Patent Publication Number: US-11643810-B2

Title: Loose-fill insulated building structures and methods for making them

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority of U.S. Provisional Patent Application No. 63/064,964, filed Aug. 13, 2020, which is hereby incorporated herein by reference in its entirety. 
    
    
     1. FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to systems and methods for supporting loose-fill insulation, such as blown-in insulation, to reduce settling thereof. 
     2. TECHNICAL BACKGROUND 
     Insulation materials such as fiberglass batts, rolls, blankets, or blown-in insulation are typically used to reduce the rate of heat transfer between two areas separated by a boundary. For example, in an attic, insulation material can be applied to the interior surface of the roof deck to slow the transfer of heat through the roof deck, that is, from the exterior of the house to the attic or vice versa. In another application, insulation material is applied to exterior walls (e.g., between wood studs) and covered with wallboards to slow the rate of heat transfer through the exterior wall and the wallboard. Insulation material can also prevent undesirable air movement (e.g., convection drafts) and resultant movement of moisture from one space to another. 
     Some of these forms of insulation, such as blown-in insulation, use a loose-fill material to fill the wall cavities. This loose-fill insulation can be quickly installed in walls and ceilings, and can be installed into wall cavities through small holes in the wall. However, over time the weight of the loose-fill insulation can cause the insulation to compress and settle. This settling can result in there being different amounts of insulation in various parts of the wall. In some cases, the settling could be severe enough to cause voids or gaps between the outside and inside surfaces of the cavity, where there would be no insulation present at all. But even in cases where no actual voids or gaps are present, reduced amounts of insulation in certain parts of a wall can cause undesirable heat loss through the wall. 
     Accordingly, what are needed are improved methods and systems for supporting loose-fill insulation. 
     SUMMARY OF THE DISCLOSURE 
     One aspect of the disclosure is an insulated building structure, the insulated building structure including
         a longitudinally-extending cavity bound by a first lateral surface, a second lateral surface, a back surface and a front surface, the cavity having a cross-sectional area in a plane normal to a longitudinal axis of the cavity;   one or more shelves extending into the cavity, each having an occluded area in the plane that is less than the cross-sectional area of the cavity; and   loose-fill insulation disposed in the cavity, loose-fill insulation being positioned above and below each of the shelves.       

     In certain such embodiments, the building structure includes
         a first stud defining the first lateral surface of the cavity;   a second stud spaced laterally from the first stud, the second stud defining the second lateral surface of the cavity;   a back panel extending between a back side of the first stud and a back side of the second stud, the back panel defining the back surface of the cavity;   a front panel extending between a front side of the first stud and a front side of the second stud, the front panel defining the front surface of the cavity.       

     Another aspect of the disclosure is a method for insulating a building structure, the method comprising:
         providing a building structure comprising:
           a longitudinally-extending cavity bound by a first lateral surface, a second lateral surface, a back surface and a front surface, the cavity having a cross-sectional area in a plane normal to a longitudinal axis of the cavity;   one or more shelves extending into the cavity, each having an occluded area in the plane that is less than the cross-sectional area of the cavity; and   
           disposing loose-fill insulation in the cavity such that loose-fill insulation is positioned above and below each of the shelves.       

     Additional aspects of the disclosure will be evident from the disclosure herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the methods and devices of the disclosure, and are incorporated in and constitute a part of this specification. The drawings are not necessarily to scale, and sizes of various elements may be distorted for clarity. The drawings illustrate one or more embodiment(s) of the disclosure and together with the description serve to explain the principles and operation of the disclosure. 
         FIG.  1    is a schematic front partial view of a prior art insulated wall. 
         FIG.  2    is a schematic cross-sectional view of an insulated wall, according to one embodiment of the disclosure. 
         FIG.  3    is a schematic cross-sectional view of an insulated wall, according to an alternative embodiment of the disclosure. 
         FIG.  4    is a schematic cross-sectional view of an insulated wall, according to another alternative embodiment of the disclosure. 
         FIG.  5    is a schematic cross-sectional view of a method for insulating a wall, according to one embodiment of the disclosure. 
         FIG.  6    is a schematic cross-sectional view of a wall having shelves for supporting insulation, according to another alternative embodiment of the disclosure. 
         FIG.  7    is a schematic cross-sectional view of a wall having shelves for supporting insulation, according to another alternative embodiment of the disclosure. 
         FIG.  8    is a schematic cross-sectional view of a wall having shelves for supporting insulation, according to another alternative embodiment of the disclosure. 
         FIG.  9    is a graph of apparent thermal conductivity versus density of several thermal insulations used as building insulation. 
     
    
    
