GB2485615A

GB2485615A - Wedge device for securing flashing

Info

Publication number: GB2485615A
Application number: GB1019780.4A
Authority: GB
Inventors: Terence Morton
Original assignee: MORTON ROOFING PRODUCTS Ltd
Current assignee: MORTON ROOFING PRODUCTS Ltd
Priority date: 2010-11-22
Filing date: 2010-11-22
Publication date: 2012-05-23
Also published as: GB201019780D0; WO2012069783A1

Abstract

The wedge 20 comprises a narrower rear side 31 tapering towards a wider front side 30 with a first 39, 40 and second 41, 42 gripping means projecting on each side respectively. The first gripping means being less stiff or easier to bend than the second gripping means. The wedge device may comprise a flexible hollow body allowing the device to compress when the second gripping means are squeezed. The device is made from a flexible or deformable plastics material such as nylon. In use the device is inserted into a chase cut between adjacent courses of brickwork, the device being located holding the flashing by being placed to form a tight fit between a portion of the flashing inserted into the chase cut and a brick course.

Description

Wedge device for securing flashing The present invention relates to a wedge device for securing flashing in chases in brickwork and the like.

Flashing is used to prevent water penetration at the junction between a roof structure and an adjacent wall, chimney or other building structure.

Flashing comprises a strip of lead, zinc or other material that is impervious to water. The flashing strip is normally bent along its longitudinal axis with one portion overlapping or overlapped by the edge of the roofing material of the roof structure and the other portion extending up the adjacent wall, chimney or other building structure. The upper edge of the flashing is usually bent horizontally to form a flange which is inserted into a chase cut between adjacent courses of brickwork. Where the junction between the brickwork and the roofing structure is on an incline, the upper edge of the flashing is cut in the form of a series of steps with the upper edges of each step folded over and placed in chases at different levels in the brickwork.

It is necessary to fix the flanges at the edges of the flashing strip in the chases at least temporarily whilst the filling of the flashing is completed and the chases in the mortar layers are filled with a sealant or mortar.

The traditional way of holding the flanges in place is to roll up pieces of waste lead and ram them into the chase between the flange and the overlying course of bricks. More recently wedges have been used that are specifically manufactured for the purpose by bending strips of metal, typically stainless steel, into a V-shaped wedge.

The metal wedges have several disadvantages. They may be permanently deformed by the action of ramming into the chase, and therefore not provide the desired grip. They may rotate as they are forced into the chase and thus not grip the flashing effectively. Their hard sharp edges may score the softer flashing material, typically lead. The sharp edges may also damage clothing or injure the operator filling the flashing.

It has also been proposed to make such V-shaped wedges of plastics material but such wedges may suffer some of these disadvantages and may not be sufficiently strong and therefore be liable to split at the base of the V where the limbs of the V are joined together.

In our earlier patent application No 0909824.5 we describe a wedge device for retaining the edge of flashing in a chase in a wall or similar structure comprising a hollow wedge structure formed in one piece from a hard thermoplastic materiaL The structure is open on its front side, that is the side that faces the operator when the device is being inserted into a chase. It has opposing top and bottom walls which are generally planar and have outer surfaces that are inclined relative to one another so as to converge towards the rear of the device, that is the side of the device that forms the leading edge of the device and is inserted first into the chase.

The planar wall portions are joined together at both of their corresponding incline sides by curved side wall. The curved wall portions hold the planar wall portions apart from one another but flex when pressure is applied to the planar wall portions to allow the planar wall portions to move towards one another when, in use, the wedge device is squeezed into a chase.

Ribs project from the outer surfaces to grip the flashing and the overlying brickwork when the device is in place in the chase.

When the device is inserted into a chase of the appropriate size, that is a chase where the spacing between to top surface of the flashing and the underside of the overlying brickwork is less than the overall height of the device, the curved wall portions act as springs which allow the structure to be squeezed under the forces caused by the ribs engaging flashing and the brickwork so that in use the device can firmly hold the flange on the flashing in place in the chase. By joining the planar wall portions together along both pairs of inclined sides a stronger structure can be achieved compared with the earlier known structure.

In practice the vertical spacing between overlying layers of bricks or building blocks can vary and the gauge of the lead or other roofing material may vary so that the vertical width of the chases in which the device may be used varies from situation to situation. The range of chase widths in which a wedge device may be required may vary from, say, 10mm to 18mm.

