Sheet Metal Web Stiffener And Chord Nailing Restrictor For Wooden I-Joist

Abstract

A monolithic sheet metal chord nailing restricting and web stiffening device features a chord plate combined with a web stiffening structure configured for lateral attachment to the web of a wooden I-joist. The chord plate is positioned on the bottom of the web stiffening structure and features a nail restricting hole having a diameter that corresponds to a predetermined diameter of a chord nail as defined by wooden I-joist manufacturers. The web stiffening structure has a web plate for attachment to the web and a buckling opposing web stiffening rib. Once the web stiffening structure is attached to the web above the bearing rest the nail restricting hole restricts chord nailing position and nail shaft diameter to manufacturer defined limits. Two devices may be combined by a web front bridge plate for simultaneous attachment of two opposite devices along an I-joist end.

Description

FIELD OF INVENTION

The present invention relates to a chord nailing restricting web stiffener for a predetermined nailing restriction to a wooden I-joist chord at an I-joist bearing rest attachment location with simultaneous buckling opposing support at the I-joist bearing rest attachment location.

BACKGROUND OF INVENTION

In the field of architectural constructions, loads carried by wooden or wood like I-joists along their free spanning lengths are transferred onto bearing rests of relatively small areas. In addition to the small contact areas and the resulting large force concentrations, the nailing of the I-joist bottom chord introduces a splicing risk and consequently a potentially degrading factor on the load carrying capacity of the I-joist in the vicinity of the bearing rest. In response, I-joist manufacturers provide detailed nailing specifications on how to nail the I-joist's bottom chord onto the bearing rest in order to minimize the structurally degrading effects of nails penetrating the bottom chord. Nailing specifications commonly include size and type of nails to be used and minimum chord edge nailing clearance, chord front nailing clearance and web nailing clearance. The compliance with nailing requirements may be visually verified by authorized inspectors at various stages during the construction process.

Wooden I-joists are highly engineered light weight products of wood or wood like materials laminated and otherwise compacted and bonded as is well known in the art. The resulting high mechanical strength of the chord materials provides for small chord cross sections with an unfavorable side effect of increased splicing tendency compared to bulk lumber material otherwise used in architectural constructions. In addition, the inner bottom chord areas accessible for nailing are much narrower than typical nailing access areas of bulk lumber used for construction. This again requires increased nailing precision during the attachment of I-joists compared to nailing of other conventional lumber materials.

As shown in Prior Art FIGS. 1, 2, the nailing of bottom chords 13 at I-joist 1 ends is particularly problematic where the available bearing rest width 2W may be shared with a well known rim board 4 having a thickness 4T resulting in an actual bearing interface depth BD that is only a fraction of the overall bearing width 2W. In addition, the splicing tendency of the chord increases towards the cutoff edge of the chord 13 as is well known in the art. The actual bearing interface depth BD may be further inadvertently reduced due to imprecise lengthening of the I-joist 1. Therefore, there exists a need for a device that provides for a precise chord nailing of I-joist's at their bearing rest attachment locations. In particular, there exists the need for a device that prevents the construction worker from nailing with erroneous nailing clearances XCS, XCW, XCF. The present invention addresses this need.

In praxis, construction workers commonly use nailing guns for expedited attaching and combining various bulk lumber elements such as boards and plywood as is well known in the art. The type nails loaded in nailing guns and the set nailing force are selected in accordance with the requirements of attaching such bulk lumber elements with fully immersed nail heads 82. Attachment of I-joist chords 13 to bearing rests 2 to the contrary may require smaller and differently configured nails 8 as shown in FIG. 3, 4, 6, 9. Construction workers may be tempted to avoid the reloading and resetting of the nailing guns for the sole purpose of attaching the I-joist 1 to the bearing rest 2 with correct nails 8. Instead, the bottom chord 13 may be nailed with oversized nails 3 to the bearing rest 2 with a nail gun setting for fully immersing the nail heads 32, which in combination likely cause the bottom chord 13 to splice and cracks 139 to form. The cracks 139 may only marginally extend beyond the bearing width 2W making the cracks 139 difficult to detect during a common inspection stage at a time when prior art web stiffeners 5 and a well known rim board 4 may already be assembled as is illustrated in Prior Art FIG. 2. Therefore, there exists a need for a device that prevents the use of oversized nails 8, prevents nail head immersion in the bottom chord top 131 and that provides for visual verification of correct chord nailing at an inspection stage with assembled web stiffener and rim board 4. The present invention addresses this need.

