A shaft wall assembly system including triangular shaped steel studs with one or more layers of wall board secured to one side of the triangular shaped steel studs. The triangular steel studs preferably rest in a notched floor runner and a notched ceiling runner. The one or more layers of wall board are then directly attached to a flat side of the triangular stud with properly sized steel screws. This system will be useful as a shaft wall system or in locations where attachment of wall board to both sides of a wall system is not feasible.

BACKGROUND 
     1. Field of the Invention 
     The invention relates generally to a shaft wall construction comprising of triangular studs used to hold wall panels in place during construction and service life of shaft walls in buildings. The system includes triangular shaped steel studs with one or more layers of gypsum board secured to one side of the triangular shaped steel studs. The triangular steel studs rest in a notched floor and ceiling runner. The one or more layers of gypsum board are then directly attached to a flat side of the triangular stud with properly sized steel screws. This system will typically be used as a shaft wall system or constructed in locations where attachment of gypsum board to both sides of a wall system is not feasible. 
     2. Background of the Invention 
     Walls around shafts, such as elevator shafts, were traditionally formed from concrete. Such installations required personnel working inside the shaft to have to wait until the walls were completed, then remove debris and other material from the concrete erection. 
     As an improvement to the concrete systems, the assignee of the present invention developed a system whereby drywall (such as SHEETROCK brand gypsum board, available from United States Gypsum Corporation of Chicago, Ill.) or other wall panels can be installed from outside the shaft, thereby significantly reducing any scaffolding, and construction debris inside the shaft. Such present day shaft wall assemblies are constructed from one side only, namely outside the shaft. By installing the wall panels from the outside, personnel working inside the shaft no longer needed to wait until the construction was completed to begin their work. 
     Such systems typically include a pair of J-runners into which a first wall panel is inserted, with the first J-runner along the top of the wall panel and a second J-runner along the bottom as well as both ends of the wall. The J-runner generally is formed from metals, such as steel, and typically includes a first short upstanding section and a second tall upstanding section in a substantially parallel configuration, each forming a substantially right angle with a middle section. Such a configuration allows for a first wall panel (or shaft panel) to be inserted between the upstanding sections to form the interior of the shaft. Additional wall panels can be affixed to the outside of the J-runners, typically to the outer surfaces of the short upstanding sections to form the interior of the room. In typical shaft wall constructions, wall studs, such as C-H studs and E-studs, are used to hold the wall panel in place. This type of construction is described by U.S. Pat. Nos. 3,943,680; 3,940,899; and 4,152,878, all to Balinski, each of which is hereby incorporated by reference in its entirety. 
     Shaft walls fasteners are not permitted to penetrate from the outermost wall through the assembly according to Fire Tests of Building Construction and Materials, UL 263, Jun. 21, 2011. ASTM E119-15 also limits fastener penetration in shaft wall assemblies. In other words the fastener, such as a nail or screw, cannot penetrate from the outer wall of the shaft wall assembly to the exposed inner space of the shaft. If fasteners do penetrate the assembly, temperature measurements are required to be measured on the heads of the fasteners. 
     To avoid fastener penetration into exposed inner space of the shaft a conventional shaft wall assembly employs a C-H stud  10  as shown in  FIG. 1 .  FIG. 2  shows a perspective view of an embodiment of such a shaft wall assembly  1  employing the C-H studs  12  and the first and second J-runners  10 ,  11  to hold the inner and outer walls in place. The first J-runner  10  and the second J-runner  11  are installed in a substantially parallel relationship as well as right and left ends which are not shown, with multiple C-H studs  12  positioned in a substantially perpendicular relationship between the first J-runner  10  and the second J-runner  11 . Each J-runner  10 ,  11  has a horizontal middle wall (section)  6 , a shorter vertical wall  2 , and a taller vertical wall  4  ( FIG. 2 ). The middle wall  4  forms a substantially planar transverse plane having opposed first and second longitudinal sides each, having a length, and opposed first and second ends, each having a width, wherein the length of each longitudinal side is greater than the width of each end. The shorter vertical wall  2  has a first height H 1  and the taller vertical wall  4  has a second height H 2 , wherein the first height H 1  is less than the second height H 2 . The shorter vertical wall  2  extends to the first height from the first longitudinal side of the middle wall  6 . The taller vertical wall  4  extends to the second height from the second longitudinal side of the middle section. The shorter vertical wall  2  and the taller vertical wall  4  are substantially parallel. The middle wall  6 , the shorter vertical wall  2  and the taller vertical wall  4  form a generally J-shape. 
