CA2730837A1 - Load-sharing bracing system for a floor - Google Patents

Abstract

There is provided a load-sharing bracing system for a floor, including a pair of joists having vertical side faces that are spaced-apart and configured to face each other. An x-shaped cross-brace assembly extends between the side faces of the joists. The assembly comprises a pair of brace members each having a pair of spaced-apart sides arranged perpendicular to the side faces of the joists. The assembly attaches to the joists in two ways: by fasteners driven comfortably through the wide face of the brace members and into the joists' faces, or into the joists' flanges in the case of an I-joist application; and by L-shaped brackets used to reinforce the assembly connection to the joists when one or two brace member legs are cut to provide passage for HVAC services. The L-shaped brackets connect the sides of the brace members to the side faces of the joists. Each bracket has a first part that abuts with and extends along one side of the brace members.
Each bracket has a second part that abuts with and extends along the side face of one of the joists. A plurality of fasteners are arranged to partially extend through the first parts and the second parts of the brackets and extend into the brace member and joists, respectively.

Description

LOAD-SHARING BRACING SYSTEM FOR A FLOOR
Field of the Invention 100011 The present invention relates to a load-sharing bracing system. In particular, the invention relates to a load-sharing bracing system for a floor.

Description of the Related Art [00021 Wood floors today are typically built with a plurality of spaced-apart joists.
The joists may be in the form of sawn lumber joists that are rectangular in cross-section or in the form of engineered joists, typically 1-j oists. Flooring such as decking is typically attached on top of the joists. Floors so built may be susceptible to annoying bounce, vibration, squeaking and the like.

100031 It is known per se to support floor joists with a plurality of cross-brace assemblies interposed between the joists so as to promote load-sharing between the joists.
When a person walks on a conventional floor supported by floor joists, the cross-brace assembly enables a plurality of adjacent joists to be engaged. The cross-brace assembly acts to transfer impact load from the joist under the person impacting the floor to adjacent joists thus reducing floor deflection and vibration amplitude that is felt by the person(s) on the floor.

[00041 An example of a known cross-brace assembly is shown in Figures 1 and 6 of United States Patent No. 4,947,612 to Taylor, which discloses a cross-brace assembly comprising a plurality of brace members 18, 19, 20, together with vertical reinforcement members 22 and 24, the brace members extending between a pair of joists 10 and 11 and the whole assembly being connected together via a plurality of truss plates 26 and 28.

[00051 United States Patent No. 5,301,486 to Taylor discloses a cross-brace assembly comprising a pair of brace members connected together via a lap joint, a pair of vertical reinforcement members and a horizontal member, here too with the assembly being connected together via a plurality of truss plates.

[0006] Each of the above assemblies requires a relatively large number of parts and may accordingly require a relatively large amount of manufacturing and installation time.
The greater number of parts of the above systems may also render these systems more prone to errors in manufacturing.

[0007] Also, each of those assemblies has a rather ideal, fixed and rigid geometry that is intended to exactly fit into the nominal space between the joists, whereas in a real life, that space is more random and, as such, such systems may not allow their assemblies to fit snugly into this space. A snug connection is critical for the performance of such devices and this rigidity may thus render such systems less reliable.

[0008] Also, existing cross-brace assemblies may not provide for passages of HVAC
services and may not provide means for reinforcing the assemblies when a homeowner or tradesperson wants to alter them, by cutting out part of a cross-brace member for example, to create space for the passage of HVAC conduits and the like.

[0009] There is accordingly a need for an improved load-sharing bracing system that effectively supports floor joists while at the same time requiring fewer parts and reducing installation and manufacturing time and costs while at the same time increasing device reliability.

BRIEF SUMMARY OF INVENTION

[0010] The present invention provides a load-sharing bracing system disclosed herein that overcomes the above disadvantages. It is an object of the present invention to provide an improved load-sharing bracing system.

100111 It is important that a given floor system have a sufficiently high stiffness to ensure that its response to impact load is acceptable to homeowners. However, regardless of how stiff single joists may be, it was discovered that the floor system response to an impact load is principally controlled by both the bracing assembly's stiffness and the attachment of the bracing assembly to the joists. The system as herein described maximizes its bracing assembly's attachment capacity to the joists thus allowing use of the full capacity of the bracing assembly itself. This in turn enables one to provide a more cost-effective cross-brace assembly having fewer parts which, with enhanced attachment capacity, effectively improves the floor system response to the impact load.