It is desirable that a wedge device should be provided whereby a single size of device can be used to secure flashing over a range of different widths of chases.

In order to secure the wedge device firmly in position, it may be necessary to force the device into the chase using tools such as a hammer and bolster. Because of the small size of the device it can be difficult to hold the wedge device in place whilst at the same time holding the tools necessary to hammer the wedge device in place.

According to the present invention, there is provided a wedge device for retaining the edge of flashing in a chase in a wall or similar structure, the wedge device comprising a wedge structure having rear and front portions integrally moulded of plastics material, in use the rear portion being inserted first into a chase and the front portion entering the chase after the rear portion so as to be closer to the outer surface of the wall or similar structure, first and second gripping means projecting from the wedge structure, the first gripping means being closer to the rear portion than the second gripping means, the first gripping means being bendable or deformable on insertion of the device into the chase so as to grip the flashing and the opposing side of the chase, the first gripping means being more easily bent or deformed than the second gripping means, whereby, in use, the rear portion of the wedge structure can be inserted into chase with relatively low force and the first gripping means are bent or deformed to grip the side of the chase and the temporarily hold the wedge device in position whilst the wedge device is being inserted further into a chase by applying greater force, and the second gripping means grip the flashing and the opposing side of the chase with a greater force to hold the flashing permanently in position.

The invention enables wedge devices to be installed easily and efficiently.

After placing the flange on the flashing in a chase the operator can initially insert wedges in accordance with the invention in the chases by hand without the aid of tools so that just the first gripping means enter the chase. The first gripping means temporarily hold the wedges in place in the chase and the operator then has both hand free to hold the tools he needs, typically a hammer and a bolster, in order to drive the wedges further into the chase. When the wedge device is fully inserted, the second gripping means grips the flashing and holds it securely in the chase to enable a permanent fixing to be achieved.

Preferably the wedge structure comprises a hollow body from which the first and second gripping means project, the body being flexible at its front end so as to allow opposing walls of the body to be move towards one another when the second gripping means are squeezed.

Preferably the hollow body comprises opposing generally planar walls joined at their sides by curved walls. The curved walls act as springs holding the planar walls apart but flexing under pressure to allow the planar walls to move towards one another.

The gripping means may comprise ribs or flanges projecting outwardly from the outer surface of the planar wall portions, In an embodiment the ribs extending generally parallel to the front of the structure, The flanges of the first gripping means are more easily bent or deformed than the flanges of the second gripping means. This may be achieved by making the flanges of the first gripping means thinner, particularly at the base where they join the planar wall portions.

To enable the first gripping means to engage the side of a chases of varying sizes the flanges may be of a size such that the overall distance between the tips of the flanges in of the order of twice the thickness of the body of the wedge device adjacent the flanges. The flanges may be in the form of flaps that normally project away from the body of the device but can be squeezed to lie close to the device.

Flanges of the second gripping means may be thicker at their base where they join the planar wall portions than at their tips.

Preferably, the tips of the flanges of second gripping means project further from the centreline of the structure than the tips of the flanges of the first gripping means.

The invention also provides a method of securing flashing in a chase in a wall or similar structure, comprising inserting a flange on the flashing into the chase and inserting a wedge device as described above in a the chase, so that the device is squeezed between a flange on the flashing and the overlying side of the chase and the device grips the flashing and the overlying wall of the chase.

Other features of the preferred embodiment of the invention are set out in the description which follows and in the dependent claims.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 shows a perspective view of a typical arrangement of flashing on a roof structure; Figure 2 shows an enlarged view of the flashing of figure 1 secured with wedge devices in accordance with to the present invention; Figure 3 shows a front perspective view of a wedge device in accordance with the invention; Figure 4 shows a rear perspective of the wedge device of figure 3; Figure 5 shows a front elevation of the wedge device of figure 3; Figure 6 shows a rear elevation of the wedge device of figure 3; Figure 7 shows the side elevation of the wedge device of figure 3; Figure 8 shows a plan view of the wedge device of figure 3.