     Positioned between the first J-runner  10  and the second J-runner  11 , and between each of the studs  12  is a single shaft liner panel  13 . Each shaft liner panel  13  has opposed vertical edges  16  (one shown) inserted into a respective cavity of a stud  12 .  FIG. 2  shows one edge  16  inserted into a first stud, while the opposed other edge is hidden within a cavity of a second adjacent stud  12 . As seen in  FIG. 2 , wall stud  12  has an in-turned lip  12   a  and the panel  13  is seated between walls of the stud  12  defining a cavity of the stud  12 . 
     Located outside the J-runners  10  and  11  are a pair of wall boards  14  and  15 . When fully installed as an inner surface of the shaft, shaft liner panel  13  forms the inside  28  ( FIG. 4 ) of the shaft, while an outer surface  17  of the wall board  14  forms the interior wall of a room. Additionally, a surface  13   a  of the shaft liner panel  13  and a surface  19  of the wall board  15  define a wall cavity  20 . The wall cavity  20  may be filled with insulation, electrical wiring, plumbing, and/or other building components. Fasteners  35  are selected from screws and nails and do not extend from the outer wall board  14  or  15  to the shaft liner panel  13 . Wall boards  14 .  15  are typically gypsum wallboard panels. 
     Typical gypsum wallboard panels and liner panels are made of Type X gypsum wallboard or Type C gypsum wallboard. ⅝″ Type X gypsum board provides one-hour fire protection when used on both sides of a steel partition. 
       FIG. 3  is a top view of a portion  30  of shaft wall assembly  1  with the J-runners omitted for clarity. This shows fasteners  35  selected from screws and nails do not extend to inside wall liner panels  13 . The C-H stud  12  is employed as part of the shaft wall assembly  1  having the inside wall made of liner panels  13  slid into opposed sides of the H-portion of the C-H stud  12  and a visible outer wall having two layers of wall board panels  15 ,  14 . The shaft wall assembly  1  employs fasteners  35  such as screws or nails to fasten panel  15  and panel  14  to C-H stud  10 .  FIGS. 2 and 3  show the inner wall liner panels  13  define the inside space  28  of the shaft wall assembly  1 , separate wall cavity  20  from the inside space  28  of the shaft wall assembly  1 , and prevents direct contact of the fasteners  35  with the inside space  28  of the shaft wall assembly  1 . 
       FIG. 3  only shows one fastener  35  attaching panels  14  and  15  to the C-H stud  12 . However, it is apparent from  FIG. 2  that some fasteners  35  attach panel  15  to the C-H stud  12  and other fasteners  35  attach both panel  14  and panel  15  to the C-H stud  12 . 
       FIG. 4  shows a modified version  40  of the shaft wall assembly of  FIG. 3 , wherein the outermost layer of panels  14  is omitted. The inside wall is made of liner panels  13  slid into opposed sides of the H-portion of the C-H stud  12 . The visible outside wall is made of one layer of gypsum wallboard panels  15  (one shown) attached to the C portion of the C-H stud  12  by fasteners  35  (one shown) selected from screws or nails. This also shows the fasteners  35  selected from screws and nails do not extend to liner panels  13 . 
     U.S. Pat. No. 7,712,267 to Lehane discloses a modification to the shaft wall assembly of  FIG. 2  wherein the first (or lower) J-runner  10  is modified to have one more lifting elements or ledge or both to permit simple centering of studs or shaft walls or both. By providing a lifting member in a lower J-runner, the studs or shaft walls or both can rest upon the lifting member to assist in vertically centering the studs or shaft walls or both when the shaft is fully constructed. Thus, the lifting elements allow for self-centering of the panel  13  between the J-runners  10 ,  11 .  FIG. 5  shows an embodiment of a shaft wall assembly employing a J-runner of Lehane having a lifting element  21 . 
     Preferably the lifting elements  21  form a flattened surface (ledge)  22  upon which the studs  12  and/or the shaft liner panel  13  can rest. Generally, shaft liner panel  13  is inserted into the J-runner  10 , pushed up the ramping edge  23  until it rests upon the ledge  22  and then slid horizontally until a first vertical edge of the shaft panel  13  is properly seated in a first stud  12 . Then the next stud  12  is put into place between the lower J-runner  10  and upper J-runner  11  and pushed against the shaft liner panel  13  to have a second vertical edge of the shaft panel  13  seat in a cavity of the second stud  12 . The lifting elements also provide a space  24  to define a drain. 
