Structural building element

Abstract

A timber I-beam 701 has a top chord 702 and a bottom chord 704 forming the flanges of I-beam and a series of side by side timber blocks 706 each separated from the next by a gap 722, together forming a uniplanar, intermittent web. Cables and pipes for a building may run transversely through the gaps 722. A method of making the I-beam is described.

1 . A timber I-beam for use as a roof truss or floor support the timber I-beam comprising a top chord and a bottom chord forming spaced flanges of an I-beam extending along a longitudinal axis, said flanges spaced from each other and supported by a series of at least two timber blocks lying in a single plane and each separated from the next by an interstitial gap adapted to receive building services, the I-beam forming a uniplanar, intermittent web,
 wherein:   the blocks are oriented with their wood grains aligned transverse to the longitudinal axis;   an inner face of the top chord and an inner face of the bottom chord abuts respective end faces of the at least two timber blocks, whereby the inner faces are substantially flat and have no groove features to engage with the end faces of the blocks;   the lengths of the blocks, in the direction parallel to the longitudinal axis of the plate are at least 50 mm and at most 240 mm;   the gaps between the blocks along the length of the I-beam is between 90 mm-500 mm; and   the thickness of the blocks is between 19 mm and 90 mm.   
     
     
         2 . A timber I-beam as claimed in  claim 1 , wherein the top and bottom chords extend parallel to one another. 
     
     
         3 . A timber I-beam as claimed in  claim 1 , wherein the blocks are of rectangular section. 
     
     
         4 . A timber I-beam as claimed in  claim 1 , wherein the width, w, of the plate is about 90 mm. 
     
     
         5 . A timber I-beam as claimed in  claim 4 , wherein the width of the block is about 45 mm. 
     
     
         6 . A timber I-beam as claimed in  claim 1 , wherein the top chord is raked relative to the bottom chord. 
     
     
         7 . A timber I-beam as claimed in  claim 1 , wherein the width of the gaps is equal along the length of the I-beam. 
     
     
         8 . A timber I-beam as claimed in  claim 1 , wherein the width of the gaps is substantially greater than the width of the blocks. 
     
     
         9 . A timber I-beam as claimed in  claim 1 , wherein the width of the gaps is at least twice the width of the blocks. 
     
     
         10 . A timber I-beam as claimed in  claim 1 , wherein the top chord is inclined in relation to the bottom chord by 0.4 to 45 degrees in order to support a drainage surface. 
     
     
         11 . A timber I-beam as claimed in  claim 10 , wherein the raked inclination is about 1-5°. 
     
     
         12 . A timber I-beam as claimed in  claim 1 , wherein the I-beam is formed by first placing a chord on a table jig and applying adhesive to specific regions where blocks will abut an internal face of the chord, positioning blocks at predetermined spaced intervals along the length of the chord, placing a second chord on the table jig to abut the free ends of the blocks but applying adhesive to corresponding regions of the second chord's inner face to abut the blocks before fixing the second chord in position, applying clamps to hold the first and second chords in spaced relationship against the interposed blocks, and applying a pair of nails to each end of each block through the outer surfaces of each respective chord. 
     
     
         13 . A timber I-beam as claimed in  claim 12 , wherein screws are applied to further hold the first and second chords to the blocks prior to the adhesive setting. 
     
     
         14 . A timber I-beam as claimed in  claim 1 , wherein the blocks are square cut and interposed between top and bottom chords raked to an angle of 2°-5°. 
     
     
         15 . A timber I-beam as claimed in  claim 3 , wherein the rectangular blocks are square cut and interposed between top and bottom chords raked to an angle of 1°-5° such that a wedge shaped space is defined between the end faces of the timber blocks and the inner face of the top chord. 
     
     
         16 . A timber I-beam as claimed in  claim 14 , wherein attachment between the respective inner faces of the top and bottom chords and end faces of the rectangular blocks includes the application of adhesive in the wedge shaped space to provide adequate support to the inclined raking chord. 
     
     
         17 . A timber I-beam as claimed in  claim 1 , wherein the top chord is curved or raked relative to the bottom chord. 
     
     
         18 . A timber I-beam as claimed in  claim 2 , wherein the top and bottom chords are curved. 
     
     
         19 . A timber I-beam as claimed in  claim 10 , wherein the raked inclination is about 0.5 to 5°.