RC CHANNEL AND RELATED WALL SYSTEM USING LIGHTWEIGHT METAL LAMINATE

Abstract

A wallboard support channel includes a web of metal laminate including a layer of polymer sandwiched between first and second layers of metal, the web being configured into a channel shape for achieving enhanced sound absorption. In the preferred embodiment, the channel shape includes a first, generally planar surface having an elongate edge, and an opposite free edge that is folded over, an inclined web disposed along the elongate edge and projecting at an obtuse angle relative to the first surface, a web edge of the inclined web opposite the first surface is shared with a second, generally planar surface, an arched support rib is formed between adjacent edges of the inclined web and the second surface to provide enhanced structural rigidity, and a second inclined web projecting from an edge of the second surface opposite the inclined web in a complementary direction to the inclined web.

Description

BACKGROUND

The present invention relates to wall and ceiling construction techniques, and more specifically to the use of resilient runner channels fabricated from lightweight metal laminate for dampening sound.

Conventional residential and office construction involves the erection of framing, typically wood or metal studs positioned vertically, and connected in spaced, parallel orientation to similarly formed, horizontally-oriented headers and footers. Framing also includes floor or ceiling joists, to which are connected the headers and footers described above, often with subfloor panels in between. Next, wallboard panels, usually made of gypsum compositions faced with paper or the like on front and rear surfaces, are secured to the framing to form walls, and in many cases, ceilings as well. In some applications where additional acoustic isolation is desired, multiple thicknesses of wallboard panels are attached to the frame. Wallboard joint compound and joint tape are used to fill and smooth the joints between adjacent wallboard panels as is well known in the art. Such construction techniques are suitable for single family residences, however, in the case of multi-family dwellings such as apartment buildings, dormitories, small hotels, barracks and the like, traditional room construction as described above is prone to the ready transmission of sound between rooms.

To address the problem of unwanted sound transmission between laterally adjacent rooms, and also between rooms stacked vertically, resilient channel was developed, as described in commonly-assigned U.S. Pat. Nos. 3,090,164 and 10,260,241, both incorporated by reference. Such resilient channel, which over time has become known in the industry as RC channel, has a pair of generally parallel, laterally displaced planar surfaces. Several lengths of the RC channel are mounted to the framing, preferably studs or joists in spaced, parallel, horizontal orientation. A first such surface is referred to as a base, and is fastened to the framing members by nails, threaded fasteners or the like. An angled flange connects the first and second surfaces, and laterally displaces the second surface from the base. Wallboard panels are secured to the second surface, which is unattached to the framing member at the opposite end from the base. Thus, the wallboard panels are held suspended away from the framing members by the RC channel.

By separating the wallboard panels from the framing, sound energy impacting the panels, which would normally be transmitted through the panels directly to the framing and distributed throughout the building, is dampened as it impacts the wallboard panels and has its transmission path interrupted by the RC channel.

Sound rated walls and floors are typically evaluated by ASTM Standard E492 and are rated as to impact insulation class (IIC). The greater the IIC rating, the less impact noise will be transmitted to the adjacent area. Floors and walls may also be rated as to Sound Transmission Class (STC) per ASTM E90. The greater the STC rating, the less airborne sound will be transmitted to the adjacent area. Sound rated walls and floors typically are specified to have an IIC rating of not less than 50 and an STC rating of not less than 50. Many building codes require an IIC rating of 50 or higher. Moreover, even though an IIC rating of 50 meets many building codes, experience has shown that in luxury condominium applications even floor-ceiling systems having an IIC of 56-57 may not be acceptable because some impact noise is still audible.

Manufacturers of building components and contractors have sought additional techniques and materials for further reducing acoustic transmission in interior wall systems. In the non-related automotive industry, demand for sound dampening in vehicle interiors has inspired the development of metal laminate for use in vehicle frames, bodies and components such as doors. One such metal laminate is sold under the trademark QUIET STEEL® or MSC SMART STEEL® laminate manufactured by Material Sciences Corporation of Elk Grove Village, IL or related entities. These products are composite sheets or panels composed primarily of metal for use in further manufacture including two outer metal skins and a non-metal sheet between the skins. However, the use of these laminates has not expanded beyond the automotive industry.