     Conventional shaft wall assemblies with C-H studs and panels have many benefits. For example, they are constructed from one side only, fire ratings are applicable from either side, they are proven by years of tests and real world use, and they provide relatively quick construction. However, a disadvantage of conventional shaft wall assemblies with C-H studs and panels is they require liner panels which can be difficult to produce and transport. Also, there is generally a limitation in size and gauge of C-H studs, for example they are employed with 24 inch wide liner panels. It would be beneficial to develop a construction that did not require liner panels. 
     SUMMARY OF THE INVENTION 
     To solve the deficiencies of conventional constructions, the shaft wall assembly of the invention is provided with one or more supporting studs having a triangular cross-section. Thus, fasteners, such as screws (for example type S drywall screws) can be screwed into the void space within the triangular stud so they are not exposed to the exposed inner space of a shaft wall assembly. The triangular studs are sized to have a depth to fit into a standard floor runner and ceiling runner. The floor runner may be a J-shaped runner or a C-shaped runner. Also, the ceiling runner may be a J-shaped runner or a C-shaped runner. Preferably, the floor and ceiling runners are C-shaped. 
     The C-runner which may be employed in the assembly of the invention includes a front upstanding section and a back upstanding section in a parallel configuration, each forming a substantially right angle with a middle section, with optional lifting elements positioned on the middle section and/or upstanding sections. The front upstanding section and the back upstanding section have about the same height. 
     The J-runner if employed in the assembly of the invention includes a short upstanding section and a tall upstanding section in a parallel configuration, each forming a substantially right angle with a middle section, with optional lifting elements positioned on the middle section and/or upstanding sections. 
     Regardless of whether the runner is a C-runner or J-runner is employed, if desired a notched runner is employed with notches every 6 to 12 inches on center (OC), typically 8 inches OC to accommodate for multiple stud spacing scenarios. The notch is an indentation or a protrusion on one of the upstanding walls of the runner. One, two, three or even 4 layers of gypsum board are secured to only one side of the triangular studs. The system will be asymmetrical with gypsum board on only one side of the wall and one face of the triangle. 
     In particular the invention provides a shaft-wall assembly comprising: 
     a shaft wall having upper, lower, left and right sides; 
     a floor runner positioned adjacent to the lower side of the shaft wall, a ceiling runner, positioned adjacent to the upper side of the shaft wall, 
     wherein each of the floor runner and the ceiling runner comprises: 
     a substantially planar transverse middle section having opposed first and second longitudinal sides each having a length and opposed first and second ends each having a width, wherein the length of each longitudinal side is greater than the width of each end; 
     a first upstanding section and a second upstanding section, wherein the first upstanding section has a first height and the second upstanding section has a second height, the first upstanding section extending to the first height from the first longitudinal side of the middle section, and the second upstanding section extending to the second height from the second longitudinal side of the middle section 
     a triangular stud of the shaft wall between the floor runner and the ceiling runner, the triangular stud having a triangular polyhedron shape comprising three sidewalls defining a triangular bottom perimeter and a triangular top perimeter; 
     the floor runner and the triangular stud sized for a first said side of the triangular stud to contact the first upstanding section of the floor runner and a vertex of the triangular stud opposed to the first side of the triangular stud to contact the second upstanding section of the floor runner. 
     If a J-runner as a floor or ceiling runner is employed the first height is less than the second height. If a C-runner is employed as a floor or ceiling runner the first height and the second height are equal. 
     The invention also provides a triangular stud for a shaft wall, the triangular stud having a triangular polyhedron shape comprising three sidewalls defining a triangular bottom perimeter and a triangular top perimeter, a lower end portion of the triangular stud having a notch for mating with a protrusion of a J-runner. 
     The invention also provides a runner comprising: 
     a substantially planar transverse middle section having opposed first and second longitudinal sides each having a length and opposed first and second ends each having a width, wherein the length of each longitudinal side is greater than the width of each end; 
     a first upstanding section and a second upstanding section, wherein the first upstanding section has a first height and the second upstanding section has a second height, the first upstanding section extending to the first height from the first longitudinal side of the middle section, and the second upstanding section extending to the second height from the second longitudinal side of the middle section, wherein the first upstanding section and the second upstanding section are substantially parallel; 
