GB2249112A

GB2249112A - Roof slating

Info

Publication number: GB2249112A
Application number: GB9023264A
Authority: GB
Inventors: Thomas Sidney Brown; Kenneth William Dickson Currie; Anthony Laurence Moseley
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-10-25
Filing date: 1990-10-25
Publication date: 1992-04-29
Anticipated expiration: 2010-10-25
Also published as: GB2249112B; GB9023264D0

Abstract

A mounting device for natural quarried slates comprising a backing plate (2) having a front face (10) on which one or more natural slates (4) can be mounted. The backing plate (2) has oppositely directed, double channels (28, 30) at its two side portions (6, 8) which provide a means for interlockingly engaging two or more of the backing plates in such a way that rainwater is unable to pass between adjacent plates (2) but is channelled down the roof. The slates 4 are nailed through hole 24, 26 in the plate to the roof battens. <IMAGE>

Description

DESCRIPTION IMPROVEMENTS IN AND RELATING TO ROOF SLATING The present invention relates to improvements in roof slating.

The overall longitudinal dimension of a natural, quarried roof slate is large in comparison to the proportion of the length of the slate which is exposed and which is to be mounted using traditional techniques visible when it is mounted on a roof. This arises because of the essentially flat nature of slates and the resulting large mutual overlap which it is necessary to provide between adjacent slates in order to eliminate any possiblity of rainwater penetrating the roof. The traditional arrangement of slates is illustrated in Fig. 4 of the accompanying drawings. The slates are laid across parallel horizontal battens 50 and nailed via holes 52 disposed adjacent their upper ends. It will be noted that each slate extends over three battens 50 and that over 50% of each slate is covered by other slates.Each slate is therefore relatively long in relation to its width, although a major part of its length is not visible.

It is an object of the present invention to provide a means for enabling the use of natural quarried slates of considerably smaller length than those which are conventially used, without actually significantly increasing the overall number of slates to be used. A much smaller slate means a saving on costs as well as natural resources.

In accordance with a first aspect of the present invention, there is provided a slate mounting device comprising a generally rectangular backing plate having a front face adapted to receive one or more natural slates and having lateral side portions which are interengageable with the lateral side portions of similar backing plates, such as to provide a barrier to water passing therebetween.

Preferably, the backing plate includes one or more batten nibs which project from a rear face thereof for engaging over a roof batten to hold the backing plate in place prior to nailing of the backing plate to that batten.

Preferably, the backing plate also includes one or more tile nibs which project from the front face thereof for supporting a slate, or slates, in position on the backing plate prior to that slate, or slates, being nailed.

Said interengageable side portions preferably comprise respective channels, each of which is adapted to interlock with a respective channel of an adjacent backing plate when a plurality of such backing plates are arranged in a lateral array.

Advantageously, the channels at the two opposite sides of the backing plate face in opposite directions, one facing forwardly and one facing rearwardly.

By virtue of the aforegoing structure, the present invention enables the slate to be used as a single lap tile, as compared to the existing double lap slate provided by the traditional slate mounting technique. The device acts as a back support for a slate, or slates, and provides interlocking sides to channel water down the finished roof.

By way of example only, a specific embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Fig. 1 is a perspective view, from the front, of one embodiment of a slate backing plate, in accordance with the present invention, with a slate ready for mounting thereon; Fig. 2 is a perspective view, from the rear, of the backing plate in Fig. 1; Fig. 3 shows a means of improving the fixing of the backing plate to a roof batten; Fig. 4 shows a conventional roof slate array; and Fig. 5 is a roof slate array, wherein the slates are mounted by means of the backing plate of the present invention.

A backing plate 2 which is adapted to receive a natural quarried roof slate 4, is provided with side portions 6, 8 which are interlockable with respective side portions of further such backing plates. The plates 2, disposed adjacently in rows which overlap from the apex of a roof, provide a means for mounting slates which are smaller than those which are used conventionally.

The backing plate 2 is generally rectangular in shape and has a front face 10 and a rear face 12. The side portions 6 and 8 comprise similarly sized double channels 28, 30, respectively, which face in opposite directions. Thus, the double channel 28 at the lefthand side of the backing plate, as viewed in Fig. 1, faces upwardly and the double channel 30 at the righthand side of the backing plate faces downwardly. By virtue of this orientation of the double channels 28, 30, the upwardly facing double channel 28 of the lefthand side portion 6 of the backing plate 2 can be inter-engaged with the downwardly facing double channel 30 of a second backing plate (identified to the backing plate 2) disposed at the left-hand side of the backing plate 2.Similarly, the downardly facing double channel 30 of the right-hand side portion 8 of the backing plate 2 can be inter-engaged with the upwardly facing double channel 28 of a third backing plate (identical to the backing plate 2) disposed at the right- hand side of the backing plate 2.

