Patent Publication Number: US-8122676-B2

Title: Top-chord bearing wooden joist

Description:
FIELD OF THE APPLICATION 
     The present application relates to wooden joists and, more particularly, to a wooden joist used in a top-chord bearing configuration. 
     BACKGROUND OF THE ART 
     Wooden joists are horizontal supporting members that run from wall to wall, wall to beam, or beam to beam to support a ceiling, roof or floor. Wooden joists have a pair of horizontal chords, interrelated by a board in an I-joist configuration, or by V-shaped webs, in an open-joist or joist configuration. 
     When wooden joists are transversely connected to beams, metal hangers are used to interrelate the joists to the beams. Hangers are brackets that are secured to the beam, and that define a U-shaped so as to support an end of a joist. Hangers are costly items, and require a non-negligible amount of skilled manpower to use. 
     Some wooden joists are used in a top-chord bearing configuration. In this configuration, the top chord has an extension projecting beyond the bottom chord at an end of the joist. The extension is seated on top of a beam, when the joist is transversely positioned on a beam. As all-wooden joists typically use an adhesive between the chords and the wooden webs/board, all-wooden joists are not used in a top-chord bearing configuration. The top-chord bearing configuration is used with open joists in which the webs are metal, or in open joists in which metal square plates interface the wooden webs to the chords. Both these open joists are relatively expensive as they use numerous metal components. 
     SUMMARY OF THE APPLICATION 
     It is therefore an aim of the present application to provide a novel wooden joist for use in a top-chord bearing configuration. 
     It is a further aim of the present application to a method for adapting a wooden joist to a top-chord bearing configuration. 
     Therefore, in accordance with the present application, there is provided a wooden joist comprising: a wooden top chord; a wooden bottom chord; a main section comprising at least one of wooden boards and wooden webs adhesively connected to the wooden top chord and to the wooden bottom chord to form at least one of an I-joist subsection and an open-joist subsection along the main section of the wooden joist; an end configuration at least one end of the main section, comprising: a wooden post extending generally perpendicularly between the wooden top chord and the wooden bottom chord and being adjacent to the main section; a wooden diagonal web extending diagonally from the wooden top chord to the wooden bottom chord; a first set of metal plates in alignment on opposed sides of the wooden joist to connect the wooden top chord to the diagonal web; a second set of metal plates in alignment on opposed sides of the wooden joist to connect the diagonal web and the post to the bottom chord; a third set of metal plates in alignment on opposed sides of the wooden joist to connect the wooden top chord to the post; and an extension defined by the wooden top chord extending beyond the diagonal web at an end of the wooden joist; whereby the wooden joist is adapted to be in a top-chord bearing relation with a beam by the extension being on top of the beam. 
     Further in accordance with the present application, there is provided a wooden joist comprising: a wooden top chord; a wooden bottom chord; a main section comprising at least one of wooden boards and wooden webs adhesively connected to the wooden top chord and to the wooden bottom chord to form at least one of an I-joist subsection and an open-joist subsection along the main section of the wooden joist; an end configuration at least one end of the main section, comprising: a first wooden post extending generally perpendicularly between the wooden top chord and the wooden bottom chord and being adjacent to the main section; a wooden diagonal web extending diagonally from the wooden top chord to the wooden bottom chord; a wooden second post extending generally perpendicularly from the wooden top chord to the wooden bottom chord at an end of the bottom chord; a first set of metal plates in alignment on opposed sides of the wooden joist to connect the wooden top chord to the diagonal web and to the first post; a second set of metal plates in alignment on opposed sides of the wooden joist to connect the diagonal web and the second post to the bottom chord; a third set of metal plates in alignment on opposed sides of the wooden joist to connect the wooden top chord to the second post; a fourth set of metal plates in alignment on opposed sides of the wooden joist to connect the wooden bottom chord to the first post; and an extension defined by the wooden top chord extending beyond the second post at an end of the wooden joist; whereby the wooden joist is adapted to be in a top-chord bearing relation with a beam by the extension being on top of the beam. 