     wherein the runner has at least one feature selected from the group consisting of vertically elongated indentations spaced along the first upstanding section and vertically elongated protrusions spaced along the first upstanding section. 
     If a J-runner is employed as a floor or ceiling runner the first height is less than the second height. If a C-runner is employed as a floor or ceiling runner the first height and the second height are equal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a top view of a C-H stud of the prior art. 
         FIG. 2  is a cut-away perspective view of a first embodiment of a shaft wall assembly of the prior art employing the C-H stud of  FIG. 1  in an installed condition. 
         FIG. 3  is a cross-sectional top view of a portion of the assembly of  FIG. 2  with the J-runners removed for clarity. 
         FIG. 4  is a cross-sectional top view of a modified version of the assembly of  FIG. 3 . 
         FIG. 5  is a cross section of the assembly of  FIG. 2  along line V-V modified to add a lifting element. 
         FIG. 6  is a perspective view of a first embodiment of a shaft wall assembly of the present invention employing triangular studs and C-runners and having a portion of a wall cut-away to show details of the embodiment. 
         FIG. 6A  is a perspective view of a first embodiment of a shaft wall assembly of the present invention employing triangular studs and J-runners and having a portion of a wall cut-away to show details of the embodiment. 
         FIG. 7  is a top cross section of a triangular stud of the assembly of  FIG. 6  having notches to assist placement. 
         FIG. 8  is a top view of a J-runner of the invention having indentations on its lower wall to assist in placing the triangular stud of  FIG. 7  in the assembly of  FIG. 6 . 
         FIG. 9  illustrates a top view of a portion of the assembly of  FIG. 6 , including the lower J-runner of  FIG. 8  and including the panels attached by fasteners to the triangular studs of the invention, however, the indentations of the J-runner of  FIG. 8  are omitted in the drawing for clarity. 
         FIG. 10  shows a top view of an alternative embodiment of the triangular stud without the notches, but having an overlapping corner forming a seam or punch connection. 
         FIG. 11  shows a perspective view of the alternative embodiment of  FIG. 10  having the overlapping corner forming the seam or punch connection. 
         FIG. 12  is a top view of a J-runner of the invention having protrusions on its higher wall to assist in placing the triangular stud of  FIG. 11  in a modified version of the assembly of  FIG. 6 . 
         FIG. 13  is a top view of the embodiment of  FIG. 12  modified to have a J-runner of the invention having protrusions on its higher wall to assist in placing the triangular stud of  FIG. 11  in a version of the assembly of  FIG. 6  employing a J-runner further modified to include stand-offs as lifting elements for drainage and to assist in placement of the triangular studs. 
         FIG. 14  is a side-view cross-section along view XIV-XIV of  FIG. 13  including the lifting elements for drainage and to assist in placement of the triangular studs. 
         FIG. 15  is a perspective-view of the embodiment of  FIG. 13  including tabs as the lifting elements for drainage and to assist in placement of the triangular studs. 
         FIG. 16  is a top view of the embodiment of  FIG. 12  modified to have a J-runner of the invention having protrusions on its higher wall to assist in placing the triangular stud of  FIG. 11  in a version of the assembly of  FIG. 6  employing a J-runner further modified to include tabs as lifting elements for drainage and to prop up the triangular studs. 
         FIG. 17  is a side-view cross-section along view XVII-XVII of  FIG. 16  including tabs as lifting elements for drainage and to assist in placement of the triangular studs. 
         FIG. 18  is a perspective-view of the embodiment of  FIG. 16  including the tabs as lifting elements for drainage and to assist in placement of the triangular studs. 
         FIG. 19  shows a top view of another alternative embodiment of the triangular stud without the notches, but having a symmetrically overlapping corner forming a seam or punch connection. 
         FIG. 20  shows a top view of another alternative embodiment of the triangular stud without the notches, but having a side including a symmetrically overlapping section forming a seam or punch connection. 
         FIG. 21  shows a top view of the embodiment of  FIG. 13  further including blocking applied to the face of the studs to add structural stability. When the panels are horizontal one screw may be employed as shown in the center stud, but when the panels are vertical two screws are employed as in the left and right triangular studs. 
         FIG. 22  shows a perspective view of the blocking of  FIG. 21 . 
         FIG. 23  is a perspective view of an embodiment of a shaft wall assembly of the invention employing triangular studs and the blocking of  FIG. 21 . 
     
