Abstract:
A foundation wall includes a frame having a front side and a back side. The frame further includes a plurality of vertical stud members having a first end and a second end, a top beam attached to the first end of the plurality of vertical stud members, and a bottom beam attached to the second end of the plurality of vertical stud members to define a plurality of cavities between adjoining vertical stud members. Rigid insulation is adapted for positioning in the plurality of cavities to become a load-bearing part of the frame. One or more structural sheets is affixed to the front side of the frame and to the back side of the frame. A waterproof bond is formed along an interface between edges of the one or more structural sheets and a periphery around the front side and the back side of the frame.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to the fields of residential and commercial construction. More specifically, the invention pertains to the construction of pre-formed structural walls which may be positioned above or below ground level in a variety of construction applications where increased structural strength for extreme weather conditions and improved resistance to fire, insects, mold, and moisture is desired. 
     2. Description of the Related Art 
     For decades, the technology relating to structural walls in residential and commercial construction has seen little progress. The predominant method for constructing the conventional structural walls, foundation walls in particular, has been to pour the concrete footer and to use cinder blocks to build the foundation wall. More recently, a foundation wall molding method has gained acceptance where mold forms are assembled and concrete is poured into a void between the mold forms to create a solid concrete foundation wall. 
     While both of these construction methods produce structurally sound foundation walls, there are a number of disadvantages associated with using these conventional construction methods. Cinder blocks and concrete are expensive to produce and require a significant outlay of labor in order to construct a foundation wall of conventional construction. This increases the complexity of the construction and increases the cost of the building constructed using these conventional methods. Walls constructed using these materials cannot be pre-assembled and shipped to the job site. Additionally, conventional cinder blocks or concrete walls have poor insulation characteristics and can often lead to mold and mildew problems. Furthermore, these walls often allow water and radon to freely pass through the wall. 
     Within the prior art, there have not been many efforts to improve upon the conventional construction techniques and create a structural foundation wall that overcomes the shortcomings of concrete walls but retains their structural strength and long-term durability. While certain attempts have been made to create facings walls, such as the assembly disclosed in U.S. Application Publication No. 2004/0182031 to Fay et al., these solutions are merely aesthetic in nature and do not provide sufficient load-bearing capacity to serve as a building foundation. The wall disclosed in Fay et al. does not have the capability to withstand both normal forces and shear forces of the magnitude encountered by a building foundation structure. Accordingly, there has been a continuing need in the art for a foundation wall system which can be produced and installed efficiently, with improved insulation characteristics, increased overall strength, and long-term durability. 
     One solution has been proposed in U.S. Pat. No. 7,694,481 to the present inventor. Within this patent, an engineered wall system for use in above ground or below ground applications uses structural fiberglass-reinforced plastic as an outside membrane to a frame constructed of zinc-borate treated timber strand studs and plates. Rigid foam insulation is placed in the voids between the studs and the inside wall is enclosed with conventional drywall panel. While this wall system overcomes the shortcomings of the prior art with respect to the load-bearing capacity, the open inside wall portion does not offer adequate protection against water damage occurring from inside the building structure. 
     An additional drawback of conventional foundation wall systems is that they lack the capability to protect the occupants and items stored within the building from bullets or shrapnel making contact with the outside wall. Because cinder blocks, fiberglass-reinforced plastic, and rigid foam insulation are generally not adequate in stopping a projectile from passing through the wall and entering the building, there is a need for a foundation wall system having bulletproof and/or shrapnel-proof characteristics. 
     SUMMARY OF THE INVENTION 
     As described in detail herein, a foundation wall system may include a frame having a front side and a back side. The frame may include a plurality of vertical stud members having a first end and a second end and one or more top beams attached to the first end of the plurality of vertical stud members and one or more bottom beams attached to the second end of the plurality of vertical stud members to define a plurality of cavities between adjoining vertical stud members. Rigid insulation may be adapted for positioning in the plurality of cavities between adjoining vertical stud members to become a load-bearing part of the frame. One or more first structural sheets may be affixed to one of the front side or the back side of the frame and one or more second structural sheets may be affixed to the other of the front side or the back side of the frame. An upper channel beam may be provided on top of the upper-most top beam. A waterproof bond may be formed along an interface between edges of the one or more first structural sheets and a periphery around the front side of the frame and between edges of the one or more second structural sheets and a periphery around the front side of the frame. 
