Patent Publication Number: US-2016230395-A1

Title: Sound damping wallboard and method of constructing a sound damping wallboard

Description:
This application claims the benefit of U.S. Provisional Application No. 62/112,560, filed Feb. 5, 2015, which is hereby incorporated by reference in its entirety. A building is typically constructed with walls having a frame comprising vertically oriented studs connected by horizontally oriented top and bottom plates or tracks. The walls often include one or more gypsum wallboards fastened to the studs and/or plates on each side of the frame or, particularly for exterior walls, one or more gypsum wallboards fastened to the studs and/or plates on one side of the frame with a non-gypsum based sheathing attached to an exterior side of the frame. A ceiling of the building may also include one or more gypsum wallboards oriented horizontally and fastened to joists, studs, or other structural members extending horizontally in the building. Walls and ceilings of this construction often have poor acoustical performance and a low sound transmission class (STC) rating, which results in noise pollution, lack of privacy, and similar issues in the various spaces of the building. One of the aspects of this poor performance is the coincidence between the human voice Hertz spectrum and the vibrational Hertz range of standard gypsum wallboard, which creates a unique dip in the acoustical curve of a standard frame and gypsum wallboard wall. 
    
    
     BACKGROUND 
     One method to improve acoustical performance of the walls and ceilings is to install insulation in the cavities of the walls before attaching wallboards to the wall frame. Other methods include the use of rubber sheets, clips, or panels attached to the frame during wall or ceiling construction. However, most of the current methods to improve wall or ceiling acoustical performance must be implemented during the initial wall or ceiling construction, and these conventional methods do not overcome the coincidence issue of standard gypsum wallboard discussed above. Further, the resulting wall may be significantly thicker than traditionally-constructed walls due to the addition of the sound damping materials. 
     Therefore, there exists a need for a sound damping wallboard that is structured for retrofit installation and attachment to a wallboard or other panel of wall material previously installed onto the frame of a wall to improve the acoustical performance of the wall and, in particular, help address any coincidence issues. Further, there exists a need for a sound damping wallboard for attachment to an installed wallboard or wall panel whereby the sound damping wallboard is sufficiently thin to minimize the skill and labor needed for installation, minimize the increase in overall wall thickness, avoid costly and labor-intensive modifications to installed wall and ceiling objects, such as existing wall outlets, switches, and wall or ceiling fixtures, and minimize any reduction in living space within the structure causing a reduction in the value of the structure. 
     SUMMARY 
     In accordance with an aspect of the disclosure, a sound damping wallboard is provided, that comprises a gypsum layer having a gypsum layer inner surface and a gypsum layer outer surface. A sound damping layer is disposed at the gypsum layer inner surface and has a sound damping layer inner surface opposite the gypsum layer inner surface. A first encasing layer is disposed at the gypsum layer outer surface, and a second encasing layer is disposed at the sound damping layer inner surface. 
     In accordance with another aspect of the disclosure, a sound damping wallboard system for a building structure is provided that comprises a first wallboard fastened to the building structure. A second wallboard comprises a gypsum layer having a gypsum layer inner surface and a gypsum layer outer surface. A sound damping layer is disposed at the gypsum layer inner surface and has a sound damping layer inner surface opposite the gypsum layer inner surface. A first encasing layer is disposed at the gypsum layer outer surface, and a second encasing layer is disposed at the sound damping layer inner surface. The second wallboard is fastened to the first wallboard with the sound damping layer inner surface disposed at the first wallboard. 
     In accordance with yet another aspect of the disclosure, a method of constructing a sound damping wallboard on a building structure is provided that comprises the steps of fastening a first wallboard to the building structure; providing a second wallboard that comprises a gypsum layer having an inner surface and an outer surface, a sound damping layer having a first surface disposed at the gypsum layer inner surface and a second surface opposite the first surface, a first encasing layer disposed at the gypsum layer outer surface, and a second encasing layer disposed at the sound damping layer second surface; and fastening the second wallboard to the first wallboard with the sound damping layer disposed between the gypsum layer and the first wallboard. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The embodiments described herein and other features, advantages, and disclosures contained herein, and the manner of attaining them, will be better understood from the following description in conjunction with the accompanying drawing figures, in which like reference numerals identify like elements, and wherein: 
         FIG. 1  is a cross sectional view of a sound damping wallboard in accordance with aspects of the present disclosure; 
         FIG. 2  is a cross sectional view of a sound damping wallboard and installed wallboard in accordance with further aspects of the present disclosure; 
         FIG. 3  illustrates a method of forming a sound damping wallboard in accordance with further aspects of the present disclosure; 