Although the use of a double channel is preferred at the side portions 6, 8, it is also possible to use a single channel. In this case, the central rib 27, 29 would be omitted from each channel region so as to leave single channels or perform the interlocking engagement between adjacent backing plates.

A pair of projecting nibs 14, 16 are provided at the bottom of the front face 10 as a means for supporting the roof slate 4 in position on the backing plate, as described further hereinafter. If, however, the backing plate 2 is manufactured by an extrusion process, the integral nibs 14, 16 must be omitted.

Further projections 18, 20 protrude perpendicularly from the rear face 12, at the top portion of the backing plate 2 to provide a means for hanging the plate 2 onto a roof batten 22.

Holes 24, 26 in the backing plate 2 provide a passage for respective nails used in fixing the slate 4 to the roof batten 22, as described further hereinafter.

The rear face 12 of the plate 2 is recessed in regions 32, leaving a central rib 34 which acts as strengthening means for the plate 2. The recessed regions 32 permit the heads of the fixing nails to remain above the surface of the slate so that a large washer, eg. of rubber, can be accommodated under each nail head, thereby increasing the security of the fixing of the slate 4 to the batten 22. The surface area covered by the pair of washers greatly increases the rigidity of the slate 4 and hence the roof covering as a whole.

A further, optional fixing device 34, as shown in Fig. 3, provides a means for securing the lower portion of the backing plate 2 onto an underlying roof batten 22. The device 34 comprises a strip of metal twisted through approximately 90O about its longitudinal axis. One end 38 of the strip is curved so as to enable it to hook onto an outer edge 40 of the upwardly facing side portion 6. Its other end 42 can be nailed to the batten 22 lying parallel to the transverse axis of the slate 2.

Furthermore, as shown in Fig. 2, an inner part 37 of the downardly facing double channel of each side portion 8 can be recessed so as to assist in accommodating the curved part 38 of the metal strip 34 when that side portion 8 is interlocked with the upwardly facing double channel of a first plate 2 over which the metal strip is engaged.

The fixing device 34 need not have the configuration shown in Fig. 3, but could be of any suitable shape capable of locking the plate 2 to the batten. In the simplest case, it could comprise a length of bent wire.

As indicated in Fig. 1, the front face 10 of the backing plate, including the area covering the downwardly facing channel portion 8 but excluding the upwardly facing channel portion 6, is arranged to support a length of natural slate 4 disposed thereon.

The bottom edge 42 of the plate 2 is chamfered to match the angle of a chamfered bottom edge 44 of the slate whereby, when viewed from ground level, as little of the backing plate as possible is visible and there is a "natural" join between the slate and supporting backing plate.

The backing plate 2 may also be provided with a water check channel 23 on its front edge to prevent capillary action of water on the roof. Primarily for aesthetic reasons, the bottom end of the right hand double channel 30 (as viewed in Fig. 1) is blocked off by a wall portion 25 (see Fig. 2).

In use, a plurality of backing plates 2 are laid over the bottomost two battens 22b, 22a, with the side portions of adjacent plates 2 in interlocking engagement as described hereinbefore. The projections 18, 20 hang over the upper batten 22b to hold the backing plates in place. A plurality of slates 4 are then applied over the top portions 10 of the backing plates, being aligned in the correct positions by the upstanding nibs 14, 16. Nails are the inserted through the slates and the holes 24, 26 in the backing plates 2, using the aforementioned washers, so as to fix the slates to the upper batten 22b of the lowermost pair of adjacent battens 22b, 22a.

Although not essential, the slates 4 may be bonded by adhesive to the backing plates 2. The slates 4 may be bonded to the plates 2 during manufacture using, for example, modified acrylic resins or bonded with suitable adhesives after the plates are complete. Bonding is, however, normally an addition, and not an alternative, to nail fixing.

In the event that it is considered desirable to use the additional fixing straps shown in Fig. 3, then these are applied as each backing plate is laid in positon on the battens 22b, 22a.

Having applied the lowermost row of backing plates with the slates already adhered thereto, or the lowermost row of backing plates to which slates have then been mounted in situ, a second row of backing plates is applied to the next batten 22c so that their lowermost edges overlie the uppermost portions of the slates already mounted in the lowermost row. It will be evident from Fig. 5 that only a small amount of longitudinal overlaps is necessary at the top of each slate since any water passing downwardly from one row to the next finds its way blocked by the opposed and interengaged channels 28, 30 between each pair of adjacent backing plates 2. As a result, the slates 4 can be approximately 40% smaller in length than slates which are to be fixed using the traditional mounting arrangement of Fig. 4.In the case, for example, of a 20" x 10" (50.8cms x 25.4cms) slate cut in half, there is a 50% saving in slate.

The backing plates 2, in an alternative embodiment, may be of such lateral dimensions as to support two or more adjacently disposed slates 4, in comparison to the illustrated embodiment where each backing plate 2 holds only one slate.

The backing plate 2 may be made of any suitable material, preferably from a plastics, polymer concrete or resin based material. An advantageous material for the plate 2 is one comprising a mixture of a resin binder and natural slate dust. For example, the material may be 15% acrylic resin and 85% natural slate. Preferred methods of manufacture include: a) Pouring the ingredients into a cold mould and leaving to set at ambient temperature.

b) Pouring the ingredients into a cold mould and applying pressure.

c) Pouring the ingredients into a hot mould and hot pressing.

The latter method, is the most advantageous as a hot process offers a faster setting time and thus allows higher productivity.

Further methods of producing the slate backing plate use high pressure injection moulding or extrusion.

There is thus provided by the present invention in arrangement which enables slates of a much shorter length to be used to cover the same roof area, thereby enabling considerable savings in material costs and in natural resources.

Claims

1. A slate mounting device comprising a generally rectangular backing plate having a front face adapted to receive one or more natural slates and having lateral side portions which are interengageable with the lateral side portions of similar backing plates, such as to provide a barrier to water passing therebetween.

2. A slate mounting device as claimed in claim 1, wherein the backing plate includes one or more batten nibs which project from a rear face thereof for engaging over a roof batten to hold the backing plate in place prior to nailing of the backing plate to that batten.

3. A slate mounting device as claimed in claim 1 or 2, wherein the backing plate includes one or more tile nibs which project from the front face thereof for supporting a slate, or slate, in position on the backing plate prior to that slate, or slates, being nailed.

4. A slate mounting device as claimed in any of claims 1 to 3, wherein said interengageable side portions comprise respective channels, each of which is adapted to interlock with a respective channel of an adjacent backing plate when a plurality of such backing plates are arranged in a lateral array.

5. A slate mounting device as claimed in claim 4, wherein the channels at the two opposite sides of the backing plate face in opposite directions, one facing forwardly and one facing rearwardly.

6. A slate mounting device as claimed in any of claims 1 to 3, wherein said interengageable side portions comprise respective double channels, each double channel being adapted to interlock with a respective double channel of an adjacent backing plate when a plurality of such backing plates are arranged in a lateral array.

7. A slate mounting device as claimed in claim 6, wherein the double channels at the two opposite sides of the backing plate face in opposite directions, one pair facing forwardly and one facing rearwardly.

8. A slate mounting device as claimed in any of claims 1 to 7, wherein the backing plate includes at least two holes, through which a slate disposed on its front face can be nailed to a batten.

9. A slate mounting device as claimed in any of claims 1 to 8, wherein the rear face of the backing plate is recessed to accommodate raised nail heads therebeneath associated with other backing plates.

10. A slate mounting device as claimed in any of claims 1 to 9, wherein the backing plate has a lower edge which is chamfered to match the chamfer of the bottom edge of a slate mounted on its front face.

11. A slate mounting device as claimed in any of claims 1 to 10, including a fixing device by which at least one of said side portions can be attached to a batten.

12. A slate mounting device as claimed in claim 10, wherein the fixing device comprises a strap adapted to be hooked at one end to said one side portion of the backing plate and to be connected at the other end to said batten.

13. A slate mounting device as claimed in any of claims 1 to 12, wherein the backing plate is moulded from a plastics resin based material, or polymer concrete.

14. A slate mounting device as claimed in any of claims 1 to 12, wherein the backing plate is moulded from a material comprising natural slate particles, resin and catalyst.

15. A slate mounting device as claimed in any of claims 1 to 14, wherein the length of the backing plate is approximately that of the batten-to-batten spacing of a roof to be tiled.

16. A slate mounting device as claimed in any of claims 1 to 15, having said one or more natural slates permanently adhered to said front face.

17. A mounting system for natural quarried roofing slates comprising a plurality of generally rectangular backing plates, each of which is adapted to support one, or a plurality, of said slates on a front surface thereof, the backing plates having lateral side portions which are adapted to interengage whereby said plurality of backing plates can be disposed in a laterally extending array, the interengagement between the backing plates being such as to provide a barrier to water passing between adjacent plates of the array.

18. A slate mounting device substantially as hereinbefore described with reference to and as illustrated in Figs 1 to 3 and 5 of the accompanying drawings.