Patent Publication Number: US-6209284-B1

Title: Asymmetric structural insulated panels for use in 2X stick construction

Description:
FIELD OF THE INVENTION 
     This invention relates generally to structural insulated panels for use in building construction and is particularly directed to a structural insulated panel having an inner plastic foam core with a rigid outer facing on one surface thereof and plastic impregnated paper on a second opposed surface of the foam core which is particularly adapted for use in 2× stick construction. 
     BACKGROUND OF THE INVENTION 
     Lumber stick construction which employs 2× dimensional structural lumber members and nails is how most houses are constructed. This handcrafted stick built approach is slow and manpower intensive requiring many hours of field work, requires a large supply of a limited natural resource, typically incorporates many thermal bridges in combination with gaps in insulation and thus is not particularly energy efficient, and affords a limited number of structural shapes. An alternative approach employs steel studs. This approach also suffers from limitations in that the steel studs are difficult to work with and are good thermal conductors of heat through walls and roofs. 
     Another approach gaining increasing acceptance involves the use of Structural Insulated Panels (SIPs). SIP construction typically employs two rigid faces on either side of a light insulating foam core. High strength bonding of the outer facings to the inner core forms a structural I-beam in the form of flat panels which are typically joined together by lumber and nails. The outer, opposed panel faces are generally formed from conventional building materials such as gypsum or cementous composites, plywood, oriented strand board (OSB), drywall, or other rigid construction boards from ¼″ to ¾″ thick. Several factors have impeded wide-spread acceptance of SIPs in building construction. For example, the use of SIPs requires a great deal of pre-planning for efficient field erection because these panels are not easily field-cut without the use of special tools. Manufacturing the panels involves 4-5 times the amount of time cutting and sizing the panels in the shop than required in laminating the panels. This increased in-shop preparation of the panels also requires additional in-house designers. In addition, these panels are generally heavy, weighing much more than conventional wallboard panels, and frequently require the use of special handling equipment such as cranes. Because SIPs are difficult to modify in the field, more precise planning and building techniques are required than the stick built approach of simply working out of a wood pile of 2× dimensional structural lumber members. Finally, current double-faced structural insulated panels are typically 5″ thick when installed with drywall. This is wider than typical stick framing of 4½″ thickness and requires special door and window jamb sizes. Current structural insulated panels are thus incompatible with the conventional 2× structural member system of construction in general use today. For these reasons, contractors have not accepted SIPs as a basic structural member in building construction on a widespread scale. 
     The present invention addresses the aforementioned limitations of the prior art by providing a lightweight, high strength, insulated panel which is easily fabricated, modified and installed in structures built with 2× stick construction. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a lightweight structural insulated panel which is easier to manufacture and adapt for a specific installation in the field than currently available structural insulated panels. 
     It is another object of the present invention to provide a structural insulated panel capable of withstanding large transverse, axial and racking loads having an outer rigid facing attached to one surface of an inner insulating core sheet and an inner facing of a high strength, structural paper attached to a second opposed surface of the core sheet and which is particularly adapted for use in and is compatible with conventional stick construction using 2× dimensional structural lumber. 
     Yet another object of the present invention is to provide a high strength planar structural insulated panel which can be incorporated in walls, ceilings, etc., constructed of 2× dimensional lumber without modifying or adding to the lumber structure. 
     A further object of the present invention is to provide a lightweight, high strength structural insulated panel having an inner insulating core and a single outer rigid facing for use in a wall, ceiling, floor or roof of a building which is easily adapted in the field for and installed in a particular installation. 
     This invention contemplates a structural panel coupling arrangement for use in 2× stick construction comprising a 2× structural member of lumber and having a given thickness and a given width; a first asymmetric structural insulated panel having an insulating core, a rigid outer facing attached to a first surface of the insulating core, and a high strength sheet of plastic impregnated paper attached to a second opposed surface of the insulating core, wherein the insulating core has a width equal to the width of the 2× structural member and includes a notched out edge portion forming an edge extension of the rigid outer facing having a thickness equal to the thickness of the 2× structural member; and means for attaching a first surface of the 2× structural member to the edge extension of the rigid outer facing and a third surface of the 2× structural member to the insulating core of the structural insulated panel, wherein the sheet of plastic impregnated paper on the panel is aligned with a third surface of the 2× structural member, and wherein the first and third surfaces are in opposed relation on the 2× structural member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characters identify like elements throughout the various figures, in which: 
     FIG. 1 a  is a partial sectional view of one embodiment of a structural insulated panel; 
     FIG. 1 b  is an exploded sectional view of the structural insulated panel installation of FIG. 1 a;    
     FIG. 2 a  is a sectional view of a wall and roof combination incorporating structural insulated panels; 