    
    
     In the figures, like numbered elements have the same configurations unless otherwise indicated. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the embodiment of shaft wall  101  of  FIG. 6 , typically, a floor C-runner  10  and a ceiling C-runner  11  are installed in a substantially parallel relationship, with multiple triangular studs  112  positioned in a substantially perpendicular relationship between the floor C-runner  10  and the ceiling C-runner  11 . 
     The triangular stud  112  of the shaft wall is between the floor C-runner  10  and the ceiling C-runner  11 . The triangular stud  112  has a triangular polyhedron shape comprising three sidewalls defining a triangular bottom perimeter and a triangular top perimeter. Preferably, all transverse cross-sections of the triangular stud  112  parallel to the top perimeter and the bottom perimeter are the same triangle. 
     Each C-runner  10 ,  11  has a horizontal middle wall (section)  6 , a first vertical wall  2 , and a second vertical wall  4  ( FIG. 6 ). Height H 1  of the first vertical wall  2  and height H 2  of the second vertical wall  4  are about the same. The middle wall  6  forms a substantially planar transverse plane having opposed first and second longitudinal sides each, having a length, and opposed first and second ends, each having a width, wherein the length of each longitudinal side is greater than the width of each end. The first vertical wall  2  extends to the first height H 1  from the first longitudinal side of the middle wall  6 . The second vertical wall  4  extends to the second height H 2  from the second longitudinal side of the middle section. The first vertical wall  2  and the second vertical wall  4  are substantially parallel. The middle wall  6 , the first vertical wall  2  and the second vertical wall  4  form a generally C-shape. 
     Unlike the conventional system  1  of  FIG. 2 , the shaft wall assembly system  101  of the present invention has no shaft liner panel positioned between the floor runner  10  and the ceiling J-runner  11 , and between each of the studs  112 . Points of the fasteners  35  end within a cavity within the triangular stud so they do not contact the inside space  28  of the shaft wall assembly  1  of the shaft wall assembly  101 . There is no need for shaft liner panels to separate the pointed inner ends of the fasteners from the inside space  28  of the shaft wall assembly. 
     Located outside the C-runners  10  and  11  are a pair of wall boards  14  and  15 . When fully installed an inner surface of wall board  15  forms the inside of the shaft, while an outer surface of the wall board  14  forms the interior wall of a room. 
     Located outside the J-runners  10  and  11  are a pair of wall boards  14  and  15 . When fully installed an inner surface of wall board  15  forms the inside of the shaft, while an outer surface of the wall board  14  forms the interior wall of a room. 
     The embodiment of shaft wall  101 A of  FIG. 6A  is substantially the same as that of  FIG. 6  but employs J-runners  10 A, and  11 A rather than C-runners. With reference to  FIG. 6A , typically, a floor J-runner  10 A and a ceiling J-runner  11 A are installed in a substantially parallel relationship, with multiple triangular studs  112  positioned in a substantially perpendicular relationship between the floor J-runner  10 A and the ceiling J-runner  11 A. 
     The triangular stud  112  of the shaft wall is between the floor J-runner  10 A and the ceiling J-runner  11 A. The triangular stud  112  has a triangular polyhedron shape comprising three sidewalls defining a triangular bottom perimeter and a triangular top perimeter. Preferably, all transverse cross-sections of the triangular stud  112  parallel to the top perimeter and the bottom perimeter are the same triangle. 
     Each J-runner  10 A,  11 A has a horizontal middle wall (section)  6 , a shorter first vertical wall  2 A, and a taller second vertical wall  4 A ( FIG. 6 ). The middle wall  6  forms a substantially planar transverse plane having opposed first and second longitudinal sides each, having a length, and opposed first and second ends, each having a width, wherein the length of each longitudinal side is greater than the width of each end. The shorter first vertical wall  2 A has a first height H 1 A and the taller second vertical wall  4 A has a second height H 2 A, wherein the first height H 1 A is less than the second height H 2 A. The shorter first vertical wall  2 A extends to the first height from the first longitudinal side of the middle wall  6 . The taller second vertical wall  4 A extends to the second height from the second longitudinal side of the middle section. The shorter first vertical wall  2  and the taller second vertical wall  4  are substantially parallel. The middle wall  6 , the shorter first vertical wall  2  and the taller second vertical wall  4  form a generally J-shape. 
     Unlike the conventional system  1  of  FIG. 2 , the shaft wall assembly system  101 A of the present invention has no shaft liner panel positioned between the floor J-runner  10 A and the ceiling J-runner  11 A, and between each of the studs  112 . Points of the fasteners  35  end within a cavity within the triangular stud so they do not contact the inside space  28  of the shaft wall assembly  1  of the shaft wall assembly  101 A. There is no need for shaft liner panels to separate the pointed inner ends of the fasteners from the inside space  28  of the shaft wall assembly. 
     Located outside the J-runners  10 A and  11 A are a pair of wall boards  14  and  15 . When fully installed an inner surface of wall board  15  forms the inside of the shaft, while an outer surface of the wall board  14  forms the interior wall of a room. 
       FIG. 7  is a top cross section of the triangular stud  112  of the assembly  101  of  FIG. 6  (and assembly  101  of  FIG. 6A ). The triangular stud  112  has notches  113  to assist placement. The notches  113  are formed by cutting and bending back wings  113   a  ( FIG. 8 ) of metal of the triangular stud at an upper end and lower end of the triangular stud. The triangular stud  112  has a hollow interior. 
