GB2325474A

GB2325474A - Roofing system having separable layers

Info

Publication number: GB2325474A
Application number: GB9807352A
Authority: GB
Inventors: John Oswald Hare
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-05-22
Filing date: 1998-04-07
Publication date: 1998-11-25
Anticipated expiration: 2018-04-07
Also published as: GB9807352D0; GB2325474B; GB9710446D0

Abstract

A roofing material comprises an uppermost waterproof layer 23, a lower insulating layer 4 and an intermediate frangible layer 22. The uppermost layer 23 may be bituminous and arranged to be or capable of being removed from the lower layer 4 without damaging it. The frangible layer 22 consists of filaments or fibres which are attached to the uppermost layer preferably as a laminate. The uppermost layer may contain a layer of mineral aggregate. Since the layers are separable, the uppermost layer 23 can be removed and replaced.

Description

ROOFING SYSTEM DESCRIPTION This invention relates to a roofing system and, also, to other aspects thereof, such as, a laminate for refurbishing an existing roofing system, as well as an associated method of refurbishment.

The invention is especially, but not exclusively, related to a roofing system having an upper waterproof layer, usually an asphalt or roofing felt layer incorporating a bituminous material.

In the known refurbishment of roofing systems o this type, either at least the existing, upper waterproof layer has to be removed, usually with difficulty, and replaced with another such layer, or a further upper waterproof layer is bonded to the existing upper waterproof layer using a suitable adhesive, such as a bituminous adhesive.

The former refurbishment method discussed above is labour intensive and, thus, expensive, whilst the latter refurbishment method can result in overloading of the underlying roof structure by continually overlaying the existing roofing felt layer with additional layers thereof.

Accordingly, it is an object of the present invention to overcome, or at least substantial reduce, the disadvantages associated with existing roofing systems and their refurbishment, as discussed above.

A first aspect of the invention resides in a roofing system comprising a supporting roof structure on which are laid a plurality of layers of material of which the upper layer is waterproof and is arranged to be or is capable of being removed readily from the lower layer beneath it, without disturbing or causing any substantial damage to that lower layer.

Preferably, the upper layer of the roofing system comprises a bituminous material for rendering that layer waterproof.

Between the upper waterproof layer and the lower layer beneath it may be provided an intermediate layer which may be adhered to ol integral with the upper layer and which enables that upper layer to be removed readily from the lower layer beneath it. In the preferred embodiment of the roofing system to be described hereinbelow, that intermediate layer is frangible and may comprise a web or sheet of frangible elements, such as filaments or fibres, which are capable of being broken, to enable the upper layer to be removed readily, such as by a peeling motion, from the lower layer beneath it. Thus, in the preferred embodiment, that intermediate web or sheet may be woven from frangible fibres or filaments. However, any other suitable form of frangible or otherwise tearable elements may be used.

The intermediate layer of frangible elements is preferably adhered to the lower layer beneath it, using, say, a bituminous adhesive. In this manner, adhesive bonds are provided between frangible elements of the intermediate layer and the lower layer beneath it. Such adhesive bonding is sufficient to provide good uplift strength and to comply with current wind uplift codes of practice. However, the individual elements themselves are sufficiently weak to be broken upon removal of the upper layer, thereby exposing the lower layer for, say, subsequent refurbishment of the roofing system.

The removable, upper layer and the intermediate frangible layer may be preformed as a two layer laminate.

The inventive system may also comprise an uppermost or top layer which overlies tne upper waterproo:t layer and which is preferably in the form of a so-called "mineral cap sheet" comprising a bittirrinous felt with aggregate on at least its uppermost or top surface, to provide suitable solar reflective properties and, also, to comply with local authority fire regulations.

Additionally or alternatively, the upper waterproof layer may have incorporated in it suitable aggregate, such as mineral aggregate, to provide a suitable solar reflective surface and, also, to comply with local authority fire regulations.

A second aspect of the invention resides in a laminate for refurbishing a roofing system, comprising a layer of frangible material provided on only one side thereof with a layer of waterproof material, such as a bituminous material.

The frangible material layer preferably comprises a web or sheet of frangible fibres or filaments which may be woven together.

Also, the layer of waterproof material may be provided with a suitable aggregate, preferably on at least the surface thereof remote from that applied to the layer of frangible material, to provide a suitable solar reflective upper surface and to comply with local authority fire regulations.