     DETAILED DESCRIPTION 
     As noted above, the present inventors have noted certain disadvantages of existing processes for insulating building structures such as walls and sloped ceilings and roofs. 
     Accordingly, one aspect of the disclosure is an insulated building structure. Such a structure will often take the form of a wall as described with respect to the Figures below, but the person of ordinary skill in the art will appreciate that other uses are possible, such as in sloped ceilings or roofs. In fact, the methods and structures described herein can be used with respect to cavity structures having portions extending in any desired plane, e.g., a vertical plane, a horizontal plane, or an inclined direction. The insulated building structure includes a longitudinally-extending cavity bound by a first lateral surface, a second lateral surface, a back surface and a front surface, the cavity having a cross-sectional area in a plane normal to a longitudinal axis of the cavity; and one or more shelves extending into the cavity, each having an occluded area in the plane that is less than the cross-sectional area of the cavity. Disposed in the cavity is loose-fill insulation, positioned both above and below each of the shelves. 
     In one typical construction, the insulated building structure includes a first stud defining the first lateral surface of the cavity; a second stud spaced laterally from the first stud, the second stud defining the second lateral surface of the cavity; a back panel extending between back sides of the first and second studs, the back panel defining the back surface of the cavity; and a front panel extending between front sides of the first and second studs, the front panel defining the front surface of the cavity, such that the two studs and two panels define the cavity therebetween. The longitudinal axis of the first stud defines the longitudinal axis of the cavity. The one or more shelves disposed in the cavity are positioned between the first stud and the second stud. As used herein, the term “stud” encompasses other substantially linear framing members, including joists. 
     Another aspect of the disclosure is a method for insulating building cavity, e.g., a wall cavity. The method comprises providing a structure as described herein (i.e., including a cavity with one or more shelves extending therein), and applying loose-fill insulation in the cavity, such that each of the one or more shelves has insulation disposed above it and below it. 
     When compared to other systems for insulating a building cavity with loose-fill insulation, the disclosed systems and methods can be advantaged in that, in certain embodiments, the shelf or shelves support at least part of the weight of the insulation. As such, the weight supported by the shelf does not act upon the insulation positioned below the shelf, thus reducing the compression and settling of the insulation over time. 
     When compared to other systems for insulating a building cavity with loose-fill insulation, the disclosed systems and methods can provide an advantage that, in certain embodiments, the shelf or shelves provide additional surface area to bear the weight of the loose-fill insulation, and thus allow for a more uniform distribution of insulation throughout the structure. The additional surface area provides greater opportunities for fiction between the fibers of the insulation and the shelves and other cavity surfaces, and such friction will reduce the compression or settling of the insulating material over time. 
     Settling of insulation may occur from vibrations that the cavities may experience at any point in their life of use. This could occur during the process of installation of the insulation into the cavity, after the cavity experiences a shock (due to earthquake, or other seismic event), or from transport of pre-filled cavities from location of manufacture to location of end use. Even the change of orientation of cavities or cavity elements that may be filled while assembled prone in a manufacturing environment to a vertical location for assembly into a larger structure could cause settlement to occur. 
     Notably, the sizes and arrangements of the one or more shelves can be selected by the person of ordinary skill in the art to allow for insulation to be blown past them during installation. In certain embodiments, each of the shelves has a first end adjacent to a first surface defining the cavity and a second end distal the first surface and spaced from a second surface defining the cavity, the second surface being opposite the first surface. For example, in certain embodiments as otherwise described herein, one or more or the shelves has a first end adjacent the first lateral surface of the cavity and a second end distal the first lateral surface of the cavity and spaced from the second lateral surface of the cavity. In certain embodiments as otherwise described herein, one or more of the shelves has a first end adjacent the second lateral surface of the cavity and a second end distal the second lateral surface of the cavity and spaced from the first lateral surface of the cavity. In certain embodiments as otherwise described herein, one or more of the shelves has a first end adjacent the front surface of the cavity and a second end distal the front surface of the cavity and spaced from the back lateral surface of the cavity. In certain embodiments as otherwise described herein, one or more or the shelves has a first end adjacent the back surface of the cavity and a second end distal the back surface of the cavity and spaced from the front surface of the cavity. 
     In certain embodiments as otherwise described herein, one or more of the shelves (e.g., each of the shelves) is oblique to the plane, with a major top surface thereof being higher at its second end higher than at its first end. The angle of a major top surface of the shelf to the plane can range, for example, up to 45 degrees, e.g., up to 30 degrees, or in the range of 5-45 degrees, or 15-45 degrees, or 5-30 degrees. 
     In many cases, a plurality of shelves will be present in the cavity, e.g., at least four shelves, at least six shelves or even at least twelve shelves. 
     Referring now to the drawings,  FIG.  1    is a front view of a portion of an example of a conventional wall  10  having loose-fill insulation  20  disposed in a cavity thereof. The wall  10  includes studs  12 A,  12 B, and  12 C each having a height of H. In the embodiment of  FIG.  1   , a top plate  11  extends along the top ends of the studs  12 A,  12 B, and  12 C. A sill plate or bottom plate  13  extends along the bottom ends of the studs  12 A,  12 B, and  12 C. The wall  10  further includes a back panel  17  extending between back sides of the studs  12 A,  12 B, and  12 C. The wall  10  further includes a front panel (not shown) extending along the front sides of the studs  12 A,  12 B, and  12 C. The studs and panels, define cavities  14 A (between studs  12 A and  12 B) and  14 B (between studs  12 B and  12 C), here also defined vertically by the plates. 
     The person of ordinary skill in the art will appreciate that the materials of the structures described herein can vary. Studs can be formed of, for example, wood or metal. The front panel and back panel can be formed of the same material or different materials. Each can be formed of a material that serves as the outer surface of the structure, such as wallboard, lath and plaster, or sheathing (e.g., gypsum board, oriented strand board (OSB), fiberboard, plywood, foam boards, brick, masonry, unitary block, stone, or other common construction materials). But the person of ordinary skill in the art will appreciate that insulation is often blown into a building cavity before the cavity is closed off with its ultimate surface material. In such cases, a sheet of flexible material. e.g., fabric, mesh, or plastic sheeting, acts as the front panel closing off the cavity for the purpose of blowing in the loose-fill insulation. An opening can be provided in such a sheet to allow access of a tube to the cavity for blowing in of the insulation. This sheet can later be covered by a surface material such as wallboard, lath and plaster, or sheathing. In certain embodiments as otherwise described herein, the back surface defining the cavity is provided by wallboard, lath and plaster, or sheathing, and the front panel defining the cavity is provided by a sheet of flexible material such as a fabric, mesh, or plastic sheet. 
     In the embodiment of  FIG.  1   , the cavities  14 A,  14 B are the same height H as the studs  12 A,  12 B,  12 C. The cavities  14 A,  14 B each have a width W equal to the distance between the two studs. For example, if the studs  12 A,  12 B,  12 C are standard two-by studs spaced according to a Sixteen Inch on Center pattern, the width W is approximately 14.5 inches. Similarly, if the studs  12 A,  12 B,  12 C are standard two-by studs spaced according to a Twenty-four Inch on Center pattern, the width W is approximately 22.5 inches. But these are just examples, and the person of ordinary skill in the art will appreciate that other widths W are contemplated herein. The cavities  14 A,  14 B have a depth D approximately equal to the depth of the studs  12 A,  12 B,  12 C. For example, the depth D is approximately 3.5 inches for 2×4 studs, approximately 5.5 inches for 2×6 studs, and approximately 7.25 inches for 2×8 studs. As above, other depths are contemplated herein. 