     FIG. 2 b  is an exploded sectional view of the wall and roof combination of FIG. 2 a;    
     FIG. 3 a  is a partial sectional view of a pair of connected wall sections incorporating structural insulated panels; 
     FIG. 3 b  is a partial exploded sectional view of the structural insulated panel wall arrangement of FIG. 3 a;    
     FIG. 4 is a sectional view showing additional details of a structural member such as a wall, roof, ceiling, or floor incorporating a pair of connected structural insulated panels; 
     FIGS. 5 a,    5   b  and  5   c  are respectively front, top planar and side elevations views shown partially in phantom of another embodiment of a structural insulated panel; 
     FIGS. 6 a,    6   b  and  6   c  are respectively front, top plan and side elevation views of a structural insulated panel; 
     FIGS. 7 a,    7   b  and  7   c  are respectively top plan, partial side elevation, and partial front views of still another embodiment of a structural insulated panel; 
     FIGS. 8 a  and  8   b  are respectively exploded and assembled sectional views of an asymmetric structural insulated panel incorporated in a 2× based structure in accordance with the present invention; 
     FIG. 8 c  is a sectional view of another arrangement for attaching an asymmetric structural insulated panel to a 2× based support structure in accordance with another aspect of the present invention; 
     FIGS. 9 a  and  9   b  are respectively exploded and assembled views of another arrangement for incorporating an asymmetric structural panel in a 2× based structure in accordance with the present invention; 
     FIGS. 10 a  and  10   b  are respectively exploded and assembled sectional views of a pair of asymmetric structural insulated panels connected in accordance with another aspect of the present invention; 
     FIGS. 11 a  and  11   b  show yet another arrangement for installing and connecting an asymmetric structural insulated panel in a 2× based structure; 
     FIG. 12 is a sectional view showing another arrangement for connecting an asymmetric structural insulated panel to a 2× base member in accordance with the present invention; and 
     FIG. 13 is a sectional view showing the manner in which a wall is connected to a ceiling in accordance with another aspect of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 1 a,  there is shown a partial sectional view of an asymmetric structural insulated panel  10 . FIG. 1 b  is an exploded sectional view of the structural insulated panel installation of FIG. 1 a.  The structural insulated panel  10  includes an inner plastic insulating foam core  12  having a rigid outer facing  14  attached to one surface thereof. Facing  14  may be comprised of a conventional construction material such as metal, oriented strand board (OSB) or plywood and is securely affixed to the surface of the plastic foam core  12  by means of a first adhesive layer  28 . Attached to a second opposed surface of the plastic foam core  12  by means of a second adhesive layer  30  is a sheet of plastic impregnated paper  22 . The first and second adhesive layers  28 ,  30  may be comprised of conventional bonding materials such as urethane cement or glue. In a preferred embodiment, the plastic impregnated paper sheet  22  is comprised of paper or box board impregnated with urethane or polysiocyanurate plastic. The plastic impregnated paper sheet  22  in one embodiment is commercially available from Weyerhauser and is sold under the trade name of P-Cell (sometimes referred to as PolyCel). The plastic impregnated paper sheet  22  serves as a vapor barrier near the inside of an exterior wall or roof deck to prevent moisture from entering the inside structure or passing through the panel&#39;s plastic foam core to the panel&#39;s outer facing  14  and wall cladding, if present. The plastic impregnated paper sheet  22  also provides this surface of the structural insulated panel  10  with a high tensile strength as described below. 
     Disposed respectively on upper and lower ends of the structural insulated panel  10  are upper and lower plates  16  and  18 . Each of the upper and lower plates  16 , 18  is typically comprised of 2× lumber members. In a typical building installation, the structural insulated panel  10  would be attached to the outer surface of a sheet of composite gypsum drywall  24 . Beads of mastic  26   a,    26   b,    26   c  and  26   d  are used to securely affix the plastic impregnated paper sheet  22  of structural insulated panel  10  to the outer surface of drywall sheet  24 . Affixed to a surface of drywall sheet  24  may be a second plastic impregnated sheet (not shown for simplicity) to further increase the tensile strength of the structural insulated panel and drywall sheet combination. The upper and lower plates  16 , 18  are used to securely connect the structural insulated panel  10  to the drywall sheet  24  by means of a couplers  32   a,    32   b  and  34   a,    34   b.  These couplers are typically nails, but may also be screws. The upper and lower plates  16 , 18  may also be used to securely attach respective upper and lower edges of the structural insulated panel  10  to upper, or ceiling, and lower, or floor, structural members, although this is not shown in the figures for simplicity. The plastic impregnated paper sheet  22  provides high tensile strength for structural panel  10  when a transverse force is applied to the panel in the direction of arrow  36  shown in FIG. 1 a.  The specified plastic impregnated sheet  22  0.015″ in thickness possesses a tensile strength approximately equal to that of 0.4375″ OSB (across the grain). This high strength of the plastic impregnated paper sheet  22  in combination with its relatively low cost of $0.07/square foot (OSB cost is approximately $0.29/square foot) makes the use of this paper particularly attractive when used in a structural insulated panel. The structural insulated panel is also much lighter and easier to handle and conform in the field to a specific installation than a double-faced structural insulated panel. Structural panel  10  thus provides a high strength panel having a single outer face which is lighter, and easier to manufacture, modify and install than prior art double faced structural insulated panels. 
