GB2375552A

GB2375552A - Masonry support assembly

Info

Publication number: GB2375552A
Application number: GB0208270A
Authority: GB
Inventors: John L Shillabeer
Original assignee: Ancon CCL Ltd; Cavity Trays Ltd
Current assignee: Ancon CCL Ltd; Cavity Trays Ltd
Priority date: 2001-04-27
Filing date: 2002-04-10
Publication date: 2002-11-20
Anticipated expiration: 2022-04-10
Also published as: GB0208270D0; GB2375552B; GB0110428D0

Abstract

The present invention provides a masonry support assembly for installation in a wall which has an outer masonry skin 12 and an inner skin 17 spaced from it by a cavity 13. The masonry support assembly comprises a support system 10 and a damp course which has a self-supporting cavity tray member 110 adapted to overlie the support system 10. The invention also provides a cavity tray for use in such assemblies, a method of building, and a wall incorporating such a masonry support assembly.

Description

MASONRY SUPPORT ASSEMBLY The present invention relates to a masonry support assembly (also termed a brickwork support assembly). In further aspects it relates to components for use in such assemblies, to a method of building, and to a wall incorporating such a brickwork support assembly.

Masonry support systems are widely used for enabling a strong inner skin of a wall to support an outer skin, typically of brickwork or other aesthetically pleasing masonry such as stone.

When a wall has two skins or leaves of different materials, it may be necessary to allow for differential movement. For a building exceeding four storeys or twelve metres in height, BS5628 part 1 requires the outer leaf to be supported at intervals of not more than nine metres or three storeys, which ever is less. To allow for a vertical movement of around 1mm per metre, movement joints are generally positioned at every storey or every second storey.

Fig. 1 shows an example of a masonry support system in use. It is, in fact, the MBC support system of Ancon Building Products. A horizontally extending L-section steel channel member 10 has a horizontal limb extending into a brickwork skin 12. Its rear upright limb is connected to steel brackets 14 which are mounted to a concrete edge beam 16 supported by a concrete blockwork inner skin 18. The brackets 14 are fixed to a channel 20 cast in the edge beam 16.

There are many other forms of support system, but all involve support elements extending between the inner skin and the outer skin. Thus there is a risk of moisture being conveyed along them, which could result in

dampness being transmitted from the outer skin to the inner skin and thus into the interior of a building. In an attempt to avoid this, it is known to install a dampcourse. This has been done using conventional dampcourse material. This is in the form of flexible (floppy) sheet material, which comes on a roll. Lengths are cut off, and installed by the builder. This tends to be somewhat hit-and-miss. The created profile varies, influenced by the accuracy of the installer and by the placement, positioning and alignment of the damp course on the metal support. The floppy material has to be supported to hold it up in the cavity, and this also influences the profile. If the damp course is supported by building it into the inner skin, then the extent it is built in and the height of the accommodating course can vary, introducing another variable. If instead the damp course is to be mechanically fixed to the inner leaf, it is difficult to hold it uniformly while this is done (typically by the application or mechanical fixing of strip supports). Floppy dpc material tends to be inconsistent and cannot lay tightly following the exact profile of the steel angle support. The brick is not consistently bedded and supported, thus the structural integrity is reduced.

According to the present invention in a first aspect there is provided a masonry support assembly for installation in a structure comprising a front skin comprising masonry and a rear supporting skin spaced from it by a cavity, said assembly comprising (1) a support system including a front portion for extending into said masonry skin and a rear portion extending rearwardly from the front portion for coupling to said rear supporting skin; and (2) a damp course comprising a cavity tray

member which is self-supporting and has a front portion adapted to overlie the front portion of the supporting system and to extend through the masonry front skin; and a rear portion adapted to extend upwardly and rearwardly through the cavity and to contact the rear supporting skin.

Preferably the cavity tray member front portion includes an upstanding portion for abutting the rear of the outer skin.

Preferably the cavity tray member front portion has a front portion defining a downward step which preferably carries soft-joint means. A front portion may be removable to expose part of the step.

Preferably the cavity tray member has adhesive means for adhesion to the front portion of the supporting system and/or to the rear supporting skin.

In a second aspect the invention provides a cavity wall incorporating a masonry supporting assembly.

It has been the practice, when using floppy DPC materials, to pass the DPC material through a joint of the front skin higher than the support girder, since otherwise it is deflected by the brackets or other discontinuous supports. This means that the brickwork support system is not totally protected. However our preformed tray can be built in at the ideal level, actually in the metal support itself.

It is preferable for the front of the cavity tray to have a downward step. This accommodates the rebated bottom brick and makes the soft-jointing and any perp weakening measures more straightforward. The tray front portion rests uniformly on the underlying brickwork.

In a third aspect the invention provides a cavity tray adapted for use in one of the preceding aspects.

In a fourth aspect the invention provides a method of building in which such a tray is installed in a masonry supporting system in a wall. Preferably the tray has a front portion bearing soft joint means. The method may include a step of removing a front portion of the soft joint means after masonry work has been carried out, thus creating a clean recess, and applying a weatherproof pointing or caulking material thereto.