         FIG. 4  illustrates a method of constructing a sound damping wall in accordance with further aspects of the present disclosure; 
         FIG. 5  is a data plot of frequency and sound transmission loss, that illustrates the performance of a sound damping wall in accordance with further aspects of the present disclosure; and 
         FIG. 6  is a data plot of frequency and sound transmission loss, that illustrates the performance of alternative embodiments of a sound damping wall in accordance with further aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description of embodiments of the present disclosure, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, and not by way of limitation, such specific embodiments. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the spirit and scope of the present disclosure. 
     Reference is now made to  FIG. 1 , which shows a sound damping wallboard  10  according to an embodiment of the present disclosure. The sound damping wallboard  10  of an embodiment generally includes a gypsum layer  12  and a sound damping layer  14 , that are sandwiched between first and second encasing layers  20  and  22 . The gypsum layer  12  includes a gypsum layer inner surface  16  and a gypsum layer outer surface  18 . The sound damping layer  14  is disposed at the gypsum layer inner surface  16 . The first encasing layer  20  is disposed at the gypsum layer outer surface  18  and the second encasing layer  22  is disposed at a sound damping layer inner surface  24  opposite the gypsum layer inner surface  16 . In an embodiment, a third encasing layer  26  is disposed between the gypsum layer  12  and the sound damping layer  14 . In an embodiment, the gypsum layer  12  is constructed using conventional gypsum wallboard manufacturing techniques, including encasing the gypsum layer  12  in an encasing material such that an encasing layer is disposed on each of the gypsum layer inner surface  16  and the gypsum layer outer surface  18 , thereby forming the first encasing layer  20  and the third encasing layer  26 . In an embodiment, the gypsum layer  12  has a higher density than a density of a gypsum layer of a conventional gypsum wallboard. 
     In one or more embodiments, the sound damping layer  14  comprises a resin or polymeric material, and preferably an elastomer. Suitable sound damping materials include, as non-limiting examples, synthetic resins, polymers and copolymers, and latex polymers as are known in the art. In a preferred embodiment, the sound damping material is an acrylic polymer or copolymer. One such non-limiting example is Acronal®, an acrylate copolymer commercially available from BASF (Charlotte, N.C.). The sound damping material may also comprise various additives, including anti-microbial materials for fungal protection and appropriate fillers such as, in non-limiting examples, vermiculite, expanded mica, talc, lead, and granulated polystyrene aluminum oxide. Additional embodiments include a tacky adhesive constructed of one or more polymers having fluidity at an ordinary temperature and one or more emulsion type or solvent type polymers consisting of one or more natural rubbers, synthetic rubbers, and polymers such as, in non-limiting examples, acrylic resin and silicone resin. A tackifier, including such non-limiting examples as petroleum resin and sap, a softener, and/or a plasticizer are included in the sound damping layer  14  in one or more embodiments of the present disclosure. Other non-limiting examples of materials used to form the sound damping layer  14  include polyester resins, resins constructed from plasticizers or peroxide being added to polyester, multiple polyesters, polyurethane foam, polyamide resin, ethylene-vinyl acetate copolymers, ethylene acrylic acid copolymers, polyurethane copolymers, and EPDM polymers. In one or more embodiments, the sound damping layer  14  comprises a polymer having a dynamic glass transition temperature at or below the working temperature at which the sound damping layer  14  will be used. 
     The sound damping layer  14  may be applied or positioned directly on the gypsum layer  12  or the third encasing layer  26 , or both. In one or more embodiments, the sound damping layer  14  is positioned or applied directly on the gypsum layer inner surface  16  as a monolithic, homogenous layer. In an alternative embodiment, the third encasing layer  26  only partially covers the gypsum layer inner surface  16  of the gypsum layer  12  such that the sound damping layer  14  is positioned or applied on both the gypsum layer  12  and the third encasing layer  26 . The sound damping layer  14  may cover substantially the entire surface of the gypsum layer  12  or the third encasing layer  26 . In yet another embodiment, after the gypsum layer  12  is constructed using traditional gypsum wallboard manufacturing techniques and the sound damping layer  14  is positioned adjacent to or applied onto the gypsum layer  12  or third encasing layer  26 , the wallboard  10  may then be encased to at least partially form the first encasing layer  20  and the second encasing layer  22 . The first encasing layer  20  may comprise both encasing material from the original encasement of the gypsum layer  12  using traditional gypsum wallboard manufacturing techniques as well as encasing material used to encase the wallboard  10  following the formation of the sound damping layer  14 . 