     Referring to FIG. 2 a,  there is shown a partial sectional view of a combination wall panel  40  and roof panels  42 . FIG. 2 b  is an exploded sectional view of the connected wall and roof panels  40 , 42  shown in FIG. 2 a.  Wall panel  40  is similar in construction to the wall panel shown in FIGS. 1 a  and  1   b  and includes an inner plastic foam insulating core  41 , a rigid outer facing  44  on a first surface of the foam core, and a plastic impregnated paper sheet  46  on a second, opposed outer surface of the foam core. The structural insulated wall panel  40  is attached to a sheet of drywall  48  by means of upper and lower plates  50  and  52  as well as by a plurality of nails or screws as shown in FIG. 2 a.  Upper plate  50  in combination with a triangular spacer plate  54  is also used to securely connect an upper end of the structural insulated wall panel  40  with the roof panels  42  as described below. The upper and lower plates  50 ,  52  as well as spacer plate  54  are preferably comprised of wood. 
     Roof panels  42  include a first upper roof panel  62  and a second lower roof panel  64 . The first roof panel  62  includes an inner foam core  66 , a rigid outer facing  68  disposed on a first surface of the foam core, and a plastic impregnated paper sheet  70  attached to the second, opposed surface of the foam core. As described above, the rigid outer facing  68  and plastic impregnated sheet  46  are affixed to opposed surfaces of the panel&#39;s insulating foam core  66  by conventional means such as urethane cement or glue. The plastic insulating foam core  66  is preferably comprised of expanded polystyrene or urethane. The second inner roof panel  64  is similarly comprised of an inner plastic insulating foam core  72 , a rigid outer facing  74  attached to a first surface of the panel&#39;s foam core, and a plastic impregnated paper sheet  76  attached to a second opposed surface of the panel&#39;s inner foam core. The roof panels  42  are positioned on a sheet of wall board  78  and are attached to the upper end of the structural insulated wall panel  40  by means of first and second coupling screws  60   a  and  60   b.  Screw  60   b  is inserted through the rigid outer facings  68  and  74  of the first and second roof panels  62 ,  64 , while screw  60   a  is inserted through rigid outer facing  74 . The ends of the first and second screws  60   a,    60   b  are further inserted into the triangular spacer plate  54  and the wall&#39;s upper plate  50  as shown in FIG. 2 a.  Disposed within the second roof panel  64  between the panel&#39;s plastic insulated paper sheet  76  and inner foam core  72  is a nailer strip  63 . The first and second screws  60   a,    60   b  are further inserted through nailer strip  63 , with the first screw  60   a  engaging the nailer strip for securely attaching the second roof panel  64  to the upper edge of the structural insulated wall panel  40 . Nailer strip  63  may be comprised of a conventional building material such as wood or OSB and is bonded to the panel&#39;s foam core  72  by a conventional adhesive such as mastic. The adjacent plastic impregnated paper sheets  70  and  75  provide the pair of roof panels  42  with a high tensile strength with respect to both upwardly and downwardly directed forces applied to the roof panels. 
     Referring to FIG. 3 a,  there is shown a partial sectional view of a pair of connected wall sections each incorporating structural insulated panels. FIG. 3 b  is a partial exploded sectional view of the structural insulated panel wall arrangement of FIG. 3 a.  The first wall section includes a first wall panel  80  having an inner insulating foam core  84 , a rigid outer facing  86  attached a first surface of the foam core, and a plastic impregnated paper sheet  88  attached to a second opposed surface of the panel&#39;s foam core. The first wall panel  80  is shown as including two sections each having a respective edge slot  122   a  and  122   b.  Edge slots  122   a,    122   b  are each adapted to receive a coupling spline  98  for securely connecting the two wall sections. Beads of mastic are shown deposited in the first and second slots  122   a,    122   b  for bonding the coupling spline  98  to adjacent sections of the panel&#39;s outer facing  86  and foam core  84  in connecting the two wall sections. Also disposed within the first wall panel  80  are first and second nailer strips  92  and  94  and a first inner corner nailer  96 . The first and second nailer strips  92 ,  94  allow the first wall panel  80  to be securely attached to an inner gypsum drywall sheet  90  by conventional couplers such as nails or screws as shown in FIG. 3 a.  Beads of mastic  91  are also used to securely attach the first wall panel&#39;s plastic impregnated paper sheet  88  to the gypsum drywall sheet  90 . The nailer strips as well as the coupling spline  98  may be comprised of conventional building materials such as wood or OSB. 
     A second wall panel  82  is similarly comprised of an inner foam core  102 , a rigid outer facing  104  attached to one surface of the foam core, and a plastic impregnated paper sheet  116  attached to a second opposed surface of the foam core. The second wall panel  82  is also comprised of a pair of wall sections connected by means of a coupling spline  106  inserted in facing slots in the two wall panel sections. The second wall panel  82  is attached to a drywall sheet  108  by means of beads of mastic  118  as well as by means of nails or screws used with nailers as in the case of the first wall panel  80 , where a second inner corner nailer  97  is shown in the figures. 