[00121 There is accordingly provided a load-sharing bracing system for a floor. The system includes a pair of joists having vertical side faces that are spaced-apart and configured to face each other. An x-shaped cross-brace assembly extends between the side faces of the joists. The cross-brace assembly has a pair of brace members connecting together via a centrally disposed lap joint. Each brace member has a top, a bottom opposite the top, and a pair of spaced-apart vertical sides each extending between the top and the bottom. The sides are thinner relative to the top and the bottom. The sides are arranged perpendicular to the side faces of the joists. Each brace member has an upper end configured to abut with an upper portion of the side face of a first one of the joists.
Each brace member has a lower end configured to abut with a lower portion of the side face of a second one of the joists. A first plurality of fasteners are disposed to extend through the tops of each of the brace members adjacent to the upper portion of the side faces of the joists and extend into the joists. A second plurality of fasteners are disposed to extend through the bottoms of each of the brace members adjacent to the lower portion of the side faces of the joists and extending into the joists.

100131 There is also provided a load-sharing bracing system for a floor according to another aspect. The system has a pair of joists having vertical side faces that are spaced-apart and configured to face each other. An x-shaped cross-brace assembly extends between the side faces of the joists and has a pair of spaced-apart sides arranged perpendicular to the side faces of the joists. A plurality of L-shaped brackets connect at least one of the sides of the cross-brace assembly to the side faces of the joists. Each bracket has a first part that abuts with and partially extends along one of the sides of the cross-brace assembly. Each bracket has a second part that abuts with and partially extends along the side face of one of the joists. A plurality of fasteners are arranged to partially extend through the first parts and the second parts of the brackets and extend into the brace member and joists, respectively. The brace members thereby connect to the joists. This system allows for the removal of a portion of one or two brace members of the cross-brace assembly with virtually no loss of stiffness through the addition of reinforcing proprietary brackets connecting the remaining portions of the cross-brace assembly to the joists. This is an important feature since each floor has HVAC
services and none of the bracing assemblies of the known art provide such a feature.

[00141 There is further provided a method of installing a load-sharing bracing system for a floor. The method includes pre-fabricating a plurality of x-shaped cross-brace members. The method includes installing a plurality of longitudinally extending joists.
The joists each have vertical side faces. The step of installing includes spacing the vertical side so as to be spaced-apart from each other and so as to face each other. The cross-brace members are shaped to extend between the vertical side faces of the joists.
The method includes toenailing the cross-brace members to the vertical sides of the joists.
100151 There is yet further provided an L-shaped bracket for connecting a load-sharing bracing assembly to a pair of joists. Each joist has a vertical side face. The bracing assembly has a vertical surface perpendicular to the side faces of the joists. The bracket has a first plate member configured to abut with and partially extend along the vertical surface of the bracing assembly. The first plate member has a pair of spaced-apart apertures extending therethrough. The apertures are shaped to receive a first pair of fasteners and thus enable the first plate member to connect via said first pair of fasteners to the bracing assembly. The bracket has a second plate member configured to abut with and partially extend along the side face of one of the joists. The second plate member has a pair of spaced-apart apertures extending therethrough. The pair of apertures of the second plate member are shaped to receive a second pair of fasteners and thus enable the second plate member to connect via said second pair of fasteners to said one of the joists.
Each of the pair of apertures of the second plate member has a diameter. The second plate member is configured such that the pair of apertures of the second plate member are spaced-apart relative to the first plate member by a distance equal to or less than twice the 5 diameter of said each of the pair of apertures of the second plate member.

BRIEF DESCRIPTION OF DRAWINGS

[00161 The invention will be more readily understood from the following description of preferred embodiments thereof given, by way of example only, with reference to the accompanying drawings:

Figure 1 is a top perspective view of a load-sharing bracing system according to one embodiment, the system having an x-shaped brace assembly comprising a pair of brace members connected together via a lap joint, and the system including a plurality of longitudinally extending joists in the form of sawn lumber;
Figure 2 is a top perspective view of one of the brace members shown in Figure 1;
Figure 3 is a top perspective view of the other of the brace members shown in Figure 1;
Figure 4 is an elevation view of the system shown in Figure 1, and also showing flooring overlaying the system;

Figure 5 is top plan view of the system shown in Figure 1, with other cross-brace assemblies also being shown extending between the joists;
Figure 6 is a plan view of the brace member shown in Figure 3, the brace member being partially broken away, and a preferred location for fasteners being shown;

Figure 7 is a perspective view of the system shown in Figure 1 being subject to a point load;