An embodiment of the invention will now be described in more detail with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a known masonry support system; Fig. 2 is a sectional view through a wall structure including a masonry support assembly embodying the present invention; Fig. 3 is a side view of a component of a damp proof course system for use in such a support assembly, being an external angle tray; Fig. 4 is a view of a pair of external angle sections of the DPC system; and Fig. 5 is an enlarged detail of Fig. 2, showing a variant.

Fig. 2 shows an outer skin of brickwork 12 separated by a cavity 13 from a concrete inner skin 17. Brackets 14 are mounted to the concrete inner skin 17 and are welded to the upright rear limb of an L-section support girder 10. This has a forwardly extending horizontal lower limb 100 which extends into a joint between two bricks of the brickwork outer skin 12. In fact, the upper brick 102 is generally provided with a rebate 104 which accommodates the support limb 100. These features

described so far are generally the same as shown in Fig.

1.

A cavity tray 110 is a self-supporting member, typically of relatively rigid plastic, e. g. polypropylene. It has a rear portion that extends through the cavity 13, from an upper portion 112 that lies against the inner skin 17, to an outer portion 114 that lies against the inner surface of the outer skin.

It is shaped to accommodate the bracket 14. The outer portion 114 is continuous with a horizontal portion that extends between the horizontal limb 100 of the girder 10 and the rebated (104) portion of the brick 102. A front stepped portion 116 extends under a soft joint 120 and terminates adjacent to the front of the front skin 12.

The cavity tray 110 is sufficiently rigid that it does not sag or distort like conventional DPC material.

It does not require to be built into the inner leaf (though a rear portion extending horizontally, or bendable to extend horizontally, could be provided for this purpose, if desired). The portion that extends through the cavity can be shape-biased, so that it urges its upper portion 112 against the inner skin, whatever the width of the cavity (within limits).

The tray 110 may incorporate an adhesive for locating it on the girder 10 and/or on the inner skin 17.

The soft joint 120 may be provided by the tray assembly 110, to provide a soft joint bedding facility.

Fig. 5 shows a variant in which the front stepped portion 116 of the tray 110 bears soft joint filler material 130 which substantially covers it. However a front portion 132 is adapted to be peeled off when masonry work has been carried out, leaving a clean recess

to which can be applied a weatherproof soft joint mastic pointing or caulking.

A suitable material for a soft joint is a closed cell foam composition.

The tray may be secured to the inner skin using a retaining strip or strap such as the type Z Cavistrap of Cavity Trays Limited.

The tray may be produced as an extrusion. It will generally be supplied in lengths. Continuity between abutting or lapping profiles may be maintained by the application of sealing strip or tape.

Angles may be jointed/linked on site. This may be done by means of a mitre joint, or angle units may be provided as such. Figs. 3 and 4 show components for an external angle tray.

Claims

Claims : 1. A masonry support assembly for installation in a structure comprising a front skin comprising masonry and a rear supporting skin spaced from it by a cavity, said assembly comprising a) a support system comprising a front portion for extending into said masonry skin and a rear portion extending rearwardly from the front portion for coupling to said rear supporting skin; and b) a damp course comprising a cavity tray member which is self-supporting and has a front portion adapted to overlie the front portion of the supporting system and to extend through the masonry front skin and a rear portion adapted to extend upwardly and rearwardly through the cavity and to contact the rear supporting skin.
2. The masonry support assembly according to claim 1, wherein the cavity tray member front portion comprises an upstanding portion for abutting the rear of the masonry front skin.
3. The masonry support assembly according to claim 1 or claim 2, wherein the cavity tray front portion has a front portion defining a downward step.
4. The masonry support assembly according to claim 3, which includes soft-joint means accommodated by the downward step.
5. The masonry support assembly according to claim 4, wherein the soft joint means includes a front portion

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which is removable after installation to provide a recess.
6. A cavity tray adapted for use in a masonry support assembly according to any one of the preceding claims.
7. The cavity tray according to claim 6, wherein the cavity tray front portion has a front portion defining a downward step.
8. The cavity tray according to claim 7, wherein the downward step accommodates soft-joint means.
9. The cavity tray according to claim 8, wherein the soft joint means includes a front portion which is removable after installation to provide a recess.
10. A cavity wall comprising a front skin comprising masonry, a rear supporting skin spaced from the front skin by a cavity, and a masonry support assembly according to any one of claims 1 to 5.
11. A method of building comprising installing a masonry support assembly according to any one of claims 1 to 5 in a wall.
12. A method of building comprising installing a masonry support assembly according to claim 5 in a wall, and further comprising removing the front portion of the soft joint means to provide a recess and applying a weatherproof soft joint mastic pointing or caulking material to said recess.

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13. A masonry support assembly substantially as described-herein with-reference to and as illustrated in the accompanying figures 2 to 5.
14. A cavity tray substantially as described herein with reference to and as illustrated in the accompanying figures 2 to 5.
15. A cavity wall comprising a front skin comprising masonry, a rear supporting skin spaced from the front skin by a cavity, and a masonry support assembly substantially as described herein with reference to and as illustrated in the accompanying figures 2 to 5.
16. A method of building comprising installing in a wall a masonry support assembly substantially as described herein with reference to and as illustrated in the accompanying figures 2 to 5.