High strength light-framed wall structure

Abstract

A light-framed wall structure contains a wall frame of studs, a bottom plate and a single top plate that together define a stud cavity; exterior sheathing attached to the wall frame and covering the stud cavity; and a polyurethane foam within the stud cavity and affixed to the exterior sheathing, studs, bottom plate and top plate.

1 . A light-framed wall structure comprising:
 (a) studs spaced apart from one another in a range of nominally  16  to nominally 24 inches on center;   (b) a bottom plate and a single top plate spanning the studs and attached to opposing ends of the studs such that the studs, top plate and bottom plate define a wall frame having opposing interior and exterior surfaces with the studs, top and bottom plate further defining a stud cavity within the wall frame, the stud cavity having a height extending from bottom plate to top plate and a width extending from one stud to another stud;   (c) sheathing spanning the width and height of the stud cavity and overlapping the studs and attached to at least one of the exterior and interior surfaces of the wall frame; and   (d) polyurethane foam forming a seal around the inside perimeter of the stud cavity and affixed to the sheathing material on at least one surface of the wall frame, the stud, top plate and bottom plate where the polyurethane foam extends at least 1.5 inches over the sheathing, studs, top plate and bottom plate along the perimeter and further is present at an average thickness of at least 3.5 inches over the volume of the stud cavity within six inches of the top plate;   
       wherein the light-framed wall structure is free of metal corner connectors or reinforcements comprising a box-shaped section against which the studs, bottom plate and top plate abut. 
     
     
         2 . The light-framed wall structure of  claim 1 , wherein the studs are 2×4 dimensional building elements spaced apart from one another a nominal 24 inches on center. 
     
     
         3 . The light-framed wall structure of  claim 1 , wherein the sheathing material is selected from structural insulated sheathing, rigid insulated sheathing and gypsum board. 
     
     
         4 . The light-framed wall structure of  claim 1 , wherein the sheathing material is structural insulated sheathing. 
     
     
         5 . The light-framed wall structure of  claim 1 , wherein the polyurethane foam entirely covers any sheathing attached to at least one of the interior and exterior surfaces of the wall frame that would otherwise be exposed within the stud cavity. 
     
     
         6 . The light-framed wall structure of  claim 1 , wherein the polyurethane foam has a thickness anywhere in the stud cavity of at least one and one half inches thick as measured perpendicularly from the sheathing material to which the polyurethane foam is affixed. 
     
     
         7 . The light-framed wall structure of  claim 1 , wherein the sheathing is exterior sheathing attached to the exterior surface of the wall frame. 
     
     
         8 . The light-framed wall structure of  claim 7 , further comprising interior sheathing spanning the width and height of the stud cavity and overlapping the studs and attached to the interior surface of the wall frame. 
     
     
         9 . A light-framed wall structure comprising:
 (a) studs nominally spaced apart from one another 24 inches on center;   (b) a bottom plate and a single top plate spanning the studs and attached to opposing ends of the studs such that the studs, top plate and bottom plate define a wall frame having opposing interior and exterior surfaces with the studs, top and bottom plate further defining a stud cavity within the wall frame, the stud cavity having a height extending from bottom plate to top plate and a width extending from one stud to another stud;   (c) exterior sheathing spanning the width and height of the stud cavity and overlapping the studs and attached to the exterior surface of the wall frame; and   (d) polyurethane foam within the stud cavity and affixed to the exterior sheathing material, studs, top plate and bottom plate defining the stud cavity, the polyurethane foam having an average thickness of at least 0.5 inches within the stud cavity;   wherein the light-framed wall structure is free of metal corner connectors or reinforcements comprising a box-shaped section against which the studs, bottom plate and top plate abut.   
     
     
         10 . A process for making the light-framed wall structure of  claim 1 , the process comprising the following steps:
 (a) assembling studs spaced apart from one another in a range of nominally 16 to nominally 24 inches on center between a single top plate and a bottom plate so as to form a wall frame having opposing interior and exterior surfaces and defining a stud cavity between the studs and top and bottom plates and affixing the studs to the top and bottom plates;   (b) affixing sheathing to at least one of the exterior and interior surfaces of the wall frame over the studs and stud cavity; and   (c) disposing a polyurethane foam into the stud cavity so as to form a seal around the inside perimeter of the stud cavity that is affixed to the sheathing material on at least one surface of the wall frame, the studs, top plate and bottom plate defining the stud cavity, the polyurethane foam being disposed in such an amount so as to have an average thickness of at least 3.5 inches in the stud cavity within six inches of the top plate and extending at least 1.5 inches over the studs, top plate, bottom plate and sheathing around the inside perimeter of the stud cavity;   
       wherein the light-framed wall structure is free of metal corner connectors or reinforcement comprising a box-shaped section against which the studs, bottom plate and top plate abut. 
     
     
         11 . The process of  claim 10 , wherein the studs are 2×4 dimensional building elements and they are assembled spaced apart from one another nominally 24 inches on center. 
     
     
         12 . The process of  claim 10 , wherein the sheathing is selected from structural insulated sheathing material, rigid insulated sheathing and gypsum board. 
     
     
         13 . The process of  claim 10 , wherein the polyurethane foam is a spray polyurethane foam and step (c) includes spraying the polyurethane foam into place. 
     
     
         14 . The process of  claim 10 , wherein polyurethane foam is disposed so as to entirely cover any sheathing attached to at least one of the interior and exterior surfaces of the wall frame that would otherwise be exposed within the stud cavity. 
     
     
         15 . The process of  claim 10 , wherein the polyurethane foam is disposed so as to have an average expanded thickness of at least 1.5 inches within the stud cavity as measured perpendicularly from the sheathing to which the polyurethane foam is affixed. 
     
     
         16 . The process of  claim 10 , wherein the polyurethane foam is disposed to a greater thickness proximate to the top plate than on average within the stud cavity. 
     
     
         17 . The process of  claim 10 , comprises affixing sheathing to both the exterior and the interior surfaces of the wall frame over the studs and stud cavities. 
     
     
         18 . The process of  claim 10 , wherein the wall frame has multiple stud cavities defined therein by the studs, top plate and bottom plate and wherein step (b) includes affixing sheathing over multiple stud cavities and step (c) includes disposing polyurethane as described into multiple stud cavities. 
     
     
         19 . A building structure comprising the light-framed wall structure of  claim 1 .