Accordingly, there is a need for an improved RC channel with enhanced acoustic absorption properties.

SUMMARY

The above-listed need is met or exceeded by the present RC channel and related wall system using lightweight metal laminate similar to that used in automotive manufacturing. By incorporating metal laminate into the RC channel, enhanced sound absorption is achieved. In the present building systems employing RC channel made of metal laminates, STC ratings in the range of 55-60 are contemplated.

The present RC channel is contemplated has having one of a selected range of alternative configurations. These configurations are commonly provided in 10 or 12 foot lengths, however it is contemplated that the length of the channel may vary to suit the application. Also, the present RC channel configurations include but are not restricted to single legged, or dual-legged or so-called “hat channel.” Also, the present RC channel is preferably provided with radiused corners and deeply knurled surfaces for positive fastener placement and for reducing unwanted shifting or wandering during installation. Also, the present RC channel is hot-dipped in galvanizing solution for enhanced corrosion protection, and optionally painted. As is known in the art, RC channel is usually secured to the framing using nails, however it is customary to attach wallboard panels to RC channel using screws. Other fasteners are contemplated depending on the application.

More specifically, a wallboard support channel is provided that is constructed and arranged for attachment to a surface of a framing member and for holding a wallboard panel suspended away from the framing member. The support channel includes a web of metal laminate including a layer of polymer sandwiched between first and second layers of metal, the web being shaped into a channel shape. In the preferred embodiment, the channel shape includes a first, generally planar surface having an elongate edge, and an opposite free edge that is folded over, an inclined web disposed along the elongate edge and projecting at an obtuse angle relative to the first surface, a web edge of the inclined web opposite the first surface is shared with a second, generally planar surface, an arched support rib is formed between adjacent edges of the inclined web and the second surface to provide enhanced structural rigidity, and a second inclined web projecting from an edge of the second surface opposite the inclined web in a complementary direction to the inclined web.

In an embodiment, at least one of the inclined web and the second, generally planar surface are knurled. In another embodiment, the web is dipped in galvanizing solution.

In an embodiment, the second inclined web is a stop flange, being shorter than the inclined web, a second arched support rib spaced from the arched support rib and formed between adjacent edges of the second surface and the stop flange.

In an embodiment, the second inclined web is similar in length to the inclined web, and has a third, generally planar surface similar in dimension and configuration to the first, generally planar surface so that the support channel is symmetrical about a vertical axis. In an embodiment, the inclined web and the second inclined web are made of expanded metal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an interior room under construction and employing prior art RC channels;

FIG. 2 is a schematic vertical cross-section of metal laminate used in the present RC channel;

FIG. 3 is a vertical cross-section of a first embodiment of the present RC-channel;

FIG. 4 is a vertical cross-section of a second embodiment of the present RC channel;

FIG. 5 is a vertical cross-section of a third embodiment of the present RC channel;

FIG. 6 is a top perspective view of the RC channel of FIG. 5;

FIG. 7 is a top perspective view of a fourth embodiment of the present RC channel.

DETAILED DESCRIPTION

Referring now to FIG. 1, a portion of a room is illustrated, generally designated 10, and includes a pair of walls 12 and 14, each supported by a frame 16 including at least one footer or base 18, at least one header or upper support member 20, and a plurality of vertical members or studs 22 joining the header(s) to the footer(s). As is well known in the art, the studs 22 are placed at a regular spacing such as 16-inch on center, or other spacing depending on the local building code. Also, while the frame 16 is typically made of wooden members, preferably 2×4 planks, other sizes of lumber, as well as alternate construction techniques are contemplated that employ metal members made of steel or the like, as well as other materials. Ceiling joists 24 are secured to the header(s) 20, and are used to support a roof or an upper floor, depending on the desired height of the building. As is known in the art, the frame 16 is assembled using fasteners such as nails or screws. The footers 18, the headers 20, the studs 22 as well as joists 24 are collectively referred to as frame members or framing members.