     In one or more embodiments, the first encasing layer  20 , the second encasing layer  22 , and/or the third encasing layer  26  comprises a material such as paper, fiberglass, foil, a polymer, or other materials known in the art. Additionally, the first encasing layer  20 , the second encasing layer  22 , or the third encasing layer  26  may be made of a low emittance or reflective material, or from virgin or recycled material. In one or more embodiments, the first encasing layer  20 , the second encasing layer  22 , or the third encasing layer  26  is constructed of a plurality of thin sheets of material having various thicknesses, each sheet having a thickness less than or equal to 0.001 inches. In one or more embodiments, each of the plurality of thin sheets of material has thickness less than or equal to 10-15 microns. In one or more embodiments, the second encasing layer  22  or the third encasing layer  26  may be constructed of or include a carrier sheet, such as a “peel &amp; stick” layer, where the carrier sheet may be removed during the wallboard manufacturing or installation process. In an embodiment, the second encasing layer  22  is constructed of a carrier sheet that is removable prior to installation, as discussed in further detail below. As shown in  FIG. 1 , the encasement of the gypsum layer  12  and/or the encasement of the sound damping wallboard  10  may include a first edge encasing layer  40  and a second edge encasing layer (not shown) connecting the first encasing layer  20  to the second encasing layer  22  and/or the third encasing layer  26 . 
     In an alternative embodiment, the second encasing layer  22  may comprise a coating that is applied to the sound damping layer inner surface  24 . The coating may be applied by various means known in the art, such as spraying or brushing. In a preferred embodiment, the coating is curable composition that is applied to the sound damping layer inner surface  24  and then cured to form the second encasing layer  22 . Suitable coatings include curable polymer compositions, such as acrylic polymer and copolymer compositions. In a preferred embodiment, the coating includes thermal or photo (e.g., UV) curing agents to facilitate curing of the second encasing layer  22 . 
     Referring now to  FIG. 2 , an embodiment of the present disclosure includes the sound damping wallboard  10  being installed such that the sound damping layer  14  is disposed between the gypsum layer  12  and an installed wallboard  28 . As used in the present disclosure, the term “wallboard,” especially with regard to the installed wallboard  28 , generally refers to any panel, sheet, or planar structure, either uniform or formed by connected portions or pieces, that is constructed to at least partially establish one or more physical boundaries. The installed wallboard  28  forms part of a building structure, such as a wall or ceiling. In the embodiment shown in  FIG. 2 , the building structure is a vertically aligned building wall  50 , which optionally has a second installed wallboard  52  connected to an opposite side of the building wall  50 . The installed wallboards  28 ,  52  are connected via one or more studs  54  of a wall frame to form the structure of the building wall  50 . One of ordinary skill will recognize the various methods and structures for fastening, adhering, or otherwise attaching or constructing the components of a wall or ceiling, including studs, plates, panels, wallboards, etc., to form a building structure such as a wall or ceiling, and such methods and structures are included in the present disclosure. 
     According to one or more embodiments, the sound damping wallboard  10  is installed in a flush relationship against the installed wallboard  28  with the sound damping inner layer  24  disposed at the installed wallboard  28 , as shown in  FIG. 2 . The sound damping wallboard  10  is installed against the installed wallboard  28 , in one embodiment, by mounting, attaching or otherwise fastening the sound damping wallboard  10  to the installed wallboard  28 . For example, the sound damping wallboard  10  may be fastened to the installed wallboard  28  using all-purpose joint compound and fasteners, including such non-limiting examples as nails, screws, and laminating screws. Fastener locations and joints between sound damping wallboards  10  are treated, in an embodiment, using conventional drywall tape and joint compound. 
     In the embodiment shown in  FIG. 2 , the second encasing layer  22  remains positioned against the sound damping layer  14  during installation of the sound damping wallboard  10  on the installed wallboard  28 . As shown in  FIG. 2 , the gypsum layer  12  of an embodiment has a gypsum layer thickness  30 , the installed wallboard  28  of the embodiment has an installed wallboard thickness  32 , and the gypsum layer thickness  30  is less than the installed wallboard thickness  32 . The thickness of a conventional wallboard panel is typically ½ inch or ⅝ inch. Thus, in one embodiment, the gypsum layer thickness  30  is less than or equal to ⅝ inch. In an alternative embodiment, the gypsum layer thickness  30  is less than or equal to ½ inch. In a preferred embodiment, the gypsum layer thickness  30  is about 5/16 inch, and more preferably about ¼ inch. 
     As discussed above, the gypsum layer  12  of an embodiment has a higher density than a density of a gypsum layer of a conventional gypsum wallboard. The density of a gypsum layer of a conventional gypsum wallboard is typically between 1300 and 1650 lbs/msf for wallboards of ½ inch thickness and generally between 1750 and 2200 lbs/msf for wallboards of ⅝ inch thickness. The density of wallboard having a thickness of ¼ or 5/16 inches is between 1200 and 1400 lbs/msf. The gypsum layer  12  of an embodiment of the present disclosure has a higher density than these densities of the gypsum layers of the conventional gypsum wallboards. For example, in gypsum slurries that contain foam, the higher density may be achieved by manipulating the amount of foam in the gypsum slurry, or by other means known in the art. In a preferred embodiment, building wall  50  comprises an installed wallboard  28  with a gypsum layer having a first density (e.g., a conventional density), and the sound damping wallboard  10  has a gypsum layer  12  with a second density that is greater than the first density of the installed wallboard. The higher density of the sound damping wallboard  10 , and the use of building wall structures where the sound damping wallboard and installed wallboard  28  have different densities are believed to contribute to improved sound damping. 