Although a laminate in accordance with the second aspect of the invention may be installed in a new roofing system, such as that defined above in accordance with the first aspect of the invention, it is preferably used to refurbish an existing roofing system, to provide a new and additional upper waterproof layer thereof, without having to disturb the existing upper layer of the system. Such an inventive laminate can be applied to an existing roofing system, for refurbishment purposes, using a suitable adhesive, such as a bituminous adhesive.

A third aspect of the invention resides in a method of refurbishing a roofing system, which method comprises applying to the upper surface of an existing roofing system a first layer of frangible material and a second, upper layer of a waterproof material, such as a bituminous material.

The first, frangible material layer may be applied to the upper surface of the existing roofing system prior to the subsequent application of the second, upper layer of waterproof material. However, in the preferred embodiment to be described in more detail hereinbelow, the first, frangible and second, upper layers are applied simultaneously, preferably in the form of a laminate, such as that in accordance with the second aspect of the invention defined above.

Such a laminate may be applied to the upper surface of the existing roofing system using a suitable adhesive, such as, a bituminous adhesive.

The adhesive may be applied to substantially the whole of the area of the upper surface of the existing roofing system prior to the application, such as unrolling, of the laminate thereto. However, in the preferred embodiment the adhesive is applied to the upper surface of the existing roofing system just in front of a roll of the laminate as it is being unrolied on to that upper surface, in accordance with the conventional, so-called "pour and roll" method.

Optionally, an uppermost or top layer in the form of, say, a mineral cap sheet, such as that described above, may be applied to the upper surface of the second, upper layer of waterproof material, again to provide the so-refurbished roofing system with suitable solar reflective properties and to comply with local authority fire regulations.

It is to be appreciated that, additionally or alternatively, the second, upper waterproof layer may be provided on at least its upper surface, preferably as an integral part thereof, with, say mineral aggregate such as that used in the optional cap sheet.

There is also provided a further method of refurbishing an existing roofing system in accordance with the first aspect of the invention, which further method comprises removing the upper waterproof layer from the lower layer beneath it, without disturbing or causing any substantial damage to that lower layer, and then applying to that lower layer another upper waterproof layer which is arranged to be or is capable of being removed subsequently from the lower layer, again without disturbing or causing any substantial damage to that lower layer.

Such replacement upper waterproof layer may be one in accordance with the second aspect of the invention defined above, in which case, the frangible material layer thereof may be applied to the lower layer of the existing roofing system using a suitable adhesive, such as a bituminous adhesive.

Again, and as an optional feature, an uppermost or top layer, such as the mineral cap sheet described above, may be applied to the replacement upper waterproof layer or, additionally or alternatively, a suitable aggregate may be applied, preferably integrally with, to at least the upper surface of that replacement upper waterproof layer.

In order that the invention may be more fully understood, preferred embodiments in accordance with the various aspects of the invention will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a sectional elevation of part of a roofing system; Figure 2 is a sectional elevation of a laminate used in the roofing system shown in Figure 1; Figure 3 is a sectional elevation of part of a refurbished roofing system; Figure 4 is a sectional elevation of part of another refurbished roofing system; Figure 5 is a sectional elevation of a modified form of the refurbishment roofing system shown in part in Figure 4; and Figure 6 is a plan vie of an arrangement showing the manner in which particular component layers of a roofing system can be laid one upon the other.

Referring to Figures 1 and 2 of the drawing, a roofing system, indicated generally at 1, for a flat roof comprises a supporting roof structure in the form of a wooden, metallic or concrete roof deck 2, a vapour barrier layer 3 overlying the deck 2 and an insulating board 4 overlying the vapour barrier layer 3.

Overlying the insulating board 4 is a double layer laminate, indicated generally at 21, comprising a layer 22 of a frangible material in the form of a fibrous sheet which, in this case, is woven and to whose upper surface is adhered a layer 23 of waterproof, bituminous material.

The laminate 21 is manufactured by passing the fibrous sheet 22 through a suitable machine which coats only one surface of that sheet 22 with the bituminous material.

The frangible fibrous sheet layer 22 of the laminate 21 is adhered to the upper surface of the insulating board 4 by, say, bituminous adhesive.

In Figure 1 of the drawings, the roofing system is shown as a new installation, with the laminate 21 forming the upper waterproof surface thereof.

If that upper surface of the roofing system 1 needs to be replaced, for whatever reason, then the waterproof layer 23 of the laminate 21 is peeled off the upper surface of the insulating board 4, with the fibres of the sheet layer 22 breaking to allow the laminate 21 to be removed both cleanly and swiftly.