Figure 9 shows a section on the line 9-9 of figure 8; Figure 10 shows a cross-section through the wall structure of figure 2 with the wedge device of figures 3 to 9 partially inserted into a chase; Figure 11 shows a cross-section through the wall structure of figure 2 with the wedge device fully inserted into the chase before re-pointing; Figure 12 shows the view of figure 11 after the chase has been pointed; and Figure 13 shows a front elevation of a wedge device in accordance with the invention inserted in a chase in brickwork.

Referring to figure 1, this shows a conventional flashing arrangement for covering the joint between a sloping pitch roof 10 and a vertical brick wall 11. A strip 12 of flashing material is bent along its longitudinal axis 13 to form an L-shaped section. Typically the flashing is made from a strip of lead. A first portion 14 of the flashing material extends under the tiles that form an edge portion of the roof structure 10. An upstanding portion 15 of the flashing material lies against the vertical surface of the adjacent wall 11. The upstanding portion 15 is cut to form a series of steps 16 by removing triangles of the flashing material. Each step 16 has an upper edge that is aligned with the mortar layers between successive courses of the brickwork. The upper edge of each step 16 is bent over at right angles to the rest of the upstanding portion 15 to form a flange 17 which is aligned with the mortar layer between courses of bricks. The mortar in the region of each flange is removed by chasing to form a chase or channel 18 into which the flange 17 is inserted.

In order to retain the flanges 17 in the chases 18 and hence hold the flashing material in place against the wall whilst the flashing is being fitted and also subsequently, wedge devices 20 in accordance with the invention are inserted into the chases 18. In the arrangement shown in figure 2, two devices 20 are used to hold each flange 17 in place. As can be seen in figures 3 and 4, the devices 20 grip the upper surface 80 of the flanges 17 on the flashing and the underside 81 of the overlying brick layer 22 to hold the flange 17 in the chase 18.

An example of a wedge device in accordance with the invention will now be described in more detail with reference to figures 3 to 9.

The wedge device 20 is injection moulded in one piece from a hard thermoplastic material, for example a polyamide, such as nylon.

Describing the device in the orientation as viewed in figure 3 of the drawings, which is as it appears to an operator inserting the wedge device into a chase, it comprises a hollow structure open on its front side 30. It has opposing top and bottom wall portions 25 and 26 which are generally planer and have outer surfaces 27 and 28 that are inclined relative to one another so as converge towards one another from the front 30 of the device to the rear 31 of the device and give the body of the device a wedge shape. The top and bottom wall portions are joined to one another at both of their corresponding inclined sides 91 and 92 and 93 and 94 by curved side wall portions 32 and 33. The curved wall portions are bowed outwardly so as to give the device a D-ended cross-section when viewed from the front. The curved wall portions are semi-frustoconical in shape so that they hold the planar wall portions apart in the wedge shape. The width of the device in the horizontal direction w is substantially greater than the height of the device h as measured between the outer surfaces of the planar wall portions at the front of the device so that the hollow body portion of the device has an elongate cross section with the major axis extending in the direction that is normally horizontal when the device is in use..

The planar wall portions 25 and 26 are also joined to one another at the rear of the device by a curved rear wall portion 34. The rear wall portion is bowed outwardly towards the rear to provide a rear abutment surface 38.

Gripping means in the form of two pairs of flanges or ribs 39 and 40 and 41 and 42 project from the outer surface 27 and 28 of the top and bottom wall portion 25 and 26.

The flanges 39 and 40 form a first gripping means near the rear of the device. The flanges are joined to the upper and lower planar wall portions near the rear of the device where the planar wall prtions join the rear curved wall portion 34. The flanges 39 and 40 extend parallel to the front and rear edges of the device and across a major part of the width of the planar wall portions. Each flange is inclined towards the front of the device at an acute angle to the centre axis 90 of the device, preferably between to 55°, typically approximately 40°. Each flange is about 10mm high measured along the surface of the flange in the direction f1 from where it joins the planar wall portion to the outer tip of the flange. The distance d1 between the outer tips of the opposing flanges is approximately 16mm in the unstressed state which is approximately twice the height h1 of the body of the device at the corresponding point. The flanges are of approximately uniform thickness and form flaps that can bend toward the adjacent planar wall portions when the tips of the flanges are pressed inwardly. When the flaps are pressed against the wall portions the overall height of the device at that point is little more than the height h1 The flanges 41 and 42 form a second gripping means near the front of the device. The flanges join the upper and lower planar wall portions near the front edge 45 of the device. The flanges 41 and 42 extend parallel to the front edge 45 of the device and extend across a major part of the width of the planar wall portions. Each flanges tapers from its base 48 where it joins the outer surface of the planar wall portion of the device, towards its outer edge or tip 49. In the example the flanges are approximately 3mm thick at their bases and taper to approximately 0.5mm at their outer tips, the rear face of each flange in inclined at approximately 200 to the vertical; the front of the flange is substantially vertical.