Figure 8 is a graph showing the extent of floor displacement resulting from six cycles of 2kN (450 lb.) point load applied in increments of 50 lb. in the manner shown in Figure 7 to the system shown in Figure 7, without detrimental effect on the load-sharing bracing system's performance;

Figure 9 is a plan view of the brace member shown in Figure 3 showing a preferred location for fasteners according to another embodiment;

Figure 10 is a plan view of the brace member shown in Figure 9 showing a preferred location for fasteners according to a further embodiment;

Figure 11 is a top perspective view of a load-sharing bracing system according to a yet further embodiment, showing a brace member connecting to a joist via an L-shaped bracket;

Figure 12 is a perspective view of the system shown in Figure I1 showing further L-shaped brackets and the locations in which they are preferably connected, with a portion or leg of one of the brace members being in hidden lines to indicate that it has been removed for the passage of HVAC services;

Figure 13 is an elevation view of a load-sharing bracing system according to yet a further embodiment, the system including engineered 1joists, the brace assembly being substantially similar to that shown in Figures 1 to 8 and flooring overlaying the system;
Figure 14 is an elevation view of a load-sharing bracing system according to yet another embodiment, the system including engineered 1 -joists, the brace assembly and system being otherwise substantially similar to that shown in Figures 11 and 12, and flooring overlaying the system; and Figure 15 is an elevation view of a load-sharing bracing system according to another embodiment, the system being similar to that shown in Figure 14, with brackets being shown according to another embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Referring to the drawings and first to Figure 1, there is shown a load-sharing bracing system 11 configured to support flooring 12 as shown in Figure 4. The system includes a plurality of longitudinally-extending joists as illustrated by the pair of joists 14 and 16. The joists have bottoms 22 and 24 and tops 26 and 28 opposite thereof.
The joists 14 and 16 have vertical side faces 18 and 20 that are spaced-apart and configured to face each other. The side faces 18 and 20 extend between the bottoms and the tops.
As shown in Figure 4, the side faces 18 and 20 have upper portions 19 and 21 located adjacent to the tops 26 and 28 of the joists and lower portions 23 and 25 located adjacent to the bottoms 22 and 24 of the joists. The joists 14 and 16 are preferably in the form of sawn lumber in this example, though this is not required.

[0018] The system 11 includes a plurality of x-shaped, prefabricated cross-brace assemblies as illustrated by cross-brace assembly 30 extending between the side faces 18 and 20 of the joists 14 and 16. As shown in Figure 5, other cross-brace assemblies 31 and 33 are spaced-apart between and along the joists 14 and 16 and are substantially the same as the cross-brace assembly 30 shown in Figure 1. Likewise, further cross-brace assemblies are spaced-apart between and along other adjacent joists that underlie the flooring, as is for example shown in Figure 7 with cross-brace assembly 74 that extends between joist 14 and further joist 72. Only cross-brace assembly 30 as shown in Figure 1 will be discussed in detail for ease of explanation. The cross-brace assembly preferably consists only of a pair of brace members 32 and 34 as best shown in Figures 2 and 3. The brace members are preferably in the form of 2 inches by 3 inches or 2 inches by 4 inches, Spruce Pine Fir Grade #2 (SPFN2) kiln-dried and planed with a moisture content of less than 19%, to minimize brace member warping and twisting, though this is not required.

[00191 The brace members 32 and 34 have tops 36 and 38 and bottoms 40 and 42 as shown in Figure 4 opposite the tops. As shown in Figures 2 and 3, the brace members 32 and 34 have a pair of spaced-apart vertical sides 44 and 46, and 48 and 50, respectively, which may also be referred to as the sides of the cross-brace assembly. The tops and bottoms of the brace members extend between the sides. The sides 44, 46, 48, and 50 are thinner relative to the tops 36 and 38 and bottoms 40 and 42. The brace members are thus generally rectangular in cross-section. As shown in Figure 5, the sides 44, 46, 48 and 50 of the brace members are arranged perpendicular to the side faces 18 and 20 of the joists.
[00201 As shown in Figure 2, brace member 32 has an opening or notch 54 extending through and from side 46 towards side 44, half-way along and through top 36.
Similarly, as shown in Figure 3, brace member 34 has an opening or notch 56 extending through and from side 48 towards side 50, half-way along and through top 38. The notches 54 and 56 are generally in the shape of rectangular prisms and are configured to enable the brace members 32 and 34 to connect together via a centrally disposed lap joint 52 as shown in Figure 1. The brace members 32 and 34 are configured to connect together in a tight, press-fit manner so as to provide a central connection with a high moment capacity. This is because the notches 54 and 56 are equal in size or just slightly wider than the sides 44, 46, 48 and 50 of the brace members.