     Each of the first and second wall panels  80 , 82  includes a beveled edge where the two panels are joined to form a 90° angle. A 90° outer corner nailer  100  comprised of OSB laminated to a sheet metal spline is inserted in opposed slots in the bevelled edges of the first and second wall panels  80 ,  82 . The outer comer nailer  100  is securely maintained in the aligned facing slots in the adjoining edges of the first and second wall panels  80 , 82  by means of mastic beads disposed within the slots. An inner sheet metal corner reinforcing angle  120  is placed in contact with the inner surfaces of the first and second inner corner nailers  96 , 97  of the first and second wall panels  80 , 82 . Nails or screws are inserted through the drywall sheets  90  and  108 , as well as through the sheet metal corner reinforcing angle  120  and the first and second inner corner nailers  96 , 97  for securely connecting the inner edges of the first and second wall panels  80 ,  82 . Similarly, nails or screws are inserted through the rigid outer facings  86  and  104  of the first and second wall panels  80 , 82  as well as through the outer corner nailer  100  for securely connecting the outer edges of the two wall panels. The plastic impregnated paper sheets  88  and  116  provide the first and second wall panels  80 , 82  with substantial tensile strength to withstand a large transverse force applied to the outer facings of these panels. The various nailer strips and the inner corner nailers  96 , 97  facilitate attaching the first and second wall panels  80 , 82  to drywall sheets  90  and  108  using either nails or screws. The nailer strips also provide the inner surface portions of the two wall panels with the capacity to withstand a large transverse force as well as the ability to accommodate large axial (along the length of the panel) and racking (along the width of the panel) loads. Bonding between the wall panels and the drywall sheets is further enhanced by mastic beads disposed between these structural members. In this as well as in the other embodiments described herein, the plastic impregnated paper sheet may be affixed to a sheet of drywall to which the structural insulated panel is attached rather than to the panel&#39;s insulating foam core to provide the panel with the increased strength described above. The rigid outer facings as well as the various nailers in the embodiment shown in FIGS. 3 a  and  3   b,  as well as in the various other embodiments described herein, may be comprised of common building materials such as metal, wood, oriented strand board, composite gypsum or cement. 
     Referring to FIG. 4, there is shown a sectional view illustrating additional details of a horizontal roof section  130  incorporating an upper roof panel  132  and a lower roof panel  134 . Although the structural member shown in FIG. 4 is described as a horizontal roof section, the structural member shown therein may also form a wall, a ceiling, or a floor in a building. As in the previously described embodiments, the upper roof panel  132  includes an inner insulating foam core  137 , an outer facing  138  attached to an upper surface of the foam core, and a plastic impregnated paper sheet  140  attached to the opposed, lower surface of the panel&#39;s foam core. Similarly, the lower roof panel  134  includes an insulating foam core  142 , a rigid outer facing  144  attached to a lower surface of the foam core, and a plastic impregnated paper sheet  146  attached to an opposed, upper surface of the panel&#39;s foam core. Disposed within the upper roof panel  132  in a spaced manner are nailers  150   a  and  150   b.  Disposed within the lower roof panel  134  in a spaced manner are a second plurality of nailers  152   a,    152   b  and  152   c.  Each of the nailers is disposed within the insulating foam core of its associated panel adjacent the panel&#39;s plastic impregnated paper sheet and is adapted to receive either a nail or a screw inserted through the outer facing of the other panel for securely joining the upper and lower roof panels  132 , 134 . Each of the upper and lower roof panels  132 , 134  is comprised of at least a pair of joined roof sections each having slots in their opposed surfaces for receiving a coupling spline. Thus, coupling spline  156  is inserted in adjacent sections of the lower roof panel  134  for securely connecting the two lower roof sections, while coupling spline  154  connects adjacent sections of the upper roof panel  132 . As shown in FIG. 4, nails or screws are inserted through each of the coupling splines in one of the roof panels as well as through a nailer in the other roof panel for securely connecting the upper and lower roof panels. A drywall sheet  136  is shown attached to the lower surface of the lower roof panel  134  by conventional means such as beads of mastic which are not shown for simplicity. 
     Referring to FIGS. 5 a,    5   b,  and  5   c,  there are respectively shown top plan, front elevation and side elevation views shown partially in phantom of a structural insulated panel  160 . Structural insulated panel  160  includes an inner insulating foam core  162 , a rigid outer facing  164  disposed on one surface of the foam core, and a plastic impregnated paper sheet  166  attached to a second opposed surface of the panel&#39;s foam core. As in the previously described embodiments, opposed edges of the structural insulated panel  160  are provided with coupling slots  168   a  and  168   b  each running the length of the panel which are adapted to receive respective coupling splines (not shown for simplicity) as described above. First and second adhesive layers  172  and  174  respectively couple the rigid outer facing  164  and the plastic impregnated paper sheet  166  to opposed surfaces of the panel&#39;s insulating foam core  162 . Disposed within the foam core  162  in a spaced manner are first, second and third internal nailers  170   a,    170   b  and  170   c.  Beads of mastic may be used to securely attach each of the internal nailers  170   a,    170   b  and  170   c  to the panel&#39;s insulating foam core  162 . Each of the internal nailers  170   a,    170   b  and  170   c  facilitates attaching the structural insulated panel  160  to a support structure such as a sheet of drywall and increases the compressive strength of the panel as previously described. Nails or screws inserted through the aforementioned support structure (which is not shown in the figures for simplicity) and into the internal nailers provide secure coupling between the structural insulated panel  160  and the support structure. 
