistance-rated systems receiving hourly ratings that provide evidence ofperformance and code compliance. Contractors and facility managers should therefore follow the tested system and manufacturerinstructions rather than developing an improvised solution in the field.
Firestopping Doesn't Have to Be Complicated
For a non-engineer, the easiest way to think about firestop products is:
Fire-rated walls and floors create barriers. Pipes, wires, cables, and joints create openings in those barriers. Firestop systems are designed toprotect those openings and help maintain the barrier's fire-resistant performance. Sealants, putties, collars, wraps, pillows, and otherproducts are simply different tools for addressing different types of openings.
The key is choosing the correct tested system for the specific application and installing it exactly as specified. Doing so helps maintaincompartmentation and supports the building's overall passive fire-protection strategy.