GB2131848A

GB2131848A - Wall-ties

Info

Publication number: GB2131848A
Application number: GB08332768A
Authority: GB
Inventors: Brian Robinson
Original assignee: Catnic Components Ltd
Current assignee: Catnic Components Ltd
Priority date: 1982-12-13
Filing date: 1983-12-08
Publication date: 1984-06-27
Also published as: GB8332768D0; GB2131848B

Abstract

The tie has a substantially planar limb 2 or 4 having a free end 8 which has a curved part 81 which extends out of the plane of the limb to provide a substantially smooth external surface. This prevents the danger of injury by snagging on a sharp free edge, in use. Inclined tabs 7 aid anchoraged in the wall skins. Cut-outs 13 provide clamp edges 14. <IMAGE>

Description

SPECIFICATION Wall-ties Technical field of the invention The invention relates to wall-ties, which are generally used to tie together spaced apart skins of multi-skin walls.

Background art Wall-ties are often used to tie together the skins of the multi-skin cavity wall. When such a wall is built, one skin is built up to a required height with the wall-ties projecting from it into the cavity to be joined. The bricklayer then builds up the adjacent skin to form the cavity, at the same time incorporating the end of the wall-tie which is to be incorporated therein in that skin, so tying the skins together with part of the wall-tie spanning the cavity. The problem is that the projecting part can, before it is incorporated in the second skin, present a hazard as the end is sharp and can injure a bricklayer.

Further, with the advent of the use of insulation in a cavity, part of the width of which is filled with such insulation, means of the wall-tie for collecting moisture can be covered up so that the wall tie forms a bridge for moisture so possibly damaging the wall.

Disclosure of invention It is an object of the invention to seek to mitigate these disadvantages of prior wall-ties.

According to one aspect of the invention there is provided a wall-tie for a multi-skin cavity wall, comprising, for anchorage with one skin of the wall, a substantially planar limb having a free end, wherein the free end has a curved part which extends out of the plane of the limb to provide a substantially smooth external surface.

The expression "curved" is defined herein to include an effective curve, that is one which is made up of a plurality of differently inclined planar parts which are integrally connected together in sequence to form what is an effect a curve.

The curved part may lead to an inclined part which may overlie the limb. Using this construction sharp ends of the wall-tie are avoided.

The inclined part may be inclined at substantially 900 to the plane of the limb.

The curved part may comprise a roll lip. This provides a relatively simple construction which avoids the forming of a sharp free edge of the limb of the wall tie.

The roll lip may comprise two separate roll lip parts, as considered transversely of the limb, separated by a notch, cut-out, slot or the like. This construction provides a method of forming the wall-tie by mass production.

The free end(s) of the roll lip or roll lip parts may touch the limb. This enables the roll lip to be substantially circular in cross-section with the free end effectively hidden so that there is no sharp edge.

The free end of the limb may extend in a curve from one side of the limb to the other, as considered in the plane of the limb.

The lateral edges of the limb may be inclined, preferably at an angle of substantially 900, to the plane of the limb. This provides limb(s) in which sharp edges are avoided.

According to a second aspect of the invention there is provided a wall-tie for a multi-skin cavity wall, comprising a limb for anchorage with a first skin of the wall, another limb for anchorage with a second skin of the wall adjacent the first skin of the wall at least one of the limbs having means for enhancing the anchorage of that limb with a skin of the multi-skin wall, connecting means for connecting the limbs comprising a depression or channel for stiffening at least a portion of the wall-tie and means for preventing or hindering moisture transfer across said wall-tie comprising a lip located adjacent one side of the depression or channel and another lip located adjacent the opposite side of the depression, each lip having at least one means where water can collect when the lips are pointing in a generally downward direction, each limb being substantially planar and at least the free end of one limb having a curved part which extends out of the plane of the limb to provide a substantially smooth external surface.

There may be a plurality of cut out or struck out portions of the lip; preferably there may be three such portions spaced apart along the length of each lip. This construction is such that in use there will always generally be a lip free of insulating material in a cavity when such insulating material is incorporated in the multiskin wall.

The wall-ties may be made of metal, preferably stainless steel. Use of stainless steel obviates corrosion and enhances the life of the wall-tie and hence that of the wall.

According to a third aspect of the invention there is provided a method of making a wall-tie as hereinbefore defined, comprising the steps of forming a substantially planar limb of the wall tie, forming a notch, cut-out, slot, slit or the like in a free end of the limb, and forming a roll lip by deforming the material of the wall-tie on each side of the notch, cut-out, slot, slit or the like into a roll lip part so that the free end of the wall tie has a curved part which extends out of the plane of the limb to provide a substantially smooth external surface.

The roll lip parts may be progressively formed to provide the roll lip.

Wall-ties embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings.

