GB2137273A

GB2137273A - Improvements in or relating to wall ties

Info

Publication number: GB2137273A
Application number: GB08308805A
Authority: GB
Inventors: Alan Geoffrey Barnett
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-03-30
Filing date: 1983-03-30
Publication date: 1984-10-03
Also published as: GB8308805D0; GB2137273B

Abstract

The inner and outer skins of a wall are secured together using a wall tie 1 in the form of a hollow tube 2. The wall tie 1 is introduced into holes in the inner and outer skins of the wall so that a first end portion 3 of the tube 2 is accommodated within a hole in one skin, a second, opposite end portion 4 of the tube 2 is accommodated within a hole in the other skin, and an intermediate portion 5 of the tube 2 extends between the inner and outer skins. A settable fixing agent is then injected into the tube 2 under pressure so as to cause the fixing agent to flow outwardly through apertures 7 and 13 in the outer surface of the tube 2 into the spaces surrounding the end portions 3 and 4 within the holes in which they are accommodated, the fixing agent being contained within these spaces by a system of annular flanges 8, 9, 11, 12, 14, 15, 16 and 17. A cap 6 is then used to close off the end of the tube 2, and a particularly strong and long lasting connection is established between the inner and outer skins when the fixing agent has set. <IMAGE>

Description

SPECIFICATION Improvements in or relating to wall ties This invention relates to wall ties for securing together the inner and outer skins of walls.

Most buildings constructed since the beginning of the century have cavity walls whose inner and outer skins are interconnected at intervals by means of metal wall ties. However, over a period of many years, these ties will deteriorate due to corrosion, and the overall strength of the wall will be reduced.

This can result in cracks or bulges appearing in the outer skin or even, in extreme cases, in the collapse of part of the wall. Older buildings were often constructed with loose infill between the inner and outer skins of their walls, and problems may also occur with such buildings due to consolidation of the loose infill which tends to force the inner and outer skin apart, thus weakening the wall. In both these cases remedial action needs to be taken to secure the existing inner and outer skins of the wall together. Previous proposals for solving this problem have suffered from the disadvantage that they are costly to put into practice or do not provide a sufficiently reiiable connection between the inner and outer skins.

It is an object of the invention to provide a novel wall tie and a method of using this tie to secure together the inner and outer skins of a wall.

According to the invention there is provided a wall tie for securing together the inner and outer skins of a wall, comprising a hollow tube having a first end portion for fitting within a hole in the inner skin of the wall, a second, opposite end portion for fitting within a hole in the outer skin of the wall, and an intermediate portion for extending between the inner and outer skins of the wall, wherein the outer surface of at least one end portion of the tube is apertured to enable a settable fixing agent introduced down the centre of the tube to flow outwardly into the space surrounding that end portion within the hole in the inner or outer skin, and at least one annular flange is provided on the outer surface of that end portion to contain the fixing agent within the hole.

In use of such a tie to secure together the inner and outer skins of an existing wall, a hole is first drilled so as to extend completely through one of the skins and partially through the other skin, and the tie is then inserted into the hole so formed. A settable fixing agent may then be injected into the tube under pressure so that it flows outwardly through the or each aperture provided in at least one end portion of the tube into the space surrounding that end portion. The fixing agent is allowed to set and a particularly strong connection is thereby provided between the tie and the inner and/or outer skins of the wall.

Although it is possible for one of the end portions of the tie to be fixed to the inner or outer skin by some other means, it is particularly convenient for both end portions of the tube to be apertured to enable the settable fixing agent to flow outwardly into the spaces surrounding both end portions within the holes in the inner and outer skins, and for annular flanges to be provided on the outer surfaces of both end portions to contain the fixing agent within the holes. In this manner a particularly strong and long lasting connection is established between the inner and outer skins when the fixing agent has set. Furthermore the fixing agent which sets within the tube serves to increase the tensile strength of the tie.

