GB2169938A - Cavity closer - Google Patents

Abstract

A cavity closer comprises a channel section member 10 having a web 11 and a pair of side limbs 12, 13, the channel 10 being disposed upright in use to close of fa cavity 22 in a multi skin wall adjacent a door or window frame (25, Fig. 3). Integral flaps 19, formed from the edges of the side limbs 12, 13 can be bent out horizontally to form masonry ties 19, embedded in use in mortar coursing joints (24, Fig. 2) of adjacent masonry leaves (20, 21, Fig. 2). By nailing (at 26, Fig. 3) through the web lithe frame (25, Fig. 3) can be secured without fixing directly into the masonry. In a modification (Figures 4 and 5), particularly devised for narrow stile windows, the frame (40, Fig. 5) is nailed to vertically disposed, integral securing elements (38, Fig. 5) bent from the side limbs 12,13 to lie parallel or coplanar with the web (31, Fig. 5) outside the cavity. Location stop means (39, Fig.5) locate the frame edge for fixing. <IMAGE>

Description

SPECIFICATION Cavity closer This invention relates to a cavity closer for vertical use in a masonry multi skin cavitywall.

It is an object of the present invention to provide a new or improved form of cavity closer capable of being used in a substantially vertical position to close a cavity in a conventional cavity wall, adjacent a door or window frame or other opening in the cavity wall.

The usual practice when fitting a frame such as a door orwindowframe in a wall under construction is to build the outer masonry leaf of the wall, linethe extreme end of the cavity with a vertical damp proof membrane of plastics or a bituminous material and then to build the block work or brick work of the inner leaf with an extension across the cavity to abutthe damp proof membrane. Thus, the inner leaf masonry has an L-shaped extension closing off the cavity. It is usually necessaryto cut blocks to fill in the gaps since the cavity is relatively small in relation to the size of a typical breeze blockforexample.

The window frame is usually fixed in position before the inner leaf block work or brick work is built up, by means of long nails which have to be fixed into the outer leaf masonry.

There are frequently drawbacks to this method of closing offthevertical end of a cavity wall. If the damp proof membrane is omitted, moisture can seep straight th rough the masonry from the outer to the inner leaf. It can also attack the edge of the window frame accessible to the cavity. The same problem may arise if the damp proof membrane slips out of position while the bridging masonry from the inner leaf is being built up across the cavity.

It can be difficult to packthewall correctly because of the necessity to use part bricks or blocks from the inner leaf. Additionally, the two leaves ofthewall are nottied together adequately attheirextreme ends since the masonry of the inner leaf merely abuts the damp proof membrane and is not structurally connected to the masonry of the outer leaf. The use of wall ties close to the end of the cavity wall is recommended but may not in fact be provided in some instances.

It is therefore an object ofthe present invention to provide a new or improved cavity closerforvertical use adjacent a door orwindowframe for example which overcomes or reduces the foregoing disadvantages.

According to the invention there is provided a cavitycloserforuse in closing the vertical end of a masonry cavity wall, the closer comprising a rigid structural member of generally channel cross section having a web and a pair of side limbs, each of said side limbs having a plurality of integrallyformed, outwardly directed tie members adapted to be inserted in mortar coursing joints of inner and outer leaves of the cavity wall during construction and one or more integral securing elements being provided by the web or by a side limb, said element or elements being adapted to be secured to an upright frame member of a door or window.

The tie members may comprise flanges pressed outwardlyfrom the limbs ofthe channel section. The flanges may be formed from edge portions of the limbs and may lie in horizontal planes in use.

Said integral securing element or elements, when formed from a side limb, may lie in a vertical plane in use, parallel to or coplanarwith the web.

Location means may be provided to locate an edge of a doororwindowframe.These location means may be provided on the web or on the integral securing means for example.

The cavity closer may be of sheet metal and is preferably of galvanised or other corrosion resistant mild steel or stainless steel.

Keying ormations may be provided on the web or the integral securing means forthe attachment of plaster or plaster board.

The cavity closer may have top and/or bottom flanges formed integrally with the web and extending in a direction away from the channel section, to anchorthe closer to the top and/or bottom of the doororwindowframe.