       FIG. 8  is a top view of the triangular stud  112  of  FIG. 7  placed on a C-runner  110  of the invention. C-runner  110  has a first vertical wall  102 , a second vertical wall  104 , and a horizontal middle wall  106 . J-runner  110  is modified to have indentations  118  on its shorter vertical wall to assist in placing the triangular stud  112  of  FIG. 7  in a shaft wall assembly such as that of  FIG. 6  or  FIG. 6A . The indentations  118  mate with the notches  113 . Preferably the indentations are 6 to 12 inches apart on center (OC), typically 8 inches apart OC. 
       FIG. 9  illustrates a top view of a portion of the assembly  101  of  FIG. 6 , modified to include the floor runner  110  of  FIG. 8  and the wall boards  14 ,  15  attached by fasteners  35  to the triangular studs  112  of the invention. However, the indentations of the floor runner  110  of  FIG. 8  are omitted in  FIG. 9  for clarity. 
       FIG. 10  shows a top view of an alternative embodiment of a triangular stud  142  of the invention without the notches, but having an overlapping corner forming a seam or punch connection  144 . A seam is when two pieces of steel are basically rolled over to connect them. A punch connection would punch out a small section of steel creating a tab that will connect the two pieces of steel. 
       FIG. 11  shows a perspective view of the triangular stud  142  of  FIG. 10  having the overlapping corner forming the seam or punch connection  144  and a hollow interior. 
       FIG. 12  is a top view of a C-runner  150  of the invention. C-runner  150  has a first vertical wall  152 , a second vertical wall  154 , and a horizontal middle wall  156 . C-runner  150  is modified to have protrusions  158  on its second wall  154  to assist in placing the triangular stud  142  of  FIG. 11  in a modified version of the assembly of  FIG. 6 . If desired the invention can employ a J-runner (not shown) modified to likewise have protrusions  158  on its higher wall  154  to assist in placing the triangular stud  142  of  FIG. 11  in a modified version of the assembly of  FIG. 6A . 
       FIG. 13  is a top view of the embodiment of  FIG. 12  further modified to include C-runner  150   a  having stand-offs  151  as lifting elements for drainage and to assist in placement of the triangular studs  142 . The lifting elements  151  allow for self-centering of the triangular studs  142  between the C-runners. Preferably only the floor C-runner  150   a  is provided with lifting elements  151 . However, if desired both upper and lower C-runners may be provided with lifting elements  151 . The triangular wall stud  142  lines up with a respective lifting element  151 . If the wall stud  142  rests on the lifting element  151 , then the wall stud  142  will be centered. These lifting elements  151  are preferably constructed to allow for self-centering of the studs  142  in a vertical direction during installation and when assembled. Self-centering means the studs  142  are spaced above the middle wall  156  of the floor C-runner  150   a . If desired the invention can employ a J-runner (not shown) modified likewise in a modified version of the assembly of  FIG. 6A . 
     A first end of the lifting element  151  is proximal to the shorter vertical wall  152  and a second end of the lifting element  151  is distal to the shorter vertical wall  152 . At least one triangular stud  142  is positioned on the lifting element  159 . Also, preferably the lifting element  151  defines a drain in the horizontal middle wall  156  below the lifting element  151 . 
       FIG. 14  is a side-view cross-section of the C-runner  150   a  of  FIG. 13  along view XIV-XIV of  FIG. 13  including the lifting elements  151  for drainage and to assist in placement. This shows a ramping edge  153  of the lifting element  151  can define an angle “a” of between 25° and 75°, preferably about 64° with respect to a y-axis parallel to the second upstanding section  154 . The lifting element  151  can have a curved profile as shown in  FIG. 14  or form a substantially transverse, top shelf (not shown). The lifting element  151  can have a total length K of about 3 to 12 inches. The lifting element  151  can have a height at its open mouth  155  of about 0.5 to 1 inch. 
       FIG. 15  is a perspective-view of the J-runner  150   a  of  FIG. 13  including the lifting elements  151  for drainage and to assist in placement. 
       FIG. 16  is a top view of the embodiment of  FIG. 12  further modified to include C-runner  150   b  having tabs  161  as a lifting elements for drainage and to assist in placement of the triangular studs  142 . The lifting elements  161  allow for self-centering of the triangular studs  142  between the C-runners. Preferably only the floor C-runner  150   a  is provided with the tabs  161  as lifting elements. However, if desired both floor and ceiling C-runners may be provided with the tabs  161 . The triangular stud  142  lines up with respective lifting elements  161 . If the wall stud  142  rests on the tabs  161 , then the wall stud  142  will be centered. These tabs  161  are preferably constructed to allow for self-centering of the studs  142  in a vertical direction during installation and when assembled. Self-centering means the studs  142  are spaced above the middle wall  156  of the floor C-runner  150   b.    
       FIG. 17  is a side-view cross-section of the C-runner  150   b  of  FIG. 16  along view XVII-XVII of  FIG. 16  including the tabs  161  as lifting elements for drainage and to assist in placement of the triangular wall studs. This shows a ramping edge  163  of the lifting element  161  can define an angle “a” of between 25° and 75°, preferably about 64° with respect to a y-axis parallel to the second upstanding section  154 . The lifting element  161  can have a curved profile as shown in  FIG. 17  or form a substantially transverse, shelf (not shown). The lifting element  161  can have a height from horizontal middle wall  156  to the highest point of its open mouth  165  of about 0.5 to 1 inch and a width at its open mouth  165  along horizontal middle wall  156  of about 0.5 to 1 inch. 
