GB2197889A

GB2197889A - Damp-proof course

Info

Publication number: GB2197889A
Application number: GB08627707A
Authority: GB
Inventors: Roger Louis Bonafont
Original assignee: RUBEROID BUILDING PRODUCTS Ltd
Current assignee: RUBEROID BUILDING PRODUCTS Ltd
Priority date: 1986-11-20
Filing date: 1986-11-20
Publication date: 1988-06-02
Also published as: GB8627707D0

Abstract

A stiffener 1 for an edge 2 of a flexible sheet damp-proofing material 3, comprises a channel-shaped member having converging limbs one 4 of which is longer than the other 5. The longer limb 4 has a stiffening means in the form of a nib, flange or projection 6 which projects substantially at right angles to the plane of the limb 4, which may be 40 mm wide in relation to the 8 mm width of the shorter limb 5. The stiffener 1 is, in the embodiment illustrated, made as a one-piece unit by extrusion moulding pvc. The stiffener enables a glued joint between two pieces of flexible damp-proofing material to be easily made. <IMAGE>

Description

DAMP-PROOF COURSE The invention relates to a damp-proof course, particularly for cavity walls.

It is often necessary to form in situ a seal between overlapping edges of a damp-proof course (dpc) where the dpc bridges a cavity in a cavity wall. Dpcs are often formed from highly flexible material such as a bituminous impregnated felt-like material.

A seal beween adjoining pieces of such a dpc, or between the dpc and a corner cloak, can be difficult because the dpc is not usually resting on a firm support where it spans the cavity. The sealing operation involves overlapping the two ends by 100 mm or so and bonding and sealing these together with a suitable adhesive.

It is accordingly an object of the invention to seek to mitigate this disadvantage.

According to one aspect of the invention there is provided a stiffener for an edge of a flexible sheet material, comprising a channel-shaped member having converging limbs one of which is longer than the other.

The longer limb may have stiffening means, preferably in the form of a depending nib, flange or projection which may preferably project at substantially 90 to the plane of the longer limb.

The stiffener may be formed in one piece for example by extrusion moulding of a suitable material such as plastic.

According to a second aspect of the invention there is provided a damp-proof system comprising overlapped edges of two sheets of flexible dpc material, the free edge of the underneath dpc being reinforced by a stiffener applied thereto.

According to a third aspect of the invention there is provided a method of making a damp-proof course in a cavity wall construction, comprising the steps of laying a first run of damp-proofing sheet material across the cavity, applying a stiffener to a free edge thereof, applying adhesive to an upper surface of the first run adjacent the stiffened free edge, and overlapping the stiffened free edge with a free edge of a further run of damp-proofing material, whereby to provide a water-proof seal at the overlapped edges at least in the cavity.

A stiffener and damp-proof system embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings.

Fig 1 shows a schematic, perspective, view of part of a cavity wall construction including a stiffener and damp-proof system according to the invention; and Fig. 2 shows a transverse view of a stiffener and damp-proof system used in Fig. 1.

Referring to the drawings, there is shown a stiffener 1 for an edge 2 of a flexible sheet damp-proofing material 3, comprising a channel shaped member having converging limbs one 4 of which is longer than the other 5.

The longer limb 4 has a stiffening means in the form of a nib, flange or projection 6 which projects substantially at right angles to the plane of the limb 4, which may be 40 mm wide in relation to the 8 mm width of the shorter limb 5. The stiffener 1 is, in the embodiment illustrated, made as a one-piece unit by extrusion moulding pvc.

In use to form a damp-proof course 7 in a cavity wall using highly flexible damp-proof sheet material such as that sold under the name HYLOAD, a first (or lower in use) sheet 3 is draped between the inner 8 and outer 9 leafs of the wall. Part 10 rests on the inner leaf 8, part 11 spans the cavity 12 and is unsupported and part 13 rests on and is supported by the outer leaf 9 of the wall. The material is not long enough to extend over the whole length of the wall so in order to provide a damp-proof system, a suitable length of stiffener 1 is cut to suit the length of the unsupported intermediate part 11 and is pushed onto the free edge 2 thereof with the wider or longer limb 4 underneath the material, which is supports in the cavity. The narrower limb 5 converges towards the wider limb 4 so that the edge 2 of the sheet material is nipped between the limbs and so that the stiffener is held in place.

Adhesive 13 is then applied (Fig. 2), and a further sheet 14 of flexible dpc material is draped over the wall so that a free edge 15 overlaps by say about 100 mm the stiffened free edge 1, 2 of the first sheet 3. Pressure is applied to ensure that the two sheets 3 and 14 are bonded together via the adhesive 13, (which may be Hyload Contact Adhesive or Hyload Mastic) to form the watertight seal and thus a sound dpc system 7.

The flange 6 acts to stiffen the stiffener 1, which itself it will be understood stiffens the unsupported edge 2 in the cavity 12 and allows a firm and reliable bonding of the two sheets 3,14 of dpc material to be achieved when one sheet 14 is pressed against the other.

Claims

1. A stiffener for an edge of a flexible sheet material, comprising a channel-shaped member having converging limbs one of which is longer than the other.

2. A stiffener according to Claim 1, in which the longer limb has stiffening means.

z. A stiffener according to Claim 2, the stiffening means comprising a depending nib, flange or projection.

4. A stiffener according to Claim 3, the nib, flange or projection projecting at substantially 900 to the plane of the longer limb.

5. A stiffener according to any preceding claim, formed in one piece.

6. A stiffener according to Claim 5, formed by extrusion moulding of plastic.

A A damp-proof system comprising overlapped edges of two sheets of flexible damp-proof course (dpc? material the flee edge of the underneath dpc reinforced by a stiftener applied thereto.

S. A method of making a damp-proof course in a cavity wall construction, comprising the steps of laying a first run of damp-proofing sheet material across the cavity, applying a stiffener to a free edge thereof, applying adhesive to an upper surface of the first run adjacent the stiffened free edge, and overlapping the stiffened free edge kith a free edge of a further run of damp-proofing material whereby to provide a water-proof seal at the overlapped edges at least in the cavity.

9. A stiffener for an edge of a flexible sheet material substantially as hereinbefore described with reference to the accompanying drawings.

10. A damp-proof system, substantially as hereinbefore described with reference to the accompanying drawings.

11. A method of making a damp-proof course, substantially as hereinbefore described with reference to the accompanying drawings.