     Accordingly, the cavities  14 A.  14 B each have a cross-section area in a plane normal to the longitudinal axis L of the first stud  12 A, e.g., the horizontal plane for vertical walls, of W×D. 
     As shown, the cavities  14 A,  14 B each contain loose-fill insulation  20 . However, the loose-fill insulation  20  has compressed and settled, leaving a voids  21  proximate the top of the cavities  14 A,  14 B. 
     Turning to  FIG.  2   , a system  100  for insulating a building cavity is shown. The system  100  includes studs  112 A,  112 B,  112 C, a top plate  111 , and a bottom plate  113  substantially similar to those shown in  FIG.  1    and described above. The system  100  further includes a back panel  117  and front panel  116  (see  FIG.  5   ) substantially similar to those described above. The studs  112 A,  112 B,  112 C, panels, and plates  111 ,  113  define cavities  114 A,  114 B. The cavities  114 A,  114 B each have a height of H, a width of W, and a depth of D (see  FIG.  1   ). Accordingly, the cavities each have a cross-sectional area in a plane normal to the longitudinal axis L of the first stud  112 A equal to W×D. 
     In the embodiments depicted herein, the system  100  forms a vertical wall  101 , and therefore the plane is the horizontal plane. However, it is to be understood that the system described can be used for ceilings and roofs, such as sloped ceilings, in which the studs  112 A,  112 B,  112 C are the ceiling joists. In certain embodiments as otherwise described herein, the cavity extends longitudinally (e.g., the studs are disposed) at an angle that is no more than 60 degrees from vertical, e.g., no more than 45 degrees from vertical. In certain embodiments as otherwise described herein, the cavity extends longitudinally (e.g., the studs are disposed) at an angle that is no more than 30 degrees from vertical. e.g., no more than 15 degrees from vertical. In certain embodiments, the cavity extends longitudinally (e.g., the studs are disposed) at an angle that is no more than 5 degrees from vertical. The systems described herein are especially advantageous with cavities that extend substantially vertically, as it is in such cavities that settling of loose-fill insulation is more of an issue. 
     The system  100  of  FIG.  2    further includes a plurality of shelves  130 A-C positioned in each cavity  114 A,  114 B. In this embodiment, each of the shelves  130 A-C is substantially similar. Shelf  130 A is discussed in greater detail below as an illustrative example. 
     The shelf  130 A of the embodiment of  FIG.  2    includes a first end  131  and a second end  132 . The first end is adjacent to a surface  118  defining one edge of the cavity  114 A. In the shown embodiment, the surface  118  adjacent to the first end  131  of the shelf  130 A is the first stud  112 A. In some forms, the first end  131  is coupled to the stud  112 A. The second end  132  is opposite the first end  131  and distal from the surface adjacent thereto (e.g., the first stud  112 A). In a preferred form, the shelf is oblique to the plane normal to the axis L, such that the second end  132  of the shelf  130 A is higher than the first end  131 . Accordingly, the weight of the first portion  120 A of insulation, the insulation located above the first shelf  130 A, partially acts to hold the portion of insulation  120 A towards the first stud  112 A. 
     The shelf  130 A has a depth of D or less. As shown, the shelf has a width W 2  that is less than the width W of the cavity  114 A. Accordingly, the shelf  130 A has an occluded area in the plane normal to L that is less than W×D. 
     The second end  132  of the shelf  130 A is spaced from surface  119  opposite the surface  118 . There is an opening  133 A proximate the second end  132  of the shelf  130 A through which insulation can flow from above the shelf  130 A to below the shelf  130 A. In operation, insulation is blown into the cavity  120 A from a single point. The point of installation may be a hole in the wall or in a film or blanket defining the front surface of the cavity. Alternatively, the point of installation may be the top of the wall through the top plate  111 . During installation, insulation passes through the openings  133 A,  133 B,  133 C so as to fill each section  115 A,  115 B.  115 C of the cavity  114 A. After installation, the insulation is partially divided into sections  120 A,  120 B,  120 C,  120 D by the shelves  130 A,  130 B,  130 C. The shelves  130 A,  130 B,  130 C partially support the weight of the section of insulation  120 A,  120 B,  120 C located above the shelf. This reduces the amount of pressure acting to compress the insulation located below the respective shelves. 
       FIG.  3    illustrates a system  200  having an alternative arrangement of shelves  230 A,  230 B,  230 C. The odd shelves  230 A,  230 C are substantially similar to the corresponding shelves  130 A,  13 C shown in  FIG.  2    and discussed above. The even shelves  230 B are mirrored compared to the corresponding shelves  130 A shown above. 
     The system  200  includes a first shelf  230 A having a first end  231  coupled to the first stud  112 A. The first shelf  230 A extends into the cavity  114 A towards the second stud  112 B. There is an opening  233 A between the second end  232  of the first shelf  230 A and the second stud  112 B. 
     The system further includes a second shelf  230 B having a first end  231  coupled to the second stud  112 B. The second shelf  230 B extends into the cavity  114 A towards the first stud  112 A. There is an opening  233 B between the second end  232  of the second shelf  230 B and the first stud  112 A. 
     As shown, the first opening  233 A and the second opening  233 B are laterally offset from each other. Accordingly, insulation directly above the first opening  233 A is at least partially supported by the second shelf  230 B. Similarly, insulation directly above the second opening  233 B is at least partially supported by a third shelf. Offsetting the openings  233 A-C in this manner reduces the amount of force acting to compress the insulation in line with the openings  233 A-C. 
     While the illustrated example shows three shelves  230 A-C in each cavity  114 A,  114 B, it is understood that the embodiment is not limited to three shelves. The system  200  includes two or more shelves in an alternating arrangement spaced along the height H of the cavity  114 A. 
       FIG.  4    illustrates a system  300  having another arrangement of shelves  330 A- 330 F. As shown, the shelves are arranged in pairs  330 A-B,  330 C-D,  330 E-F. Each pair of shelves are substantially level with each other, being installed at common locations along the height H of the cavity  114 A. In this embodiment, the pairs of shelves are installed so that their angles mirror each other; however, the person of ordinary skill in the art will appreciate that other arrangements are possible. The shelves  330 A-F divide the insulation into sections  320 A-D. 
     Shelf  330 A has a first end  331  adjacent to a first surface  118 . In the shown embodiment, the first surface  118  is the first stud  112 A. The shelf  330 A has a second end  332  distal from the first surface  118 . The second shelf  330 B has a first end  331  adjacent to a second surface  119  opposite the first surface  118 . In the shown embodiment, the second surface  119  is the second stud  112 B. The second shelf  330 B has a second end  332  distal from the second surface  19 . The second ends  332  of the two shelves  330 A-B are spaced apart from each other, defining an opening  333 A therebetween. As discussed above, the opening  333 A enables insulation to flow between sections  115 A,  115 B of the cavity  114 A during installation. 
     The remaining pairs  330 C-D,  330 E-F are substantially similar to the pair  330 A-B described above. In the shown form, the openings  333 A-C are aligned. However, it is understood that the lengths of the shelves  330 A-F could be adjusted to offset the openings for the reasons discussed above. 
     As shown, the shelf  330 A has a shorter width W 3  than the shelf  130 A of the embodiment of  FIG.  2   . Shortening the shelf  330 A in this manner reduces the amount of torque on the joint between the first end  331  of the shelf  330 A and the first surface  118 . The torque can further be reduced by attaching the second ends  332  of the pair of shelves  330 A-B by a plate located at the front and/or back thereof. 