Two embodiments of cavity closer embodying the invention will now be described in more detail by way of example only reference to the accompanying informal drawings in which: FIGURE 1 is an isometric view of a cavity closer embodying the invention.

FIGURE2 is a vertical sectional viewthrough a brick/block masonry cavity wall in which the cavity closer has been fitted.

FIGURE3 is a horizontal sectional view of a wall and associated window frame, showing the cavity closer in use.

FIGURE4is an isometric view of a second embodiment of cavity closer, specifically intended for use with narrow stile door or window frames.

FIGURE5 is a horizontal sectional view of a wall and associated window frame showing the cavity closer of Figure 4 in use.

Referring firstly to Figure 1 ofthe drawings, the cavity closer generally indicated at 10 comprises a generally rectangular metal channel section member of corrosion resistant stainless steel or galvanised mild steel for example. The channel section comprises a web 11 and a pairof parallel limbs 12 and 13. The web 11 is provided with punched out holes 14to useasfasteningsfora doororwindow frame. The upper and lower ends of the web are provided with outwardly turned flanges 15, 16 which are also provided with nail holes 17,18 which can be used to secure the door orwindowframe to the cavity closer at the top and bottom. These are optional and may be omitted.It will be appreciated that other cavity closers may be used at the top and bottom ofthe frame or, for example, a load bearing lintel may be placed across the top of the opening.

In use, the cavity closer is mounted upright as shown in Figure land andtheframeiseitheratthisstage or subsequently nailed to the cavity closer. The inner and outer leaf masonry of a multi skin cavity wall is built up againstthe limbs 12, 1 3 of the cavity closer.

It will be seen that flaps 19 are pressed outwardly from the metal ofthe limbs 12 and 13toform integrally provided tie members. The shape of the tie members 19 can be seen most clearly in Figure 3 of the drawings where it can be seen thattheytaper outwardly towards their outer ends. This reduces any tendency forthe tie members to pull out of mortar coursing joints of the masonry inner and outer leaves of the wall. Additionally, holes 20 are provided in the tie members 19 to assist in anchoring them in the mortar.

Figures 2 and 3 show the cavity closer in use.

Referring to Figure 2 of the drawings, a masonry wall comprises an outer leaf 20 of brickwork and an inner leaf 21 of larger sized blocks such as breeze blocks. A cavity 22 is provided between them. A damp proof membrane 23 is positioned above the cavity closer in generally known manner.

Alternatively, a conventional type of lintel may be used to support masonry above the head of a door or window.

The tie members 19 can now be seen lying in mortar coursing joints 24 of the masonry. Thus, the rigid structural cavity closer is combining the functions of closing the end of the cavity and tying the inner and outer leaf masonry together very close to the free ends of these masonry leaves.

Additionally, the cavity closer is secured by nailing directly to the door or window frame at the end of the wall. This can be seen in Figure 3 of the drawings which is a horizontal section. The door or window frame is represented at 25 and it will be seen that nails 26 pass through the holes 14 in the web 11 of the closer.

Figures 4 and 5 illustrate a modified form of cavity closer, primarily intended for use with thin stile window frames which do not overlap, or do not substantially overlap the cavity. Referring firstly to Figure 5 of the drawings, a cavity closer 30 is of generally channel shape in cross section and includes a web 31 and a pair of side limbs 32,33.

The side limbs 32 and 33 are separated by the width of a cavity 34 which is provided between an outer skin 35 and an inner skin 36 of masonry in a cavity wall. As before, flaps 37 are turned outwardly from the side limbs 32,33 adjacent their free edges at positions spaced apart by the equivalent of the height of one or more courses of masonry. The flaps 37 lie in the mortar coursing joints of the masonry.

As will be seen from Figure 4 of the drawings, not all the flaps 37 may necessarily be used in any particular situation. In particular, since breeze blocks or similar materials often used for inner skin construction are of much greater height than standard bricks, it is likely that only one in three of the inner skin flaps 37 will be used where the inner skin masonry is of blockwork.

In addition to the flaps 37, which lie in horizontal planes in use, further integral securing elements 38 are provided in the form of flaps projecting laterally from the channel section cavity closer 30 in a vertical plane which is either coplanar with the web 31 or parallel to it. Small location lugs 39 are pressed out of the material of the integral securing elements 38.

