System and Method for Preventing Hose Stream Penetration Through Fire-Rated Wall Assemblies

[0001] This application is directed to systems and methods for preventing hose stream penetration through fire-rated wall assemblies.

[0002] Office buildings and residential buildings use fire-resistant drywall panels (also known as plasterboard, wallboard, sheetrock, gypsum board, and the like), on the interior walls of rooms. Conventional drywall panels typically comprise gypsum (calcium sulfate dihydrate), which is extruded between thick sheets of facer and backer paper. When positioned on a wall structure (e.g., vertical studs between an upper plate and a lower plate), the drywall panels may be painted, coated with plaster, covered with wallpaper, or otherwise decorated. The drywall panels also provide a degree of fire protection. For example, a ½-inch-thick drywall panel is considered to have a half-hour fire rating. A ⅝-inch-thick drywall panel is considered to have a one-hour fire rating. Accordingly, a person within a room formed by wall structures comprising conventional drywall panels may have a short time during which the person is protected from a fire on the outside of the room. However, the protection provided by the wall structures may be substantially reduced when the drywall panels are breached by a high-pressure hose stream from a fire suppression nozzle.

[0003] A need exists for a system and method for preventing the water from a high-pressure fire hose from penetrating a fire-rated wall assembly.

[0004] One aspect in accordance with the embodiments disclosed herein is a method that prevents hose stream penetration into an interior of an enclosure from firefighting activity in a location adjacent to the enclosure. The method forms a wall structure between the enclosure and the adjacent location. The wall structure is covered with a laminated wall panel having a noncombustible wallboard secured to a metallic sheet. Each wall panel is secured to studs of the wall structure with the metallic sheet against studs of the wall structure. The metallic sheets block water of a hose stream from penetrating into the enclosure. The wall structure may also include laminated wall panels secured to the exterior side of the wall structure. Even if the noncombustible wallboard on one of the exterior laminated panels is weakened or destroyed by a fire or by the hose stream in the location adjacent to the enclosure, the metallic sheet of the exterior laminated wall panel blocks hose penetration.

[0005] Another aspect in accordance with the embodiments disclosed herein is a method of preventing hose stream penetration into an interior of an enclosure from firefighting activity in a location adjacent to the enclosure. The method comprises forming a wall structure between the enclosure and the location adjacent to the enclosure. The wall structure has an interior side facing the interior of the enclosure and has an exterior side facing the location adjacent to the enclosure. The method attaches a first plurality of laminated wall panels to the interior side of the wall structure. Each laminated wall panel comprises a noncombustible wallboard secured to a metallic sheet. Each laminated wall panel is attached to the support studs of the wall structure with the noncombustible wallboard facing the interior of the enclosure and with the metallic sheet facing the support studs. The metallic sheets of the laminated wall panels block water of a hose stream in the location adjacent to the enclosure from penetrating the interior side of the wall structure and entering the enclosure.

[0006] In certain embodiments in accordance with this aspect, the method further comprises attaching a second plurality of the laminated wall panels to the exterior side of the wall structure with the metallic sheets of the laminated wall panels facing the support studs of the wall structure. The metallic sheets of the second plurality of laminated wall panels block water of the hose stream in the location adjacent to the enclosure from penetrating the exterior side of the wall structure even if the noncombustible wallboard on one or more of the laminated panels of the second plurality of laminated panels is weakened or destroyed by a fire or by the hose stream in the location adjacent to the enclosure.

[0007] In certain embodiments in accordance with this aspect, the enclosure is a room.

[0008] In certain embodiments in accordance with this aspect, the enclosure is a passageway that provides egress from a room.

[0021] The following detailed description of embodiments of the present disclosure refers to one or more drawings. Each drawing is provided by way of explanation of the present disclosure and is not a limitation. Those skilled in the art will understand that various modifications and variations can be made to the teachings of the present disclosure without departing from the scope of the disclosure. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment.

[0022] The present disclosure is intended to cover such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present disclosure are disclosed in the following detailed description. One of ordinary skill in the art will understand that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present disclosure.

