When we install fire protection
in a building, we are focused on active protection systems such as fire alarms, fire sprinklers, clean agents or smoke control. For the most part, we don’t pay too much attention to passive fire protection except for when we have to activate fire or smoke dampers or release smoke doors. We interface with those systems to help maintain smoke compartments and prevent smoke or fire from traveling from one area of a building to other areas. How much do you pay attention to firestopping? Knowing when you have to protect openings in floors and walls, and protecting them properly, is an important part of the installation. I’m sure you have all see plenty of holes in firewalls in the past, probably with a cable running through it. A diligent fire inspector will typically catch this on new construction, but what about after that? 


Not all walls or floors need to be firestopped, only those installed as a fire or smoke barrier. You can consult the building plans to determine fire-rated wall or floor locations. Fire doors may have a label on the inside edge of the door or doorframe to help identify what the hourly fire rating is. Typical areas where firestopping is required include stair enclosures and shafts for elevators, electrical or mechanical systems, or those connecting multiple levels. In some cases, corridors must be fire-rated. If you are in a jurisdiction that uses the International Building Code, you will find a lot of good information in Chapter 6, Types of Construction, and Chapter 7, Fire and Smoke Protection Features. Any fire or smoke wall, barrier or partition required to have protected openings has to be identified with signs or stencils.


When firestopping, you need to know a number of things, such as the type of building assembly that requires firestopping (is it a floor or a wall?). You will need to know the type of material the building assembly is made of (concrete, wood, gypsum, etc.) and the thickness of the material. You will need to know what is penetrating the building assembly. There are different applications for cables, cable trays and metallic and nonmetallic raceways. You also need to know the hourly rating of the assembly that you must penetrate. 


UL’s Fire Resistance Directory is available online at http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/fireressrch.html to help you find firestop applications for numerous configurations. The UL Category Code for firestopping is “XHEZ.” Once in the directory, the individual firestop systems are identified with an alphanumeric system. The first letter will be either F, W or C (floor, wall or combination). The second letter will be the material to be penetrated, such as an “A,” meaning you plan to penetrate a concrete floor less than or equal to 5 inches thick. More than one letter may be used for combination systems that could apply to either a floor or a wall. The third identification category will be a four-digit number to indicate the penetrating material. For example, if you need to protect an opening through which a metallic pipe or conduit will pass, the number will be in the range of 1000–1999. Nonmetallic pipe or conduit is between 2000–2999. The numbering range goes from 0000–0999 to 8000–8999 for a variety of penetrating materials. UL has a link to a short training course on fire protection that may be helpful. AFAA also has a series of online firestopping courses available at www.afaa.org. Some of the information in this article came from that series. These are just two examples of training programs available to improve your knowledge of firestopping requirements.


Here is a brief review of various materials for firestopping. Caulks may be used in openings where the penetrating items are subject to movement or vibration. As part of a UL-classified assembly, the caulk is used for firestop designs of specific material thicknesses and may include mineral fiber or damming material. 


Collars can be used for penetrating nonmetallic pipes and may contain intumescent material that expands with heat while the plastic pipe melts, closing the opening.


Putty can be used for various configurations of cables, cable trays, electrical receptacles or conduit. The putty may be combined with mineral or ceramic fiber or fiberboard. This method is useful when penetrations are going to be reused. 


Pillows are useful when a cable tray is making a penetration. 


In addition to the putty or caulk materials, cementitious materials have the properties of cement and would typically be used for larger openings. 


This is not a complete list of materials that can be used for firestopping; it’s merely intended to give you some idea of the variety of materials available, some resources to find more information, and a couple of training opportunities for you and your staff.