- If the products are advertised as tested and listed for use in assemblies rated in hours (one-hours, two-hours, etc.), they were probably tested for resistance to a test fire according to the procedure in NPFA 251 (ASTM E119, UL 263), Methods of Tests of Fire Resistance of Building Construction and Materials. This test rates how well (and for how long) an assembly of materials like studs, drywall board, insulation, and fasteners will resist the effects of the test fire in a laboratory.
- If the products are advertised as “fire rated” class A, B, or C, they were probably tested for flame spread and smoke developed according to the procedure in NFPA 255 (ASTM E84, UL 723), Standard Method of Test of Surface Burning Characteristics of Building Materials, when compared to the two standard test materials (cement board = 0, red oak = 100) (photo 1). This test affects how a surface material (paint, wall covering, ceiling tiles, etc.) may be used in exit passageways, stairways, and in other locations regulated by building and fire codes. It is not the same “fire rating” as a wall, a door and frame assembly, or a floor-ceiling assembly. If a door and frame assembly has been rated for resistance to a test fire, it should have been tested according to the procedure in NFPA 252 (ASTM E152, UL 10B), Methods of Fire Tests of Door Assemblies (photo 2).
- If a window and frame assembly, or a glass block assembly, has been rated for resistance to a test fire, it should have been tested according to NFPA 257 (UL 9), Fire Test for Window and Glass Block Assemblies.
- If carpeting is advertised as “fire rated,” it has probably been tested according to NFPA 253 (ASTM E648), Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source. This test includes ease of ignition, flame spread, and smoke developed. It is unlikely that the floor covering has been tested according to NFPA 251 as part of a fire-rated assembly.
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Examples of advertised testing and listing results that could need additional research before approval of a material for code compliance include the following:
- Fire-rated suspended ceiling tile: These tiles are usually tested and rated for the speed of flame spread and the amount and density of smoke developed according to NFPA 255 (photo 1). If they are actually “fire-rated,” they will also have been tested according to NFPA 251 as part of a floor-ceiling assembly that includes the suspended ceiling tiles, grid, and its supports.
- Fire-rated carpeting: This is usually tested according to NFPA 253, Method of Test for Critical Radiant Flux of Floor Covering Systems Using a Radiant Heat Energy Source. This carpet test does not apply to carpet applied as a wall covering or as a surface material for cubicle partitions, since the flame spread will be more rapid in a vertical position than when horizontal.
- Plastic foam insulation to be injected into concrete block walls that is advertised to increase the hourly rating of the masonry wall above that which it can achieve without the insulating foam: A check of the UL Fire Protection Directory (or comparable document from FM or another agency) may not include the material in a rated assembly, which suggests that either the advertising is false or that the manufacturer did not have its independent laboratory results verified by UL or another listing service before publication. A properly constructed masonry wall assembly will achieve its fire rating without the assistance of injected plastic foam. At the temperatures inside the wall assembly during the fire test, most plastic foams will deteriorate, shrink, or liquefy, and provide little insulating value after the first few minutes of the test.
- One foam insulation manufacturer states that based on testing according to ASTM E119, conducted by an independent laboratory, the use of its product will not reduce the hourly rating of the listed masonry wall assembly in which it is used (photo 3). A check of this assembly in the UL Fire Protection Directory indicates that this statement is true.
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Even if we check on the fire resistance claims of manufacturers in new construction, building managers and owners often make selections for redecorating and other in-house projects based on appearance and price, with little regard for the suitability of the material according to code requirements, and without verifying the truth in the advertising. This could be another topic for future public fire education.
The Factory Mutual Approval Guide is available on-line at www.fmglobal.com or www.approvalguide.com/. There is no charge for its use after free registration and logging in with password.
Gregory Havel is a member of the Burlington (WI) Fire Department; a retired deputy chief and training officer; and a 30-year veteran of the fire service. He is a Wisconsin-certified fire instructor II and fire officer II, an adjunct instructor in fire service programs at Gateway Technical College, and safety director for Scherrer Construction Co., Inc. Havel has a bachelor’s degree from St. Norbert College; has more than 30 years of experience in facilities management and building construction; and has presented classes at FDIC.
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Subjects: Building construction for firefighters