     Referring to FIGS. 6 a,    6   b  and  6   c,  there are respectively shown top plan, front elevation and side elevation views of a structural insulated panel  180 . As in the previously described embodiment, the structural insulated panel  180  includes an inner foam core  182 , a rigid outer facing  184  attached one surface of the front core, and a plastic impregnated paper sheet  186  attached to a second opposed surface of the panel&#39;s foam core. In the embodiment shown in FIGS. 6 a,    6   b,  and  6   c,  three external nailers  188   a,    188   b  and  188   c  are attached to the outer surface of the panel&#39;s plastic impregnated paper sheet  186  by conventional means such as beads of mastic. As in the previously described embodiments, external nailers  188   a,    188   b  and  188   c  facilitate attachment of the structural insulated panel  180  to a structural support member such as a sheet of drywall (not shown in the figures for simplicity) and substantially increase the panel&#39;s compressive strength. 
     Referring to FIGS. 7 a,    7   b  and  7   c  there are respectively shown top plan, partial side elevation, and partial front views of a structural insulated panel  200 . FIGS. 7 a,    7   b  and  7   c  are shown partially in phantom to illustrate additional details of this embodiment of the invention. The structural insulated panel  200  includes an inner insulating foam core  202 , a rigid outer facing  204  affixed to one surface of the foam core, and a plastic impregnated paper sheet  206  affixed to a second, opposed surface of the panel&#39;s foam core. Conventional adhesives are used to bond the rigid outer facing  204  and the plastic impregnated paper sheet  206  to opposed surfaces of the panel&#39;s insulating foam core  202 . Disposed in a spaced manner within an outer surface of the panel&#39;s foam core  202  are first, second and third internal nailers  208   a,    208   b  and  208   c  in the form of elongated, linear strips of metal, wood or OSB. A conventional bonding agent such as mastic is used to affix each of the first, second and third internal nailers  208   a,    208   b  and  208   c  to the panel&#39;s foam core  202  as well as to the plastic impregnated paper sheet  206 . Coupling slots  210   a  and  210   b  in opposed edges of the insulating foam core  202  allow the structural insulated panel  200  to be securely connected to adjacent similar structural insulated panels by means of connecting splines as described above. Disposed within the foam core  202  and extending the width of the structural insulated panel  200  are first and second horizontal electrical chases  212   a  and  212   b.  Also disposed within the foam core  202  and extending the length of the panel  200  is a vertical electrical chase  214  which intersects each of the first and second horizontal electrical chases  212   a  and  212   b.  In a preferred embodiment, the panel&#39;s insulating foam core  202  is comprised of expanded polystyrene, urethane or polysiocyanurate foam, while a preferred bonding agent is Morton 640 series adhesive. The panel&#39;s external rigid outer facing  204  and each of the internal nailers  208   a,    208   b  and  208   c  are preferably comprised of OSB. 
     Referring to FIGS. 8 a  and  8   b,  there are respectively shown exploded and assembled sectional views of an arrangement for installing an asymmetric structural insulated panel  222  in a 2× structure in accordance with the present invention. The asymmetric structural insulated panel  222  includes a rigid outer facing  224 , an inner plastic impregnated paper sheet  230 , and an insulating core  226  disposed between and coupled to the rigid outer facing and plastic impregnated sheet. Structural insulated panel  222  further includes one or more vertically aligned internal nailers  228  (shown in dotted line form in the figures) each in the form of an elongated, linear strip disposed in the panel&#39;s insulating core  226 . The panel&#39;s insulating core  226  may be comprised of plastic foam, wheat-, straw-, or agricultural board, or virtually any conventional structural insulating material. The rigid outer facing  224  may be comprised of oriented strand board, or a cement or gypsum composite. Structural insulated panel  222  is adapted for connection to a bottom plate  236  which is coupled to and supported by a floor  240  which, in turn, is coupled to and supported by a support wall  242 . Structural insulated panel  222  is further adapted for connection to first and second top plates  232   a  and  232   b  as shown in FIG. 8 b.  The structural insulated panel  222  and the first and second top plates  232   a,    232   b  are moved in the direction of arrows  234  and  238  to form the assembled structure shown in FIG. 8 b.  First and second couplers or fasteners such as nails, screws or staples  244   a  and  244   b  are inserted through an upper edge of the panel&#39;s rigid outer facing  224  and into the first and second top plates  232   a  and  232   b.  A third coupler  246  is inserted through a lower edge of the panel&#39;s rigid outer facing  224  and into the bottom plate  236 . 