Where the wall tie is to be introduced through a hole extending completely through one of the skins, the outer surface of the end portion of the tube which is to be accommodated within that hole is preferably provided with a respective annular flange on each side of the aperture(s) in that end portion so as to prevent the fixing agent from flowing out of the hole in either direction. In practice it is convenient for each end portion of the tube to be provided with a respective annular flange on each side of the aperture(s) in that end portion, such an arrangement enabling the tie to be used with either end portion, or even both end portions, accommodated within a hole extending completely through the associated skin.

In a preferred embodiment of the invention, each end portion of the tube is provided with two annular flanges on each side of the aperture(s) in that end portion. Furthermore the tie may also include a plug for sealing off an end of the tube after introduction of settable fixing agent from that end of the tube. In addition the outer surface of the intermediate portion of the wall tie advantageously includes an annular drip for preventing moisture from running along the intermediate portion between the outer skin and the inner skin of the wall.

The invention also provides a method of securing together the inner and outer skins of a wall, using a wall tie in the form of a hollow tube, comprising introducing the wall tie into holes in the inner and outer skins of the wall so that a first end portion of the tube is accommodated within a hole in the inner skin, a second, opposite end portion of the tube is accommodated within a hole in the outer skin, and an intermediate portion of the tube extends between the inner and outer skins, and injecting a settable fixing agent into the tube under pressure so as to cause the fixing agent to flow outwardly through one or more apertures in the outer surface of the tube into the space surrounding at least one of the end portions within the hole in which that end portion is accommodated, thereby securely fixing that end portion within the hole when the fixing agent has set.

In order that the invention may be more fully understood, a wall tie in accordance with the invention will now be described, by way of example, with reference to the accompanying drawing in which the single figure is a perspective view of the tie.

The illustrated wall tie 1 is made of polypropylene and comprises a hollow tube 2 having a first end portion 3 for fitting within a hole in the inner skin of the wall, a second, opposite end portion 4 for fitting within a hole in the outer skin of the wall, and an intermediate portion 5 for extending between the inner and outer skins of the wall. In addition the wall tie 1 includes a cap 6 for closing off one end of the tube 2.

The first end portion 3 is provided with an aperture 7 extending through the wall of the tube 2, a pair of annular sealing flanges 8 and 9 on the outer surface of the tube 2 intermediate the adjacent end 10 of the tube 2 and the aperture 7, and a further pair of annular sealing flanges 11 and 1 2 intermediate the aperture 7 and the intermediate portion 5. Furthermore the second end portion 4 is provided with an aperture 1 3 extending through the wall of the tube 2, a pair of annular sealing flanges 14 and 1 5 intermediate the intermediate portion 5 and the aperture 73, and a further pair of annular sealing flanges 1 6 and 1 7 intermediate the aperture 12 and the adjacent end 18 of the tube 2.

The intermediate portion 5 is provided with an annular drip 1 9 for preventing moisture from running along the intermediate portion 5 between the outer skin and the inner skin of the wall.

In order to secure together the inner and outer skins of an existing cavity wall, a hole is drilled from the outside completely through the outer skin and partially through the inner skin, the diameter of this hole being slightly less than the outside diameter of the annular flanges on the tube 2. After the drilling has been completed the hole is cleaned and a suitably sized wall tie 1 is introduced into the hole from the outside.The length of the tie 1 and the relative disposition of the apertures and flanges of the tie 1 should be such that the aperture 7 and flanges 8, 9, 11 and 1 2 of the first end portion 3 are disposed within the hole in the inner skin, the aperture 1 3 and flanges 14, 15, 1 6 and 1 7 of the second end portion 4 are disposed within the hole in the outer skin, and the drip 1 9 of the intermediate portion 4 is disposed within the cavity of the wall.Thixotropic epoxy resin is injected under pressure by means of a suitable injection device into the tube 2 through the end 18 so that it flows along the tube 2 and into the spaces surrounding the first and second end portions 3 and 4 of the tube 2 by way of the apertures 7 and 1 3. The injection device is then removed and the cap 6 fitted on the end 18 of the tube 2.