Prior art I-joists 1 are commonly configured with relatively thin web thickness 12T, which may require lateral enforcement in the vicinity of a bearing rest. Such lateral enforcement is commonly provided by a well known prior art web stiffeners 5 that are commonly blocks of wood or wood like materials nailed on both sides of the web 12 above the bearing rest 2. Such prior art web stiffeners 5 have a voluminous structure with a width 5W that may be up a recess depth 1R and a height 5H less than a vertical chord spacing 12H. The sandwiched web 12 is consequently stiffened and the buckling tendency is brought down below predetermined safety limits as is well known in the art. To keep the construction process efficient, it is desirable to keep the number of devices and/or structures attached to the I-joist 1 above the bearing rest 2 to a minimum. Therefore, there exists a need for a combined web stiffener and chord nailing restricting device. The present invention addresses also this need.

SUMMARY

An I-joist chord nailing restricting device features a chord plate monolithically combined with a sheet metal web stiffening structure configured for lateral attachment to the web of a wooden I-joist. The chord plate is positioned on the bottom of the web stiffening structure and features a nail restricting hole having a diameter that corresponds to a predetermined diameter of a chord nail as defined by wooden I-joist manufacturers. The nail restricting hole is in a web nailing clearance from a web face of the volume structure and in a chord front nailing clearance to an I-joist front flush face of the I-joist chord nailing restricting device. The web stiffening structure has a web plate for contacting a web side of the I-joist and web stiffening rib for buckling opposing stiffening of the web at the device attachment location. Once the device is attached to the web above the bearing rest such that the web face is contacting the web side, the nail restricting hole is accurately positioned between the web and the bottom chord side in accordance with well known requirements for web nailing clearance and chord edge nailing clearance defined by the wooden I-joist manufacturers.

A web front bridge plate may combine two web plates in a U-profile along the vertical protrusion direction of two respective web stiffening structures such that the two web faces of respective web plates are facing each other while forming a web gap that corresponds to the web thickness. The web plate(s) may have attachment features such as web claws, fastener holes and/or web bite edges.

The nail restricting hole may also be in a chord front nailing clearance to an I-joist front flush face of the chord plate, web plate or the web front bridging plate. Once the device is attached along an end of the wooden I-joist with its I-joist front flush face being flush with the I-joist front, the nail restricting hole may also be accurately positioned in a chord front nailing clearance in accordance with clearance requirements defined by the wooden I-joist manufacturers. This may be particularly suitable at I-joist ends to be nailed to a respective bearing rest.

Around the nail restricting hole may be a centering funnel for an easy centering of a suitable nail or the nail gun at the nail restricting hole. For increased strength at the bottom of the device and around the chord nailing access cavity, the chord plate may be angularly combined with a web plate that is parallel to and recessed from the web face. The chord nailing access cavity may also be open to a side lateral to the web face such that the nail restricting hole is additionally accessible along the I-joist front flush face.

BRIEF DESCRIPTION OF THE FIGURES

Prior Art FIG. 1 is a first top perspective view of a portion of a representative prior art I-joist destructively nailed with its end on a prior art bearing rest.

Prior Art FIG. 2 is a first bottom perspective view on the assembly of Prior Art FIG. 1 with additional prior art web stiffener and prior art rim board attached.

FIG. 3 shows a second top perspective view of a representative prior art I-joist nailed to a representative prior art bearing rest by means of a monolithic web stiffening and nail restricting device according to a first embodiment of the invention.

FIG. 4 is a side view of FIG. 3.