     Each of the embodiments above illustrate systems in which the shelves are adjacent to a first stud  112 A and spaced from a second stud  112 B, thus leaving an opening between the shelf and the second stud  112 B through which insulation can flow. However, a similar affect can be achieved by having shelves expanding the entire width of the cavity  114 A that is adjacent to one of the back panel and the front panel and spaced from the other of the back panel and the front panel. Such arrangement are shown in  FIG.  5    and discussed below. 
       FIG.  5    illustrates a system  400 .  FIG.  5    is a cross section of a cavity  114 A showing the top plate  111 , bottom plate  113 , front panel  116 , and back panel  117 . It is understood that the cavity  114 A is further defined by a first stud  112 A and second stud  112 B as shown in previous embodiments. The front panel  116  is formed of a flexible sheet, such as a blanket for securing the insulation  420  in place during installation. When the wall is completed, the front panel  116  will be replaced by or covered by a solid wall material, such as sheathing, wallboard, or lath and plaster. Alternatively, the front panel  116  may remain in place and be permanently covered by an additional solid wall material layer such as sheathing, wallboard, or lath and plaster. 
     The system  400  includes a plurality of shelves  430 A-C disposed within the cavity  114 A. The shelves  430 A- 430 C are substantially similar. The first shelf  430 A is described below as an illustrative example, 
     The shelf  430 A has first end  431  adjacent to a first surface  418  defining the cavity  114 A. In the shown form, the first surface  418  is the back panel  117 . The shelf  430 A has a second end  432  distal from the first surface  418 . The shelf  430 A is oblique to the plane normal to the axis L such that the second end  432  is higher than the first end  431 . 
     The shelf  430 A extends the entire width W of the cavity  114 A. The shelf  430 A is coupled to the first stud  112 A and the second stud  112 B. However, the shelf  430 A has a depth D 2  less than the depth D of the cavity  114 A. Accordingly, the shelf  430 A has an occluded area in the plane normal to the axis L that is less than W×D. 
     The second end  432  of the shelf  430 A is spaced from the front panel  116 , defining an opening therebetween.  FIG.  5    illustrates the installation process of the insulation  420 . As shown, a hose  401  is positioned in an aperture  402  in the front panel  116 . The end of the hose  401  is in the section  115 C of the cavity  114 A between the second shelf  430 B and third shelf  430 C. Insulation  420  is blown into the cavity  114 A from the hose  401 . The insulation  420  flows through the opening  433 A-C between the shelves  430 A-C and the front panel  116  to fill each section  115 A-D of the cavity  114 A. As in previous embodiments, each shelf  430 A-C at least partially supports the weight of the section  420 A-C of insulation positioned thereabove. 
     While the shelves  430 A- 430 C are each adjacent to the same surface  418 , it is understood that other embodiments similar to those discussed above are considered herein. For example, the even shelves  430 B can be mirrored to be adjacent to the opposite surface  419  so as to offset the openings  433 A-C as in  FIG.  3   . Alternatively, the shelves  430 A-C can be arranged in pairs as shown in  FIG.  4   . 
     In other embodiments the shelves can project from the back panel without contacting the studs. In such cases the shelves can be affixed to the back panel and extend forward towards the front panel. In certain such embodiments, the shelves extend a distance that is less than W to serve to segment the cavity into zones where insulation can build up, but still have areas that allow the insulation to be distributed to other zones within the cavity. 
     For example, in the various embodiments shown in  FIGS.  6 - 8   , the shelves are not connected to any of the studs  112 A-C. Turning first to  FIG.  6   , the system  500  has a plurality of shelves  530 A-D. The shelves  530 A-D are coupled to the back panel  117 . 
     Shelf  530 A is located between studs  112 A and  112 B. Shelf  530 A is spaced from both studs  112 A and  112 B. Shelf  530 B is horizontally spaced from shelf  530 A and also located between studs  112 A and  112 B. Shelf  530 B is spaced from both studs  112 A and  112 B. Accordingly, the cavity sections  115 B and  115 C are connected by three channels  533 A-C to aid in the installation of loose fill insulation (not shown) as described above. As shown, the shelves  530 A and  530 B are horizontal. However, shelves can also be angled such as shelves  530 C and  530 D. 
     Shelves  530 C-D are positioned between studs  112 B and  112 C. The shelves  530 C-D are horizontally spaced from each other and are each horizontally spaced from both studs  112 B and  112 C. Accordingly, the shelves  530 C-D similarly define three channels through which insulation can flow. 
     Turning to  FIG.  7   , the system  600  includes a plurality of shelves  630 A-C having an arc shape. The shelves  630 A-C are each spaced from all studs  112 A-C and are instead coupled to the back panel  117 . 
     In some forms, the shelves  630 A have an upward facing arc shape. The upward facing arc shape is configured to support insulation when the system  600  is in a vertical orientation. In alternative forms, the shelves  630 B-C have different orientations, such as one upward and one downward. The different orientations of shelves provide support for the insulation as the system  600  is turned or flipped, such as in applications within prefabricated structures as described below. 
     In some forms, the shelves  630 B-C are arranged in interlocking pairs. The first end of shelf  630 B interlocks with the second end of shelf  630 C to form a single, continuous shelf. In alternative forms, additional interlocking shelves can be in turn connected to opposite ends of shelf  630 B or  630 C to form a still longer continuous shelf. 
       FIG.  8    illustrates a system  700  having additional alternative shelf shapes. The system  700  includes stepped shelves  730 A and V-shaped shelves  730 B. The shelves  730 A- 730 B are spaced from the studs  112 A-C. The shelves  730 A- 730 B are coupled to the back panel  117 . 
     The stepped shelves  730 A have a first horizontal portion  771  and a second horizontal portion  772  connected by a vertical portion  773 . However, it is understood that the stepped shelf  730 A can be installed in alternative orientations such that the parallel sections  771  and  772  are vertical or oblique to the vertical axis. 
     The V-shaped shelves  730 B are formed of two sections  775  and  776  angled relative to each other. While each of the shown shelves  730 B are vertical, it is understood that one or more of the shelves  730 B can be rotated to provide support for insulation in different directions. 
     In each of the embodiments above, the shelves are represented by solid lines. However, shelves formed of non-solid materials are considered herein. For example, any of the shelves discussed above can be formed of mesh, slats, rods, pins, or other materials. In some forms, the shelves are formed of wood, metal, or plastic with one or more apertures therethrough. The apertures or openings in non-solid shelves enable air flow through the shelves during pneumatic filling operations. This additional air flow aids in an even distribution of insulation throughout the cavity. 
     Based on the disclosure herein, the person of ordinary skill in the art can select sizes and patterns of shelves to provide a reduced degree of insulation settling while still allowing loose-fill insulation to substantially fill the cavity in a blown-in installation process. 
     Each of the shelves has an occluded area in the plane normal to the longitudinal direction of the cavity. The occluded area is the cross-sectional area of the cavity that is blocked by the shelf. As noted above, the occluded area is less than the cross-sectional area of the cavity (i.e., in the plane normal to the longitudinal direction thereof). In certain embodiments as otherwise described herein, each shelf has an occluded area of no more than 90% of the cross-sectional area of the cavity. In certain desirable embodiments, each shelf has an occluded area of no more than 80%, no more than 70%, no more than 60%, or even no more than 50% of the cross-sectional area of the cavity. In certain embodiments as otherwise described herein, each shelf has an occluded area of at least 5% of the cross-sectional area of the cavity. In certain desirable embodiments, each shelf has an occluded area of at least 10%, at least 15%, or even at least 20% of the cross-sectional area of the cavity. For example, in various embodiments, each shelf has an occluded area in the range of 5-90%, e.g., 5-80%, or 5-70%, or 5-60%, or 5-50%, or 10-90%, or 10-80%, or 10-70%, or 10-60%, or 10-50%, or 15-90%, or 15-80%, or 15-70%, or 15-60%, or 15-50%, or 15-90%, or 20-80%, or 20-70%, or 20-60%, or 20-50% of the cross-sectional area of the cavity. The person of ordinary skill in the art will select shelf sizes together with number of shelves to provide a configuration that allows insulation to be blown in past the shelves during insulation yet provide sufficient support to the insulation after installation. 