     In accordance with one embodiment of the foundation wall system, the one or more first and second structural sheets may be fiberglass-reinforced plastic sheets. According to yet another embodiment of the foundation wall system, the one or more first structural sheets may be a fiberglass-reinforced plastic sheet and the one or more second structural sheets may be an armored panel. The armored panel is desirably bulletproof. In accordance with a further embodiment of the foundation wall system, the one or more first and second structural sheets may be armored panels. 
     According to a further embodiment of the foundation wall system, a center stud may be provided at an approximate midpoint of the frame in the longitudinal direction, wherein the center stud is different from the plurality of vertical stud elements. Each of the plurality of vertical stud elements may be a timber strand stud. Each of the plurality of vertical stud elements may have a center core made from a timber strand material encased in one or more layers of fiberglass-reinforced plastic material. Each of the plurality of vertical stud elements may have a 2″×8″ depth/width measurement, while the center stud may have a 4″×8″ depth/width measurement. A wiring chase may extend through one or more vertical stud members. 
     In accordance with another embodiment, a foundation wall system may have an opening defined through the foundation wall system, wherein the opening is sized to receive a door or window therein. The one or more of the first and second structural sheets may be affixed to one or both of the frame and the rigid insulation by an adhesive, such as a water-based adhesive. Alternatively, the one or more of the first and second structural sheets may be affixed to one or both of the frame and the rigid insulation by a plurality of fasteners. 
     Further details and advantages of the present invention will become apparent from the following detailed description read in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of one embodiment of a foundation wall system; 
         FIG. 2  shows a perspective view of a wall frame used with the foundation wall system illustrated in  FIG. 1 ; 
         FIG. 3  shows a side view of the foundation wall system illustrated in  FIG. 1 ; 
         FIG. 4  shows a side view of the foundation wall system in accordance with a second embodiment of a foundation wall system; 
         FIG. 5  shows a side view of the foundation wall system in accordance with a third embodiment of a foundation wall system; and 
         FIGS. 6A and 6B  show cross-sectional views of a vertical stud member in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     For purposes of the description hereinafter, spatial orientation terms, as used, shall relate to the referenced embodiment as it is oriented in the accompanying drawing figures or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and configurations. It is also to be understood that the specific components, devices, and features illustrated in the accompanying drawing figures and described herein are simply exemplary and should not be considered as limiting. 
     Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, an embodiment of a foundation wall system  10  is shown and is generally described hereinafter for use in constructing a foundation of a building. Unless expressly noted otherwise, various embodiments of the foundation wall system  10  may be referred to as “a wall system  10 ”, “the wall system  10 ”,or simply as “wall  10 ”. While the present disclosure describes the use of foundation wall system  10  for installation at or above ground level, its use is equally applicable to situations where a foundation is constructed below ground level. 
     With reference to  FIGS. 1 and 2 , a single section of the foundation wall system  10  according to one embodiment of the present invention is illustrated. The wall system  10  includes a frame  20  constructed from a plurality of vertical stud members  30 . Each vertical stud member  30  is separated from an adjacent stud member  30  by a predetermined distance, such as approximately 16″ between the vertical stud member  30  centers. The vertical stud members  30  are generally rectangularly shaped, with the longer sides of the rectangle being arranged substantially parallel between adjacent vertical stud members  30 . Each vertical stud member  30  optionally has a wiring chase  40  extending therethrough such that a wiring passage is created between adjacent vertical stud members  30  for passing wiring therethrough. The vertical stud members  30  desirably have conventional dimensions well known in the construction industry. For example, a cross-sectional profile of each vertical stud member  30  may be dimensioned to correspond to the industry standard for 2″×4″, 2″×6″, 2″&#39;8″, 2″×10″, or 2″×12″ studs. One of ordinary skill in the art will understand that various other sizes of the vertical stud member  30  may be utilized. 