FIG. AA is a cross sectional view as indicated in FIG. 4 by cross section line A-A.

FIG. BB is a cross sectional view as indicated in FIG. 4 by cross section line B-B.

FIG. 5 is a second top perspective view of the device of FIGS. 3, 4, AA.

FIG. 6 is the first top perspective view of a representative prior art I-joist nailed to a representative prior art bearing rest by means of a monolithic dual nail restricting device according to a second embodiment of the invention.

FIG. 7 is the second top perspective view of the device of FIG. 6.

FIG. 8 is the first top perspective view of a representative prior art I-joist nailed to a representative prior art bearing rest by means of a monolithic web stiffening and nail restricting device according to a third embodiment of the invention.

FIG. 9 is the second top perspective view of the device of FIG. 8.

DETAILED DESCRIPTION

Referring to Prior Art FIGS. 1, 2, a commercially available wooden I-joist 1 has a top chord 11, a central web 12 and bottom chord 13 commonly adhesively combined by an adhesive 14 in top and bottom chord grooves 115, 135 as is well known in the art. Wooden I-joists 1 are fabricated in a number of dimensional standards including standardized web height 12H, web recess depth 1R, web thickness 12T, and chord widths and heights such as bottom chord width 13W and bottom chord height 13H. A wooden I-joist 1 in context with the present invention includes well known I-joists made of wood and/or wood like materials such as laminated wood and the like. Also in context with the present invention, the bottom chord 13 may have a top 131, sides 132, front 133 and a bottom 134 and the web 12 may have a web side 122 and a web front 123.

Prior to assembly, I-joist 1 may be cut to a predetermined length between two opposing I-joist 1 ends. In the depicted assembly example where the I-joist 1 rests with its front perpendicularly on the bearing rest 2, chord fronts such as bottom chord front 133 and web front 123 may be substantially coplanar with respect to each other and perpendicular with respect to the I-joist's 1 protrusion direction.

The I-joist 1 rests with the bottom chord bottom 134 on the bearing surface 21 defining a bearing interface having a bearing interface depth BD and a bearing interface width BW. The bearing interface width BW equals the bottom chord width 13W. The bearing interface depth BD may be a fraction of the overall surface width 2W such that a well known rim board 4 with its thickness 4T may be additionally assembled on top of the bearing surface 21. The bearing interface depth BD may be further reduced by inaccurately positioned bearing rest 2 and/or inaccurately lengthened I-joist 1.

For a given load carried by the I-joist 1, the pressure in the bearing interface increases with decreasing bearing interface depth BD. In addition, a reduced bearing interface depth BD may tempt a construction worker to nail the bottom chord 13 with an erroneous chord front nailing clearance XCF that is below a minimum defined by I-joist 1 manufacturers for keeping a well known splicing risk of the bottom chord 13 at a minimum. Besides a wrongly chosen chord front nailing clearance XCF erroneous web nailing clearance XCW or erroneous chord edge nailing clearance XCS may additionally increase a splicing risk and formation of bottom chord cracks 139 along the bottom chord 13.

Besides the risk of erroneous nail positioning, an erroneously sized and/or shaped nail 3 may be used by construction workers. Such oversized nail 3 may have a shaft diameter 3D exceeding a well known maximum chord nail diameter as defined by I-joist 1 manufacturers again to keep the chord splicing risk to a minimum. Another reason for chord splicing may be nail head 32 immersion into the bottom chord top 131 as is well known in the art.

Because of the large force concentration in the I-joist 1 in the vicinity of the bearing interface, prior art web stiffeners 5 may be laterally attached on both web sides 122 keeping the web's buckling tendency to a minimum above the bearing interface. Such prior art web stiffeners 5 may have a width 5W of up to the web recess depth 1R and a height 5H of less then web height 12H. Prior art web stiffeners 5 are commonly attached by fasteners such as nails or screws. Attached prior art web stiffeners 5 and prior art rim boards 4 may keep eventual chord cracks 139 undetected. Undetected chord cracks 139 may excessively reduce load transfer capabilities in the bearing interface from the I-joist 1 onto the bearing rest 2.