     Still further in accordance with the present application, there is provided a wooden joist comprising: a wooden top chord; a wooden bottom chord; a main, section comprising at least wooden boards adhesively connected to the wooden top chord and to the wooden bottom chord to form at least an I-joist subsection along the main section of the wooden joist; an end configuration at least one end of the main section, comprising: a wooden post extending generally perpendicularly between the wooden top chord and the wooden bottom chord and being adjacent to the I-joist subsection of the main section; a first set of metal places in alignment on opposed sides of the wooden joist to connect the wooden top chord to the wooden post; a second set of metal plates in alignment on opposed sides of the wooden joist to connect the post to the bottom chord; and an extension defined by the wooden top chord extending beyond the post at an end of the wooden joist; whereby the wooden joist is adapted to be in a top-chord bearing relation with a beam by the extension being on top of the beam. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a joist-end configuration in accordance with a first embodiment of the present disclosure, the first joist-end configuration being adjacent to an open-joist section of a joist; 
         FIG. 2  is a schematic view of the joist-end configuration of  FIG. 1 , as adjacent to an I-joist section of a joist; 
         FIG. 3  is a schematic view of the joist-end configuration of  FIG. 1 , with a support block; 
         FIG. 4  is a schematic view of the joist-end configuration of  FIG. 3 , as adjacent to an I-joist section of a joist; 
         FIG. 5  is a schematic view of the joist-end configuration of  FIG. 3 , with a secondary post; 
         FIG. 6  is a schematic view of the joist-end configuration of  FIG. 1 , as adjacent to an I-joist section of a joist; 
         FIG. 7  is a schematic view of the joist-end configuration of  FIG. 5 , with a support block; 
         FIG. 8  is a schematic view of the joist-end configuration of  FIG. 7 , as adjacent to an I-joist section of a joist; 
         FIG. 9  is a schematic view of the first joist-end configuration of  FIG. 1 , with a secondary top chord; 
         FIG. 10  is a schematic view of the joist-end configuration of  FIG. 9 , as adjacent to an I-joist section of a joist; 
         FIG. 11  is a schematic view of the joist-end configuration of  FIG. 9 , with a longer secondary top chord; 
         FIG. 12  is a schematic view of a joist-end configuration in accordance with another embodiment of the present disclosure, the joist-end configuration being adjacent to an open-joist section of a joist; 
         FIG. 13  is a schematic view of the joist-end configuration of  FIG. 12 , as adjacent to an I-joist section of a joist; 
         FIG. 14  is a schematic view of the joist-end configuration of  FIG. 12 , with a support block; 
         FIG. 15  is a schematic view of the joist-end configuration of  FIG. 14 , as adjacent to an I-joist section of a joist; 
         FIG. 16  is a schematic view of a joist-end configuration in accordance with yet another embodiment of the present disclosure, the joist-end configuration being adjacent to an I-joist section of a joist; 
         FIG. 17  is a longitudinal view of a joist with the joist-end configuration of  FIG. 2  at one end; 
         FIG. 18  is a longitudinal view of a joist with the joist-end configuration of  FIG. 7  at one end; 
         FIG. 19  is a longitudinal view of an I-joist section with the joist-end configurations of  FIG. 2  at both ends; and 
         FIG. 20  is a longitudinal view of an I-joist section with the joist-end configuration of  FIG. 10  at one end. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, and more particularly to  FIGS. 1 to 19 , joist-end configurations are illustrated at the ends of joists comprising a top chord  1 , a bottom chord  2 , and a main section of joist comprising at least one of an open-joist subsection of wooden webs  3  ( FIG. 1 ), and an I-joist subsection of wooden boards  4  ( FIG. 2 ). Reference numerals  1  to  4  are used hereinafter to refer to these components. The joists of  FIGS. 1-19  are said to be all-wooden, in that the top chord  1 , the bottom chord  2 , the open-joist subsection of wooden webs  3  and the I-joist subsection of wooden boards  4  are interconnected by an adhesive, and complementary joints (e.g., finger joints). 
     Referring to  FIG. 1 , a first joist-end configuration is illustrated at  10 , at the end of an open-joist section of a joist. The first joist-end configuration  10  has a diagonal  11  (a.k.a., an end web) and a post  12  (i.e., column) between the top chord  1  and the bottom chord  2 . The diagonal  11  is connected to the top chord  1  by a first set  13  of metal plates (one shown, but with one on each side of the top chord  1 ). The diagonal  11  and the post  12  intersect at the bottom chord  2 , with a second set  14  of metal plates (one shown) connecting the bottom chord  2 , the diagonal  11  and a bottom end of the post  12 . The diagonal  11  has a double-cut end so as to have a first surface in planar contact with the bottom chord  12 , and a second surface in planar contact with the post  12 . A top end of the post  12  is connected to the top chord  1  by a third set  15  of metal plates. For clarity of the illustrations, the sets of metal plates are shown as being transparent throughout  FIGS. 1 to 10 . 
     The metal plates of the sets  13 ,  14  and  15  and all other sets described hereinafter are of the type having serrated surfaces that will grip into the wooden components when pressed against them. The metal plates (which may be a plurality of sub-plates) are paired up such that metal plates are in alignment on opposed sides of the chords  1  and  2 . Moreover, the sets  13 ,  14  and  15  may have any suitable dimension. Accordingly, the various wooden components of the joist-end configurations described above and hereinafter, such as the diagonal  11  and the post  12 , have the same width as the top chord  1  and the bottom chord  2 , for the metal plates to form a planar joint when connecting such pieces. It is not required to use adhesives to connect the wooden components with the top chord  1  and the bottom chord  2 , when metal plates are used. 