100211 The system 11 may also include adhesive 53, as shown in Figure 2, disposed along portions of the brace members adjacent to notches 54 and 56. The adhesive 53 further connects the brace members together and further increases the brace members' moment capacity, though adhesive is not strictly required.

[00221 As best shown in Figure 4, the brace members 32 and 34 have upper ends and 60 configured to abut with the upper portions 19 and 21 of the side faces 18 and 20 of the joists 14 and 16. The brace members 32 and 34 have lower ends 62 and 64 configured to abut with lower portions 23 and 25 of the side faces of the joists. Ends 58, 60, 62, and 64 are in the form of cut, parallel, vertical planes that smoothly abut with the side faces 18 and 20 of the joists and closely extend between and fit within the space between the joists. The use of kiln-dried or drier lumber inhibits twisting and warping of the brace members and thus further promotes continued good contact between the brace members and the joists. The lap joint 52 is preferably interposed midway between the upper ends 58 and 60 and the lower ends 62 and 64.

[00231 Referring to Figures 1 and 4, the system 11 includes a first plurality of fasteners, as shown by fastener 66, disposed to extend through the tops 36 and 38 of the brace members in a region of the tops 36 and 38 that is adjacent to the upper portions 19 and 21 of the side faces 18 and 20 of the joists and extend into the joists.
The system 11 also includes a second plurality of fasteners, as shown by fastener 68 in Figure 4, disposed to extend through the bottoms 40 and 42 of the brace members in a region of the bottoms that is adjacent to the lower portions 23 and 25 of the side faces 18 and 20 of the joists and extend into the joists. In this example the fasteners are nails that are toenailed to the upper and lower portions of the side faces of the joists 18 and 20.
However, alternative fasteners such as screws, staples and the like may be used. The fasteners preferably extend into the joists at an angle a of 45 degrees relative to the side faces of the joists.

100241 Figure 6 shows a preferred arrangement of the fasteners 66 for each of the fastening or nailing regions shown in Figure 4 and in this example for the top 38 of brace member 34. There are preferably provided three fasteners when member 34 is 2 inches by 3 inches, each fastener having a shaft diameter d. There are preferably provided four fasteners when member 34 is 2 inches by 4 inches. The fasteners are arranged in a row and spaced-apart by a distance equal to at least 8-times the diameter of the fasteners. The fasteners are spaced-apart from edge 70 of the top 38 by a distance equal to 12-times the diameter of the fasteners and in this example by a distance of 1.2 inches.
Outer fasteners 66i and 66iii are spaced-apart by a distance equal to at least 4 times the diameter of the fasteners and in this example 0.4 inches from the sides 50 and 48, respectively, of the brace member. Inner fastener 66ii is spaced-apart from each other and spaced-apart relative to fasteners 66i and 66iii, respectively, by a distance equal to at least 8 times the diameter of the fasteners, in this example, 0.9 inches.

[0025] The size of the tops and bottoms of the brace members allows the fasteners to 5 be arranged in more than one row. This is shown in Figure 9 where fasteners are arranged in a two row pattern for a load-sharing bracing system 11.1 having a first row 78 of fasteners and a second row 80 of fasteners spaced-apart therefrom. The system 11.1 shown in Figure 9 is otherwise substantially similar to that shown in Figures 1 to 8, with like parts having like numbers and function with addition of ".1". A maximum of four 10 fasteners per row may be used for brace members that are 2 inches by 3 inches in cross-section. A maximum of six fasteners per row may be used for brace members that are 2 inches by 4 inches in cross-section. One may also want to add fasteners through the sides of the brace members and into the joists so as to provide additional connection.

[0026] Figure 10 shows a further variation in the arrangement of the fasteners. The fasteners are arranged in a two row pattern for a load-sharing bracing system 11.2 having a first row 78.2 of fasteners and a second row 80.2 of fasteners spaced-apart therefrom. In this case fasteners 81 of row 80.2 are staggered relative to the fasteners of row 78.2.
System 11.2 shown in Figure 10 is otherwise substantially similar to that shown in Figures 1 to 8, with like parts having like numbers and function with addition of ".2".

[0027] Referring back to Figures 1 to 8, the system 11 as described herein reacts very well to a force applied to it. A floor's ability to withstand the impact, which is in essence a design check for the serviceability of the floor, is typically tested according to building codes based on point load deflection criteria. This is shown in Figures 7 and 8. Figure 7 shows the system 11 with the addition joist 72, the additional cross-brace assembly 74 which is substantially the same as assembly 30, flooring 12 extending over top of the system 11 and a force as indicated by arrow 76 being applied to the flooring 12. The responsiveness of the system 11 is shown in Figure 8.