In a first embodiment of the invention depicted in FIGS. 3, 4, AA, BB, 5, a device 6S for restricting nailing on a wooden I-joist 1 may feature a nail restricting hole 63 in a chord plate 62 that has a web edge 629. The nail restricting hole 63 is with its center axis 8A in a web nailing clearance CW to the web edge 629 and in a chord front clearance CF to a I-joist front flush face 621/6521. The nail restricting hole 63 may have a restricting diameter 63D such that only a suitable nail 8 having a shaft diameter 8D of up to the restricting diameter 63D may be nailed through the nail restricting hole 63. Web and chord nailing clearances CW, CF as well as restricting diameter 63D may be selected in accordance with well known chord nailing standards established by wooden I-joist 1 manufacturers. The chord plate 62 has a top 627 and bottom 628.

The I-joist front flush face 621/6521 is preferably perpendicular to the web edge 629. In case of an employed web front bridge plate 652 described in more detail further below, the I-joist front flush face is preferably the I-joist front flush face 6521. In case of an employed I-joist front flush plate 6222 as described in more detail under FIGS. 8, 9, the chord front bridge plate 6222 features the I-joist front flush face 6223. In case of a chord plate 62 utilized without either web front bridge plate 652 or I-joist front flush plate 6222, the I-joist front flush face 621 may be employed.

The device 6S may include a web stiffening structure 60, which may be monolithically fabricated together with the chord plate 62. The web stiffening structure 60 may include a web plate 65, a web stiffening rib 66 and web fastening features including web fastener holes 67 and/or web claws 671 and/or web bite edges 672. The web plate 65 is preferably substantially coplanar with the web edge 629 and substantially perpendicular with respect to the chord plate 62. The web plate 65 has a web plate height 65H of up to about the web height 12H such the web plate 65 spans substantially across the entire web height 12H. The web stiffening rib 66 is preferably substantially perpendicular with respect to the chord plate 62 and in an angle with respect to the web plate 65. The web stiffening rib 66 extends substantially along the web plate height 65H providing buckling stiffness to the web plate 65 as may be well appreciated by anyone skilled in the art. Web bite edges 672 may be preferably employed in combination with the web front bridge plate 652 as described further below.

The device 6S may also feature a web front bridge plate 652 combining two web plates 65 in a U-profile along the web height 65H such that two of the web plates 65 face each other while forming a web gap 65G. The inside of the web front bridge plate 652 may operate as the I-joist front flush face 6521 pointing towards said web gap 65G. The I-joist front flush face 6521 provides accurate chord front nailing clearance CF once the I-joist front flush face 6521 is in contact with the web front 123. Chord plates 62, web plates 65, web stiffening ribs 66 and web front bridge plate 652 may be fabricated from sheet metal, preferably as a monolithic structure.

The device 6S may be initially attached at a respective web side(s) 122 with the chord plate 62 being in a snug contact with the bottom side top 131 and the I-joist front flush face 621/6223/6521 being brought in flush alignment with respective I-joist 1 front features such as the web front 123 or the bottom chord front 133. Following the snug attachment of the web plate(s) 65 to respective web side(s) 122, the bottom chord 13 may be nailed via the nail restricting hole 63 onto the bearing rest 2.

In the case of two web plates 65 combined by the web front bridge plate 652, the two web plates 65 may be U-clamped to the web 12. The web gap 65G is predetermined in conjunction with the web thickness 12T such that the device 6S may be slid onto the web 12 via the I-joist 1 front and brought into a snug friction based connection with the web 12 prior to final attachment of the two web plates 65 to the respective web sides 122 via the fastening features 67, 671, 672. This may improve the positioning and attachment of the device 6S since the device 6S may not need to be held in position during the final attachment of the web stiffening structures 60 on both web sides 122.