In applications where transmission of sound between rooms is intended to be suppressed, it is common to install standard RC channel or runners 26 in spaced, parallel orientation directly to the studs 22 or other framing members using suitable fasteners (not shown), so that the channels 26 extend transversely to the framing members. Wallboard panels 28, made of gypsum wallboard or the like, are then secured to the RC channels 26 using conventional fasteners, such as screws, nails or chemical adhesives. Thus, the wallboard panels 28 are held a spaced distance from the frame 16 by the RC channel 26, thus interrupting the path of acoustical transmission from the panels to the frame, and thus reducing room-to-room noise transmission.

As described above, in practice, there is a need to further reduce sound transmission in interior rooms. Referring now to FIGS. 2-5, to address this need, an improved RC channel is provided, and generally designated 40. The present RC channel 40 is intended to replace the standard RC channel 26 described above in relation to FIG. 1. A main feature of the present RC channel 40 is that it is constructed of a web of metal laminate seen in FIG. 2, which is made up of a layer of insulative, non-metal material 42 referred here as polymeric, that is sandwiched between first and second metal layers 44 and 46, and the three layers are bound together to form a unitary composite material. Such material is known in the art as MSC QUIET STEEL® or MSC SMART STEEL® laminate manufactured by Material Sciences Corporation of Elk Grove Village, IL or related entities. It will be understood that the relative thicknesses of the layers 42, 44, 46 may vary to suit the application. Also, it will be understood that the particular embodiments of the present channel 40 and alternate embodiments described below are fabricated of this metal laminate.

Included in the present RC channel 40 is a first, generally planar surface 48 having an elongate edge 50, and an opposite free edge 52. In FIGS. 3 and 4, a width of the first planar surface is ½ inch, however other dimensions are contemplated depending on the application. An inclined web or wall 54 is disposed along the elongate edge 50 and projects at an oblique angle α relative to the first generally planar surface 48. In the preferred embodiment, the angle α is obtuse, and it is further preferred that the angle α is approximately 110-115°. A web edge 56 of the inclined web 54 opposite the first surface 48 is shared with a complementary edge of a second, generally planar surface 58. An important feature of the inclined web 54 is that it is dimensioned to separate the web edge 56, which contacts the wallboard panel 28, from the frame 16 a distance “D” of at least ½-inch measured normally from a surface 60 of the frame 16, preferably the stud 22 or other framing member. However, it is contemplated that the distance “D” may vary to suit the application.

A stop flange edge 62 is located on the second planar surface 58 and is generally horizontally aligned with the web edge 56. Also, the stop flange edge 62 is located at an intersection of adjacent or complementary edges of a second inclined web 64, here referred to as a stop flange 64 and the second planar surface 58, and forms the base from which projects the stop flange, which is shorter than the inclined web 54, and projects from the second planar surface 58 opposite the inclined web 54.

Referring now to FIGS. 3-6, the support channel 40 and its alternate embodiments are preferably produced by roll forming and stamping the entire structure from a length of the web of metal laminate made of layers 42, 44, 46, preferably coated with a galvanizing composition 66 (FIG. 3) or otherwise corrosion-protected as is well known in the art, which is then formed into the shape as illustrated. During the manufacturing process, the inclined web 54 is preferably provided with a plurality of linearly spaced cutouts 68 (FIG. 6) for increasing resiliency when mounted to the vertical frame member 22. It is contemplated that the shape of the cutouts 68 may vary to suit the application, but is contemplated as being circular, oval, ovoid, elongate slot, or the like. In addition, enhanced structural rigidity is provided to the channel 40 by preferably forming arched support ribs 70 at the web edge 56 as well as the stop flange edge 62, however fewer ribs are contemplated depending on the application.

As seen in FIGS. 3 and 4, the stop flange 64 projects from the second planar surface 58 at an angle β which is similar to an angle defined between the second planar surface and the inclined web 54. In the preferred embodiment, the angle β is approximately 90-110°, however variations are contemplated. To further enhance the strength of the support channel 40, the free edge 52 is folded over upon itself. Also, as best seen in FIG. 6, the first planar surface 48 is preferably provided with linearly spaced mounting apertures 72 used to secure the RC channel 40 to the frame 16. It is also preferred that the stop flange 64 extends a distance “E” in FIG. 3 at least ½ -inch from the stop flange edge 62 to prevent bending of the channel 40 relative to the frame member so that the fastener can more easily penetrate the channel. However other dimensions are contemplated depending on the application.