     As described above, in one embodiment, the second encasing layer  22  is removable such that the second encasing layer  22  is removed prior to installation of the sound damping wallboard  10  on the installed wallboard  28 . In a preferred embodiment, the second encasing layer  22  may comprise an adhesive layer with a release sheet or carrier sheet, such as used in “peel &amp; stick” applications, where the carrier sheet may be removed before the wallboard  10  is fastened to the installed wallboard  28  by contact with the adhesive. In embodiments where the sound damping layer  14  itself comprises a tacky or adhesive material, the second encasing layer  22  may comprise a release sheet without a further adhesive layer. For example, the release sheet may comprise a plastic film or paper sheet with a release coating, such as a silicone coating, as are known in the art. 
     Referring now to  FIG. 3 , one or more embodiments of the present disclosure include a method  110  of forming a sound damping wallboard  10  for installation on an installed wallboard  28 . In an embodiment, the method  110  includes forming, at step  112 , a gypsum layer  12  having a gypsum layer inner surface  16  and a gypsum layer outer surface  18  and encasing, at step  114 , the gypsum layer  12  with a first encasing layer  20  disposed at the gypsum layer outer surface  18 . In an embodiment, the method  110  further includes encasing the gypsum layer  12  with a third encasing layer  26  disposed at the gypsum layer inner surface  16 . The method  110  further includes applying, at step  116 , a sound damping layer  14  to the gypsum layer inner surface  16  such that the sound damping layer  14  includes a sound damping layer inner surface  24  opposite the gypsum layer inner surface  16  and encasing, at step  118 , the sound damping layer  14  with a second encasing layer  22  disposed at the sound damping layer inner surface  24 . The method  110  of one or more embodiments further includes removing, at step  120 , the second encasing layer  22  prior to installation of the sound damping wallboard  10  on the installed wallboard  28 . In an embodiment, the gypsum layer  12  is formed to a gypsum layer thickness  30  less than an installed wallboard thickness  32 . In an embodiment, the gypsum layer  12  is formed to a gypsum layer thickness  30  that is about 5/16 inch or less, and more preferably about ¼ inch or less. In one or more embodiments, the sound damping layer  14  is comprised of an elastomer material. Any structures, materials, applications, or similar details described in the present disclosure with regard to the sound damping wallboard  10  may be incorporated into one or more embodiments of the method  110 . 
     Referring now to  FIG. 4 , one or more embodiments of the present disclosure include a method  210  of constructing a sound damping wallboard  10 . In an embodiment, the method  210  includes providing, at step  212 , a sound damping wallboard  10  having a gypsum layer  12 , a sound damping layer  14 , a first encasing layer  20  disposed adjacent the gypsum layer  12 , and a second encasing layer  22  disposed adjacent the sound damping layer  14 . The method  210  further includes providing, at step  214 , an installed wallboard  28  attached to a building wall or ceiling and attaching, at step  216 , the sound damping wallboard  10  to the installed wallboard  28  such that the sound damping layer  14  is disposed between the gypsum layer  12  and the installed wallboard  28 . In an embodiment, the method  210  further includes removing the second encasing layer  22  from the sound damping wallboard  10  prior to installing the sound damping wallboard  10  on the installed wallboard  28 . 
     In an embodiment, the first encasing layer  20  is disposed at a gypsum layer outer surface  18  and the second encasing layer  22  is disposed at a sound damping layer inner surface  24 . The gypsum layer  12  of an embodiment has a gypsum layer thickness  30 , the installed wallboard  28  has an installed wallboard thickness  32 , and the gypsum layer thickness  30  is less than the installed wallboard thickness  32 . According to an embodiment, the gypsum layer  12  has a gypsum layer thickness  30  that is about 5/16 inch or less, and more preferably about ¼ inch or less. The sound damping layer  14  of an embodiment is a polymer material, and more preferably an elastomer. Any structures, materials, applications, or similar details described in the present disclosure with regard to the sound damping wallboard  10  may be incorporated into one or more embodiments of the method  210 . 
     The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventors to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the scope of the invention. 
     Example 1 
     A sound damping wallboard was prepared comprising a ¼ inch gypsum layer and an Acronal® sound damping layer. A paper facing or encasing layer was disposed on either side of the sound damping wallboard and between the gypsum and sound damping layers. The sound damping wallboard was then attached or retrofit to a conventional ⅝ inch wallboard, as described above using standard gypsum wallboard fasteners. The retrofit sound damping wallboard was tested for sound transmission loss in a full scale wall test according to the ASTM E-90 standard. The results were compared to a control wallboard without the retrofit sound damping wallboard. The sound transmission loss in decibels (dB) was measured at various frequencies, as shown in Table 1 and  FIG. 5 . 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
             