     In certain embodiments, each of the shelves has a depth that is at least 25% of the depth of the cavity (i.e., at the position where it is disposed). For example, in certain embodiments, each of the shelves has a depth that is at least 40%, e.g., at least 50%, or at least 60% of the depth of the cavity. When a shelf does not extend the full width of the cavity (e.g., extends no more than 70%, no more than 60%, no more than 50% of the width of the cavity), it can in some embodiments extend the full depth of the cavity. In certain embodiments in which a shelf extends a substantial fraction of the full width of the cavity (e.g., at least 50%, at least 60%, or at least 70% of the width of the cavity), the shelf extends no more than 70% of the depth of the cavity, e.g., no more than 60%/o, or no more than 50% or no more than 40% of the depth of the cavity. In certain embodiments as otherwise described herein, each of the shelves has a depth in the range of 25-100% of the depth of the cavity, e.g., 25-70%/o, or 25-60%, or 25-50%, or 40-100%, or 40-70%, or 40-60%, or 50-100%, or 50-70%, or 60-100% of the depth of the cavity. 
     In certain embodiments, each of the shelves has a width that is at least 20% of the width of the cavity (i.e., at the position where it is disposed). For example, in certain embodiments, each of the shelves has a width that is at least 30%. e.g., at least 40%, or at least 50% of the width of the cavity. When a shelf does not extend the full depth of the cavity (e.g., extends no more than 70%, no more than 60%, no more than 50% of the depth of the cavity), it can in some embodiments extend the full width of the cavity. In certain embodiments in which a shelf extends a substantial fraction of the full depth of the cavity (e.g., at least 50%, at least 60%, or at least 70% of the depth of the cavity), the shelf extends no more than 70% of the width of the cavity, e.g., no more than 60%, or no more than 50% or no more than 40% of the width of the cavity. In certain embodiments as otherwise described herein, each of the shelves has a width in the range of 25-100% of the depth of the cavity, e.g., 25-70%, or 25-60%, or 25-50%, or 40-100%, or 40-70%, or 40-60%, or 50-100%, or 50-70%, or 60-100% of the width of the cavity. 
     In certain embodiments, shelves are provided in a cavity so that the average insulation height, i.e., taken as an average height of insulation (between shelves, or between a shelf and a top of the body of insulation, or between the bottom of the cavity and a shelf) in the longitudinal direction (e.g., parallel to the first stud) is no more than 4 feet. That is, averaged over the cavity, the height of the body of insulation between supporting surfaces is no more than 4 feet. For example, in certain embodiments as otherwise described herein, the average height of insulation is no more than 3 feet, e.g., no more than 2 feet. 
     In certain embodiments, shelves are positioned in the cavity so that the maximum insulation height possible in the longitudinal direction in a fully-filled cavity is no more than 4 feet. For example, in certain embodiments as otherwise described herein, the maximum possible insulation height in the longitudinal direction is no more than 3 feet, e.g., no more than 2 feet. 
     Shelves can be arranged by the person of ordinary skill in the art in a variety of fashions based on the disclosure herein. For example, in certain embodiments, shelves extend in an alternating fashion, e.g., alternating between extending from the first stud or the second stud, or alternating between extending from the front panel and the rear panel. But in other embodiments, shelves extend in the same direction throughout the cavity. e.g., from the back panel. 
     Shelves can be formed from a variety of materials, e.g., plastic, wood, fabric (e.g., supported or made rigid), cardboard, gypsum or metal. They can be affixed to studs and/or panels in a variety of manners, e.g., with nails, staples, screws, brackets, pressure sensitive adhesives or glue. 
     The disclosure also provides a method for insulating a building structure, such as a wall, ceiling or roof as described above. The method includes providing a building structure in any configuration as described above, e.g., including a first stud; a second stud spaced laterally from the first stud; a back panel extending between a back side of the first stud and a back side of the second stud; a front panel extending between a front side of the first stud and a front side of the second stud, wherein the first stud, second stud, back panel, and front panel define a cavity therebetween having a first cross-sectional area in a plane normal to a longitudinal axis of the first stud; and a first shelf disposed in the cavity, wherein the first shelf has an occluded area in the plane smaller than the first cross-section area. The method further comprises disposing loose-fill insulation in the cavity such that loose-fill insulation is positioned above and below each of the shelves. As described above, a plurality of shelves can be disposed in the cavity to provide improved support for insulation while still allowing insulation to flow around the shelves in the blowing-in process; loose-fill insulation will be disposed above and below each of the shelves. 
     The building structure itself (i.e., not including the insulation) can be as described in any of the various embodiments above. 
     The methods and structures of the disclosure can be useful in a variety of construction contexts. For example, a building structure including shelves as described herein can be provided as part of a building, then insulated by blowing in insulation. 
     The present inventors have also determined that the methods and structures described herein can be especially useful in the manufacturing of prefabricated building structures. Prefabricated structures are formed of wall and/or ceiling sections that are made offsite, such as at a factory, then later installed onsite as part of a building. Accordingly, in certain embodiments as otherwise described herein, the insulated building structure is prefabricated and is not installed as part of a building. Such an insulated building structure can be transported to a building site, then installed as part of a building. Notably, during manufacturing, transportation, and installation, the prefabricated wall may be flipped, shaken, and otherwise moved. Conveniently, prefabricated building structures can be transported horizontally. In typical prefabricated wall or ceiling sections, this can cause settling of the insulation. The shelves reduces the amount of settling of the insulation as a result of this movement. In the methods and structures described herein, the shelves can help to prevent settling of the insulation during manufacturing, transportation, and installation. 
     One method of manufacturing a structure includes assembling a wall out of a plurality of studs, a top plate, a base plate, and inner and outer sheathings, with one or more shelves, such as those shown in  FIGS.  2 - 8    above, positioned in the cavities of the wall. The wall cavity is also filled with loose-fill insulation. 
     While in methods for making a prefabricated building structure the insulation can be blown-in to an already fabricated cavity as described above, in other embodiments the insulation is dispensed in the cavity before one of the back surface and the front surface closes the cavity. This can allow for the insulation to more easily be deposited relatively uniformly throughout the cavity space, and then the front or back panel (e.g., a sheathing) can be installed to close the cavity. One advantage of such installation is that there need be no holes made in a fabric or the sheathing material. In certain embodiments, the building structure is disposed such that its longitudinally-extending direction is within 15 degrees of horizontal, e.g., within 5 degrees of horizontal when the loose-fill insulation is disposed therein 
     A variety of loose-fill insulation materials can be used in the practice of the methods and structures described herein. For example, known insulation materials include stonewool, rockwool, fiberglass, polyester, cellulose, polystyrene pellets, vermiculite and cotton. Such materials can be provided as a bindered material or in the absence of binder, and are desirably free from adhesives, liquid and moisture that promote clumping and aggregating of fibers or nodules of material. Loose-fill materials can be products made specifically for the purpose of installing into cavities, such as Insulsafe® brand insulation (available from CertainTeed LLC), or be insulation that was formerly in the form of a batt or blanket and has been shredded or cubed to reduce the size of the particles for transport into a cavity. 
