Abutting irregular hexagons as beam ties for a dual beam joist supporting a truss

Abstract

A roof structure supporting a roof comprising a truss and a joist supporting the truss, the joist having two elongated wooden beam members on the bottom of the truss connected with beam tie members comprised of a pair of congruent truncated mirror image parallelograms forming hexagons with mutually facing and abutting portions. Each beam tie member is connected to outer sides of top and bottom elongated wooden beams and is adjacent to the next beam tie connected to outer sides of top and bottom elongated wooden beams. The tied beams allow use of smaller, less expensive beam members yet providing good truss support in a joist.

Claims

1. A roof structure comprising: a roof truss made of beams having a width and a span; and a joist supporting the roof truss, that joist having, a pair of coextensive, spaced apart beams having parallel lengths, widths and a height, at least as long as the span of the truss, the beams spaced by a plurality of spaced apart blocks joined to the beams at intervals; a plurality of beam ties affixed along the length of the beams, the beam ties being formed by pairs of congruent irregular hexagons having a height that is approximately the same as the spaced apart beams, the pairs being symmetric truncated mirror image parallelograms forming the hexagons with mutually facing and abutting noses, wherein the extent of nose-to-nose abutment of the noses is at least one-third of the height of the irregular hexagons, whereby the beam ties form tiles that abut the beams and mutually abut in the space between the beams thereby adding strength and load support to the joist.

2. The roof structure of claim 1, wherein the joist further comprises wooden support straps affixed to the beams on a side of the beam opposite the beam ties.

3. The roof structure of claim 1, wherein the height of the beams measured from a lower beam to a top beam is approximately 12 inches.

4. The roof structure of claim 1, wherein the beam ties have dimensions of approximately 11×3½×½inches.

5. The roof structure of claim 1, wherein the wooden straps have dimensions of approximately 2½ by 11 by ½ inches.

6. The roof structure of claim 1, wherein the beams are of the type known as 2-by-4 beams.

7. The roof structure of claim 1, wherein the beam ties are wooden.

8. The roof structure of claim 1, wherein the beam ties are metal.

9. The roof structure of claim 1, wherein the support blocks are spaced apart approximately 16 inches from the next support block.

10. The roof structure of claim 1, wherein the beams are connected to the truss through metal truss plates having nail holes.

11. The roof structure of claim 1, wherein clips are used to connect beams to the truss.

12. The roof structure of claim 1, wherein the beam ties, beam, truss and support blocks are comprised of wood.

13. A truss assembly comprising: a wooden truss comprised of a pair of sloped top chords meeting at a peak and a web of beam members forming triangular structures connected to the top chords; and a wooden joist comprised of a pair spaced apart beams spaced by a plurality of spaced apart blocks joined to the beams at intervals and extending in parallel from one sloped top chord to the other; a plurality of beam tie members affixed along the length of the beams, the beam tie members being formed in symmetric pairs, each member comprising a symmetric truncated mirror image parallelogram forming an irregular hexagon, the tie members having mutually facing noses and a height that is approximately the same as the spaced apart beams, wherein the beam tie pairs are adjacent to each other appearing as tiles that abut the beams and mutually abut in the space between beams thereby adding strength and load support to the joist.

14. The truss assembly of claim 13, wherein the beam ties are wooden.

15. The truss assembly of claim 13, wherein the beam ties are metal.

16. The truss assembly of claim 13, wherein the beam tie pairs are aluminum.

17. A roof structure comprising: a roof truss made of beams having a width and a span; and a joist supporting the roof truss, that joist having, a pair of coextensive, spaced apart beams having parallel lengths, widths and a height, at least as long as the span of the truss, the beams spaced by a plurality of spaced apart blocks joined to the beams at intervals; a plurality of beam tie members affixed along the length of the beams, the beam tie members being formed in symmetric pairs of congruent irregular hexagons having a height that is approximately the same as the spaced apart beams, the pairs being symmetric truncated mirror image parallelograms forming the hexagons with mutually facing and abutting noses, whereby the beam ties form tiles that abut the beams and mutually abut in the space between the beams thereby adding strength and load support to the joist.

18. The roof structure of claim 17, wherein the extent of nose-to-nose abutment of the noses of tie members is at least one-third of the height of the irregular hexagons.

19. A method of forming a joist for a truss comprising: stacking two parallel coextensive beams having a length spanning a truss dimension where support is designed, the beams having a non load bearing surface; joining the beams along the non load bearing surface, with ties fastened to the two beams, the ties being formed in symmetric pairs, each member of each of the ties comprising a symmetric truncated mirror image parallelogram forming an irregular hexagon and having mutually facing and abutting noses, the ties being tiled to have a corrugated shape along the beam length mutually abutting in the space between the beams thereby forming a truss joist, the corrugated tiles having a height that is approximately the same as the spaced apart beams.

20. The method of claim 19 further defined by forming the ties as abutting irregular hexagons.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIGS. 1A-I are front views of prior art trusses known in the art.

(2) FIG. 2 is a front view of an embodiment of a roof structure featuring a roof truss with a joist.

(3) FIG. 3A is a front view of beam tie members.

(4) FIG. 3B is a top view of the beam tie members of FIG. 3A.

(5) FIG. 3C is a side view of beam tie members of FIG. 3B.