     There are various advantages in connecting the asymmetric structural insulated panel  222  to 2× structural support members. For example, it is much simpler to cut off the ends of the plastic impregnated paper sheet  230  and the insulating core  226  to match the size of the opening than in the case of prior art double-faced structural insulated panels. Matching the distance between the 2× structural members between which a double-faced structural insulated panel is to be connected requires grooving out the inner foam core of the panel disposed between its pair of outer facings. A 2× structural member is then positioned in the thus formed groove. Forming this groove is difficult and time consuming, particularly when using tools typically available in the field. It is easier and simpler to merely notch out the insulating core of an asymmetric insulated panel by cutting it from the open side of the panel in sizing the panel to accommodate a pair of spaced 2× structural members. In addition, attaching the single outer face of the asymmetric structural panel to the bottom and top plates as shown in FIG. 8 b  is easier and faster than attaching both outer facings of conventional dual-faced structural insulated panel to the 2× plates. Finally, an asymmetric structural insulated panel has the same thickness as common 2× stick construction and can be used in combination with the 2× stick construction in the same structure without modification such as the addition of jamb extensions around doors and windows formed in a wall. 
     Referring to FIG. 8 c,  there is shown another arrangement in accordance with the present invention incorporating an asymmetric structural insulated panel  250  in a common 2× stick construction structure. Structural insulated panel  250  includes an insulating core  252  and a rigid outer facing  254  disposed on and attached to one surface of the insulating core. Disposed on and attached to a second, opposed surface of the panel&#39;s insulating core  252  is a plastic impregnated sheet  262 . Disposed in the panel&#39;s insulating core  252  is an electrical chase  260  as well as a plurality of spaced nailer strips, where one of the nailers is shown in dotted line form as element  256  in the figure. An edge of the panel&#39;s insulating core  252  is placed in abutting contact with a 2× lumber sill plate  268 , with an adjacent edge of the panel&#39;s rigid outer facing  254  attached to the sill plate by means of a staple  272 . Beads of mastic  264   a,    264   b  and  264   c  are disposed between the lumber sill plate  268  and the edge of the panel&#39;s insulating core  252  to provide a high degree of adhesion and a good seal between these two structural components. A second 2× lumber sill plate  270  may be disposed in abutting contact with the lower surfaces of the panel&#39;s rigid outer facing  254  and the lumber sill plate  268 . A bead of mastic  266  may be disposed between the two sill plates  268  and  270  for bonding these two structural members together. An inner gypsum drywall sheet  258  (shown in the figure in dotted line form) may be attached to the plastic impregnated paper sheet  262  of the structural insulated panel  250  by conventional means such as by an adhesive. In addition, the inner gypsum drywall sheet  258  may be attached to the lumber sill plate  268  by other conventional means such as staples, nails or screws (also not shown for simplicity). 
     Referring to FIGS. 9 a  and  9   b,  there are respectively shown exploded and assembled sectional views of first and second asymmetric structural insulated panels  278  and  286  connected together in a structure of 2× construction. The first structural insulated panel  278  includes an inner insulating core  284 , a rigid outer facing  280  disposed on a first surface of the insulating core, and a plastic impregnated paper sheet  282  disposed on and attached to a second opposed surface of the panel&#39;s insulating core. Disposed within the insulating core  284  and engaging the plastic impregnated paper sheet  282  is a nailer  300  typically comprised of wood. The rigid outer facing  280  is preferably comprised of an oriented strand board (OSB) composition or a cement or gypsum composite, while the insulating core  284  is preferably comprised of expanded polystyrene. The second structural insulated panel  286  is similarly comprised of an insulating core  292 , a rigid outer facing  288  disposed on and attached to a first surface of the insulating core, and a plastic impregnated paper sheet  290  disposed on and attached to a second, opposed surface of the panel&#39;s insulating core. Respective ends of the insulating cores  284  and  292  have been notched out so that each of the rigid outer facings  280  and  288  extend beyond their associated insulating cores. The notched out portions of the insulating cores  284 ,  292  are adapted to receive a 2× lumber nailer  294 . Various beads of mastic  296   a - 296   e  are deposited between the insulating cores, the outer facings, and the 2× lumber nailer  294  to securely join and form a seal between these structural members. First and second staples  297   a  and  297   b  connect the rigid outer facing  280  of the first structural insulated panel  278  to the 2× lumber nailer  294 . A third staple  298  connects the rigid outer facing  288  of the second structural insulated panel  286  to the 2× lumber nailer  294 . A first inner drywall sheet  308  (shown in dotted line form) is disposed on the inner surface of the first structural insulated panel  278  and engages its plastic impregnated sheet  282 . The first inner drywall sheet  308  is attached to the first structural insulated panel  278  by means of a coupler, such as a nail,  304  inserted through the drywall sheet and into the panel&#39;s nailer strip  300 . A second inner drywall sheet  310  (also shown in dotted line form) is attached to the inner surface of the second structural insulated panel  286  also by means of a coupler  306  inserted into the internal nailer strip  302  within the panel. It should be noted that in the corner coupling arrangement shown in FIGS. 9 a  and  9   b,  the width of the two structural insulated panels is equal to the width of the 2× lumber nailer  294  as particularly shown for the case of the second structural insulated panel  286 . 