     In certain embodiments as otherwise described herein, the insulation used to insulate the structure is an insulation that achieves a k-value of no more than 0.31 at a density of no less than 0.37 lbs per cubic foot, a k-value of no more than 0.29 at a density of no less than 0.6 lbs per cubic foot, a k-value of no more than 0.27 at a density of no less than 0.7 lbs per cubic foot, a k-value of no more than 0.26 at a density of no less than 0.8 lbs per cubic foot, a k-value of no more than 0.25 at a density of no less than 1.0 lbs per cubic foot, a k-value of no more than 0.24 at a density of no less than 1.2 lbs per cubic foot, and a k-value of no more than 0.23 at a density of no less than 1.3 lbs per cubic foot. 
     The person of ordinary skill in the art can use any convenient technique to dispose the loose-fill insulation. Such insulations are typically blown in through tube, e.g., through an aperture in the front panel. Notably, because the loose-fill insulation can pass along the shelves during insulation, the insulation can be introduced into the cavity in at relatively few locations (e.g., through relatively few apertures in the front panel). For example, in certain embodiments, the insulation is introduced into the cavity at three or fewer locations, e.g., three locations, or two locations, or only one location. In a contrasting example, the insulation may be deposited manually or by machine into cavities that are positioned horizontal to the normal plane, such as in a factory to make a pre-manufactured building structure, and as such care can be taken that insulation is being installed at a specific density as well as a uniform density within the cavity space, and along the surfaces of the shelves. The presence of the shelves can help to prevent settling of the insulation due to movement shipment and assembly into a building, as well as settling over time. Of course, the person of ordinary skill in the art will appreciate that other techniques can be used to put insulation into a cavity as described herein. 
     The present inventors have noted that settling of insulation can greatly affect the overall insulating value of a building structure. In the extreme case, settling can result in voids near the top of wall; when no insulation is present in part of a wall cavity, that part of the wall can allow for heat to be efficiently transmitted therethrough. But even when voids do not form, the settling may result in a variance in the density of insulation through the wall cavity.  FIG.  9    is a graph of apparent thermal conductivity versus density of several thermal insulation used as building insulation. The graph demonstrates that differences in insulation density can dramatically affect insulating quality of the insulation, especially at lower insulation densities. For example, decreasing the density of rock wool or glass fiber/fiberglass insulation from 2 pounds per cubic foot to 1 pound per cubic foot can increase the apparent thermal conductivity by more than 20%. These areas of higher thermal conductivity form thermal channels through which heat can more rapidly pass through the wall, lowering the overall U value of the structure. To protect against this, insulation is conventionally installed at a higher density than nominally required for a desired insulation value, to allow for the insulation value to remain within the specification even after some degree of settling. Use of shelves as described herein can help to reduce the variability of the insulation density, and thus can allow for use of relatively less insulation material to achieve a desired insulation value. 
     Referring to the graph of  FIG.  9   , a target insulation density is conventionally chosen along the flat part of a curve for a given material, so that a reduction in density at certain points due to settling does not cause a large increase in thermal conductivity (typically greater than 2.4 lbs per cubic foot for fiberglass insulation materials and greater than 4 pounds per cubic foot for rockwool). Accordingly, conventional insulation is dispensed at a density somewhat higher than strictly necessary, so as to insure that a desired level of thermal insulation remains even if density in certain areas of the structure is reduced due to settling. With the use of shelves as described herein to support the insulation in the cavity, the need to be at an increased density can in certain embodiments be reduced or eliminated. As such, in certain embodiments as otherwise described herein, an equivalent thermal performance density can be selected, such as 1.6 lbs per cubic foot for fiberglass insulation (a reduction of 30% as compared to conventional) or a density of 3 lbs per cubic foot for rock wool insulation (a reduction of 25% as compared to conventional) to provide a roughly equivalent thermal conductivity value or k value. While such densities are closer to the edge of a dropoff of insulation value with respect to a reduction in density, a reduction of density is far less likely as a result of the presence of the shelves. As will be understood by one of skill in the art, at similar k values (which are the inverse of R-values) a wall section can thus meet a thermal R value requirement with considerably less mass of insulation material installed. 
     In a typically wall assembly, it is desirable to achieve either an R-11, R-13, R-14 or R-15 in the space of a standard 2×4 wall stud cavity (3.5 inches of actual depth D), R-19, R-21 or R24 in a standard 2×6 wall stud cavity (5.5 inches of actual depth D), or R-29 or R-31 in a standard 2×8 wall stud cavity (7.25 inches of actual depth D). 
     Fora 2×4 wall stud cavity, an R-14 wall requires a k-value of 0.25, and an R-15 wall requires a k-value of 0.24. Being able to deliver such a k-value at closer to the target design density of 1.0 lbs per cubic foot for fiberglass insulation compared to the more typical 1.6 to 2.4 lbs per cubic foot density required to ensure that settling does not greatly affect heat conductivity occurs can reduce the use of material by anywhere from 30% to 58%. To achieve the higher k-values of 0.27 required for the R-13 wall and 0.32 required for R-11, the respective densities could be reduced to 0.7 lbs per cubic foot for R-13 and even 0.37 lbs per cubic foot for R-11. These are far lower than the typical densities that would be required in conventional cavity wall installation of loose-fill fiberglass materials—which often quote a density of 1.2 lbs per cubic foot at a minimum for a 2×4 construction. 
     The effect can become even more pronounced for thicker wall sections. In the case of an R-19 wall with a 2×6 stud cavity (5.5 inches of depth D), a k-value of 0.29 is required thermally. But if a minimum density of 1.6 lbs per cubic foot was required to provide for a degree of settling, such a wall would be over-insulated because the required density to achieve the 0.29 k-value is only 0.6 lbs per cubic foot. Being able to achieve this thermal value through use of shelves as described herein can result in a savings of 62% of the material used and still achieve the same overall R-value performance. Similarly, a density of 0.8 lbs per cubic foot could deliver the k-value of 0.26 required for the R-21 wall of 2×6 construction (5.5 inches of depth D). Finally, the R-24 wall of 2×6 construction (5.5 inches of depth D) requires a k-value of 0.23 to achieve its thermal rating—which can now be achieved at 1.3 lbs per cubic foot density rather than at 1.6 lbs per cubic foot or higher as typically prescribed (still a savings of over 18%). 
     For a 2×8 wall (7.25 inches of depth D), to achieve an R-29 a k-value of 0.25 is required. This is conventionally a recommended installation density of 1.2 lbs per cubic foot—but the desired k-value could be achieved at a 20% lower density of 1.0 lbs per cubic foot instead using shelves to prevent settling as described herein. As for an R-31 wall (k-value of 0.24), 1.2 lbs per cubic foot density could be provided when using shelves as described herein, as compared to the conventional density of 1.6 lb per cubic foot (25% savings of material). 
     As loose-fill insulation is typically sold in the form of a bag or compressed bale of material, this reduction of density means that fewer bags of insulation material would be required for insulating the same space to the same R-value as required by the appropriate local code. This reduction means a more efficient use of natural resources, fewer bags of insulation that need to be lifted and handled by the installer, and fewer bags of insulation that would need to be delivered to the jobsite for installation—providing for economic, environmental and ergonomic improvements for all. 
     Additional aspects of the disclosure are provided by the enumerated embodiments below, which can be combined in any number and in any fashion that is not technically or logically inconsistent. 
     Embodiment 1. An insulated building structure comprising: 
     