Brief description of drawings Fig. 1 is a plan view of a wall-tie according to the invention; Fig. 2 is a side elevational view of the wall-tie of Fig. 1 showing it, schematically, in position in a cavity wall; Fig. 3 is an enlarged view of a free end of a limb of the wall-tie of Figs. 1 and 2 Fig. 4 is an enlarged plan view of a free end of a limb of a second wall tie embodying the invention; and Fig. 5 is a cross-sectional view of the end shown in Fig. 4, taken along line 'A'-'A'.

Referring firstly to Figs. 1, 2 and 3 of the drawings the wall-tie 1 shown is made from stainless steel and has a limb 2 for anchorage in one skin 3 of a multi-skin wall and another limb 4 for anchorage in another skin 5 of the cavity wall which is parallel to and adjacent the first skin 3 and spaced therefrom by a cavity 6 (Fig. 2). Both limbs 2 and 4 have means for enhancing anchorage in the respective skin in the form of upwardly (as considered in use and as shown in Fig. 2) inclined tabs which are semi-circular and are struck out of the limbs. There are five such tabs 7 in each limb 2 and 4.

The free ends 8 of each limb 2 and 4 each have a curved part 8' which extends out of the plane of the limb 2, 4 to provide a substantially smooth surface. In Figs. 1, 2 and 3, the free ends 8 are upwardly inclined, from the curved part 8' about the same height as the tabs 7, and terminate inboard of the free ends of the limbs 2 and 4. The free ends are inclined at about 250 to the respective limbs 2 and 4 which are generally planar.

The limbs 2 and 4 are connected by connecting means 9 in the form of a downwardly open (as considered in use and in Figs. 1 and 2) elongate depression of channel 10 which extends from one limb 2 to the other 4 and is raised out of the plane of the (co-planar) limbs and rises to an apex 11, the depression or channel 10 being flanked by incurved and downwardly extending lips 12 each of which has means in the form of three spaced semi-circular cut-out or struck out portions 1 3 in its lowermost edge, each portion 13 providing points 14 at which moisture can condense and collect, and hence from which it can drip off the wall tie 1 in the cavity 6 as drops, so that passage of moisture across the cavity via the wall tie from one skin 3 to the other 5 is prevented or hindered.

In use, the wall tie 1 is mounted by anchoring say the limb 2 in the skin 3 if that skin 3 is being built up first. The wall tie 1 is embedded up to the connecting means 9 as shown by the dashed line 15, the surface of the skin 3. The tabs 7 enhance anchorage by becoming embedded in mortar between courses of bricks, blocks etc of the skin 3. The mortar also passes through the holes in the limb 2 left behind when the tabs 7 are struck out.

Also, the upturned free end 8 acts as an additional anchorage. The upturned free end 8 of the protruding limb 4 being inclined to the plane of the limb 4, presents the relatively smooth, nonsharp curved part 8' which does not have a sharp edge externally (as considered of the wall-tie) edge so that a bricklayer or other workman is not likely to be injured should he snag himself on the protruding free end in the course of his work. The free limb 4 is entirely embedded in the skin 5 when that skin 5 is erected to complete the cavity wall, the connecting means 9 being exposed in the cavity 6, the wall tie 1 tying the two skins together. The relatively narrow nature of the connecting means 9 as compared to the width of the limbs 2 and 3 means that there is a relatively small surface area for collection of mortar falling from higher up the wall as it is raised.The falling mortar as it strikes the wall tie 1 tends to slide off, to the bottom of the wall. Thus "bridging" is avoided in other words no build up occurs of a deposit of mortar which spans the cavity and provides a path for moisture from the outer to the inner skin. Likewise any moisture condensing on the wall tie 1 is encouraged to rundownwards towards the cut out or struck out portions 1 3 because the only path is downwards as shown, from the central raised peak or apex 11 the sides of the channel or depression 10 merging smoothly with the inwardly curved lips 12 which in turn lead to the portions 1 3 where the moisture collects and forms drops which eventually drop off into the cavity 6, from the points 14.

If insulating material 1 6 is used in the cavity, as shown by chain-dashed lines, that material 1 6 does not fill the cavity 6 between the skins 3 and 5 because it would form a bridge for moisture. It stops short of one skin, as shown (Fig. 2).

However, when in position it tends to mask some of the cut-out or struck out portions 1 3, but as there is a plurality of those portions, there is always at least one which is free of insulating material and is thus exposed for collection of moisture and preventing passage of the moisture across the cavity.

Referring now to Figs. 4 and 5 there is shown therein part of a second embodiment of wall-tie 20 embodying the invention. The wall-tie 20 is similar to the wall tie 1 in that it has co-planar limbs (of which one 21 is shown) both having means, for enhancing anchorage in skins of a multi-cavity wall, in the form of upwardly inclined tabs (not shown) which are semi-circular and are struck out of the limbs and are like the tabs 7 previously described with reference to Figs. 1 to 3. The limbs are connected by connecting means like the means 9 previously described with reference to Figs. 1 to 3, so details thereof are omitted for clarity. Figs. 4 and 5 showing the free end of the limb 21.

