IE56802B1

IE56802B1 - Joist hanger

Info

Publication number: IE56802B1
Application number: IE208385A
Authority: IE
Original assignee: Press Bat Holdings Ltd
Priority date: 1984-09-17
Filing date: 1985-08-23
Publication date: 1991-12-18
Also published as: GB8520897D0; IE852083L; GB2164676A; GB8423482D0; GB2164676B

Abstract

The hanger comprises a shoe 11 having a projecting base 13 and a pair of side members 14. Side members 14 are obliquely folded to provide laterally extending triangular wings which themselves are folded along a line parallel with base 13 to define bearing elements 12 adapted to rest on a supporting wall. The hanger is formed from a single blank. A suitable blank is described. Side members 14 may include gussets 16. Stiffening formations 19 may be pressed into the wings and extensions to rigidify their junction.

Description

This invention relates to a joist hanger.

If is customary building practice to provide a metal hanger for supporting a generally horizontal structural timber or timber assembly from a load bearing wall of a building. The structural timber may be a joist or a roof truss for example. Such a hanger will be referred to in this description under the generic term joist hanger irrespective of what type of timber or timber assembly it is intended to support.

A conventional form of joist hanger employe a generally lazy Z section of thin gauge galvanised steel, having side straps welded between the upright and lower horizontal parf of the section. In use, the joist sits in the shoe formed by the upright and lower horizontal part and the straps. The upper horizontal part forms a bearing portion which rests on top of a masonry element such as a brick or block of the load bearing wall.

Joist hangers of this general type have been in use for many years but they have certain disadvantages. Firstly, the welding required to form the shoe can only be achieved if the zinc coating on the metal is relatively thin or if the hanger is galvanised after welding.

The latter method is unsatisfactory as it is expensive and can cause distortion. However, up-grading of building standards mean that a thin galvanic coating is unacceptable.

Additionally, the width of the aotfcX strip forming the X&xy Z ©action is equivalent to the width of the joist and therefore forme a relatively narrow hearing portion resting on the load hearing wall. Xt does not aproftd- the load substantially along the length of the wall nor does it offer much lateral restraint to the joist.

Two-part hangers have been proposed but may give rise to jointing problems even where welding lo not used.

It Ig an object of the present invention to provide a new or improved joist hanger which overcomes or reduces these disadvantages and which is economical to produce. 1.

According to the Invention there i-s provided a jointless joist hanger formed by pressing from a single sheet metal blank, the hanger comprising a shoe having a base and a pair of side members, oach side member ineluding three integrally connected portions namely; an upright portion connected to the base; a wing portion connected to th© upright portion and lying in a plan© sloping obliquely upwardly from the front of the hanger to the back and extending In a direction aw&y from the other side member; and an extension connected to the wing portion and lying in a different plan©? the two extensions being coplanar and being adapted to be scoured to a wall in us©, to support a joist disposed in said shoe.

The extensions may be generally parallel to th© b&ei^o Further extensions may be bent downwardly at the free ends of the extensions to hook over a supporting wail.

The front of the hanger is that face from which the joist projects in use. The back of the hanger is that face which is adjacent the supporting wall in use.

Said oblique plane of the wing portion may intersect 5 that of the upright portion at right angles.

The extensions may project outwardly away from the base as seen in plane view.

The base may project forwardly from the remainder of the shoe. The upright portion of the side member may include a gusset which tapers rearwardly from adjacent the base.

The extensions may have their terminal edges truncated so as to be generally parallel to the upright portions of the side walls.

Stiffening formations such as ribs may be pressed into the material of the hanger for added rigidity. Such formations may be provided for example at the fold lines between the wing portions and their respective extensions and/or in the upright portions of the side members.

The invention will now be described in more detail 4 by way of example only with reference to the accompanying drawings in which:FXGtjJlSlg 1. lo fi side elevational view of a typical 5 joist hanger embodying the invention.

FXGTOg 2 is a front elevational view of the hanger. 3, is a plan view of the hanger.

FSGUB3S 4. is a diagrammatic layout, on a reduced scale, of blanks suitable for making the joist hanger shown in Figures 1-3. £ shows the joist hanger of the invention modified for use in supporting a joist at the junction of two walls.

Referring firstly fo Figures 1 to 3 of the drawings, a joist hanger generally indicated at 10 comprises a shoe generally indicated at 11 which is adapted to receive a joist (not shown). The hanger 10 further comprises a pair of bearing elements 12. The whole hanger is made from a single sheet metal blank of, for example, heavy gauge galvanised mild steel sheet. The blank will be referred fo in more detail below. The sheet can have a thick galvanic coating because it does not need to be welded fo form the joist hanger according to the invention.

The shoe 11 comprises a base 13 on which the joist br rests in use. A pair of upright walls 14 are disposed adjacent the aide faces of the joist. The base 13 and the immediately adjacent parts 15 of the side walls project forwardly by a greater distance than the remainder of the joist hanger ao as fo support the joist along a substantial length adjacent its ends, typically at least 75 mm. I The remainder of the side member 14 includes a fi rearwardly tapering gusset 16 between the base and the upper part of the side member, provided for extra strength and to support the base more rigidly. The side member also comprises a wing 17, The wing 17 is generally triangular in shape and is formed by folding the side member into a plane which is at an angle, for instance at right angles to that of the upright portion 14 of the side member and which slopes obliquely upwardly from the front to the back of the hanger. The wing portion 13 of each side member is triangular and its upper edge ends in a further fold line 18, from which an extension of the wing projects horizontally, parallel to and in an opposite direction from the base 13, to form the bearing element 12.

