GB2327956A

GB2327956A - Retention of cavity closers

Info

Publication number: GB2327956A
Application number: GB9816452A
Authority: GB
Inventors: Roger Gamble
Original assignee: Epwin Group PLC
Current assignee: Epwin Group PLC
Priority date: 1997-07-30
Filing date: 1998-07-28
Publication date: 1999-02-10
Anticipated expiration: 2018-07-28
Also published as: GB9816452D0; GB2327956B; GB9716110D0

Abstract

A cavity closer (3) is anchored to a perimeter wall (5,6) by a wall tie (2), which fits into a recess (31) in the cavity closer (3) and has an arm projecting away from the cavity. The projecting arm is received between layers of the wall (5,6) and is preferably anchored there by the provision of a loop (22) at the end of the arm, which may receive cement. The projecting arm may pivot relative to the cavity closer (3). The cavity closer tie (2) may be made of a metallic wire, so that it can be easily bent into the confirmation which enables it to fit into the cavity closer (30 and to be received by the layers of the wall (5,6).

Description

RETENTION OF CAVITY CLOSERS The present invention relates to cavity closers and, in particular, to the retention of cavity closures in walls.

As a result of building regulations in respect of the conservation of energy, most buildings are built with cavity walls, and most builders and developers have adopted thermoplastic extrusions to closer the cavity created between the outer structure and the inner structures of perimeter wall. These cavity closers prevent moisture crossing the cavity and are also frequently filled with thermal insulation material, to cut down any heat loss from the cavity.

Cavity closers are often means for fixing or retaining windows and doors, and therefore it is obviously very important that the cavity closer is firmly anchored to both the inner and outer structures of the perimeter wall. It is also a further requirement to building design and control that the inner and outer structure of the wall are firmly linked together around all apertures.

When linking the inner and outer structures of cavity walls, the most commonly used means is by way of a metal tie, which correspond to BS1243. However metal ties are not used at present with cavity closers, and these are normally retained by use of plastic ties. This is because of the difficulty of supplying suitable locations on the cavity closers at which to anchor a metal tie. The plastic ties used are generally bulky and expensive to produce, as they must provide the strength of a similar metal tie. In addition, the plastic ties used are seen to be alien to the building industry.

A first aspect of the present invention therefore proposes that a cavity closure tie be made of metal wire which has been bent to a suitable shape to attach to the cavity closure and to be received between two layers of the wall.

The use of a metal wire makes the cavity closure tie cheap to produce, and also less bulky than the known plastic ties. The use of a metal tie is also familiar to the building industry, and whilst it would be possible to make ties similar to existing plastic ties, but of sheet metal, they would not offer all the advantages of the wire tie provided by the present invention.

Since the tie secures the cavity closure to the wall, the end (or ends) of the tie which is received between layers of the wall needs to be shaped so as to offer good retention characteristics. Therefore, it is preferable that this end of the tie comprises one or more loops. This has the further advantage that cement, or other material securing together the layers of the walls, will be received within those walls, thereby retaining the tie.

The tie must also be secured to the cavity closure.

Therefore, the cavity closure needs a recess in it to receive a part of the tie. Again, it is preferable that this part of the tie is in the form of a loop, since that is easy to shape, and there are no abrupt corners.

Preferably, the recess is in the form of a dovetail slot since this is easy to mould into a plastics cavity closure. However, other shapes of recess may be used if desired. The dovetailed slot provides a three-point contact for a loop of the tie, so that the loop of the tie is firmly held in the recess.

It has also been realised that, since the mouth of such a dovetailed slot would normally be wider than the diameter of the wire of the tie, the tie will be able to pivot in that slot. This offers the advantage that, with the given size of tie, the lateral displacement of the end of the tie remote from the cavity closure may be changed to adjust to different widths of cavity. Thus, for a narrow cavity, the tie is rotated in the recess to a position in which the tie extends away from the cavity closure close to the central line of the cavity, but sufficient to extend into the wall. For a wider cavity, the tie may be used to a position in which its end remote from the cavity closure is as far as possible from the central line of the cavity, thereby permitting the cavity closure and tie to be used with a relatively wide cavity.

This feature of pivoting of the tie in the cavity closure, although it has been developed as a preferred feature of the first aspect of the present invention using a wire tie, may be embodied with ties which are of materials other than metal wire, and is therefore a second, independent, aspect of the present invention.

In the above discussion, it is preferred that the tie attaches to the cavity closure adjacent an end thereof. This is not essential; it is possible to have the attachment of the tie to the cavity closure at an intermediate part of the tie, e.g. by providing a loop at that intermediate part which is received in a suitable recess of the cavity closure, as previously described.

This has the advantage that tie then has two free ends, which may then be received between layers of each wall, with the tie extending across the cavity. Whilst such an arrangement may still be arranged to pivot within the recess, this is less important in such an arrangement.

The present invention has been described above in terms of combination of the cavity closure and the tie.

However, the present invention also relates to the tie itself, a cavity closure adapted for the attachment of such a tie, and to the method of attaching the cavity closure using such a tie. Kits-of-parts comprising one or more cavity closures and associated ties may be sold, and it is also possible to sell ties for use with existing cavity closures, provided that such cavity closures have an appropriate recess for receiving part of the tie.

Embodiments of the present invention will now be described in detail, by way of example with reference to the following drawings in which: Fig. 1 is the view from above of a cavity closer in cross section and wire tire according to the present invention; Fig. 2 is a view from above of the cavity closer and wire tie of Fig. 1 adapted to fit a narrower cavity; and Fig. 3 is a view from above of a cavity closer wire wall tie in which the wire. wall tie and the cavity closer are shown separately.