100281 The system was subjected to a repetitive load of 2kN (450 lb.) as per a standard test for intermediate devices in Canada (CCMC Master Format 06190).
The corresponding displacement of the flooring was then measured. The test is now being introduced in ASTM standard procedures. Even after six cycles there is no noticeable yield in the device or device connections to the joists. A displacement downwards of the flooring 12, from the perspective of Figure 7 and as set out on the x-axis of the graph in Figure 8, of less than 0.10 inches results from a given force against the floor of 450 pounds, as is set out on the y-axis of the graph,. As is evident from the test results displaced on the graph, the system also responds very linearly, meaning that there is no yield in connections between the brace assembly 30 and joists.

100291 Figures 11 and 12 show a load-sharing bracing system 11.3 according to a further embodiment. Like parts have like numbers and function as the embodiment shown in Figures 1 to 8 with the addition of ".3". System 11.3 is substantially the same as system 11 shown in Figures 1 to 8 with the exception that a plurality of L-shaped brackets as shown by L-shaped brackets 82 and 84 in Figure 11, are used in addition to fasteners (such as nails) to connect the sides 46.3 and 44.3 of the brace members 32.3 to the side faces 18.3 of the joists 14.3.

[00301 L-shaped bracket 82 has a first part or plate member 86 that abuts with and partially extends along side 46.3 of the brace member 32.3. First plate member 86 has a top edge 87 and a bottom edge 89 opposite thereof. Bracket 82 has a first pair of apertures 88 that extend through its first plate member 86 and which in this example are staggered. Bracket 82 has a second part or plate member 90 that abuts with and partially extends along side face 18.3 of joist 14.3. Second plate member has a top edge 97 and a bottom edge opposite thereof 99. Second plate member 90 is disposed perpendicular to the first plate member 86. The plate members 86 and 90 are connected via corner 101, which defines an axis 103. In this example edges 87 and 89 of plate member 86 extend horizontally from the perspective of Figure 11 and relative to plate member 90. Bracket 82 has a second pair of apertures 92 that extend through its second plate member 90.
Each of the apertures 92 has a diameter D. The apertures 92 are disposed in a row adjacent to the bend of the bracket and adjacent to the first plate member 86 of the bracket 82. The second plate member 90 is configured such that the apertures 92 are preferably spaced-apart relative to the first plate member 86 by a distance equal to or less than twice the diameter of each of the apertures 92, in this example by a distance of less than the diameter of each of the apertures 92. Thus, apertures 92 are arranged so as to be significantly adjacent to side 46.3 of the brace member 32.3.

[00311 A plurality of fasteners, in this example screws 94, extend through the apertures of the first and second plate members of the bracket 82 and into the brace member 32.3 and joist 14.3, the brace members and joists connecting together thereby.
Because the brace members are rectangular in cross-section with tops 36.3 being relatively wide, this enables longer fasteners to be used for connecting first plate member 86 of the bracket to the brace member 32.3.

100321 Advantageously, the locations of apertures 92 close to side 46.3 of brace member 36.3, together with screws 94 passing therethrough, increases connection stiffness. This is because two forces - one force pulling the brace member 32.3, and the other force holding the bracket 82 to the joist 14.3, are practically in the same plane. This arrangement inhibits any moment acting on the second plate member 90 of the bracket, which would otherwise occur if the apertures 92 were more spaced-apart from the brace member 32.3 in a more conventional bracket arrangement, such as is shown by apertures 91 in Figure 11, which are not required in the system as herein described.
Such seemingly minor details in the fastener and aperture arrangement as herein disclosed make a big difference in the overall stiffness of the system 11.3.

[00331 Referring to Figures 11 and 12, preferably L-shaped brackets 82 are arranged on both sides 46.3 and 44.3 of brace member 32.3 adjacent to the member's lower end 62.3 and upper end 58.3, as shown by bracket 95 in Figure 12. Brackets may also be added to the sides of brace member 34.3 for further support though this is not required nor shown in the embodiment shown in Figure 12.

[00341 The use of brackets further enhances the strength of connection between the brace members and the joists. This enables one or two portions or legs of the brace members, as shown by leg 96 in ghost lines for brace member 34.3, to be removed and to create more space thereby between the joists to better facilitate servicing and/or the disposal of heating, ventilation, and air conditioning (HVAC) service conduits, wiring and the like.