     In the embodiment of  FIG. 1 , the diagonal  11  is connected to the top chord  1  adjacent to an end thereof, thereby defining an extension  16  (i.e., a bearing extension). The extension  16  is the interface of the top chord  1  with beam A when the joist is in a top-chord bearing relation with the beam A, as illustrated in  FIG. 1 . Accordingly, by the diagonal  11  being adjacent to the extension  16 , the joist-end configuration  10  has the diagonal  11  in tension. 
     Referring to  FIG. 2 , a joist-end configuration is shown at  20 , and is similar to the joist-end configuration  10  of  FIG. 1 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  10  and  20  is that the joist-end configuration  20  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  10 . The joist-end configuration  20  therefore also has the diagonal  11  in tension. 
     Referring to  FIG. 3 , a joist-end configuration is shown at  30 , and is similar to the joist-end configuration  10  of  FIG. 1 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  10  and  30  is that the joist-end configuration  30  has a support block  31 . The support block  31  is connected to the top chord  1  by the first set  13  of metal plates, and interfaces the top chord  1  to the beam A when the joist is in the top-chord bearing relation with the beam A. The joist-end configuration  30  advantageously has the set  13  of metal plates above the bearing interface between the beam A and the support block  31 . This configuration increases the capacity of the joist. 
     Referring to  FIG. 4 , a joist-end configuration is shown at  40 , and is similar to the joist-end configuration  30  of  FIG. 3 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  30  and  40  is that the joist-end configuration  40  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  30 . 
     Referring to  FIG. 5 , a joist-end configuration is shown at  50 , and is similar to the joist-end configuration  10  of  FIG. 1 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  10  and  50  is that the joist-end configuration  50  has a second post  51 . The second post  51  is connected to the top chord  1  at an intersection with the diagonal  11 , whereby the top chord  1 , the diagonal  11  and the second post  51  are interconnected by the first set  13  of metal plates. The second post  51  is connected to the bottom chord  2  by a fourth set  52  of metal plates. Accordingly, the second post  51  has the same width as the top chord  1 , the bottom chord  2 , the diagonal  11  and the post  12 . Because of the second post  51 , the first set  13  of metal plates have a greater gripping surface with wooden components of the joist, thereby increasing the capacity of the joist. 
     Referring to  FIG. 6 , a joist-end configuration is shown at  60 , and is similar to the joist-end configuration  50  of  FIG. 5 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  50  and  60  is that the joist-end configuration  60  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  50 . 
     Referring to  FIG. 7 , a joist-end configuration is shown at  70  is similar to the joint-end configurations  30  ( FIG. 3) and 50  ( FIG. 5 ), whereby like elements will bear like reference numerals. Essentially, the joist-end configuration  70  has the support block  31  and the second post  51 , as well as the appropriate sets of metal plates to interconnect these wooden components to a remainder of the joist. The joist-end configuration  70  therefore benefits in terms of capacity from the presence of the support block  31  and of the second post  51 . 
     Referring to  FIG. 8 , a joist-end configuration is shown at  80 , and is similar to the joist-end configuration  70  of  FIG. 7 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  70  and  80  is that the joist-end configuration  80  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  70 . 
     Referring to  FIG. 9 , a joist-end configuration is shown at  90 , and is similar to the joist-end configuration  10  of  FIG. 1 , whereby like elements will bear like reference numerals. The joist-end configuration  90  has a secondary top chord  91 . The secondary top chord  91  is connected against an undersurface of the top chord  1 , from extends along the joist from the post  12  to the extension  16 . The sets  13  of metal plates connect the top chord  1 , the diagonal  11  and the secondary top chord  91 . The sets  15  of metal plates connect the top chord  1 , the top end of the post  12  and the secondary top chord  91 . The secondary top chord  91  lies on the beam A when the joist is in top-chord bearing relation with the beam A. The addition of the secondary top chord  91  increases the capacity of the joist. 
     Referring to  FIG. 10 , a joist-end configuration is shown at  100 , and is similar to the joist-end configuration  90  of  FIG. 9 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations and  100  is that the joist-end configuration  100  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  90 . 
     Referring to  FIG. 11 , a joist-end configuration is shown at  110 , and is similar to the joist-end configuration  90  of  FIG. 9 , whereby like elements will bear like reference numerals. However, in the joist-end configuration  110 , the portion of the top chord  1  extending from the post  12  to the extension  16  is longer than that of the joist-end configuration  90  of  FIG. 1 . Accordingly, the diagonal  11  and secondary top chord  111  are longer than the joist-end configurations of  FIGS. 1 to 10 . It is observed that the sets  14  and  15  of metal plates do not connect the post  12  to the top chord  1  and to the bottom chord  2 , as chords  1  and  2  are wider than the post  12 . Although not illustrated, the joist-end configuration  110  may be used adjacent to I-joist sections. 
