Cavity closer system

Abstract: A fixing clip (6) for use with a cavity closer (1) comprises a central springy tongue (7) integral with a substantially planar frame (8), the springy tongue (7) extending in a direction away from the plane of the frame (8) and the frame also having at least one integral penetrating projection (9, 10) directed away from the plane of the frame in an opposite direction to that of the springy tongue (7). In use, the penetrating projections (9, 10) of a number of fixing clips are arranged to engage opposite faces of a cavity closer (1) formed solely from a length of rigid, water resistant insulation material so that when the cavity closer (1) and fixing clips (6) are inserted into a wall cavity opening, the springy tongue (7) of each of the fixing clips (6) act as a wedge between the cavity closer (1) and adjacent wall (14, 15) to hold the cavity closer in place.

Description: The present invention relates to a cavity closer system which insulates and closes a cavity in an external cavity wall around window and door openings. Closing the wall cavity around window and door openings is difficult to achieve using traditional cut brick and damp proof course methods. Failure to do so can lead to cold bridging and water penetration resulting in wet reveals, rotting frames, mould growth and cracked plaster. A modern solution to the problem is to provide a cavity closer comprising a rigid PVC-U channel extrusion filled with polyisocyanurate foam insulation: such a cavity closer system is available in the UK under the tradename THERMABATE (Registered Trade Mark). The PVC-U extrusion sleeve supports the foam insulation and provides a waterproof barrier. The dimensions of the rigid PVC-U channel extrusion are chosen according to the width of the cavity, normally laid down in the appropriate building regulations, and cut according to the height or length of the opening. In this system the rigid PVC-U extrusion cavity closer is also provided with a number of T-shaped projecting flanges running along its length which give a key for plastering and provide protection against water penetration across the cavity. Separate PVC-U moulded wall fixing ties are provided which are adapted to slot between the T-shaped flanges provided on the cavity closer and key into a mortar bed joint to hold the cavity closer in position. This system is relatively expensive due to the amount of plastics material used to form the body of the cavity closer. According to a first aspect of the present invention, a fixing clip for use with a cavity closer comprises a central springy tongue integral with a substantially planar frame, the springy tongue extending in a direction away from the plane of the frame and the frame also having at least one integral penetrating projection directed away from the plane of the frame in an opposite direction to that of the springy tongue. In use, the penetrating projections of a number of fixing clips of the present invention are arranged to engage opposite faces of a cavity closer so that when the cavity closer and fixing clips are inserted into a wall cavity opening, the springy tongue of each of the fixing clips acts as a wedge between the cavity closer and adjacent wall to hold the cavity closer in place. Preferably, the fixing clip further comprises a first flange formed on an end edge of the frame which, in use, aligns with an outwardly exposed face of the cavity closer and forms a support ledge to limit the extent to which the cavity closer can be inserted into a wall cavity opening. Preferably, the first flange is provided with a keying means. Preferably, the fixing clip includes a second flange formed on an opposite end edge of the frame which, in use, is arranged to overlie the opposite, inwardly exposed face of the cavity closer. This second flange acts as a fitting guide so that when the flange overlies the face of the cavity closer, the first flange is aligned with the opposite face of the cavity closer. Furthermore, the second flange counteracts any levering effect that the springy tongue has when it is depressed which might otherwise detach the fixing clip from the cavity closer before it can be properly inserted into the cavity opening. Preferably, the at least one penetrating projection comprises a saw toothed flange formed on at least one side edge of the frame. The at least one penetrating projection secures the fixing clip to the cavity closer whilst the cavity closer is inserted into the cavity opening. Preferably, the fixing clip is formed from a sheet metal blank. More preferably, the fixing clip is formed from stainless steel. According to a second aspect of the present invention, a cavity closer system comprises the combination of a cavity closer formed solely from a length of rigid, water resistant insulation material having a generally rectangular cross-section and a number of fixing clips in accordance with the first aspect of the present invention. The advantage of the second aspect of present invention is that the cavity closer is formed solely from water resistant insulation material which is sufficiently rigid that it does not require any additional protective plastics sleeve and consequently, may be manufactured relatively cheaply. A slot may be formed in one face to act as a water break and help to prevent water crossing the cavity. Preferably, the insulation material is extruded polystyrene. Extruded polystyrene is inherently waterproof and is a good insulation material. Furthermore, extruded polystyrene will readily receive a fixing to hold the cavity closer in place. Other suitable insulation materials include expanded polystyrene, polyurethane, phenolic, glass fibre and rock wool. Preferably, a surface of a face of the cavity closer is formed with a keying surface. The present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a length of cavity closer for use in the cavity closer system of the present invention; Figures 2a to 2d show views of a fixing clip in accordance with the present invention for use with the cavity closer of Figure 1; and, Figure 3 shows a view of a cavity closer system in accordance with the present invention used to close a reveal in a cavity wall. Figure 1 shows a cavity closer 1 comprising a length of extruded polystyrene material having a substantially rectangular cross-section and provided with indentations 2 which, in use, form a keying surface. The indentations 2 are formed on the face 4 of the cavity closer 1 by rolling a shaped surface over the polystyrene material as it is being extruded. The dimensions of the cavity closer 1 are determined by the dimensions of a cavity which the closer is intended to fit. In this example, the depth of the side walls 3 is selected to correspond to the dimensions of the fixing clip (see Figures 2a to 2d). The advantage of this cavity closer is that it is formed solely from water resistant insulation material which is sufficiently rigid that it does not require any additional protective plastics sleeve and consequently, may be manufactured relatively cheaply. The extruded polystyrene is inherently waterproof and is a good insulation material. Furthermore, as will be described below, extruded polystyrene will readily receive a fixing to hold the cavity closer in place. Figures 2a to 2d show views of a fixing clip 6 for use with the cavity closer 1 shown in Figure 1. Fixing clip 6 is formed from a sheet of stainless steel material having a thickness of around 0.5mm and comprises a central springy tongue 7 integral with a planar frame 8, a pair of saw tooth flanges 9, 10 which form penetrating projections, a support flange 11 and a fitting guide flange 12. In use, fixing clip 6 is fitted to the side walls 3, (see Figure 1) of the cavity closer 1 by pressing the penetrating projections 9, 10 into the polystyrene material so that the support flange 11 is aligned with the plane of the upwardly exposed face 4 of the closer with the guide flange 12 overlying the lower face 5. The support flange 11 forms a support ledge to limit the extent to which the cavity closer can be inserted into a wall cavity opening. The support flange 11 is provided with a keying surface 13. The guide flange 12 acts as a fitting guide so that when the guide flange 12 overlies the face 5 of the cavity closer 1 the support flange 11 is aligned with the opposite face 4 of the cavity closer. Furthermore, the guide flange 12 counter-acts any levering effect that the springy tongue 7 has when it is depressed which might otherwise detach the fixing clip from the cavity closer before it can be properly inserted into a cavity opening. Figure 3 shows a perspective view of a reveal in a cavity wall comprising a brick outer leaf 14 and a block inner leaf 15. Cavity board insulation 16 is inserted within the cavity. In this example, the cavity closer 1 is inserted between the brick outer leaf and brick inner leaf and held in place by the fixing clips 6 spaced at intervals on either side of the cavity closer. The springy tongue 7 of the fixing clip 6 is sufficiently resilient to hold the cavity closer in position whilst the support flange 11 of each fixing clip ensures that the cavity closer 1 cannot be inserted too far into the cavity. In this example, the cavity closer extends in a vertical direction but it may also be used to close reveals which extend horizontally such as those found around doors and windows.