[00351 Figure 13 shows a load-sharing bracing system 11.4 according to yet a further embodiment. Like parts have like numbers and function as the embodiment shown in Figures 1 to 8 with the addition of ".4". The system 11.4 is substantially the same as that shown in Figures 1 to 8 with the exception that joists 14.4 and 16.4 are engineered I-joists, rather than sawn lumber. Joists 14.4 have chords 98 and 100 at their upper portions 19.4 and 21.4, chords 102 and 104 at their lower portions 23.4 and 25.4, and web members 106 and 108 received by and extending between the chords 98 and 102, and 100 and 104, respectively. The chords provide the side faces to which the brace members 32.4 and 34.4 connect via fasteners 66.4 and 68.4.

[00361 Figure 14 shows a load-sharing bracing system 11.5 according to yet another embodiment. Like parts have like numbers and function as the embodiment shown in Figures 1 to 8 and 11 to 13 with the addition of ".5". The system 11.5 is substantially the same as that shown in Figure 13 with the exception that L-brackets 82.5 and 95.5 are used to connect brace member 32.5 to the side faces of chords 98.5 and 104.5.
Leg 96.5 has been removed from brace member 34.5 to create a larger opening for HVAC
services.
The L-brackets are substantially the same as those described in Figures 11 and 12.

100371 Figure 15 shows a load-sharing bracing system 11.6 according to another embodiment. Like parts have like numbers and function as the embodiment shown in Figures 1 to 8 and 11 to 13 with the addition of ".6". The system 11.6 is substantially the same as that shown in Figure 14 with the exception that the L-shaped brackets as shown by bracket 82.6 have first plate members 86.5 with top edges 87.5 and bottom edges 89.5 that extend in parallel with top 38.5 and bottom 40.5 of brace member 34.5.
Thus the first plate members follow the slope of the brace members in this embodiment. Put another way, the top edge 87.5 and the bottom edge 89.5 of the first plate member 86.5 extend outwards at a non-perpendicular angle of P relative to axis 103.5. In this example, edges 87.5 and 89.5 are angularly spaced-apart from said axis 103.5 by an angle of (3 of approximately 60 degrees relative to said axis, though this angle will vary depending on the slope of the brace members.

[00381 While the slanted brackets 82.6 are shown in Figure 15 for use with I -Joists, such slanted brackets may also be used for the sawn lumber joists that are, for example, shown in Figures 11 and 12.

100391 The systems as herein described reduce floor bounce, vibration and squeaking arising from an impact foot-steps load on the floor, by reducing deflection amplitude and the floor's dynamic response work, while at the same time increasing floor frequency and damping. This significantly increases floor performance in the serviceability, strength and stiffness capacity and reliability domains. An increase in damping of the floor is generated by elastic deformation of the bracing assembly where the brace members are bent around the pivot point in the central lap joint. A significant part of the impact energy is absorbed in order to deform the bracing assembly. Put another, the systems as herein described reduce vibration or creaking arising from a footstep loads on the floor, reduce point load deflection in the middle of the flooring, reduce floor dynamic response work under footstep loads, significantly increase vibration serviceability performance of floors and also act to increase strength and stiffness capacity. The systems provide an elastic response to loads by bending their members, and thus absorbing impact energy imparted on the floor and reducing floor vibration amplitude. In addition to reduction of floor vibration amplitude due to the increase floor damping ratio, floor vibration ends (fades-out) more rapidly than with known brace assemblies of the prior art.

100401 The systems as herein described result in better performing floors that use less lumber compared to the other known systems for supporting floors. The systems as herein described thus result in economic savings and, by requiring fewer parts, are more eco-friendly. Also, the assemblies as herein described, by eliminating the need for additional vertical reinforcement members and/or horizontal members, provide yet further space and accommodation for heating, ventilation, air conditioning and electrical cables (HVAC) service conduits and the like that may pass between the joists.

5 [00411 The systems as herein described are optimized for and are particularly well suited for sawn lumber floors and also for roof joists. The systems and assemblies may be used in the initial construction of buildings and also for retrofitting existing structures.
[00421 It will be appreciated that many variations are possible within the scope of the invention described herein. Also, it will be understood by someone skilled in the art that 10 many of the details provided above are by way of example only and are not intended to limit the scope of the invention which is to be determined with reference to the following claims.