In another form of hanger (outside the scope of the present: invention) shewn in Figure 5, the wing portion 17 is emitted at one side of the hanger and the side member 40 is vertical. lhe extension 41 is folded horizontally along a line 42 parallel fo the fold between the base and the side wall, to enable the hanger fo be used adjacent a right angled corner between two walls 43 and 44.

In a modified form of the hanger shown in Figures 1 to 4, a return flange to hook over the supporting wall is provided as a further folded extension (not shown) of the a bearing element.

In a further form of hanger, the extensions are bent vertically upwardly from the wings to enable bolts fo be used to make a fair face fixing to an upright face of a concrete wall or beam, for example.

In the joist hanger shown in Figures 1 to 4, a 5 stiffening dart 19 is provided at the fold line IB to ensure that the bearing element is held rigidly against flexing in use, when the hanger has been loaded with a jo 1st* The bearing element 12 has a pair of holes, the larger 20 of which is intended as a key for mortar where the joist hanger is laid in a coursing joint of a masonry wall, and the smaller 21 of which is a nail hole for use where the joist hanger is laid on a timber wall plate. (The same blank io used for fair face fixings, where the holes 20 provide means for bolting vertical extensions to the upright face of the wall).

The upright portions of the side members 14 are also provided with holes 22 through which nails pass into the joist to secure it in the shoe 11 in use. The side walls also have pressed ribs 23 which act as stiffening forma20 tions.

In the rear edge of the wall members of the joist hanger, a pair of cut out notches 24 and 25 are provided. These can accommodate fixing brackets for extra bolted fixings fo improve lateral restraint, especially when used for a face fixing.

« Referring to Figure 3 of the drawings, it will be seen that the obliquely folded wing portions 17 extend into the bearing elements 12 in such a way that the bearing elements spread outwardly from each other, in opposite directions away from the centrally disposed shoe portion 11. The extreme free edges 26 of the bearing elements are truncated so as to be approximately parallel to the upright portions 14 of the side walls. This is done partly so as to enable a builder fo position the joist close to a corner between two walls at right angles, and partly to reduce the amount of metal necessary for the manufacture of the hanger. This will be referred to later in connection with the blank layout shown in Figure 4.

However, it will be seen that the bearing portions of the joist hanger extend along a substantial length of the wall, much greater than the width of the joist within the shoe part 11. This means that the load of the joist can be spread along the wall to a much greater extent than in a conventional Hlazy Z shaped hanger. This is particularly of importance where relatively soft lightweight building blocks are used in a load supporting wall, since such blocks have a relatively low crushing strength. Additionally, the length of the bearing area along the wall gives improved resistance to rocking of the joist hanger from side to side and hence holds the joist more rigidly, with greater lateral support.

Turning to Figure 4 of the drawings, this shows a layout in which a first blank 30, a second blank 31 and a third blank 32 are cut from a single sheet metal strip having a width equal to the front to back depth of the base 13 of a hanger.

It will be seen that the truncated edges 26 of the extensions 12 of the hangers 31 and 32 lie alongside the gussets 16 of the hanger 30, enabling more blanks to be cut from the strip. The extreme free ends 33 of the hangers 31 and 32 abut the upper edges of the side wall parts 15 adjacent the base 13 of the hanger 30.

The position of the fold lines of the joist hanger blank 30 are shown in chain dotted lines at 34 and 35.

It will be appreciated that a large number of hanger blanks will normally be stamped out of a continuous sheet metal strip with little or no wastage, simultaneously piercing the necessary holes. The folds are then provided in subsequent pressing operations,

Claims

1. lo A joi ntlesn joist hanger formed hy pressing from a single sheet metal blank, the hanger comprising a shoe having a base and a pair of aido members, each side member including three integrally connected portions namely; an upright portion connected to the base; a wing portion connected fo the upright portion and lying in a plane sloping obliquely upwardly from the front of the hanger to the back and extending in a direction away from the other aide member; and an extension connected fo the wing portion and lying in a different plane; the two extensions being coplanar and being adapted to be secured to a wall in use, to support a joist disposed in said shoe.

2. 3. A joist hanger according fo Claim 1 wherein the extensions are generally parallel to the base. 3· A joist hanger according to Claim 2 wherein the extensions project outwardly away from the base as seen in plan view.

3. 4. a joist hanger according to any preceding claim wherein each extension terminates in a further extension projecting downwardly, whereby the hanger is adapted to be hooked over a supporting wall.

4. 5. a joist hanger according to any preceding claim wherein the oblique plane of the wing portions intersects that of the upright portions at right angles.

5. 6. a joist hanger according to &ny preceding claim wherein the base projects forwardly from the remainder of the shoe.

6. 7. A joist hanger according to any preceding claim wherein the upright portion of the side member includes a gusset whleh tapers rearwardly from adjacent base. Θ. A joist hanger according to any preceding claim 5 wherein the extensions have their terminal edges truncated so && to. be generally parallel to the upright portions of th© side members. 4 9. A joist hanger according to any preceding claim wherein stiffening formations such as ribs are pressed

7. 10 into the material of the hanger. 10. a joist hanger according to claim 9 wherein said stiffening formations are provided at the fold lines between the wing portions and their respective extensions. 15

8. 11. A joist hanger according to claim 9 wherein said stiffening formations are provided in the upright portions of the side members.

9. 12. A jointlesc joist hanger substantially as hereinbefore described with reference to and as illus20 trated in Figures 1 to 3 of the accompanying drawings.

10. 13. A jointless joist hanger formed from a blank substantially as hereinbefore described with reference to and as illustrated in Figure 4 of the accompanying drawings.