Web claws 671 may be integrally formed together with the web plate 65 by well known sheet metal fabrication techniques such as bending and punching. The web claws 671 may be fabricated in a non engaging position as depicted. During attachment and while the respective web plate 65 is held in position, the web claws 671 may be hammered or otherwise pressed into the web 12, whereby the base of the web claws 671 plastically deforms and continues to hold the claws inside the web 12.

The web bite edge 672 may be preferably employed in combination with two U-profiled web stiffening structures 60. The web bite edge 672 extends laterally across the web plate's 65 side intended for contacting the web side 122. The web bite edge 672 has a sharp edge configured to cut into the web side 122 in a wedge like fashion to increase the friction forces holding the web plates 65 in place. The U-profiled web stiffening structures 60 may be hammered or otherwise pressed onto the web 12 in protrusion direction of the I-joist 1. The U-profiled web stiffening structures 60 provide for a balanced contact pressure on both opposite web sides 122 assisting in an increased contact pressure and consequently increased friction based fix of the U-profiled web stiffening structures 60 on the web 12 along its web front 123. The web bide edge 672 may have a barbed cut edge for increased holding strength as may be well appreciated by anyone skilled in the art.

In the case of a single web stiffening structure 60 being laterally attached to the web side 122, the respective chord plate 62 may likewise be in a snug contact with the bottom chord top 131. In case of a single web stiffening structure 60 attached with its chord plate along an I-joist front, the I-joist front face 621 of the chord plate 62 may be employed for flush positioning of the device 6S with respect to the chord front 133 and consequently with a correct chord front nailing clearance CF. A single web stiffening structure 60 may also be employed in a case where the bearing interface is in a distance to the I-joist 1 front.

In a second embodiment of the device 6N depicted in FIGS. 6, 7, two chord plates 62 are combined by an I-joist front plate 6222 extending substantially perpendicular away from the bottom side of the chord plates 62. Each of the two chord plates 62 has a chord front edge 6224 substantially collinear to each other and perpendicular to respective web edges 629. The web edges are facing each other substantially parallel spaced apart by web contacting gap 65G. Chord plates 62 and I-joist front plate 6222 may be fabricated from sheet metal, preferably as a monolithic structure. The device 6N operates mainly as nail restricting device. An independent well known web stiffener 5 may be attached after placement of the device 6N.

In the first and second embodiment device 6S, 6N a centering funnel 64 may be provided by the chord plate 62 surrounding the nail restricting hole 63. In case of the chord plate 62 being made of sheet metal, the centering funnel 64 may be embossed into the chord plate 62 with the chord plate 62 bottom remaining planar for a snug contact with the bottom chord top 131.

Due to the precisely defined position and diameter 63D of the nail restricting hole 63, use of correct nails 8 with a maximum allowed shaft diameter 8D is warranted and nail head 82 immersion is avoided. Consequently, the formation of cracks 139 may be prevented or its risk brought to a minimum while a buckling tendency of the web 12 above the bearing rest 2 is reduced to a predetermined safety limit. Due to the thin wall sheet metal construction of the device 6S, the correct nailing location may remain visible for inspection. In case type markings are employed on the nail heads, correct nail 8 type may also be visually verified during inspection.

In a third embodiment of the nail restricting and web stiffening device 6B depicted in FIGS. 8, 9, two substantially coplanar chord plates 62 may be combined by web stiffening structure 60 as described under the first embodiment device 6S. Nevertheless the third embodiment may include a configuration in which the two chord plates 62 are combined by the chord front plate 6222 as described under the second embodiment device 6N. In the third embodiment device 6B, chord nailing is completely restricted by the closed surface of the chord plates 62. Attachment of the I-joist 1 to the bearing 2 is provided directly via bearing attachment holes 624 of two bearing plates 623 connected with respective chord plates 62 via two chord height bridging plates 622. The two chord height bridging plates 622 are combined with the chord plates along chord side flush edges 626 that are parallel spaced apart by an extension width 622W corresponding to the chord width 13W.