Each flange is about 6mm high measured along the rear wall surface in the direction f2 from where it joins the planar wall portion to the outer tip 49 of the flange. The distance d2 between the outer tips of the flanges is approximately 19mm in the unstressed state. Thus, the tips of the flange 41 and 42 of the second gripping means that are nearest the front of the device are further from the centreline 90 of the device and from one another than the tips of the ribs 39 and 40 of the first gripping means that are nearer the rear of the device. The distance d2 is approximately twice the height h of the body of the device a this point.

As the flanges 39 and 40 are thinner than the flanges 41 and 42, particularly at their base where thy join the planar wall portions, they are more easily bent or deformed than the flanges 41 and 42.

The whole device is injection moulded so that the wall portions 25 26, 32, 33 and 34 and the flanges 39 to 42 are continuous.

The device has a notch or recess 60 formed in the front edge 59 of each of the curved wall portions. A cylindrical reinforcing rib or gusset 70 is formed on the inside of each curved wall portion adjacent the notch 60. The notches are designed to receive the tip of a tool such as a bolster. They also enable the cylindrical walls to flex more easily at the front edge.

The embodiment described above is symmetrical about the horizontal plane through the centreline 90.

Figures 10 to 13 show the disposition of the device when inserted into a chase between the flange 17 on the lead flashing and the under side 81 of the overlying brick 22. The flange 17 rests on the brick 64 which lies under the chase.

Figure 10 shows the device in the initial stage of insertion into the chase.

The device can be inserted into this position by hand without the aid of tools. The rear edge of the device is inserted first into the chase. The flanges 40 and 39 of the first gripping means engage the flashing and the overlying brickwork respectively and are bent forwardly to fit into the space between the flashing and the overlying brickwork. The flap-like flanges are bent toward the adjacent planar surface. The tips of the flanges grip the flashing and the overlying brickwork so as to hold the device in place. The device does not fall out of the chase when the manual pressure of the operator is released. In this way several devices can be placed in the chase and temporarily held in place in a short time.

The flanges 41 and 42 abut the outer surface of the brickwork. The device cannot be pushed any further into the chase without the use of tools because the flanges 41 and 42 are too stiff.

To push the device into its final position in the chase, a hammer and bolster are used. The tip of the bolster 80 is engaged in the notches 60 in the side walls of the device and force is applied to the bolster with a hammer. Since the device has been held in position by the first gripping means 39 and 40, the operator has both hands free to use the hammer and bolster.

The ribs 70 reinforce the sides of the device adjacent the notches 60 and prevent the action of the bolster splitting the sides of the device.

The force of the bolster pushes the device further into the chase. The sloping rear sides 80 of the flanges 41 and 42 engage the front edges of the chase and flashing and assist in causing the flanges to be squeezed towards each other so that they can fit into the chase. The body of the structure is squeezed so that the opposing planar wall portions are moved towards one another at the front end of the device. The tips of the flanges 41 and 42 may also be bent or displaced by the forces acting on them in order to squeeze into the space between the flashing and the overlying brickwork.

The resilience of the device, and the spring action of the curved side wall 32 and 33 ensure that the flashing is held firmly in the chase by the flanges 41 and 42.

The abutment 38 formed by the curved rear wall 34 of the device engages the mortar 61 which defines the back wall 62 of the chase 18 to limit how far the device can be inserted into the chase.

Once the device is in place, the chase is filled with mastic or mortar 99 and pointed to provide a weatherproof finish.

The devices in accordance with the present invention as described above being moulded of plastics material are light in weight compared with metal wedges and are easy to carry. They have no sharp edges to injure the operator or his clothing and they can be easily carried in the pocket.

The device is made of a suitable plastics material which is strong, elastic resilient, flexible but has sufficient degree of stiffness. We have found that nylon is suitable but other suitable materials may be used.