     The frame  20  further includes one or more top beams  50  and one or more bottom beams  60  provided along the top and bottom portions of the vertical stud members  30 . The top beam  50  and the bottom beam  60  are desirably dimensioned to correspond in width to the width of the vertical stud members  30  in the cross-sectional plane. The top beam  50  and the bottom beam  60  are secured to each vertical stud member  30  by mechanical fasteners (not shown) or other fastening means known in the art. A completed frame  20  showing a single top beam  50  and a single bottom beam  60  is illustrated in  FIG. 2 . Additional top and bottom beams may be provided in a vertically-stacked arrangement for added strength of the wall  10 . 
     In certain embodiments, frame  20  includes a center stud  70  provided at an approximate longitudinal midpoint of the frame  20 . The center stud  70  has identical height to the vertical stud members  30  of the frame  20 . However, the center stud  70  desirably has a larger profile to provide increased strength and load-bearing capacity of the frame  20  at its longitudinal midpoint. For example, in one non-limiting embodiment, vertical stud members  30  have a 2″×8″ profile And the center stud  70  has a 4″×8″ profile. 
     The vertical stud members  30 , the center stud  70 , the top beam  50 , and/or the bottom beam  60  desirably take the form of a timber strand stud. This is a specific type of stud that has increased load-bearing capacity and resistance to environmental damage compared to conventional studs. Unlike a traditional, saw-cut wooden stud that has a unitary construction, a timber strand stud is engineered lumber having a plurality of wood strands (poly strand material) of one or more types of wood glued together, compressed, and treated with anti-weathering and pest-resistance chemicals (e.g., zinc borate). In use, timber strand studs offer predictable strength and resistance to environmental damage compared to their conventional saw-cut wooden counterparts. 
     In alternate embodiments illustrated in  FIGS. 6A and 6B , vertical stud members  30 , the center stud  70 , the top beam  50 , and/or the bottom beam  60  have the form of a fiberglass-reinforced plastic (FRP) timber strand stud. While the following description of the embodiment illustrated in  FIGS. 6A and 6B  is made with reference to a vertical stud member  60 , one of ordinary skill in the art will appreciate that the center stud  70 , the top beam  50 , and/or the bottom beam  60  can be manufactured in a similar manner. In the embodiment shown in  FIG. 6A , vertical stud member  60  includes a center core  200  made from a timber strand material encased in a layer  210  of FRP material. The layer  210  desirably extends around the entire outer perimeter of the center core  200 . A plurality of layers  210  may be added to strengthen the vertical stud member  60 . Alternatively, as shown in  FIG. 6B , FRP material can be added only on one or more sides of the center core  200 . Adding the FRP material to the exterior of the center core  200  increases the loading strength of the vertical stud member  60 . Additionally, the layer  210  of FRP material adds an additional measure of protection to the center core  200  from damage by water, insects, and/or mold. 
     With continuing reference to  FIGS. 1 and 2 , rigid insulation  80  is fitted between the vertical stud members  30  of the frame  20 . The rigid insulation  80  is dimensioned to fit within each cavity formed between adjacent vertical stud members  30 , top beam  50 , and bottom beam  60 . The rigid insulation  80  thus becomes a part of the frame structure and contributes to the load-bearing capacity of the frame  20 . In one non-limiting embodiment, the rigid insulation  80  may be constructed from expandable polystyrene foam material having an R-value of  30 . One of ordinary skill in the art will understand that various other forms of rigid insulation may be amenable for use in the wall system  10 . Because the rigid insulation  80  is a structural part of the wall system  10 , conventional fibrous insulation which is generally attached to a backing paper is not suitable for use in the wall system  10 . This conventional insulation cannot be considered to be a suitable substitute for the rigid insulation  80  due to its fibrous properties. 
     With reference to  FIGS. 1 and 3 , front and back sides of the frame  20  are covered with sheet  90  which covers substantially all of the surface area on the front and back sides of the frame  20 . One sheet  90  is desirably affixed to each of the front and back sides of the frame  20  and/or the rigid insulation  80  using a waterproof adhesive (not shown). The sheet  90  generally does not provide any load-bearing function to the wall system  10 , but serves as a thermal barrier. 