         
         
           
             a longitudinally-extending cavity bound by a first lateral surface, a second lateral surface, a back surface and a front surface, the cavity having a cross-sectional area in a plane normal to a longitudinal axis of the cavity; 
             one or more shelves extending into the cavity, each having an occluded area in the plane that is less than the cross-sectional area of the cavity; 
             loose-fill insulation disposed in the cavity, loose-fill insulation being positioned above and below each of the shelves.
 
Embodiment 2. The insulated building structure of embodiment 1, wherein the building structure comprises:
 
             a first stud defining the first lateral surface of the cavity; 
             a second stud spaced laterally from the first stud, the second stud defining the second lateral surface of the cavity; 
             a back panel extending between a back side of the first stud and a back side of the second stud, the back panel defining the back surface of the cavity; 
             a front panel extending between a front side of the first stud and a front side of the second stud, the front panel defining the front surface of the cavity.
 
Embodiment 3. The insulated building structure of embodiment 1 or embodiment 2 wherein each of the shelves has a first end adjacent to a first surface defining the cavity and a second end distal the first surface and spaced from a second surface defining the cavity, the second surface being opposite the first surface.
 
Embodiment 4. The insulated building structure of any of embodiments 1-3 wherein one or more of the shelves has a first end adjacent the first lateral surface of the cavity and a second end distal the first lateral surface of the cavity and spaced from the second lateral surface of the cavity.
 
Embodiment 5. The insulated building structure of any of embodiments 1-4 wherein one or more of the shelves has a first end adjacent the second lateral surface of the cavity and a second end distal the second lateral surface of the cavity and spaced from the first lateral surface of the cavity.
 