Claims (28)

1. A load-sharing bracing system for a floor, the system comprising:

a pair of joists having vertical side faces that are spaced-apart and configured to face each other;

an x-shaped cross-brace assembly extending between the side faces of the joists, the cross-brace assembly comprising a pair of brace members connecting together via a centrally disposed lap joint, each said brace member having a top, a bottom opposite the top, a pair of spaced-apart vertical sides each extending between the top and the bottom and being thinner relative to the top and the bottom, the sides being arranged perpendicular to the side faces of the joists, an upper end configured to abut with an upper portion of the side face of a first one of the joists, and a lower end configured to abut with a lower portion of the side face of a second one of the joists;

a first plurality of fasteners disposed to extend through the tops of each of the brace members adjacent to the upper portion of the side faces of the joists and extending into the joists; and a second plurality of fasteners disposed to extend through the bottoms of each of the brace members adjacent to the lower portion of the side faces of the joists and extending into the joists.

2. The system as claimed in claim 1 wherein the cross-brace assembly consists only of the pair of brace members.

3. The system as claimed in claim 1 wherein the fasteners are nails, some of the nails being toenailed to the upper portions of the side faces of the joists through the tops of the brace members adjacent to the upper ends of the brace members and others of the nails being toenailed to the lower portions of the side faces of the joists through the bottoms of the brace members adjacent to the lower ends of the brace members.

4. The system as claimed in claim 1 wherein the brace members are configured to connect together in a tight, press-fit manner so as to provide a central connection with a high moment capacity.

5. The system as claimed in claim 4 wherein the brace members connect together through notches, the notches being equal in size with the sides of the brace members.

6. The system as claimed in claim 4 wherein the brace members connect together through notches, the notches being slightly wider than the sides of the brace members.

7. The system as claimed in claim 1 further including adhesive disposed along the lap joint, the adhesive being configured to further connect the brace members together.

8. The system as claimed in claim 1 wherein the joists are engineered joists, typically I-joists, each of said I-joists comprising a pair of chords with a web member extending therebetween, the brace members connecting to the side faces of the chords.

9. The system as claimed in claim 1 wherein the tops of the brace members adjacent to the upper ends of the brace members have outer edges configured to abut the side faces of the joists, the bottoms of the brace members adjacent to the lower ends of the brace members have outer edges configured to abut the side faces of the joists, each fastener has a shaft diameter, the fasteners are spaced-apart from the outer edges by a distance equal to at least 12 times the diameters of the fasteners and the fasteners include outer fasteners spaced-apart from the respective sides of the brace members by a distance equal to at least 4 times the diameters of the fasteners.

10. The system as claimed in claim 1 wherein the cross-brace assembly consists only of the pair of brace members and wherein the fasteners extend into the joists at a 45 degree angle relative to the side faces of the joists.

11. The system as claimed in claim 10 wherein the fasteners are arranged in two or more rows, the fasteners being arranged according to one from the group consisting of: an in-line arrangement; and a staggered arrangement.

12. The system as claimed in claim 1, wherein each brace member comprises two legs on either side of the lap joint and wherein the system enables one of the legs to be removed for accommodating HVAC services by further including L-shaped brackets and fasteners therefor to reinforce the connection of the other of the legs to the joists, the L-shaped brackets each having a first part that abuts with and partially extends along one of the sides of said cross-brace assembly and a second part that abuts with and partially extends along the side face of one of the joists, the fasteners being arranged to partially extend through the first parts and the second parts of the brackets and extend into the brace members and joists, respectively.

13. The system as claimed in claim 1 wherein the lap joint is configured to provide a partial moment capacity with the upper and lower ends of the brace members configured to act as ends of a cantilever beam, the brace members so configured thus allowing partial bending of the cantilevered ends, which in turn enables the system to adjust to spacing variations between the joists.

14. The system as claimed in claim 1 wherein the lap joint is configured to provide a partial moment capacity with the upper and lower ends of the brace members configured to act as ends of a cantilever beam, the brace members so configured thus allowing partial bending of the cantilevered ends to absorb footstep impact load and promote damping of the floor.

15. A load-sharing bracing system for a floor, the system comprising:

a pair of joists having vertical side faces that are spaced-apart and configured to face each other;

an x-shaped cross-brace assembly extending between the side faces of the joists and having a pair of spaced-apart sides arranged perpendicular to the side faces of the joists;

a plurality of L-shaped brackets connecting at least one of the sides of the cross-brace assembly to the side faces of the joists, each said bracket having a first part that abuts with and partially extends along one of the sides of said cross-brace assembly and each said bracket having a second part that abuts with and partially extends along the side face of one of the joists; and a plurality of fasteners arranged to partially extend through the first parts and the second parts of the brackets and extend into the brace member and joists, respectively, the brace members thereby connecting to the joists.