       FIG. 18  is a perspective-view of the C-runner  150   b  of  FIG. 17  including the tabs  161  as lifting elements for drainage and to assist in placement. 
       FIG. 19  shows a top view of another alternative embodiment of the triangular stud  162  without the notches, but having a symmetrically overlapping corner forming a seam or punch connection  164 . 
       FIG. 20  shows a top view of another alternative embodiment of the triangular stud  172  without the notches, but having a side including a symmetrically overlapping section forming a seam or punch connection  174 . 
       FIG. 21  shows a top view of the embodiment of  FIG. 13  further including blocking  180  applied to the face of the studs to add structural stability. If the wall boards  14 ,  15  are horizontal then one screw  35  may be sufficient as shown in the center stud  142 , but when the panels are vertical two screws are employed as shown in the left and right triangular studs  142 . 
       FIG. 22  shows a perspective view of the blocking  180  of  FIG. 21 . The blocking  180  has a center wall  186  and upright walls  184  defining a series of gaps  188  for engaging respective triangular studs  142 . 
       FIG. 23  is a perspective view of an embodiment  191  of a shaft wall assembly of the invention employing floor C-runner  150   a , ceiling C-runner triangular studs  142 , and the blocking  180  of  FIG. 21 . 
     The studs  12  can take the form of any stud having a triangular cross section suitable for placing in the present C-runner or J-runner. Typical materials for the studs include steel. 
     For beginning or terminating a wall, typically a metal framing member with a C or L profile is used. 
     The C-runners, J-runners, and the triangular studs of the invention can be formed of any suitable material. Typical materials include steel, for example 24 gauge (0.024 in, 0.6 cm) or 20 gauge (0.035 in, 0.9 cm) or other suitable gauges. The C-runners and J-runners and triangular studs can be formed by stamping or roll forming. To form the lifting elements, e.g. lifting element  151  or protrusions  158  of a runner, the runner can be lanced, stamped, pierced or notched. 
     C-runners and J-runners employed in the present invention including a bottom (middle) section  71 , a shorter wall  69 , and lifting elements  129 . With reference to  FIG. 15 , C-runner  150   a  typically has a total width “A” of from about 2 to 6 inches (5.1 to 15.2 cm), typically either 2.5 or 4.0 inches (6.4 or 10.2 cm), between its first upstanding wall  152  and its second upstanding wall  154 . The first and second upstanding walls typically have a height “B” of from about 0.75 to 2.0 inches (1.9 to 5.1 cm), preferably approximately 1 inch (2.54 cm). 
     J-runners are the same except the shorter upstanding wall typically has a height of from about 0.75 to 2.0 inches (1.9 to 5.1 cm), preferably approximately 1 inch (2.54 cm), while the taller upstanding wall typically has a height of from about 1.5 to 4 inches (3.8 to 10.2 cm), preferably about 2.0 to 2.5 inches (5.1 to 6.4 cm), more preferably about 2.1 inches (5.3 cm). 
     Although  FIG. 20  shows an installation with a floor C-runner  110  of the invention, i.e., with lifting elements  159 , and the ceiling C-runner  11  without any lifting elements, it is considered within the scope of the invention to utilize two same C-runners of the invention, e.g., two C-runners  110 , i.e., one above the triangular studs  142  and one below the triangular studs  142 . Likewise, it is considered within the scope of the invention to utilize a first J-runner of one embodiment of the invention in combination with a C-runner of another embodiment of the invention. Likewise it is within the scope of the invention to substitute the different embodiments of triangular studs for each other. Likewise, a similarly modified J-runner may be employed for both the floor runner and ceiling runner. 
     The invention has many advantages. It employs one or more, preferably two or more, most preferably 2 or 3, layers of wall board attached to one side of the triangular studs. The studs are triangular so the pointed end of the screw goes into the stud and is not exposed. Thus, the shaft wall of the invention does not need an inner liner panel wall as do shaft walls made with C-H studs. All the wall boards of the present shaft wall assembly are actually attached to studs rather than having some attached and others slidingly held by a runner and C-H studs. 
     Generally in assembling the shaft wall assembly the triangular studs are not attached to the top or bottom J-runner. Thus, to assist in placing the triangular stud, preferably the triangular stud has the notch described above for mating with an indentation on the inner shorter wall of the J-runner. Another preferred enhancement to assist in placing the triangular stud is for the J-runner to have the above-described protrusions along its outer taller wall to form cavities in which to locate an edge of the triangular stud. 
     Triangular studs are stronger than C-H studs for a given composition and gage of metal from which they are made. Thus, the shaft wall assemblies of the present invention can be made taller than shaft wall assemblies made with C-H studs. 
     CAD EXAMPLES 
     A Computer Assisted Design (CAD) simulation was run to compare a conventional 20 Gauge C-Stud with a 25 Gauge Triangle Studs of the present invention. The 25 Gauge Triangle Studs of the present invention was notched as shown by  FIG. 7  and had the cross-section configuration shown in  FIG. 10 . 
     TABLE 1 shows mechanical properties achieved out of the CAD computer simulations. This data shows the 25 Gauge triangular stud at 3⅝″ was equivalent to a 20 Gauge C-Stud at 3⅝″ deep. 
     