     The sheet  90  may be constructed using a plurality of materials. In the embodiment shown in  FIG. 3 , sheet  90  which is applied on a side of the frame  20  which faces the exterior of a building may be a ¼″ fiberglass-reinforced plastic material. Similar material may be applied on a side of the frame  20  which faces the interior of the building. Alternatively, sheet  90  used on this side may have increased thermal and/or fire protection properties in compliance with American Society of Testing and Materials (ASTM) standards. For example, for sheet  90  used on the side of the frame  20  which faces the interior of the building, the fiberglass-reinforced plastic material may have a flame spread value of approximately 15 and a smoke development value of approximately 80. 
     With continuing reference to  FIGS. 1 and 3 , wall system  10  includes an upper channel beam  100  which is placed on the top beam  50 . The upper channel beam  100  is desirably manufactured from a high-strength and lightweight material, such as fiberglass-reinforced plastic (FRP). As shown in detail in  FIG. 3 , the upper channel beam  100  includes a top portion  110  and two side portions  120  extending from the sides of the top portion  110 . The upper channel beam  100  is dimensioned such that the top portion  110  extends across the width of the top beam  50  and the side portions  120  extend along the sides of the top beam  50  in a downward direction. The sheet  90  provided on the front and back sides of the frame  20  extends into the space created between the frame  20  and each of the side portions  120 . A plurality of upper channel beans  100  may be stacked for a higher load capacity. 
     The wall system  10  creates a modular construction which can be easily assembled offsite and delivered to the construction site in a finished state. In use, one or more wall systems  10  may be aligned in a desired manner to create the foundation wall of a building. For example, a plurality of wall systems  10  may be aligned to form a continuous wall section that extends in a linear direction. Alternatively, a plurality of wall systems  10  may be aligned to make a corner connection. The wall system  10  is desirably installed on a level footing surface  130  which constitutes the foundation of the building. The wall system  10  is desirably bolted, or otherwise secured, to the concrete footing surface  130 . As shown in  FIG. 3 , the wall system  10  may be secured to the footing surface  130  by being bolted to an angle bracket  140 . The footing surface  130  is desirably made from concrete. 
     In an alternate embodiment, the frame  20  may be positioned between a pair of beam columns  150  having an H-shaped cross section to retain the frame within a space provided on the beam columns  150 . A bottom portion of each beam column  150  is cast within a footer  160 . The beam columns  150  are spaced apart such that wall system  10  may be inserted between the beam columns  150  by lowering the wall system  10  between them. A part of the footer  160  may extend across the bottom of the frame  20 . In this manner, a modular wall system  10  is created which can be assembled offsite and transported to the construction site. A wall system  10  with a built-in footer  160  eliminates the need for pouring a concrete footer on the construction site before the wall system  10  can be assembled. 
     With reference to  FIG. 4 , an alternate embodiment of the wall system  10  is illustrated. In this embodiment, one or more armored panels  170  are substituted for one sheet  90 . The armored panel  170  used in this embodiment is desirably designed to withstand penetration by bullets of various caliber and shrapnel hitting the panel. In some embodiments, the armored panel  170  may be constructed from a ballistic-grade fiberglass-reinforced plastic material or a fiberglass material. The armored panel  170  may be placed on either side of the frame  20 . The user may install conventional drywall on top of the armored panel  170  for the purpose of concealing it. 
     With continuing reference to  FIG. 4 , the wall system  10  includes a sheet  90  applied to one side of the frame  20  and the armored panel  170  applied on the opposing side of the frame  20 . While the sheet  90  may be adhered to the frame  20  in a manner described above, armored panel  170  is desirably bolted or otherwise secured to the frame  20  via a plurality of fasteners  180 . Due to the increased weight of the armored panel  170  compared to the weight of sheet  90 , the armored panel  170  desirably rests upon the surface of a footer or a similar structure capable of withstanding its load. As shown in  FIG. 4 , the armored panel  170  rests on the footing surface  113 . Similar to the embodiment shown in  FIG. 3 , the wall system  10  shown in  FIG. 4  includes an upper channel beam  100  which is placed on top of the frame  20 . The upper channel beam  100  is desirably manufactured from a high-strength and lightweight material, such as fiberglass-reinforced plastic. The upper channel beam  100  is dimensioned such that the top portion  110  extends across the width of the top beam  50  and the side portions  120  extend along the sides of the top beam  50  in a downward direction. The sheet  90  provided on one side of the frame  20  extends into the space created between the frame  20  and the first side portion  120 , while the armored sheet  170  extends into the space created between the frame  20  and the second side portion  120  of the upper channel beam  100 . 