Fig. 4 and Fig. 5 are views of examples of a second embodiment of a cavity closer according to the present invention.

In Fig. 1 the cavity to be closed is defined by the inner and outer structures 5, 6 of the perimeter wall.

As the wall is being built up, the cavity closer 3 is inserted into the cavity, to close it. The cavity closer 3 has a dovetail slot 31, two removable sections 32 and 33, and attachment points 34 for door or windows.

When it is desired to attach the cavity closer to one of the walls 5,6 a loop 21 of the metal wire tie 2 is inserted into the dovetail slot 31 of the cavity closer 3 at its top end, and slid down until it comes to rest on the course of bricks of wall 5. As the cavity is broad, the main shaft of the tie 2 runs parallel with cavity closer 3.

At the end of the wire tie 2 is a large wire loop 22 which is sandwiched between courses of bricks of wall 5.

The cement which holds the course of bricks together fills in the loop, thus giving it the wire tie 2 a secure fixing. As tie 2 is securely fixed, so is the cavity closer 3.

A plurality of wall ties 2 may be used along the length of the cavity closer 3 in order firmly to secure it. These wall ties 2 may all point in the same direction, ie all be secured in wall 5, or some may be secured in the opposite wall 6. If this is desired the wall tie 2 may be inserted into the dovetail slot 3 the other way around, and be pivoted at an angle to the cavity closer 3 so that the wire loop 22 rests between courses of bricks in wall 6.

Fig.2 shows a further embodiment of the present invention in which the cavity closer 3 and wall tie 2 are adapted to fit a narrower cavity between walls 5 and 6.

The cavity closer 3 has been altered by the removal of sections 32 and 33 so that it fits between walls 5 and 6.

The wall tie 2 has been moved by rotating the wire loop 21 in slot 31 of the cavity closer so that the large wire loop 22 at the end of wire wall tie 2 sits firmly between courses of bricks in wall 5. The wire wall tie 2 is inserted into the cavity closer 3 in the same way as described above, and it is also possible for the wall ties to point in the opposite direction to that shown, so that the cavity closer is also fixed to wall 6.

Another embodiment of a wire wall tie 4 is illustrated in Fig. 3, which can be used if it is desired to attach the cavity closer to both inner and outer structure of the perimeter wall at the same point on the cavity closer 3 which is the same as the cavity closers in the previous two embodiments. In this embodiment, the wire wall tie 4 is provided with a loop 41 to engage in the dovetail slot of the cavity closer 31, and two loops 42 at distal ends of the wall tie 4 to be secured in the inner and outer parts of the perimeter wall.

Therefore the present invention now provides a kit of parts in which simply and cheaply produced wire wall ties can be used to retain a cavity closer, therefore satisfying all the requirements of modern building control regulations as well as being simple to use, and therefore suitable for use in everyday situations in the building trade.

Figure 4 shows an alternative embodiment of a cavity closer suitable for use in the present invention. The recess into which the retaining projection of the tie can fit is generally rectangular in shape, and has two tabs partly blocking its receiving entrance. The tabs narrow the entrance to the recess, and provide a three-point contact for the loop of the tie. In this way, the loop of the tie is held firmly in the recess of the cavity closer.

The cavity closer may be dimensioned according to the width of cavity into which it can fit. Figure 5 shows a cavity closer having a width B, which represents the distance between one edge of the cavity closer and the other. The width depends on the number of removable sections (shown as 32 in Fig. 1), and the size of the recess into which the projecting loop of the cavity closer tie can fit.

The width B of the cavity closer in Fig. 5 exceeds the corresponding width, A, of the cavity closer shown in Fig. 4. Hence, the former cavity closer is suitable for closing a wider cavity than the latter cavity closer.

Claims

CLAIMS:

1. The combination of a cavity closer and a cavity closer tie for anchoring said cavity closer in a wall, which cavity closer has a recess into which a retaining projection of said tie is retainably fittable, the tie having an arm projecting away from said retaining projection and receivable between layers of the wall, wherein the cavity closer tie comprises a metallic wire.

2. A combination according to claim 1, wherein, when said tie is fitted to said cavity closer, the angle of projection of the arm of the tie is variable relative to the cavity closer.

3. The combination of a cavity closer and a cavity closer tie for anchoring said cavity closer in a wall, which cavity closer has a recess into which a retaining projection of said tie is retainably fittable, the tie having an arm projecting away from said retaining projection and receivable between layers of the wall, wherein, when said tie is fitted to said cavity closer, the angle of projection of the arm of the tie is variable relative to the cavity closer.

4. A combination according to any one of claims 1 to 3, wherein the arm of said tie has at least one loop at an end distal to said retaining projection.

5. A combination according to any of the preceding claims wherein said retaining projection of the tie comprises a loop, and said recess of the cavity closer comprises a slot.

6. A combination according to any one of the preceding claims wherein the retaining projection of said tie and the recess of said cavity closer make three points of contact with each other.

7. A combination according to any one of the preceding claims wherein the tie has two said arms projecting away from the retaining projection in generally opposed directions.

8. A combination according to any one of the preceding claims substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings.

9. A combination according to any one of the preceding claims having a plurality of said cavity closers and/or a plurality of said cavity closer ties.

10. A method of anchoring a cavity closer in a wall, the cavity closer having a recess into which a retaining projection of said tie is retainably fittable, the tie having an arm projecting away from said retaining projection and receivable between layers of the wall; including the steps of: fitting said retaining projection into said recess, pivoting said projecting arm relative to said cavity closer so that it lies on a course of bricks in said wall, and laying at least one further brick on top of said projecting arm to anchor it in said wall.