Embodiment 6. The insulated building structure of any of embodiments 1-5 wherein one or more of the shelves has a first end adjacent the front surface of the cavity and a second end distal the front surface of the cavity and spaced from the back lateral surface of the cavity.
 
Embodiment 7. The insulated building structure of any of embodiments 1-6 wherein one or more or the shelves has a first end adjacent the back surface of the cavity and a second end distal the back surface of the cavity and spaced from the front surface of the cavity.
 
Embodiment 8. The insulated building structure of any of embodiments 3-7 wherein one or more of the shelves (e.g., each of the shelves) is oblique to the plane such that a major top surface of the shelf is higher at its second end than at its first end.
 
Embodiment 9. The insulated building structure of embodiment 8, wherein the major top surface of each said shelf forms an angle to the plane up to 45 degrees, e.g., up to 30 degrees, or in the range of 5-45 degrees, or 15-45 degrees, or 5-30 degrees.
 
Embodiment 10. The insulated building structure of any of embodiments 1-9, comprising at least four shelves, e.g., at least six shelves or at least twelve shelves.
 
Embodiment 11. The insulated building structure of any of embodiments 1-10, wherein the one or more shelves include a first shelf and a second shelf positioned directly below the first shelf.
 
Embodiment 12. The insulated building structure of any of embodiments 1-11 wherein the one or more shelves include a first shelf and a second shelf, in which
 
             the first shelf has a first end adjacent to a first surface defining the cavity and a second end distal the first surface and spaced from a second surface opposite the first surface, and 
             wherein the second shelf has a first end adjacent to the second surface and a second end distal the second surface and spaced from the first surface.
 
Embodiment 13. The insulated building structure of embodiment 12 wherein the first surface is the first lateral surface.
 
Embodiment 14. The insulated building structure of embodiment 12 wherein the first surface is the front panel or the back panel.
 
Embodiment 15. The insulated building structure of any of embodiments 1-14, wherein the back surface defining the cavity is provided by wallboard, lath and plaster, or sheathing, and the front panel defining the cavity is provided by a sheet of flexible material such as a fabric, mesh, or plastic sheet.
 
Embodiment 16. The insulated building structure of any of embodiments 1-15, wherein the cavity extends longitudinally (e.g., the studs are disposed) at an angle that is no more than 60 degrees from vertical, e.g., no more than 45 degrees from vertical.
 
Embodiment 17. The insulated building structure of any of embodiments 1-16, wherein each of the shelves has an occluded area of no more than 90% (e.g., no more than 80%, no more than 70%, no more than 60%, or no more than 50%) of the cross-sectional area of the cavity.
 
Embodiment 18. The insulated building structure of any of embodiments 1-17, wherein each of the shelves has an occluded area of at least 5% (e.g., at least 10%, at least 15%, or at least 20%) of the cross-sectional area of the cavity.
 
Embodiment 19. The insulated building structure of any of embodiments 1-18, wherein each of the shelves has an occluded area in the range of 5-90%, e.g., 5-80%, or 5-70%, or 5-60%, or 5-50%, or 10-90%, or 10-80%, or 10-70%, or 10-60%, or 10-50%, or 15-90%, or 15-80%, or 15-70%, or 15-60%, or 15-50%, or 15-90%, or 20-80%, or 20-70%, or 20-60%, or 20-50% of the cross-sectional area of the cavity.
 
Embodiment 20. The insulated building structure of any of embodiments 1-19, wherein an average insulation height in the longitudinal direction is no more than 4 feet, e.g., no more than 3 feet, or no more than 2 feet.
 
Embodiment 21. The insulated building structure of any of embodiments 1-20, wherein a maximum possible insulation height in the longitudinal direction is no more than 4 feet, e.g., no more than 3 feet, or no more than 2 feet.
 
Embodiment 22. The insulated building structure of any of embodiments 1-21, wherein the insulated building structure is prefabricated and is not installed as part of a building.
 
Embodiment 23. The insulated building structure of any of embodiments 1-22, wherein the insulation used to insulate the structure is an insulation that achieves a k-value of no more than 0.31 at a density of no less than 0.37 lbs per cubic foot, a k-value of no more than 0.29 at a density of no less than 0.6 lbs per cubic foot, a k-value of no more than 0.27 at a density of no less than 0.7 lbs per cubic foot, a k-value of no more than 0.26 at a density of no less than 0.8 lbs per cubic foot, a k-value of no more than 0.25 at a density of no less than 1.0 lbs per cubic foot, a k-value of no more than 0.24 at a density of no less than 1.2 lbs per cubic foot, and a k-value of no more than 0.23 at a density of no less than 1.3 lbs per cubic foot.
 
Embodiment 24. A method of insulating a building cavity (e.g., to form an insulated building cavity according to any of embodiments 1-23), the method comprising:
 
             providing a building structure comprising:
           a longitudinally-extending cavity bound by a first lateral surface, a second lateral surface, a back surface and a front surface, the cavity having a cross-sectional area in a plane normal to a longitudinal axis of the cavity;   one or more shelves extending into the cavity, each having an occluded area in the plane that is less than the cross-sectional area of the cavity; and   
         
             disposing loose-fill insulation in the cavity such that loose-fill insulation is positioned above and below each of the shelves.
 
Embodiment 25. The method of embodiment 24, wherein the building structure is as described in any of embodiments 2-23.
 
Embodiment 26. The method of embodiment 24 or embodiment 25, wherein the loose-fill insulation is disposed in a cavity by being blown in.
 
Embodiment 27. The method of any of embodiments 24-26, wherein the insulation is introduced into the cavity at three or fewer locations.
 
Embodiment 28. The method of any of embodiments 24-27, wherein the building structure is not installed as part of a building when the loose-fill insulation is disposed therein.
 
Embodiment 29. The method of embodiment 28, wherein the building structure is disposed such that its longitudinally-extending direction is within 15 degrees of horizontal, e.g., within 5 degrees of horizontal when the loose-fill insulation is disposed therein.
 
Embodiment 30. The method of any of embodiment 28 or embodiment 29, wherein after the loose-fill insulation is disposed in the cavity, and then the building structure is moved to a building site and installed as part of a building.
 
           
         
       
    
     It will be apparent to those skilled in the art that various modifications and variations can be made to the processes and devices described here without departing from the scope of the disclosure. Thus, it is intended that the present disclosure cover such modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.