            
               
                   
                   
               
               
                   
                   
                 Sound Transmission Loss (dB) 
               
            
           
           
               
               
               
               
               
            
               
                   
                 Frequency (Hz) 
                 Control (CW) 
                 Retrofit (SDW) 
                 Difference 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 100 
                 17 
                 22 
                 5 
               
               
                   
                 125 
                 13 
                 19 
                 6 
               
               
                   
                 160 
                 13 
                 15 
                 2 
               
               
                   
                 200 
                 17 
                 22 
                 5 
               
               
                   
                 250 
                 23 
                 27 
                 4 
               
               
                   
                 315 
                 23 
                 27 
                 4 
               
               
                   
                 400 
                 29 
                 34 
                 5 
               
               
                   
                 500 
                 32 
                 35 
                 3 
               
               
                   
                 630 
                 34 
                 37 
                 3 
               
               
                   
                 800 
                 38 
                 40 
                 2 
               
               
                   
                 1000 
                 40 
                 43 
                 3 
               
               
                   
                 1250 
                 42 
                 47 
                 5 
               
               
                   
                 1600 
                 44 
                 50 
                 6 
               
               
                   
                 2000 
                 43 
                 51 
                 8 
               
               
                   
                 2500 
                 36 
                 48 
                 12 
               
               
                   
                 3150 
                 34 
                 48 
                 14 
               
               
                   
                 4000 
                 38 
                 50 
                 12 
               
               
                   
                 5000 
                 43 
                 52 
                 9 
               
               
                   
                   
               
            
           
         
       
