Patent Publication Number: US-2006000670-A1

Title: Prefabricated sound attenuating wall system

Description:
FIELD OF THE INVENTION  
      The invention relates to the construction of sound attenuating building barriers such as walls, partitions and the like, which are partially prefabricated in a factory, and are deliverable to a construction site in sections ready for installation.  
     BACKGROUND OF THE INVENTION  
      In the construction of building elements such as walls, floors, ceilings, partitions, herein, and the like, it is well known that sound tends to travel relatively easily through partitions, when made of conventional construction. This can create problems both in commercial and industrial and also in residential construction. In residential construction it is particularly troublesome in the construction of semi-detached or row houses and in the construction of condominiums. It is also troublesome in commercial buildings where complete privacy maybe required in a particular space, for example, a medical office, a private meeting room, or the like.  
      In the past, efforts have been made to reduce the sound transmission through partitions and building fabric by the use of sound attenuating batting, and a variety of other materials have been proposed.  
      Where cost was unimportant, soundproofing to a large extent has been achieved in the past, but, only by the use of expensive construction techniques and costly materials. Poured concrete, concrete block walls, and even layers of lead sheeting incorporated in partitions, have been used. The general principle and intent behind these more costly techniques was that provided the partition was thick enough, it would be substantially soundproof. These solutions, however, were not practical particularly in residential construction and of course, in most commercial construction. For example, in residential construction, there are practical limits on the thickness of the partition that can be used, without reducing the size of the room. In commercial office construction, and in highrise buildings, there are restrictions on the load which can be placed on the floor of a building. For these reasons generally speaking, and especially in condominiums and in commercial highrise construction, partitions in buildings are made as thin and as light as possible, so as to reduce the floor loading. Only very limited privacy can be achieved using these lightweight construction techniques.  
      Clearly there is a need for a sound attenuation construction for building elements such as partitions, which is both cost effective, relatively lightweight and “space effective”, i.e. it can be installed without causing any noticeable reduction in the space available. It must also be such that it can use readily available material, and that it can be put up by conventionally trained construction labour, using conventional tools, with a minimum of special training.  
      A sound attenuating partition is described in Canadian Patent Application No. 2,157,659 Filed Jun. 13, 1995, which discloses significant advantages. However, it was designed to be constructed on site and required a number of construction frames and layers each of which was built on site, using costly construction labour and time.  
      It is apparent that if the partition can be at least partly preassembled in a factory and delivered to a job site ready for installation, there will be significant savings. Prefabrication of sound attenuating partitions would provide several benefits to an employer. There would be less labour costs on site for construction of the walls or partitions, and there would not be a need for specially skilled workers on site, thus reducing skilled labour costs. Use of prefabricated partitions would allow faster completion times on any particular construction project, thus enabling the contractor to schedule more contracts and increase productivity and profits.  
      Prefabrication or partial prefabrication of sound attenuating walls or partitions in a factory, allows for higher quality control of the end product and in a faster mass production of the product which then lowers the production cost of each unit.  
     BRIEF SUMMARY OF THE INVENTION  
      The invention seek to provide the foregoing improvements by the use of a partially prefabricated sound attenuating partition construction, and other sound attenuating structures. The sound attenuation partition comprises two separate spaced apart prefabricated panel assemblies defining opposite sides of the partition, with a hollow interior. The panel assemblies are received in respective pairs of upper and lower generally L-shaped receivers mounted to the building fabric, to receive the respective panel assemblies therein. Sound attenuating sheets of a flexible material are incorporated in one of the panel assemblies. The sound attenuating sheet is loosely attached to its panel assembly, for maximum effect. The other partially prefabricated panel assemblies preferably includes a sound attenuation acoustical batting insulation mounted within the hollow interior. When installed there is a predetermined airspace between said acoustical batting insulation and said sound attenuating sheet. 
    
    
     IN THE DRAWINGS  
       FIG. 1  is a perspective partially cut away illustration of a partition wall illustrating the invention;  
       FIG. 2  is a section along line  2 - 2  of  FIG. 1 ;  
       FIG. 3  is a section along the line  3 - 3  of  FIG. 2 , shown partially assembled;  
       FIG. 4  is a front elevation of a panel assembly, partially cut away. 
    