The chord height bridging plates 622 extend substantially perpendicularly away from chord plate's 62 bottom sides. The chord height bridging plates 622 may have an extension height 622H corresponding to the bottom chord height 13H. The two bearing plates 624 are each combined with a respective one of the two chord height bridging plates 622 along bearing edges 6232. The two bearing plates 624 protrude away from each other and are substantially coplanar with respect to each other and plane parallel with respect to the chord plates 62. The chord plate 62 has a top 627 and bottom 628.

In the most basic configuration of device 6B, only one chord plate 62, chord height bridging plate 625 and bearing plate 623 are utilized. The bottom chord 13 is limited in its lateral movement towards the chord height bridging plate 625 and limited in its vertical movement away from the bearing surface 21 by the chord plate 62. Two basic devices 6B oppositely and independently assembled on both sides of the bottom chord 13 may fully fix the bottom chord 13 in lateral and vertical direction. The I-joist 1 may be fixed in protrusion direction by other well known means such as the rim board 4. Separate web stiffeners 5 may also be employed.

In an intermediate configuration of the device 6B, a single web stiffening structure 60 is combined with the chord plate 62 for single side buckling opposing stiffening of the web 12 in combination with fixing the bottom chord 62 on the bearing rest 2. Since the web stiffening structure 60 may be directly attached to the web side 122, the I-joist 1 may be simultaneously fixed in protrusion direction as well. Two intermediately configured devices 6B oppositely and independently assembled on both sides of the bottom chord 13 may fully fix the bottom chord 13 in lateral and vertical and protrusion direction.

In an advanced configuration of the device 6B, double side web stiffening is accomplished by two web stiffening structures 60 combined in a U-profile as described above, which provides maximum attachment strength to the web 12 along its web front 123 and maximum buckling opposing web support due to the increased overall stiffness of the two combined web stiffening structures 60 as may be well appreciated by anyone skilled in the art.

The device 6B may be directly attached to the bearing rest 2 via well known fasteners such as nails or screws guided through the bearing attachment hole(s) 624 and fixedly holding the bearing plate(s) 623 in a snug contact with the bearing surface 21. The bottom chord 13 remains free of penetrating fasteners in the vicinity of the bearing interface. Fasteners for attaching the bottom chord 13 may be consequently selected independently of the chord nail requirements defined by I-joist 1 manufacturers.

Accordingly, the scope of the invention as described in the Figures and the Specification above is set forth by the following claims and their legal equivalent:

Claims

1. A monolithic I-joist chord end nailing restricting device comprising:

a. a chord plate having a web edge;

b. a I-joist front flush face substantially perpendicular to said web edge; and

c. a nail restricting hole in said chord plate, said nail restricting hole being in a web nailing clearance to said web edge and in a chord front nailing clearance to said I-joist front flush face, said nail restricting hole having a diameter corresponding to a predetermined chord nail diameter.

2. The device of claim 1 further comprising:

a web stiffening structure combined with said chord plate along said web edge and protruding substantially perpendicularly away from a top side of said chord plate, said web stiffening structure having: a. a web plate substantially coplanar with said web edge and substantially perpendicular with respect to said chord plate, said web plate having a web plate height; b. a web stiffening rib substantially perpendicular with respect to said chord plate and in an angle to said web plate, said web stiffening rib extending substantially along said web plate height such that said web stiffening rib provides buckling stiffness to said web plate; and c. a web fastening means including at least one of a web fastener hole, a web claw and a web bite edge.

3. The device of claim 2, further comprising a web front bridge plate combining two of said web plate in an U-profile along said web plate height such that two of said web plate are oppositely facing each other while forming a web gap, and wherein said I-joist front flush face is on an inside of said web front bridge plate pointing towards said web gap.

4. The I-joist chord end nailing restrictor of claim 3 being U-clamped to a web of a wooden I-joist via said U-profile while said two of said web plate are snug attached via said web fastening means at respective sides of said web, while said web front bridge plate is contacting a web front, while said chord plate is in a snug contact with a bottom chord top, such that a buckling tendency of said web is reduced below a predetermined safety limit.