[0023] FIG. 1 illustrates a partial perspective inside view of an enclosure (e.g., a room) 100 in a residence, an office or another habitable structure. The room is formed by a first wall structure 110 and a second wall structure 112, which are secured to a floor 114. Additional wall structures (not shown) complete the room. The first wall structure is erected between the room and another location such as an adjacent room, the exterior of the structure, a corridor (e.g., a hallway), or the like. The illustrated wall structure is a solid wall structure without openings; however, a portion of the wall structure can be replaced with a door and frame wherein the door and the frame are constructed in accordance with fire protection requirements to complete a fire-resistant barrier. The construction and operation of such doors and frames are known and are not described herein. Portions of the wall structures may have openings for electrical switches and outlets and for plumbing lines as required.

[0024] The second wall structure 112 is also erected between the room 100 and another location. The following description directed to the first wall structure 110 is applicable to the second wall structure.

[0025] As shown by a broken-away portion of the first wall structure 110 in FIG. 1, the first wall structure comprises a plurality of vertical studs 120 that extend between a lower plate 122 and an upper plate 124. The studs, the lower plate and the upper plate may comprise conventional framing lumber (e.g., 2×4's, 2×6's or the like). In the illustrated embodiment, the studs and plates comprise conventional metal (e.g., lightweight cold-formed steel (CFS) framing elements such as C-channel studs, U-channel lower and upper plates, and the like).

[0026] As further shown in FIG. 1, a plurality of wall panels 130 are mounted on the studs 120, the lower plate 122 and the upper plate 124 of the first wall structure 110. The vertical edges of the wall panels are adjacent to each other along a vertical stud so that the wall panels are effectively continuous along the face of the wall structure, with the small gaps between the vertical edges being sealed by the underlying stud. The wall panels are secured to the studs, the lower plate and the upper plate by a plurality of fasteners 132 that pass through the wall panels and engage the underlying studs and plates. In the illustrated steel-framed embodiment of the wall structure, the fasteners are self-tapping drywall screws. In a wood-framed embodiment of the wall structure, the fasteners may be coarse thread laminating screws. In the embodiment of FIG. 1, the wall panels are drywall panels comprising gypsum or other suitable material extruded between a layer of facer paper and a layer of backer paper. The drywall panels are positioned with the backer paper against the vertical studs and with the facer paper exposed to the interior of the room.

[0027] A second plurality of wall panels 140 are mounted on the opposing sides of the studs 120 of the first wall structure 110. In the illustrated embodiment, where the first wall structure separates two interior rooms, the second plurality of wall panels are advantageously constructed and installed in the same manner as the first plurality of wall panels. In the illustrated embodiment, the second plurality of wall panels also comprise drywall. In alternative embodiments, where the opposite side of the wall structure is exposed to the exterior, the second plurality of wall panels may have a different construction.

[0028] As described herein, the first plurality of wall panels 130 comprise the “inner wall” of the first wall structure 110. The second plurality of wall panels 140 comprise the “outer wall” of the first wall structure.

[0029] In conventional interior wall construction, the first plurality of wall panels 130 and the second plurality of wall panels 140 of the first wall structure 110 provide a modicum of fire protection for the room 100 when constructed using conventional gypsum drywall. For example, a wall structure of ½ inch drywall panels may have a fire-rating of approximately one-half hour. Substituting ⅝-inch drywall panels may result in a wall structure having a fire-rating of approximately one hour. In many situations, the specified fire ratings may provide an occupant (or occupants) of a room sufficient survival time until a fire exterior to the room is extinguished.