     Referring to FIGS. 10 a  and  10   b,  there are respectively shown exploded and assembled sectional views of first and second asymmetric structural insulated panels  316  and  324  coupled in accordance with another aspect of the present invention. As in the previous embodiments, the first structural insulated panel  316  includes an insulating core  322 , a rigid outer facing  318  disposed on and attached to a first surface of the insulating core, and a plastic impregnated paper sheet  320  disposed on and attached to a second, opposed surface, of the panel&#39;s insulating core. The insulating core includes a slot  317  in one end thereof. The insulating core  322  further includes a second slot within which is inserted an internal nailer strip  319 . Similarly, the second structural insulated panel  324  includes an insulating core  331 , a rigid outer facing  326  attached to and disposed on a first surface of the insulating core, and a plastic impregnated paper sheet  328  disposed on and attached to a second, opposed surface of the panel&#39;s insulating core. The insulating core  331  of the second panel is also provided with a first internal slot  325  and a second internal slot within which is inserted a nailer strip  327 . 
     Several beads of mastic  330   a,    330   b  and  330   c  are disposed in the joint between the assembled first and second structural insulated panels  316  and  324  as shown in the figures. Mastic bead  330   c  is preferably applied in a continuous, serpentine manner to one of the insulating cores and extends the entire length of the joined panels. In addition, a coupling spline  332  is inserted in the facing slots  317  and  325  of the first and second structural insulated panels  316 ,  324 . A pair of staples  334  and  336  are respectively inserted through the rigid outer facings  318  and  326  of the first and second structural insulated panels and into the coupling spline  332  for securely joining the two panels. Coupling spline  332  as well as the nailer strips  319  and  327  are preferably comprised of wood. 
     An inner drywall sheet  323  (shown in FIG. 10 b  in dotted line form) is attached to the inner surfaces of the first and second structural insulated panels  316  and  324  by means of first and second couplers  321  and  329  inserted through the drywall sheet and into nailer strips  319  and  327 , respectively. 
     Referring to FIGS. 11 a  and  11   b,  there are respectively shown exploded and assembled sectional views of another arrangement for connecting a generally horizontal asymmetric structural insulated panel  340  to a vertical wall juncture. Structural insulated panel  340  includes an inner insulating core  342 , a rigid outer facing  344  attached to a first upper surface of the insulating core, and a plastic impregnated paper sheet  350  attached to a second, opposed lower surface of the insulating core. Disposed within the panel&#39;s insulating core  342  are first and second nailers  346  and  348  which are also disposed in contact with the panel&#39;s inner plastic impregnated paper sheet  350 . In connecting the structural insulated panel  340  to a wall juncture, a notch is cut through the plastic impregnated paper sheet  350  and into the insulating core  342  so as to form a slot  356  in the insulating core. A 2× insert member  354  is then inserted in slot  356  in the direction of arrow  358 . The 2× insert member  354  is secured to the panel&#39;s rigid outer facing  344  by conventional means such as a staple  345 . Beads of mastic  347   a  and  347   b  are deposited at the juncture of the rigid outer facing  344 , the insert member  354 , and the panel&#39;s insulating core  342 . The beads of mastic increase the strength of the connection between the structural insulated panel and the 2× insert member  354 . 
     A 2× wall header  368  is attached to the 2× insert member  354  by means of a coupler such as a nail or screw  374 . The 2× wall header  368  extends across the 2× insert member  354  to the respective portions of the insulating core  354  on both sides of the insert member. First and second drywall sheets  370  and  372  (shown in the FIG. 11 b  in dotted line form) are attached to respective opposed surfaces of the 2× wall header  368  by means of couplers  376   a  and  376   b.  The first and second drywall sheets  370 ,  372  form opposed surfaces of a wall structure attached to the structural insulated panel  340  by means of the 2× insert member  354  and wall header  368 . Third and fourth drywall sheets  360   a  and  360   b  (also shown in dotted line form) are attached to respective lower portions of the structural insulated panel  340  by means of couplers  362  and  364  inserted through the drywall sheets and into nailers  346  and  348 , respectively. Beads of mastic  366  are disposed between the panel&#39;s plastic impregnated paper sheet  350  and the third and fourth drywall sheets  360   a,    360   b  as well as between the 2× insert member  354  and 2× wall header  368 . The panel connection arrangement shown in FIGS. 11 a  and  11   b  represents an easy, efficient way to form a juncture between a ceiling or roof panel and a wall using 2× structural components and an asymmetric structural insulated panel in accordance with another aspect of the present invention. 