5. The device of claim 2 being snug attached to a web side of a wooden I-joist via said web plate, while said chord plate is in a snug contact with a bottom chord top, such that a buckling tendency of said web is reduced below a predetermined safety limit by said web stiffening structure.

6. The device of claim 5, wherein said I-joist front flush face is part of said chord plate and substantially flush with a bottom chord front of said I-joist.

7. The device of claim 1, wherein two of said chord plate are combined by an I-joist front plate extending perpendicularly away from a bottom of said chord plates, said two of said cord plate having a chord front edge substantially collinear with respect to each other and substantially perpendicular with respect to two respective of said web edges while said two respective web edges are facing each other substantially parallel spaced apart in a web contacting gap.

8. The device of claim 1 being made of sheet metal.

9. The device of claim 8, being a monolithic structure.

10. The device of claim 1, wherein said chord plate further comprises a centering funnel surrounding said nail restricting hole.

11. A device for combined I-joist chord nailing restriction and web stiffening, said device comprising:

a. a chord plate having; i. a web edge; ii. a chord front edge; iii. a chord side flush edge; iv. a bottom side; v. a top side;

b. two chord height bridging plates combined with respective ones of said two chord plate along respective ones of said chord side flush edges and extending away from respective ones of said plate bottoms substantially perpendicular with respect to said two chord plates, each of said chord height bridging plates having a bearing contact edge in a substantially parallel offset to a respective one of said chord side flush edge; and

c. two bearing plates each combined with a respective one of said two chord height bridging plates along respective ones of said bearing edges, said two bearing plates protruding away from each other and being substantially coplanar with respect to each other and plane parallel with respect to said two chord plates, each of said bearing plates having a bearing attachment hole.

12. The device of claim 11, wherein two of said chord plate are substantially coplanar and opposing each other with respective one of said web edge, wherein said respective web edges are substantially parallel and spaced apart by a web contacting gap, wherein said respective ones of said chord side flush edge are substantially parallel and spaced apart in a bottom chord distance, and wherein said two chord contacting plates are combined with each other by at least one of an I-joist front plate and a web stiffening structure, said I-joist front plate extending from both chord front edges, said web stiffening structure including two web plates and a web front bridge plate combining said two web plates in an U-profile protruding substantially perpendicular away from said plate top and holding said two web plates in a web contacting space, each of said web plates being combined with said chord plates along a respective one of said web contacting edges.

13. The device of claim 11, further comprising a web plate combined with said chord plate along said web edge and perpendicularly protruding away from said top side, said web plate having a web fastening means including at least one of a web fastener hole, a web claw and a web bite edge.

14. The device of claim 13, further comprising a web stiffening rib substantially perpendicular with respect to said chord plate and in an angle to said web plate, said web stiffening rib extending substantially along said web plate height such that said web stiffening rib provides buckling stiffness to said web plate.

15. The device of claim 11, being made of sheet metal.

16. The device of claim 15, being a monolithic structure.

17. The device of claim 11, being U-clamped to a web of a wooden I-joist via said U-profile while said web edge is substantially coplanar with a side of said web, while at least one of said chord front flush edge is substantially flush with a bottom chord front of said I-joist and said web front bridge plate is contacting a web front, while said chord plate is in a snug contact with a bottom chord top, such that a buckling tendency of said web is reduced below a predetermined safety limit by said volume structure.

18. The device of claim 11, being attached to a web of a wooden I-joist via said web plate while said web edge is substantially coplanar with a side of said web, while said chord front flush edge is substantially flush with a bottom chord front of said I-joist, while said chord plate is in a snug contact with a bottom chord top, such that a buckling tendency of said web is reduced below a predetermined safety limit by said volume structure.

19. The device of claim 11, being attached to a bearing rest via a fastener guided through said bearing attachment hole and fixedly holding said bearing plate in a snug contact with a bearing surface of said bearing rest while said chord height bridge plate is limiting lateral movement of a wooden I-joist chord in lateral direction towards said chord height bridge plate and while chord plate is limiting vertical movement of said wooden I-joist chord in vertical direction towards said chord plate.