[0030] The foregoing fire ratings assume the integrity of the first wall structure 110 between the occupied room and the area of the fire is maintained during the rating period. However, many factors affect the integrity of the wall structure and may result in injury to or the death of the occupants of the room. One factor affecting the integrity of the wall structure is the process of fighting a fire in an area bounded by the outer wall of the wall structure. As illustrated in FIGS. 2 and 3, a fire suppression nozzle 200 generates a high-pressure hose stream 210 to extinguish a fire (not shown). The force of the high-pressure hose stream striking one or more of the conventional second plurality of wall panels 140 of the first wall structure 110 can readily penetrate the second plurality of wall panels, penetrate the first plurality of wall panels 130, and enter the interior of the room 100 protected by the wall structure. The hose stream may have sufficient force to injure occupants within the room. Furthermore, the breach of the conventional wall panels by the hose stream allows the exterior fire to enter the interior of the room and engage combustible material within the room. Once the breach occurs, the fire rating of the wall structure in the area of the breach may be reduced to zero.

[0031] FIGS. 4-6 illustrate a laminated wall panel 300 that is incorporated into an improved wall structure to prevent the penetration of the hose stream into the room. The laminated wall panel comprises a first layer 310 of wallboard (a non-combustible board) laminated to a second metallic layer 320 (e.g., a sheet of steel). In FIG. 4, an upper right portion of the non-combustible board is broken away to expose the underlying metallic sheet. Examples of the laminated wall panel are described in U.S. Pat. No. 5,768,841 for Wallboard Structure and in U.S. Pat. No. 8,079,188 for Energy Absorbing Blast Wall for Building Structure, which are incorporated herein by reference.

[0032] In one embodiment, the first layer 310 of non-combustible board comprises a conventional wallboard, such as, for example, drywall. Such wallboard is also referred to as plasterboard, gypsum board, Sheetrock®, and the like, and is commercially available from a number of sources, such as, for example, USG Corporation of Chicago, Ill. The wallboard may also comprise cement board (e.g., Durock® cement board from USG Corporation, HardieBacker cement board from James Hardie Building Products Inc. of Chicago, Ill., or the like), magnesium oxide board, or other suitable fire-resistant materials. The wallboard has a selected thickness. For example, in one embodiment, the wallboard has a nominal thickness of ⅝ inch.

[0033] In the illustrated embodiment, the metallic sheet 320 of the panel 300 comprises steel. In the illustrated example, the steel is 14-gauge steel having a nominal thickness of approximately 0.078 inch. Although described herein as steel, other metallic sheets (e.g., aluminum) may also be used. Other gauges of steel or other metal may also be used (e.g., 20-gauge (0.0375 inch) steel). The metallic sheet and the wallboard (non-combustible board) are laminated to each other by bonding the two layers using a layer 330 of a suitable bonding material. Preferably, the bonding layer comprises an adhesive, such as, for example, epoxy, glue, or the like. The adhesive layer is advantageously sprayed, brushed or rolled onto a surface 340 of the metallic sheet. The adhesive layer can also be sprayed, brushed or rolled onto a surface of the wallboard layer. The three layers are then forced together under pressure to permanently engage the two surfaces and form the laminated panel. The bonding method is disclosed, for example, in U.S. Pat. No. 5,768,841.

[0034] In the illustrated embodiment, the wallboard 320 of each panel 300 has a nominal width of approximately 48 inches and a nominal length of approximately 96 inches. The metallic sheet 320 may have a smaller width and a smaller length of, for example, approximately 47.5 inches by 95.5 inches to provide a border around the metallic sheet when attached to the wallboard. The lengths of the panels are chosen to span the required distances between the lower plate 122 and the upper plate 124 of the first wall structure 110 and the second wall structure 112 described above. For example, in certain embodiments, the lengths may be 8 feet. In other embodiments, the lengths may be 10 feet or 12 feet. For a wall structure having a height less than the length of an available panel, the panel may be cut to the appropriate length. For a wall structure having a height greater than the length of an available panel, an upper panel may be installed above a lower panel. In such cases, a framing cross-member (not shown) is installed between adjacent studs where the lower and upper panels are abutted to provide a location to secure the horizontal edges and to seal the gap between the lower panel and the upper panel.