    
     DESCRIPTION OF A SPECIFIC EMBODIMENT  
      Referring to  FIG. 1 , it will be seen that the invention is there illustrated in the form of a partition construction for use in a building having walls ( 10 ), a ceiling ( 12 ) and a floor ( 14 ). The invention illustrated herein is not confined to walls either interior or exterior, but is of application to any vertical or substantially vertical construction elements or barriers where it is desired to produce substantial sound attenuation. With some modifications it may also be used in floors and ceilings.  
      As illustrated in  FIG. 1 , the invention is illustrated as a partition, in this case a wall, and comprises a first sound attenuation panel assembly ( 20 ) and a second sound attenuation panel assembly ( 22 ). Each of the first and second sound attenuating panel assemblies ( 20 ) and ( 22 ) has an interior side ( 24 ) and an exterior side ( 26 ). The first panel assembly ( 20 ), as illustrated in the present embodiment of the invention, comprises two rectangular panels ( 30 ) and ( 32 ) of material, in this case gypsum drywall panelling. The two panels ( 30 ), ( 32 ) are preassembled and framed by a vertical side channels ( 34 ) which encompasses the vertical edges of the two panels ( 30 ,  32 ).  
      The panels ( 30 ) and ( 32 ) are of a width typically of about two feet and are offset from one another, so that the edge of one panel projects beyond the edge of the other panel. The channel ( 34 ) is shaped with two side walls ( 36 ) and a generally dog leg wall ( 38 ) ( FIG. 3 ). In this way the two panels ( 30 ) and ( 32 ) and the channels ( 34 ) provide vertical edges of generally zig-zag shape in section, which are of a type known as “shiplath”. When assembled edge to edge ( FIG. 3 ) the zig-zag formations of the channels ( 34 ) overlap and provide an effective sound barrier.  
      The overlapping of the channels ( 34 ) also provide what is in effect a form of composite vertical stud, between the pairs of panels ( 30 ) and ( 32 ), holding the panels ( 30 ) and ( 32 ) at intervals, in this case two foot intervals.  
      The panels ( 30 ) and ( 32 ) along their upper and lower edges, have no need of such channels for reasons to be described.  
      First panel assembly ( 20 ) further comprises a curtain sheet of sound attenuation material ( 40 ).  
      Curtain sheet ( 40 ) is a form of rubberised sheet material having the ability to provide substantial attenuation of sound waves. Curtain sheet ( 40 ) is held in position by channel walls ( 36 ) along opposite side edges of panels ( 30 ,  32 ). This places such sound attenuation curtain sheets ( 40 ) on the inwardly facing surfaces of the first panel assembly ( 20 ).  
      The curtain sheets ( 40 ) are secured only along their respective vertical edges, and are otherwise free of attachment to panel ( 32 ). This renders such curtain sheets ( 40 ) somewhat loose and flexible, which enhances their ability to attenuate sound waves.  
      The second panel assembly ( 22 ) also comprise two rectangular panels ( 42 ) and ( 44 ) of wallboard material, held together along their vertical side edges by channels ( 46 ), similar to channels ( 34 ).  
      Panels ( 42 ) and ( 44 ) are offset from one another and, with the channels ( 46 ) they provide a zig-zag shape in section. In this way when placed edge to edge the panel assemblies ( 22 ) abut to form a “ship lath” type of joint.  
      The two channels ( 46 ) which abut in each such joint provide a form of stud for supporting the panel assemblies ( 22 ), as described above.  
      A piece of batting material ( 48 ), having sound attenuation properties, is secured on the inwardly facing surface of panel ( 44 ) of second panel assembly ( 22 ).  
      Batting ( 48 ) is cut somewhat short at the top and bottom, for reasons to be described.  
      In order to form the first and second panel assemblies ( 20 ,  22 ) into a composite partition, generally L shaped mounting receiver strips ( 50  are provided. Receiver strips ( 50 ) are typically steel roll formed sections, of a thickness adequate to hold the panel assemblies at the top and bottom thereof in position.  
      Receiver strips ( 50 ) are secured to the floor and ceiling respectively, along the line of the partition in two parallel spaced apart lines. The strips ( 50 ) are mounted so that they are open outwardly to opposite sides of the eventual partition.  
      To erect the actual partition the first panel assembly ( 20 ) is cut to the height spacing between upper and lower L shaped receiver strips ( 50 ) and is then placed in position between them, resting along its upper and lower edges on the L shaped receiver strips ( 50 ). Dry wall screws (not shown) fasten the first panel assembly  20 ) at top and bottom to the L shaped receiver strip ( 50 ).  
      Further such first panel assemblies ( 20 ) are then placed side by side, in side in edge to edge abutting relation. The channels ( 34 ) interfit in a shiplath fashion to provide joints between the first panel assemblies ( 20 ) of great strength.  
      The adjacent channels ( 34 ) are then secured together by dry wall screws (not shown). In this way each pair of adjacent interfitted channels ( 34 ) and ( 34 ) form composite studs, at two foot centres, giving great structural strength to the partition system.  
      When erected in this way the sound attenuating curtain sheet ( 40 ) of each first panel assembly ( 20 ) faces inwards and will not be visible from the exterior of the partition. In order to cover the junction line between two adjacent channels ( 34 ), a further strip ( 52 ) of sound attenuating sheet material is fastened by adhesive to each pair of adjacent first panel assemblies ( 20 ). Such strip ( 52 ) reaches from top to bottom, and is of a width sufficient to overlap each channel ( 34 ) by a margin sufficient to permit adhesive bonding to the underlying sound attenuating sheets ( 40 ) on each first panel assembly ( 20 ).  
      An optional addition might be the addition of horizontal strips (not shown) of sound attenuating material along the top and bottom of the first panel assemblies. In practice however this has not been found to be needed in most cases.  
      Once this has been completed, the second panel assemblies ( 22 ) are then erected.  
      This is done in essentially the same way as for the first panel assembly ( 20 ).  
      The second panel assembly ( 22 ) is cut to fit the height spacing betweem upper and lower L-shaped strips ( 50 ). As explained above the batting ( 48 ) has already been cut short at the top and bottom. The second panel assembly ( 22 ) is then placed in position between the top and bottom L-shaped strips ( 50 ). It is fastened in position by dry wall screws (not shown) to the L-shaped strip ( 50 ).  
      Further such second panel assemblies ( 22 ) and then placed in edge abutting side edge to side edge relation. The adjacent channels ( 46 ) overlaps and are fastened together by dry wall screws (Not shown).  
      The exterior of the entire partition is then covered in, preferably on both sides, by further sheets of dry wall panelling ( 54 ).  
      Such further sheets are applied in transverse horizontal fashion, so as to enable such sheets ( 54 ) to be screwed with dry wall screws (not shown) to the channels ( 34 ,  46 ) holding the first panel assemblies ( 20 ) and the second panel assemblies ( 22 ). The usual wall finishing steps of taping and patching and filling can then be completed.  
      The foregoing is a description of a preferred embodiment of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims.