![]() Nonshrink grout, not properly tested or evaluated, can crack and spall in the presence of high heat and flames, causing the firestopping system to dislodge. There are no tested systems for nonshrink grout installed in the annular space around cables or steel conduits. Nonshrink grout is an acceptable firestopping system. In some cases, wire mesh may be desired as a security method to prohibit unauthorized access to the firestopping system. It is important to consult the individual tested designs to determine whether or not wire mesh is required. Several of the more prominent firestopping manufacturers have successfully tested their materials to eliminate the need for wire mesh. Wire mesh is required for pillow and cushion-type firestopping systems. When this happens, be sure to check 3000 series UL Classified systems to find an appropriate design for cables (only) penetrating the barrier. Terminating the trays may make firestopping easier in some types of applications. Using UL’s alphanumeric system for firestop systems, be sure to check the 4000 series numbers for cable tray systems that penetrate the barrier. And the 2003 UL Fire Resistance Directory Volume II has more than 200 classified through-penetration firestopping systems that are specifically designed for cable trays passing through fire-rated wall assemblies. Again, there is no specific limitation within the codes that would preclude running trays through rated walls so long as they are properly firestopped. ![]() The codes do require this! Cable trays are not approved to pass through fire-rated barriers. One more thing about sleeves: Make sure that they are attached to the barrier. Be sure to choose a design that is appropriate for your selection. Whether you elect to use sleeves or not, appropriate UL Classified systems are available for either installation choice. Sleeves and nonhardening firestop putties are a great choice for datacom cable penetrations subject to frequent moves, adds or changes. Sleeves are often preferred for cabling penetrations because they act as a container for both the cables and the firestopping material. The use of sleeves is totally at the discretion of the specifier or installer. While sleeves are often used to create openings for cables passing through fire-rated barriers, there is nothing in the codes to specifically require them. Sleeves are always required for cabling passing through fire-rated barriers. Before selecting an insulation material, make sure suitable firestop systems are available. For this reason, UL Classified systems are material-specific to insulation type, thickness, density and firestopping material. However, low-density polymer foam insulation, for the same reasons noted above, can be much more challenging to firestop. Some noncombustible insulation such as mineral wool actually resists fire and aids in the firestopping process. Not true! The fire performance of pipe insulations can vary dramatically. All pipe insulations are firestopped the same way. This makes them a poor choice as a fire-barrier material unless they have been specifically formulated and appropriately tested for this type of use. Low-density polymer foams typically ignite very readily and are quickly consumed by fire. This type of listing also applies to paints, wallpapers and certain furnishings. For example, insulation foams in aerosol cans typically bear a label that indicates flame spread and smoke development ratings. Even then you must be careful that the affixed third-party listing applies to fire resistance. Polyurethane foam is an adequate firestop.ĭon’t assume that any product is a firestop product unless it bears the correct markings from a third-party testing or listing agency. To avoid misapplications, carefully read the label and UL test. Nonintumescent sealants are designed for metallic pipes (noncombustible penetrants) and are nonexpanding. Intumescent sealants expand with heat to close off combustible penetrants. For example, many leading firestopping manufacturers color their intumescent sealants red and use other colors for nonintumescents while others make no distinction. In fact, firestopping sealants and caulks come in a variety of colors to differentiate the type of product and its use. There are no code requirements that specify that a firestop sealant or caulk must be red. Firestopping caulks and sealants must be red in color. Let’s dispel some of the myths surrounding firestopping. It is amazing how certain fallacies or inaccuracies can develop and spread like wildfire throughout the industry. Having worked in technical services for a firestopping manufacturer for many years, I have heard just about everything regarding firestopping products and practices.
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