[0035] FIGS. 7 and 8 illustrate a modified room (or other enclosure) 400 formed in part by a first improved wall structure 410 and a second improved wall structure 412 that inhibit or prevent altogether the breaching of the wall structure by a high-pressure hose stream. The first and second improved wall structures are similar to the previously described wall structures 110, 112; and like elements are numbered as before. In the improved wall structures of FIGS. 7 and 8, the first plurality 130 of conventional wall panels of FIG. 1 on the inside surfaces of the improved wall structures are replaced with laminated wall panels 300 of FIGS. 4-6. In FIGS. 7 and 8, the second plurality 140 of conventional wall panels remain on the outer surfaces of the improved wall structures.

[0036] When the first wall structure 410 and the second wall structures 412 are completed as illustrated in FIGS. 7 and 8, openings (not shown) may be formed in the wall structure for boxes for wall outlets and switches and for plumbing elements, or the like. Any gaps remaining after installing the boxes, plumbing or other elements are filled with fire-resistant expanding foam sealant or other suitable material. For example, Abesco FP200 Fire Rated Expanding Foam, which is commercially available from Abesco Fire LLC of Orlando, Fla.

[0037] When the first improved wall structure 410 and the second improved wall structure 412 of FIGS. 7 and 8 are completed to form the two illustrated wall structures of the room 400, the visible surfaces of the improved wall structures and the conventional wall structures 110, 112 of the room 100 appear to be the same. The wallboard 320 of each laminated wall panel 300 facing the interior of the room can be painted or plastered and can be covered with wallpaper just like drywall panels 130, 140 of the conventional first and second wall structures 110, 112 of FIGS. 1-3.

[0038] Unlike the previously described conventional wall structures 110, 112, the first improved wall structure 410 and the second improved wall structure 412 are highly resistant to hose stream penetration as illustrated in FIGS. 7 and 8. When the high-pressure hose stream 210 from the fire suppression nozzle 200 impinges on the improved wall structure, the hose stream is blocked from penetration by the second layer (metallic sheet) 320 of the laminated wall panel 300 on the inner surface of the first improved wall structure 410. Thus, the hose stream does not enter the room 400.

[0039] In FIGS. 9 and 10, a further modified room (or other enclosure) 500 includes a first further-improved wall structure 510 and a second further-improved wall structure 512. Each of the two further-improved wall structures comprises a plurality of the laminated wall panels 300 on the inside surfaces and on the outside surfaces of the wall structure. As shown in FIG. 10, even if the hose stream 210 from the fire suppression nozzle 200 is sufficiently strong to remove a portion of the wallboard layer 310 from one of the laminated panels on the exterior surface of the first further-improved wall structure, the metallic layer 320 of the laminated wall panel blocks the hose stream from penetrating the exterior of the wall structure. In addition to blocking penetration by the hose stream, the additional protection provided by the metallic layer of the exterior laminated wall panels prevents flames from entering the wall structure. Thus, even if the studs 120 (FIG. 1) of the first wall structure comprise wood, the flames cannot reach the wooden studs because the wall is not breached.

[0040] FIG. 11 illustrates a further implementation of the laminated wall panels 300 into a first wall structure 610 and a second wall structure 612 forming the sides of an egress passageway 600. For example, in an office building, hotel or other multiple-room structure, an occupant of a room may need to move from a room to an egress passageway (e.g., a hallway) to exit safely from a burning building. As shown in FIG. 11, the wall structures forming the sides of the egress passageway prevent hose stream penetration from rooms in which fires are being suppressed with water. In FIG. 11, a floor 620 and a ceiling 622 of the egress passageway comprise concrete or other hard material used to form the floors and ceilings of multiple-story buildings. Such materials have resistance to hose stream penetration. If, for example, the egress passageway has a dropped ceiling or the like, the ceiling may also be constructed using the laminated wall panels.

[0041] The previous detailed description has been provided for the purposes of illustration and description. Thus, although there have been described particular embodiments of a new and useful invention, it is not intended that such references be construed as limitations upon the scope of this invention except as set forth in the following claims.