     With reference to  FIG. 5 , another alternate embodiment of the wall system  10  is illustrated. In this embodiment, one or more armored panels  170  are substituted for both sheets  90  provided on the front and back sides of the frame  20 . Similar to the embodiment described above with reference to  FIG. 4 , the armored panel  170  used in the embodiment shown in  FIGs. 6A-6B  is desirably designed to withstand penetration by bullets of various caliber and shrapnel hitting the panel. The user may install conventional drywall on top of the armored panel  170  on one or both sides of the frame  20  for the purpose of concealing the armored panel  170 . 
     With continuing reference to  FIG. 5 , the wall system  10  includes the armored panel  170  applied to one side of the frame  20  and the armored panel  170  applied on the opposing side of the frame  20 . The armored panel  170  is desirably bolted or otherwise secured to the frame  20  via a plurality of fasteners  180 . Due to the increased weight of the armored panel  170  compared to the weight of sheet  90  used in other embodiments, the armored panels  170  should desirably rest upon the surface of a footer or a similar structure capable of withstanding its load. As shown in  FIGs. 6A-6B , the armored panel  170  rests on the footing surface  130 . Similar to the embodiment shown in  FIGS. 3 and 4 , the wall system  10  shown in  FIG. 5  includes an upper channel beam  100  which is placed on top of the frame  20 . The upper channel beam  100  is desirably manufactured from a high-strength and lightweight material, such as fiberglass-reinforced plastic. The upper channel beam  100  is dimensioned such that the top portion  110  extends across the width of the top beam  50  and the side portions  120  extend along the sides of the top beam  50  in a downward direction. The armored panels  170  provided on both sides of the frame  20  extend into the space created between the frame  20  and the side portions  120  of the upper channel beam  100 . 
     Having described the structure of various embodiments of the wall system  10 , a method of assembling the wall system  10  will now be described. A frame  20  is constructed by aligning a plurality of vertical stud members  30  in a parallel arrangement in equally-spaced intervals and securing the vertical stud members to a top beam  50  and a bottom beam  60 . In some embodiments, a plurality of mechanical fasteners may be used to secure the vertical stud members to a top beam  50  and a bottom beam  60 . Each of the vertical stud members  30  may have a wiring chase  40  extending therethrough. 
     In the next step, the rigid insulation  80 , usually in the form of sheets, is placed into each cavity formed between adjacent vertical stud members  30 , top beam  50 , and bottom beam  60 . The rigid insulation  80  thus becomes a part of the frame structure and contributes to the load-bearing capacity of the frame  20 . 
     In the following step, depending on the embodiment, a pair of sheets  90  are then affixed to the front and back sides of the frame  20  using a waterproof adhesive. In an embodiment shown in  FIG. 4 , one sheet  90  is affixed to one side of the frame  20  while an armored panel  170  is affixed to the opposing side of the frame  20  using a plurality of fasteners  180 . In the embodiments shown in  FIGs. 6A-6B , armored panels  170  are secured to each side of the frame  20 . Next, an upper channel beam  100  is secured to the top beam  50  to create a modular wall system  10 . A plurality of individual wall systems  10  may be aligned to form a continuous foundation wall structure. In certain embodiments, wall system  10  includes the beam columns  150  which facilitate aligning the wall systems  10  to form a continuous foundation wall structure. Beam columns  150  may be designed to enable placing individual framed sections of the wall system  10  in a linear manner. Alternatively, beam columns  150  may be designed to enable placing an individual framed section of the wall system  10  to form a corner connection.