Referring now to FIG. 4, an alternative embodiment to the RC channel 40 is generally designated 80. Components shared with the channel 40 are designated with identical reference numbers. A main distinction between the channels 40 and 80 is the width of the second planar surface 82, which is 1 5/16 inches, where the second planar surface 58 in the channel 40 is 1¾ inches.

Referring now to FIGS. 5 and 6, another embodiment of the present channel 40 is generally designated 90. Components shared with the channels 40 and 80 are designated with identical reference numbers. A main difference of the channel 90 from the channels 40 and 80 is that it is a so-called “hat” channel, where instead of the stop flange, a second inclined web 92 is similar in length to the inclined web 54, and has a third, generally planar surface 94 similar in dimension and configuration to the first, generally planar surface 96 so that the support channel 90 is symmetrical about a vertical axis “A” (FIG. 5). In addition, the first planar surface 96 is 7/16 inch wide, however other dimensions are contemplated depending on the application. Also, the third, generally planar surface has a free edge 98 similar to the edge 52, which is also folded over.

Referring now to FIG. 6, another feature of the channel 90, which is shared with the channels 40 and 80, is that at least one of the inclined web 54, the second generally planar surface 58 and the second inclined web 92 is deeply knurled at 100. The purpose of the knurled surface 100 is for achieving positive fastener placement and for reducing unwanted shifting or wandering during installation.

Referring now to FIG. 7, another embodiment of the present RC channel 40, 80, 90 is generally designated 110. Components shared with the channels 40, 80 and 90 are designated with identical reference numbers. Like the channel 90, the channel 110 is a so-called “hat” channel. However, in the channel 110, the inclined web 112 and the second inclined web 114 are made of expanded metal, being an open web with many openings 116. It has been found that the use of expanded metal in this application has resulted in enhanced sound attenuation. Preferred dimensions for the channel 110 are 1 5/16 inch for the second planar surface 58, 7/16 inch for the first planar surface 48, a vertical height of ½ inch and a total edge 52 to edge 98 length of 2¾ inches, however such dimensions may vary to suit the application.

The use of the present RC channel 40, 80, 90 and 110 fabricated from the layers 42, 44, 46 as described above is expected to achieve significantly reduced sound transmission in rooms constructed using the channels. STC values in the range of 55-60 are contemplated.

While a particular embodiment of the present RC channel and related wall system using lightweight metal laminate has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.

Claims

1. A wallboard support channel constructed and arranged for attachment to a surface of a framing member and for holding a wallboard panel suspended away from the framing member, comprising: a web of metal laminate including a layer of polymer sandwiched between first and second layers of metal;said web being shaped into a channel shape including: a first, generally planar surface having an elongate edge, and an opposite free edge that is folded over;an inclined web disposed along said elongate edge and projecting at an obtuse angle relative to said first surface;a web edge of said inclined web opposite said first surface is shared with a second, generally planar surface;an arched support rib formed between adjacent edges of said inclined web and said second surface to provide enhanced structural rigidity; anda second inclined web projecting from an edge of said second surface opposite said inclined web in a complementary direction to said inclined web.

2. The wallboard support channel of claim 1, wherein at least one of said inclined web and said second, generally planar surface being knurled.

3. The wallboard support channel of claim 1, wherein said web is dipped in galvanizing composition.

4. The wallboard support channel of claim 1, wherein said second inclined web is a stop flange, being shorter than said inclined web, a second arched support rib spaced from said arched support rib and formed between adjacent edges of said second surface and said stop flange.

5. The wallboard support channel of claim 1, wherein said second inclined web is similar in length to said inclined web, and has a third, generally planar surface similar in dimension and configuration to said first, generally planar surface so that said support channel is symmetrical about a vertical axis.

6. The wallboard support channel of claim 5, wherein said inclined web and said second inclined web are made of expanded metal.