The present disclosure relates to area separation firewalls. More particularly, the disclosure relates to an improved firewall for use in area separation firewall systems, with this system including wider, thinner pieces of gypsum wallboard that are easier to manufacture and install as compared to traditional 1″ thick shaft liner wallboard.
International, state, regional and local building codes require that multi-family residential buildings include certain fire protection features, such as firewalls between residential units. The standard for qualifying fire rated systems is either ASTM E119 (“Standard Test Methods for Fire Tests of Building Construction and Materials”) or ANSI/UL 263 test (“the Standard for Safety of Fire Tests of Building Construction Materials”). During this testing, an area separation firewall system therein is heated to 1000° F. and then ramped to 2000° F. The firewall must be able to resist this heat for a specified period of time, such as two hours. Another aspect of this testing is a hose stream test, wherein a pressurized stream of water is directed at the vertical fire resistive wall assembly after fire endurance exposure simulating a fire being extinguished. The vertical firewall must be able to maintain its structural integrity, and not allow water to pass through it.
For decades, multi-family residential firewalls have been constructed with two pieces of 1″ thick shaft liner wallboard. These wallboard panels are particularly difficult to manufacture and typically slows production by a factor of two or more. These thick pieces of wallboard are also cumbersome and only 2′ wide—as compared with a 4′ width for other wallboard panels—in order to manage the weight thereof. This decreased width translates to added materials and labor when installing the firewall, since the 2 pieces of shaft liner wallboard must be joined with the next section using a metal H-Stud. Despite the long tenure of these firewalls, little improvement has been made to the conventional design. As such, there remains a great need for an improved firewall wallboard that can be efficiently manufactured and installed.
Various embodiments of the present disclosure will be understood more fully from the detailed description given below and from the accompanying drawings. In the drawings, like reference numbers may indicate identical or functionally similar elements. Embodiments are described in detail hereinafter with reference to the accompanying figures, in which:
The following disclosure provides many different embodiments or examples. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
In any embodiment, the material used for the wallboard 30 is typically more fire resistant than that used for the interior walls 50. In some embodiments, the wallboard 30 may be comprised of gypsum, fiber glass, and vermiculite. In one or more embodiments, the wallboard 30 comprises one or more of a dispersant, a fire retardant (retarder), a chelating agent, a soap, a binder or adhesive, an accelerator, a surfactant, an acid, a stabilizing agent, and/or a foaming agent. In some embodiments, the dispersant may include polynaphthalene sulfonate in a sodium or calcium salt solution (having 2-80% solids content). In some embodiments, the binder or adhesive may include starch, such as acid-modified corn starch (AMCS) or pre-gelatinized corn starch. In some embodiments, the retarder or chelating agent may include pentasodium diethylenetriaminepentaacetate. In some embodiments, the acid may include boric acid. In some embodiments, the stabilizing agent is sodium trimetaphosphate (STMP). In some embodiments, the soap, surfactant, and/or foaming agent may include ammonium alkyl ether sulfate. In one embodiments, the wallboard may have the following formulation:
In one or more embodiments, the wallboard 30 may be a commercially available wallboard from American Gypsum sold under the tradename M-BLOC® Ekcel™ TYPE X. In one or more embodiments, the wallboard 30 does not include asbestos and/or does not include detectable levels of formaldehyde. Since the firewall 80 is usually installed prior to the completion of the roof and exterior walls, the wallboards 30 may be exposed to the elements for a period of time. As such, in some embodiments, an exterior surface of the wallboard 30 may be wrapped in a mold and moisture resistant covering. In some embodiments, the mold and moisture resistant covering may be one that has scored at least a 8, 9 or 10 under the ASTM D3273 (Standard Test Method for Resistance to Growth of Mold on the Surface of Interior Coatings in an Environmental Chamber). In some embodiments, coverings, such as the mold and moisture resistance covering discussed above, may cover the face and back of the wallboard 30. In some embodiments, the coverings comprise a paper or a glass mat.