     In  FIGS. 1 to 12 , the diagonal  11  connects to the top chord  1  adjacent to the beam A, and connects to the bottom chord  2  adjacent to the post  12 . 
     Referring to  FIGS. 12 to 15 , alternatives embodiments are shown, in which the diagonal is oriented differently than in  FIGS. 1 to 11 , and is therefore in compression. Referring to  FIG. 12 , a joist-end configuration  120  is similar to the joist-end configuration  10  of  FIG. 1 , whereby like elements will bear like reference numerals. In the joist-end configuration  120 , diagonal  11 ′ connects to the too chord  1  adjacent to the post  12 , by the set  13  of metal plates interconnecting the three components. The secondary post  51  is connected to the bottom chord  2  by the set  14  of metal plates, and is connected to the top chord  1  by a fourth set  121  of metal plates. The post  12  is connected to the bottom chord  2  by set  15 ′ of metal plates. Because of the orientation of the diagonal  11 ′, the joist-end configuration  120  has smaller metal plates than for a different orientation of diagonal, thereby representing lesser costs. 
     Referring to  FIG. 13 , a joist-end configuration is shown at  130 , and is similar to the joist-end configuration  120  of  FIG. 12 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  120  and  130  is that the joist-end configuration  130  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  120 . 
     Referring to  FIG. 14 , a joist-end configuration  140  is similar to the joist-end configuration  120  of  FIG. 12 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  120  and  140  is the use of the support block  31  has interface between the beam A and the top chord  1 . The joist-end configuration  140  advantageously has the fourth set  121  of metal plates above the bearing interface between the beam A and the support block  31 . This configuration increases the capacity of the joist. 
     Referring to  FIG. 15 , a joist-end configuration is shown at  150 , and is similar to the joist-end configuration  140  of  FIG. 14 , whereby like elements will bear like reference numerals. A difference between the joist-end configurations  140  and  150  is that the joist-end configuration  150  is adjacent to an I-joist section of the joist, as opposed to an open-joist section for the joist-end configuration  140 . 
     It is pointed out that the bottom chord  2 , the diagonals  11 / 11 ′ the vertical posts  12  and the second posts  51  may all have a secondary twin member, as the top chord  1  does with the secondary top chord  91  (in  FIG. 9 ). Secondary twin members would increase the capacity of the joist. 
     Referring to  FIG. 16 , another joist-end configuration is illustrated at  160 , with reference to reference numerals used previously for similar elements of the other joist-end configurations. In the joist-end configuration  160 , there is no diagonal, but rather a single vertical post  12  connected to the bottom chord  2  by a set  161  of metal plates. 
     Now that a plurality of the joist-end configurations are described, different types of joists using such configurations are shown. Although the addition of elements increase the structural integrity of the joists, some applications are exposed to lesser loads in which simple configurations such as the joist-end configuration  10  of  FIG. 1  or the joist-end configuration  160  of  FIG. 16  are suitable and cost-efficient. 
     In  FIG. 17 , a joist  170  has the joist-end configuration  10  (amongst all other possibilities) in top-chord bearing relation with the beam A, whereas another end is in a bottom-chord bearing relation with beam B. Adjustments to the length of the joist  170  are made by removing a given length of the wooden panels  4  of the I-joist subsection, to then add the various elements of the configuration  10 . This is typically done off-site. 
     Referring to  FIG. 18 , the joist  180  has the joist-end configuration  70  (amongst all other possibilities) in top-chord bearing relation with beam A. As the joist-end configuration  70  is adjacent to an open-joist subsection, a longitudinal adjustment of the joist  180  may be done on-site by removing an exceeding length of the I-joist subsection. 
     It is pointed out that the joists and joist-end configurations described for  FIGS. 1-16  may be used at both ends of a joist, for the joist to be in top-chord bearing relation at both ends. As an example thereof,  FIG. 19  illustrates a joist  190  having a set of the joist-end configurations  20  supported by beams A. Any other suitable combination of joist-end configurations is considered. 
     Referring to  FIG. 20 , joist  200  has the joist-end configuration  100  in top-chord bearing relation with beam A. The joist  200  is an I-joist that is in a bottom-chord bearing relation with beam B at the other end. Accordingly, a portion of the I-joist section may be removed prior to installation, for the joist  200  to have a selected length. Although not illustrated, it is pointed out that both ends of the joist  200  may each have the joist-end configuration  100 .