     
     As illustrated in the chart of  FIG. 5 , the sound damping wallboard  10  with the sound damping layer  14  provides enhanced acoustical performance in the Hertz ranges from 100 Hz to 5000 Hz. The sound transmission loss value of the sound damping wallboard  10  with sound damping layer  14 , indicated by the line SDW, is substantially higher than a sound transmission loss value of a standard, non-damping control wallboard, indicated by the line CW. In particular, the retrofit sound damping wallboard  10  with the sound damping layer  14  of the embodiment of  FIG. 5  provides improved acoustical performance, particularly in the Hertz range from 1250 Hz to 5000 Hz. 
     Example 2 
     Four test walls (Walls  1 - 4 ) utilizing different density materials were prepared and tested for acoustical performance. The walls were constructed of ⅝ inch gypsum wallboard over steel studs and insulation, and were assembled using conventional construction techniques. Except as noted, the gypsum wallboard comprised a conventional density gypsum layer and was commercially available as Gold Bond® Fire-Shield® Gypsum Board (National Gypsum Company, Charlotte, N.C.). 
     Wall  1  was constructed with a ⅝ inch gypsum wallboard on each side of the wall assembly. Wall  2  was constructed with two ⅝ inch gypsum wallboards on the first side of the wall assembly, and one ⅝ inch gypsum wallboard on the second side of the wall assembly. Wall  3  was constructed with a ⅝ inch gypsum wallboard and a ⅝ inch sound damping wallboard on the first side of the wall assembly, and one ⅝ inch gypsum wallboard on the second side of the wall assembly. The sound damping wallboard of Wall  3  comprised an Acronal® sound damping layer sandwiched between two ¼ inch gypsum boards having higher density gypsum layers. Wall  4  was constructed with a ⅝ inch gypsum wallboard and a ¼ inch sound damping wallboard on the first side of the wall assembly, and one ⅝ inch gypsum wallboard on the second side of the wall assembly. The sound damping wallboard of Wall  4  comprised an Acronal® sound damping layer applied to a single ¼ inch gypsum board having a higher density gypsum layer. 
     Walls  1 - 4  were tested for sound transmission loss in a full scale wall test according to the ASTM E-90 standard. The sound transmission loss in decibels (dB) was measured at various frequencies, as shown in Table 2 and  FIG. 6 . As shown in  FIG. 6 , the retrofit addition of a sound damping wallboard (Walls  3 ,  4 ) was found to provide significant improvement in sound transmission loss over conventional construction Wall ( 1 ) or the use of two conventional wallboard panels (Wall  2 ). Furthermore, the sound damping wallboards comprising two gypsum boards (Wall  3 ) and only one gypsum board (Wall  4 ) were found to fall within the same STC rating. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                   
                 Sound Transmission Loss (dB) 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 Frequency (Hz) 
                 Wall 1 
                 Wall 2  
                 Wall 3 
                 Wall 4 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 100 
                 — 
                 — 
                 20 
                 26 
               
               
                   
                 125 
                 20 
                 26 
                 28 
                 30 
               
               
                   
                 160 
                 27 
                 33 
                 33 
                 33 
               
               
                   
                 200 
                 33 
                 38 
                 38 
                 38 
               
               
                   
                 250 
                 38 
                 40 
                 43 
                 43 
               
               
                   
                 315 
                 41 
                 45 
                 50 
                 46 
               
               
                   
                 400 
                 48 
                 50 
                 53 
                 51 
               
               
                   
                 500 
                 49 
                 52 
                 56 
                 54 
               
               
                   
                 630 
                 52 
                 53 
                 59 
                 57 
               
               
                   
                 800 
                 52 
                 55 
                 60 
                 59 
               
               
                   
                 1000 
                 52 
                 54 
                 61 
                 59 
               
               
                   
                 1250 
                 55 
                 57 
                 63 
                 59 
               
               
                   
                 1600 
                 55 
                 57 
                 64 
                 58 
               
               
                   
                 2000 
                 47 
                 50 
                 59 
                 54 
               
               
                   
                 2500 
                 40 
                 46 
                 56 
                 52 
               
               
                   
                 3150 
                 43 
                 48 
                 60 
                 56 
               
               
                   
                 4000 
                 47 
                 52 
                 62 
                 60 
               
               
                   
                   
               
            
           
         
       
     
     The sound damping wallboard  10  according to an embodiment of the present disclosure improves the acoustical performance of an existing, installed, or otherwise established wallboard, wall panel, ceiling panel, or similar structural boundary or surface. Such existing, installed, or otherwise established wall or ceiling structures comprise materials that may include, as non-limiting examples, gypsum, stone, ceramic, wood, composite, or metal materials. One of ordinary skill will recognize the sound damping benefit and applicability of the sound damping wallboard and methods of the present disclosure to the many structures and materials used to form wall and ceiling structures. 
     The sound damping wallboard  10  according to an embodiment of the present disclosure is sufficiently thin to allow its installation onto a wall or ceiling without substantially increasing an overall wall or ceiling thickness. Further, the sound damping wallboard  10  of the present disclosure is sufficiently thin to avoid significant modifications to installed wall and ceiling objects, such as existing wall or ceiling outlets, switches, or ceiling fixtures, thereby reducing the time, labor, and materials needed to improve existing walls and ceilings by renovating or retrofitting the walls or ceilings with sound damping material. 
     While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the present disclosure. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this disclosure.