(6) FIG. 4 a partial perspective view of two beam ties of FIG. 2 without joist beams.

(7) FIG. 5 is a rear view of the embodiment of the invention of FIG. 2.

DETAILED DESCRIPTION

(8) With reference to FIG. 2, there is seen a roof structure 200 having a truss 202 and a joist 204 featuring beam ties 206a-g for strengthening the truss 202 for roof support. In a preferred embodiment, the truss and joist beams are made from lumber. The truss has a beam web 208 forming triangular patterns for carrying axial forces. This triangular pattern example is the same as that found in a Howe Girder truss depicted in FIG. 1E. Though this embodiment will be described with reference to the Howe Girder triangular beam web pattern, various truss beam web and truss designs may be strengthened by the joist described herein.

(9) As seen in FIG. 2, the joist 204 comprises a pair of coextensive, spaced apart beams 210a and 210b having parallel lengths, widths and a height, the lower beam beam 210b at least as long as the span of the truss and the upper beam 201a at least as long as a shorter span of the truss. With reference to FIG. 4, the dimensions of beam ties 206b and 206c are seen. Typically the dimensions of each beam tie are the same. Each beam tie has, in one example, a total height th of approximately 11 inches, a leg width lw for the lower flat sides 406a, 406b, 406c, 406d of approximately 3½ inches, a total width tw of approximately 12 inches, an upper width uw of approximately 2.5 inches for each of the upper flat sides 408a, 408b, 408c, 408d, a notch width nw of approximately 5 inches and a depth d of approximately inch. Lower sloping sides 400a, 400b, 400c, 400d of each beam tie forms a notch 402, 404 having, in one example, a notch of 60 degrees. Adjacent upper sloping sides 402a, 402b, 402c, 402d of beam ties form a notch when adjacent with another upper sloping side 404 having a notch angle of, for example 60 degrees. Notch angles are not critical. The length of the abutment al is, for example 4½ inches. The inner side length il is approximately 4½ inches.

(10) As seen in FIGS. 2 and 5, the beams 210a and 210b are affixed to the truss 202, for example, using clips 212 such as metal TECO clips and nails. “TECO” was formerly a registered trademark for metallic wood beam connectors but now is generic for same. The web 208 is connected to the top chords 214a and 214b using, for example, clips 212. Where the truss has sloped top chords 214a and 214b, the beams 210a and 210b are connected, for example, at the lower ends of the top chords of the truss 202. Beam ties 206a and 206g have been trimmed on the ends. In other examples the beam ties on the end are not trimmed.

(11) With reference to FIG. 5, the joist beams 210a and 210b are spaced apart by a plurality of spaced apart blocks 516a-h centered in and joined to beams 210a and 210b at intervals. In one example, the support blocks have a height of 4 inches, a width of 4 inches and a depth of 2 inches.

(12) Referring back to FIG. 2, the beams are tied to each other with a plurality of beam ties 206a-g affixed along the length of the beams 210a and 210b. The beam ties may be nailed, adhered or otherwise affixed to the beam ties 210a and 210b.

(13) With reference to FIGS. 3A-C, the beams ties 206a-g are each formed by a pair of congruent irregular hexagon members 318a and 318b that are joined to the beam members and placed adjacent to each other. In a preferred embodiment the beam ties are plywood. In other embodiments the beam ties may comprise metal, for example ⅛ inch thick aluminum. The hexagon members (and the beam ties they form) have a height th that is approximately the same as the spaced apart beams. The beam height bh, as seen in FIG. 2, is, for example, approximately 11 inches with approximately, for example, a 3 inch space s (FIG. 5) between beams. The beam tie pair members are symmetric truncated mirror image parallelograms forming the irregular hexagons. The members of each pair have mutually facing and abutting wedge shaped noses 320a and 320b that provide lateral, i.e., sideways, and torsional stability since pairs of abutting pieces form unitary structures by tiling. A running length of such tiled tie members resemble stiff corrugations applied to a non load bearing surface of a joist. In one example, at least one third of the height th of the irregular hexagon member 318a is abutting the other irregular hexagon member 318b of the pair.

(14) In one embodiment, the beam tie pairs 206 are adjacent to the next beam tie pair 206 along the length of the beams 210a and 210b. In another example, the beam ties 206 are spaced apart along the length of the beams. An upper portion of the beam tie is connected to the upper beam 210a of the pair of beams and a lower portion of the beam tie is connected to the lower beam 210b. This arrangement provides load distribution to the legs 216a-n of the beam ties 206a-g and strengthens the truss 202 providing for strong roof support, even for long span trusses.

(15) Referring to FIG. 5, on the other side of the joist, plywood straps 518a-k may be secured to the beams 210a and 210b at intervals to provide further support. In one example, the wooden support straps have a width of approximately 2½ inches, a height of approximately 11 inches and a depth of approximately ½ inches. The wooden support straps may be secured by for example, nails, or some other mechanism.

(16) In a method of forming a joist for a truss, two parallel coextensive beams having a length spanning a truss dimension are stacked. The beams have a non load bearing surface. Ties are fastened to the beam and are tiled to have a corrugated shape along the beam length thereby forming a truss joist.

(17) The number, size and spacing of the beam ties used may vary as can the truss web and frame design. Ancillary common TECO clips and nails are used where appropriate.