16. The system as claimed in claim 15 wherein each said bracket has a first pair of spaced-apart apertures extending through its first part for receiving the fasteners and each said bracket has a second pair of spaced-apart apertures extending through its second part, the second pair of apertures being disposed in a row adjacent to the first part of the bracket.

17. The system as claimed in claim 16, wherein each of the second pair of apertures has a diameter, the second part of the bracket being configured such that the second pair of apertures are spaced-apart relative to the first part of the bracket by a distance equal to or less than the diameter of said each of the second pair of apertures.

18. The system as claimed in claim 15 wherein the cross-brace assembly consists only of a pair of brace members and wherein the fasteners are one from the group consisting of nails, staples, and screws.

19. The system as claimed in claim 15 wherein the cross-brace assembly comprises a first brace member and a second brace member, each said brace member having an upper end abutting an upper portion of the side face of one of the joists and having a lower end abutting a bottom portion of the side face of the other of the joists, the first brace member having a pair of sides disposed perpendicular to the side faces of the joists, the first parts of the L-shaped brackets configured to abut with and partially extend along the sides of the first brace member.

20. The system as claimed in claim 15 wherein the cross-brace assembly comprises a first brace member and a second brace member, the first brace member having an upper end abutting an upper portion of the side face of one of the joists and having a lower end abutting a bottom portion of the side face of the other of the joists, the second brace member connecting to the first brace member via a centrally disposed lap joint, the first brace member having a pair of sides disposed perpendicular to the side faces of the joists, the first parts of the L-shaped brackets configured to abut with and partially extend along the sides of the first brace member, the second brace member having only one end that abuts one from the group consisting of the bottom portion of said one of the joists and the upper portion of said other of the joists, the system providing an opening thereby for accommodating HVAC services.

21 21. The system as claimed in claim 15 wherein the joists are engineered I-joists, each I-joist comprising a pair of chords with a member extending therebetween, the brace members connecting to the side faces of the chords.

22. The system as claimed in claim 15 wherein the joists are made of sawn lumber, the brace members are made from spruce pine fir grade #2 (SPFN2) lumber with moisture content of less than 19% and the brace members are one from the group consisting of 2 x 3 planed lumber and 2 x 4 planed lumber.

23. The system as claimed in claim 15 wherein the first parts of the brackets have top and bottom edges that extend in parallel with the sides of the cross-brace assembly.

24. The bracket as claimed in claim 19, wherein the first parts of the brackets are angled to essentially follow the slope of the brace members.

25. A method of installing a load-sharing bracing system for a floor, the method comprising:

pre-fabricating a plurality of x-shaped cross-brace members;

installing a plurality of longitudinally extending joists, the joists each having vertical side faces, the step of installing spacing the vertical side so as to be spaced-apart from each other and so as to face each other, the cross-brace members being shaped to extend between the vertical side faces of the joists;
and toenailing the cross-brace members to the vertical sides of the joists.

26. The method as claimed in claim 25, the step of pre-fabricating further including:
lap joining the cross-brace members together.

27. An L-shaped bracket for connecting a load-sharing bracing assembly to a pair of joists, each joist having a vertical side face, the bracing assembly having a vertical surface perpendicular to the side faces of the joists, the bracket comprising:

a first plate member configured to abut with and partially extend along the vertical surface of the bracing assembly, the first plate member having a pair of spaced-apart apertures extending therethrough, the apertures being shaped to receive a first pair of fasteners and thus enable the first plate member to connect via said first pair of fasteners to the bracing assembly; and a second plate member configured to abut with and partially extend along the side face of one of the joists, the second plate member having a pair of spaced-apart apertures extending therethrough, the pair of apertures of the second plate member being shaped to receive a second pair of fasteners and thus enable the second plate member to connect via said second pair of fasteners to said one of the joists, each of the pair of apertures of the second plate member having a diameter, the second plate member being configured such that the pair of apertures of the second plate member are spaced-apart relative to the first plate member by a distance equal to or less than twice the diameter of said each of the pair of apertures of the second plate member.

28. The bracket as claimed in claim 27 wherein the first plate member and the second plate member of the brackets are perpendicular to each other and are connected via corner, the corner defining an axis, and wherein the first plate member has a top edge and a bottom edge opposite thereof, the top edge and the bottom edge of the first plate member extending outwards at a non-perpendicular angle relative to said axis.