In some embodiments, the interior walls 50 may be formed from ½″ or ⅝″ thick gypsum board available from American Gypsum under the tradenames LIGHTROC® or CLASSICROC® or any other fire rated or non-fire rated wallboard panel.
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When the fasteners 94 are employed, they may be configured in a random assortment or they may be configured in a pattern 90. In the embodiment shown in
With reference to
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In any of the above embodiments, the fasteners 94 may be spaced such that any one fastener 94 has at least one adjacent fastener 94 within a set maximum distance. The at least one adjacent fastener 94 may be on the same side of the firewall 80 as the any one fastener 94 or may include fasteners 94 on the opposite side of the firewall 80. In some embodiments, the set maximum distance is from about 6″ to about 24″, about 8″, about 12″, about 14″, about 16″, about 18″, about 20″, about 22″, or about 24″.
With reference to
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Although the firewall 80 is described herein as comprising four pieces of wallboard 30, the firewall may include, for example, three, five, or six pieces of wallboard 30. In any embodiment, the thickness of the firewall 80 may be maintained at, for example, approximately 2″ by appropriately adjusting the thickness of the wallboard 30. For example, three pieces of wallboard 30 may each have a thickness of about ⅔″.
According to embodiments of the present disclosure, the firewall 80 may provide similar or improved fire protection as compared with conventional firewalls while significantly decreasing the cost of production and installation. As discussed above, conventional 1″ thick, 2′ wide wallboard can slow production by a factor of two or more. Conversely, the wallboard 30 disclosed herein does not cause such reduction of production. Additionally, even though four pieces of wallboard 30 are used for each panel (as compared to two in conventional firewalls) and fasteners 94 may be required, installation of the firewall 80 of the present disclosure is still faster than that of conventional firewalls. This is primarily because the wider pieces of wallboard 30 result in fewer H-studs 20 being required.
An area separation firewall generally as shown in
An area separation wall was assembled as described in Example 1, except that the wood studs were spaced at 24″ o/c. This assembly was then tested according to standard ASTM E90-09 (2016). The results of this test are shown in
An area separation wall was assembled as described in Example 2. This assembly was then tested according to standard, Fire Tests of Building Construction and Materials, UL 263 (ASTM E119), 14th Edition dated Aug. 5, 2021 and the Standard, Standard Methods of Fire Endurance Tests of Building Construction and Materials CAN/ULC-S101-14, Fifth Edition, dated Dec. 2, 2020. The observations during the fire test are summarized in Table 2 below.
As shown above, the assembly met the requirements for a 2½ hour (150 minutes) load bearing wall. The finish rating is defined as the time necessary to raise the average temperature measured on the face of the wood studs nearest the fire by 250° F. or the time required to raise the temperature on the wood studs by 325° F. at any point. The average temperature measured on the wood studs was 65° F. before the test. Therefore, the average limiting temperature was 315° F. and the individual limiting temperature was 390° F.
The limiting temperatures for the unexposed surfaces did not occur during the 159 min. test duration. The average limiting average temperature and individual limiting temperatures were 162° F. and 180° F. , respectively, at 159 min.
No suspected hot spots developed during the test requiring the application of cotton waste or the roving thermocouple.
Next, a duplicate assembly was heated according to the above standards for 1 hour prior to a hose stream test. The observations during the heating are summarized in Table 3 below.
The assembly was then subjected to the impact, cooling, and eroding action of a 30 psi water stream applied through a 1⅛ in. diameter nozzle at a distance of 20 ft. for 2½ min. During the hose stream test, no water penetrated through the 4 layers of ½″ gypsum. boards that created the area separation wall. Also, no water penetrated beyond the unexposed surface during the 2½ minute hose stream test. Instead, the assembly remained intact during the 2½ minute hose stream test.
Although various embodiments have been shown and described, the disclosure is not limited to such embodiments and will be understood to include all modifications and variations as would be apparent to one of ordinary skill in the art. Therefore, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed; rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.
The present application claims benefit of U.S. Provisional Patent Application No. 63/262,268 filed Oct. 8, 2021, titled “AREA SEPARATION FIREWALL SYSTEM,” which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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63262268 | Oct 2021 | US |