The limb 21, which is substantially planar, has a free end having a curved part 22 which extends out if the plane of the limb 21 to provide a substantially smooth external surface, ('external' meaning externally of the wall tie, in a direction that is opposite the other limb of the wall-tie 20).

The curved part comprises a substantially circular roll lip formed of roll lip parts 23 and 24 separated by a slot 25. The roll lip parts 23 and 24 are formed so that the free ends 26 thereof contact the limb and are thus "hidden" under the main body of the respective roll lip part 23 or 24 (as considered from above (Fig. 5) so that no free or sharp edges are present. Thus there is no free or sharp edge present to snag or catch on and thus possibly to injure a bricklayer or other workman should he snag himself on the protruding free end in the course of his work. (The wall-tie 20 is used in a similar manner to the use of the wall-tie 1, previously described).

The free end of the limb 21 is rounded or radiused as shown in (Fig. 4) to provide a smooth continuous curve in the plane of the wall tie, from one lateral edge to the other. This makes it easier to form the roll-lip parts 23 and 24 and to fqld them.

The wall-ties 1 and 20 above described and shown in the drawings may be modified. For example, the lateral edges of each limb 2 and 4 may be inclined to the plane of the limbs, for example they may be turned upwardly through an angle of substantially 900. This construction, like the smooth ends 8', 22 provides for ease of handing by avoiding sharp exposed edges.

There may also be more or fewer tabs 7 than the five shown in each limb.

The wall-ties may be stamped out of a strip of - metal preferably stainless steel in a continuous automatic process, the length of the wall tie being equivalent to the width of the strip of metal. The wall tie 20 is made by such an automatic process, the free end of each limb 21 being rounded, the notch, cut-out or slot, slit or the like 25 being formed centrally in the parent metal of the wall tie, and the material on each side of the slot being subsequently automatically progressively bent or folded to provide the substantially circular roll lip parts shown, and hence the curved part 22 with the smooth external surface.

The wall ties described are used in brick-cavitybrick multi-skin wall constructions. If the limbs are disposed at substantially 900, the wall ties can be used for timber-cavity-brick multi-skin wall constructions. (It will be understood that the term "brick" includes breeze blocks, stone slabs and other similar building units).

Claims

1. A wall-tie for a multi-skin cavity wall, comprising, for anchorage with one skin of the wall, a substantially planar limb having a free end, wherein the free end has a curved part which extends out of the plane of the limb to provide a substantially smooth external surface.

2. A wall-tie according to Claim 1, the curved part leading to an inclined part which overlies the limb.

3. A wall-tie according to claim 2, the inclined part being inclined at substantially 900 to the plane of the limb.

4. A wall-tie according to Claim 1, the curved part comprising a roll lip.

5. A wall-tie according to Claim 4, the roll lip comprising two separate roll lip parts, as considered transversely of the limb, separated by a notch, cut-out, slot, slit or the like.

6. A wall-tie according to Claim 4 or Claim 5, the free end of the roll lip or roll lip parts touching the limb.

7. A wall-tie according to any of Ciaims 4 to 6, in which the free end of the limb extends in a curve from one side of the limb to the other, as considered in the plane of the limb.

8. A wall-tie according to any preceding claim, the lateral edges of the limb being inclined to the plane of the limb.

9. A wall-tie according to Claim 8, the lateral boundary edges being inclined at substantially 900 to the plane of the limb.

10. A wall-tie for a multi-skin cavity wall, comprising a limb for anchorage with a first skin of the wall, another limb for anchorage with a second skin of the wall adjacent to first skin of the wall, at least one of the limbs having means for enhancing the anchorage of that limb with a skin of the multi-skin wall, connecting means for connecting the limbs comprising a depression or channel for stiffening at least a portion of the wall-tie and means for preventing or hindering moisture transfer across said wall-tie comprising a lip located adjacent one side of the depression or channel and another lip located adjacent the opposite side of the depression, each lip having at least one means where water can collect when the lips are pointing in a generally downward direction, each limb being substantially planar and at least the free end of the one limb having a curved part which extends out of the plane of the limb to provide a substantially smooth external surface.

11. A wall tie according to any preceding claim, made of stainless steel.

12. A wall tie for a multi-skin cavity wall, substantially as hereinbefore described with reference Figs. 1 to 3 or 4 and 5 of the accompanying drawings.

13. A method of making a wall tie according to Claim 1, comprising the steps of forming a substantially planar limb of the wall tie, forming a notch, cut-out, slot, slit or the like in a free end of the limb, and forming a roll lip by deforming the material of the wall-tie on each side of the notch, cut-out, slot, slit or the like into a roll lip part so that the free end of the wall tie has a curved part which extends out of the plane of the limb to provide a substantially smooth external surface.

14. A method according to Claim 13, the roll lip parts being progressively formed.

1 5. A method of making a wall tie according to Claim 1, substantially as hereinbefore described.