In use, the cavity closer is placed upright and the narrow stile window frame 40 is positioned against the integral securing element 38 and nailed by means of nails 41. The outer skin masonry 35 is built to the desired height, incorporating all or some of the flaps 37 in the mortar coursing joints. It will be noted that the nails do not pass into the masonry but simply attach the frame 40 to the integral securing flap 38.

The inner leaf masonry 36 is then built up as before, slightly after the outer leaf, leaving the cavity 34 closed by means of the cavity closer. Figure 4 shows the web 31 of the cavity closer provided with a pattern of keying formations 42 which may be of any suitable form. In the example shown they are flaps pressed from the metal of the web 31 so as to provide keying for plaster or plaster board to be attached across the web 31 to make good the surface up to a position flush with the window frame 40. Similar keying formations are shown at 43 on the flaps 37. These are to improve mortar keying to the coursing joints of the walls.

The integral securing elements 38 may be spaced from the plane of the web 41 and in this case the location lugs 39 could be omitted and the window frame 40 allowed to locate against the corner of the cavity closer.

The cavity closer is impervious to moisture and so there is no path for moisture to penetrate into the inner leaf masonry. In order to prevent cold bridging through the metal of the cavity closer, a block of insulation material such as foamed polystyrene 27 can be inserted in to the channel. Alternatively, where cavity wall insulation is being provided throughout the wall, it will penetrate normally in to the cavity closer so no additional insulation is required.

It will be seen that, by using the cavity closer described above, the door or window frame is securely fixed in relation to the wall without any need for fastenings to be driven into the masonry.

Furthermore, there is no need for additional wall ties to be used to hold the inner and outer leaf masonry together.

The critically difficult part of closing off a cavity wall by conventional means is now avoided entirely since it is not necessary to place a damp proof member adjacent the outer leaf masonry 20 and it is not necessary to extend the inner blockwork 21 across the cavity with the consequential need to cut the inner leaf blockwork and use small packing or filling blocks. Thus, considerably better building speeds can be achieved using the cavity closer and a sounder, structurally more secure result can be obtained.

Claims (17)

1. A cavity closer for use in closing the vertical end of a masonry cavity wall, the closure comprising a rigid structural member of generally channel cross section having a web and a pair of side limbs, each of said side limbs having a plurality of integrally formed, outwardly directed tie members, adapted to be inserted in mortar coursing joints of inner and outer leaves of the cavity wall during construction and one or more integral securing elements being provided by the web or by a side limb, said elements being adapted to be secured to an upright frame member of a door or window.

2. A cavity closer according to Claim 1 wherein the tie members comprise flanges pressed outwardly from the limbs of the channel section.

3. A cavity closer according to Claim 2 wherein the flanges are formed from edge portions of the limbs.

4. A cavity closer according to Claim 2 or Claim 3 wherein the flanges lie in horizontal planes in use.

5. A cavity closer according to any one of Claims 1 to 4 wherein said integral securing element or elements, when formed from a side limb, lie in a vertical plane in use.

6. A cavity closer according to Claim 5 wherein said vertical plane is parallel to the web.

7. A cavity closer according to Claim 5 wherein said vertical plane is coplanar with the web.

8. A cavity closer according to any preceding claim wherein location means are provided to locate an edge of a door or window frame relative to the cavity closer.

9. A cavity closer according to Claim 8 wherein the location means are provided on the web.

10. A cavity closer according to Claim 8 wherein the location means are provided on the integral securing means.

11. A cavity closer according to any preceding claim made of sheet metal.

12. A cavity closer according to Claim 11 wherein the sheet metal is galvanised or corrosion resistant mild steel.

13. A cavity closer according to Claim 11 wherein the sheet metal is stainless steel.

14. A cavity closer according to any preceding claim wherein keying formations are provided on the web for the attachment of plaster or plaster board.

15. A cavity closer according to any preceding claim haing top and/or bottom flanges formed integrally with the web and extending in a direction away from the channel section, to anchor the closer to the top and/or bottom of the door or window frame.

16. A cavity closer substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings.

17. A cavity closer substantially as hereinbefore described with reference to and as illustrated in Figures 4 and 5 of the accompanying drawings.