       
         
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Triangular Shaped Stud 
                 Conventional C  
               
               
                   
                 (Mass Properties CAD of 
                 Studs 
               
               
                 Parameter 
                 FIG. 10 triangular stud) 
                 (SSMA 2015 IBC)* 
               
               
                   
               
             
             
               
                 Area (A) (in 2 ) 
                 0.242 
                 0.194 
               
               
                 Moment Of Inertia 
                 0.709 
                 0.381 
               
               
                 (MOI X) (in 4 ) 
                   
                   
               
               
                 Moment Of Inertia  
                 1.468 
                 0.033 
               
               
                 (MOI Y) (in 4 ) 
                   
                   
               
               
                 Effective Section 
                 0.3484 
                 0.156 
               
               
                 Modulus (S X) (in 3 ) 
                   
                   
               
               
                 Gauge 
                 25 gauge (0.0188 in.) 
                 20 gauge (0.0312 in.) 
               
               
                 Depth (in.) 
                 3⅝ in. 
                 3⅝ in. 
               
               
                 Width (in.) 
                 4 3/16 in. 
                 1¼ in. 
               
               
                   
               
               
                 *Steel Stud Manufacturer's Association 2015 International Building Code 
               
             
          
         
       
     
     The CAD simulation showed the triangular stud configuration has multiple advantages. It has greater moment of inertia about strong “X” access allowing for increase in limiting heights. It also has much greater weak moment of inertia about “Y” access allowing for greater unbraced lengths, especially in instances where wallboard sheathing is only on one side. The stud allows easy of installation in case of a vertical board joint since there is more space for two rows of fasteners. 
     It should be apparent that embodiments other than those specifically described above may come within the spirit and scope of the present invention. Hence, the present invention is not limited by the above description.