     Referring to FIG. 12, there is shown a sectional view of another arrangement for attaching an asymmetric structural insulated panel  380  to a 2× sill plate  398  in accordance with the present invention. As in the previous embodiments, the structural insulated panel  380  includes an insulating core  384 , a rigid outer facing  382  attached to a first surface of the insulating core, and a plastic impregnated paper sheet  394  attached to a second, opposed surface of the panel&#39;s insulating core. Disposed within the panel&#39;s insulating core  384  is an electrical chase  386  as well as one or more internal nailers  390  shown in dotted line form in the figure. The structural insulated panel  380  is connected to the 2× sill plate  398  by means of a staple  402  inserted through an edge portion of the panel&#39;s rigid outer facing  382  and into the sill plate. Attached to the 2× sill plate  398  by means of a plurality of spaced couplers  406  is a generally L-shaped wind clip  392 . Wind clip  392  is securely attached to the 2× sill plate  398  by means of a plurality of spaced couplers  406  inserted through the wind clip and into the sill plate. The wind clip  392  is also connected to the structural insulated panel  380  by means of a plurality of couplers  404  inserted through the wind clip and into the internal nailers  390  within the panel. Wind clip  392  extends along the entire length of the structural insulated panel  380  and is preferably comprised of a high strength material such as sheet metal. A second 2× sill plate  400  may be attached to the first 2× sill plate  398  by conventional means which are not shown in the figure for simplicity. Beads of mastic  396   a - 396   d  are inserted in the junctures between the structural insulated panel  380  and the first 2× sill plate  398  and in also between the two sill plates as shown in the figure. A thermal barrier in the form of a ½ inch drywall sheet  388  (shown in the figure in dotted line form) is attached to the inner surface of the structural insulated panel  380  by conventional means such as an adhesive or by couplers inserted through the drywall sheet and into the spaced internal nailers  390  within the panel. 
     Referring to FIG. 13, there is shown a simplified sectional view of an arrangement for connecting an asymmetric structural insulated panel  410  to a roof beam  412  and ceiling joist  416  in accordance with another embodiment of the present invention. In FIG. 13, the roof beam  412  is connected to the ceiling joist  416  by means of a metal nailing plate  414  and nails  415  inserted through the metal nailing plate and into the roof beam and ceiling joist. A metal truss  418  is connected to the roof beam  412  by means of first nails  417  and is further connected to an upper wall plate  423  by means of second nails  419 . Beads of mastic  422  are placed between the upper wall plate  423 , which is a conventional 2× structural member, and the ceiling joist  416 . A structural insulated panel  410  is placed in contact with and supported from the upper wall plate  423 . Structural insulated panel  410  includes an inner insulating core  426 , a rigid outer facing  420  attached to one surface of the insulating core and preferably comprised of oriented strand board or a cement or gypsum composite, and an insulating sheet  424  such as comprised of plastic foam or wheat-, straw-, or agricultural board attached to a second, opposed surface of the panel&#39;s insulating core. The structural insulated panel  410  is attached to the metal truss  418  as well as to the upper wall plate  423  by means of the aforementioned nails  419  inserted through an upper edge of the panel&#39;s rigid outer facing  420 . A bead of mastic  424  is disposed between the upper wall plate  423  and the upper edge of the panel&#39;s insulating core  426 . The bead of mastic  424  forms a seal between and bonds the panel&#39;s insulating core  426  to the upper wall plate  423 . Because the panel&#39;s insulating core  426  and the upper wall plate  423  have the same thickness, an inner drywall sheet  425  (shown in the figure in dotted line form) may be attached to the inner surfaces of the insulating core and upper wall plate by conventional means such as an adhesive or nails or screws. The outer surface of the inner drywall sheet  425  is flush, or in intimate abutting contact, with the panel&#39;s plastic impregnated paper sheet  424  as well as with the upper wall plate  423 . A second drywall sheet  427  also shown in dotted line form may be attached to and suspended from the ceiling joist  416  also by conventional means such as an adhesive or nails or screws. 
     There has thus been shown an asymmetric structural insulated panel for building construction which includes an insulating core, a rigid outer facing affixed to one surface of the insulating core, and a plastic impregnated paper sheet attached to a second, opposed surface of the panel&#39;s insulating core. The plastic impregnated paper provides a high tensile strength for the structural insulated panel to accommodate large transverse loads applied to the panel. The plastic impregnated paper sheet may also be bonded to a sheet of drywall to which the panel is attached rather than to the panel&#39;s insulating core to provide the panel with increased strength. The insulating core is comprised of a wheat-, straw-, or agricultural board or a plastic such as expanded polystyrene or urethane, while the rigid outer facing is comprised of oriented strand board, cement or gypsum composite, or plywood. Elongated nailers also comprised of OSB or wood are disposed in a spaced manner within the panel&#39;s insulating core and in contact with the plastic impregnated paper sheet to provide the paper coated surface of the panel with high compressive strength to withstand large axial or racking loads. The panels are compatible with 2× stick construction and are easily incorporated in this type of structure. An edge of the panel&#39;s insulating core is notched out to permit the panel&#39;s rigid outer facing to be attached to 2× structural members by conventional means such as nails, screws, staples or an adhesive. The panel&#39;s inner insulating core is of the same thickness as a 2× structural member. This permits an inner facing member such as of gypsum wallboard to be placed in contact with and adhered to the panel&#39;s plastic impregnated paper sheet and to be attached to the 2× structural member. This eliminates the need for window or door jamb extensions. Openings, such as for windows, can be incorporated in the asymmetric structural insulated panels in the field using a conventional device such as a circular saw. 
     While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects. Therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. The matter set forth in the foregoing description and accompanying drawing is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.