Claims: A fixing clip (6) for use with a cavity closer (1), comprising a central springy tongue (7) integral with a substantially planar frame (8), the springy tongue (7) extending in a direction away from the plane of the frame (8) and the frame also having at least one integral penetrating projection (9, 10) directed away from the plane of the frame in an opposite direction to that of the springy tongue (7). A fixing clip (6) according to claim 1, further comprising a first flange (11) formed on an end edge of the frame (8) which, in use, aligns with an outwardly exposed face (4) of the cavity closer (1) and forms a support ledge to limit the extent to which the cavity closer (1) can be inserted into a wall cavity opening. A fixing clip (6) according to claim 2, in which the first flange (11) is provided with a keying means (13). A fixing clip (6) according to any preceding claim, in which the fixing clip (6) includes a second flange (12) formed on an opposite end edge of the frame (8) which, in use, is arranged to overlie the opposite, inwardly exposed face (5) of the cavity closer (1). A fixing clip (6) according to any preceding claim, in which the at least one penetrating projection (9, 10) comprises a saw toothed flange formed on at least one side edge of the frame (8). A fixing clip (6) according to any preceding claim, in which the fixing clip (6) is formed from a sheet metal blank. A cavity closer system comprising the combination of a cavity closer (1) formed solely from a length of rigid, water resistant insulation material having a generally rectangular cross-section and a number of fixing clips (6) in accordance with any preceding claim. A cavity closer system according to claim 7, in which the insulation material is extruded polystyrene. A cavity closer system according to claim 7 or 8, in which a surface of a face (4) of the cavity closer (1) is formed with a keying surface (2). A cavity closer system according to any of claims 7 to 9, in which a slot is formed in one face (5) of the cavity closer (1).

Inventors: BALDWIN DAVID ANTHONY, MACHON DANIEL, BALDWIN, DAVID ANTHONY, MACHON, DANIEL
Applicants: OWENS CORNING POLYFOAM UK LIMI, OWENS CORNING POLYFOAM UK LIMITED
Application year: 1995
Main classification: E06B1
IPC codes: E06B1