The annular flanges provided on the tube 2 serve to ensure that the epoxy resin which flows outwardly through the apertures 7 and 1 3 is contained within the holes in the inner and outer skins, and the cap 6 prevents the epoxy resin which remains within the tube 2 from flowing out of the tube 2. When the epoxy resin has set a secure connectiqn is established between the first end portion 3 and the inner skin and between the second end portion 4 and the outer skin, and the resin within the tube 2 serves to impart additional strength to the tie. After an appropriate setting time the external visual defect caused by drilling of the hole can be repaired. Tie strengths of the order of 1 460N are readily obtainable by this invention, and the ties are typically distributed at between 2 and 5 per square metre.

Various modifications to the illustrated wall tie may be made to suit particular applications without departing from the scope of the invention. For example, additional apertures and/or sealing flanges may be provided along the first and second end portions 3 and 4 of the tube 2, or an additional cap may be provided for sealing the end 10 of the tube 2. Furthermore the tube 2 may be made of materials other than polypropylene, such as some other plastics material, glass, glass fibre or a nonferrous metal.

Claims

1. A wall tie for securing together the inner and outer skins of a wall, comprising a hollow tube having a first end portion for fitting within a hole in the inner skin of the wall, a second, opposite end portion for fitting within a hole in the outer skin of the wall, and an intermediate portion for extending between the inner and outer skins of the wall, wherein the outer surface of at least one end portion of the tube is apertured to enable a settable fixing agent introduced down the centre of the tube to flow outwardly into the space surrounding that end portion within the hole in the inner or outer skin, and at least one annular flange is provided on the outer surface of that end portion to contain the fixing agent within the hole.

2. A tie according to claim 1, wherein both end portions of the tube are apertured to enable the settable fixing agent to flow outwardly into the spaces surrounding both end portions within the holes in the inner and outer skins.

3. A tie according to claim 1 or 2, wherein annular flanges are provided on the outer surfaces of both end portions to contain the fixing agent within the holes.

4. A tie according to claim 1, 2 or 3, wherein, where the tie is intended to be introduced through a hole extending completely through one of the skins, the outer surface of the end portion of the tube which is to be accommodated within that hole is provided with a respective annular flange on each side of the aperture(s) in that end portion so as to prevent the fixing agent from flowing out of the hole in either direction.

5. A tie according to claim 4, wherein the outer surface of each end portion of the tube is provided with a respective annular flange on each side of the aperture(s) in that end portion.

6. A tie according to any preceding claim, wherein the outer surface of at least one end portion of the tube is provided with two arinular flanges on at least one side of the aperture(s) in that end portion.

7. A tie according to any preceding claim, which also includes a plug for sealing off an end of the tube after introduction of settable fixing agent from that end of the tube.

8. A tie according to any preceding claim, wherein the outer surface of the intermediate portion of the tie includes an annular drip for preventing moisture from running along the intermediate portion between the outer skin and the inner skin of the wall.

9. A method of securing together the inner and outer skins of a wall, using a wall tie in the form of a hollow tube, comprising introducing the wall tie into holes in the inner and outer skins of the wall so that a first end portion of the tube is accommodated within a hole in the inner skin, a second, opposite end portion of the tube is accommodated within a hole in the outer skin, and an intermediate portion of the tube extends between the inner and outer skins, and injecting a settable fixing agent into the tube under pressure so as to cause the fixing agent to flow outwardly through one or more apertures in the outer surface of the tube into the space surrounding at least one of the end portions within the hole in which that end portion is accommodated, thereby securely fixing that end portion within the hole when the fixing agent has set.

10. A method according to claim 9, wherein a hole is first drilled so as to extend completely through one of the skins and partially through the other skin, and the tie is then introduced into the hole so formed.

11. A wall tie for securing together the inner and outer skins of a wall, substantially as hereinbefore described with reference to the accompanying drawing.

12. A method of securing together the inner and outer skins of a wall, substantially as hereinbefore described with reference to the accompanying drawing.

1 3. A wall having inner and outer skins sedured together by a wall tie according to any one of claims 1 to 8 and 11 or by a method according to any one of claims 9, 10 and 12.