Thereafter, a replacement laminate 21 is applied to the now-exposed upper surface of the insulating board 4. Such application of the replacement laminate 21 may be effected by the conventional "pour and roll" method on to the upper surface of the insulating board 4 with a bituminous adhesive 5 and then unrolling a roll of the laminate 21 on to that adhesive, such that the bond between the laminate 21 and the insulating board 4 is provided substantially by the fibres of the frangible layer 22.

In a modification of the roofing system 1, a bituminous roofing felt layer or asphalt layer may be located between the insulating board 4 and the laminate 21, in which case, and for refurbishment purposes, the laminate 21 may be peeled off that roofing felt or asphalt layer and a replacement laminate 21 applied thereto, as discussed above.

In Figure 3, there is shown an existing roofing system 31 comprising a structural roof deck 32 of, say, wood, concrete, asbestos, metal or any combination thereof, a vapour barrier layer 33 overlying the deck 32, an insulating board 34 overlying the vapour barrier layer 33 and a layer 35 of bituminous roofing felt adhered to the upper surface of the insulating board 34, in known manner.

To this conventional form of roofing system is applied, by way of refurbishment, the inventive two part laminate 21.

The frangible layer 22 of that laminate 21 is adhered to the upper surface of the bituminous roofing felt 35 by means of a layer 5 of bituminous adhesive, such that the laminate 21 is bonded substantially thereto by the fibres of the frangible layer 22, rather than the whole surface area of the laminate 21.

The laminate 21 has been applied to the bituminous roofing felt 35 of the existing roofing system in the manner described above with reference to Figure 1.

In both cases, once the bituminous adhesive layer 5 has been laid but before it has set, the laminate 21 is rolled on to it, preferably by the conventional "pour and roll" method described above.

Once the laminate 21 has reached the end of its useful life, then its waterproof layer 23 can be readily peeled back, to make way for a replacement laminate 21.

Referring now to Figure 4, here is shown another existing roofing system 41 comprising a corrugated metal roof deck 42, a vapour barrier layer 43 overlying the deck 42, an insulating board 44 overlying the vapour barrier layer 43 and a layer 45 of asphalt adhered to the upper surface of the insulating board 34, in known manner. A layer of socalled "sheathing felt" (not shown) may be provided between the insulating board 44 and the asphalt layer 45.

The asphalt layer 45 has been applied as two poured and levelled sub-layers 45' and 45'', again in known manner. To this conventional form of roofing system is applied, by way of refurbishment, the inventive two part laminate 21.

The frangible layer 22 of that laminate 21 is adhered to the upper surface of the asphalt layer 45 by means of, again, a bituminous adhesive layer 5, such that the laminate 21 is bonded substantial3y thereto by the fibres of the frangible layer 22, rather than the whole surface area of the laminate 21.

The laminate 21 has been applied to the asphalt layer 45 of the existing roofing system 41 in the manner described above with reference to Figures l and 3.

In such cases, once the bituminous adhesive layer 5 has been laid but before it has set, the laminate 21 is rolled on to the adhesive.

As discussed above, the fibres of the sheet layer 22 which are adhered to the insulating board 4, the bituminous roof felt layer 35 or the asphalt layer 45, provide sufficient uplift strength to comply with current wind uplift codes of practice, whilst the individual fibres themselves are sufficiently weak to be broken to allow the upper waterproof layer 23 of the roofing system 1, 31 or 41 to be removed readily, such as by peeling off, for subsequent refurbishment of the systems, preferably using a further, replacement laminate 21.

Also, an uppermost or top layer in the form of, say, a so-called "mineral cap sheet' comprising a bituminous felt with aggregate on at least its uppermost or top surface, may be laid over the upper surface of the upper waterproof layer 23 of the laminate 21. In this manner, the roofing system 1, 31 or 41 is provided with suitable solar reflective properties and, also, complies with local authority fire regulations. Such an arrangement is shown in Figure 5, as a modification to the roofing system 41 shown in Figure 4 wherein the uppermost or top mineral cap sheet is referenced at 46.

In addition or as an alternative to the uppermost or top layer of mineral cap sheet 46, as shown in Figure 5, at least the upper surface of the upper waterproof layer 23 of the laminate 21 may be provided with mineral aggregate. As discussed above, that aggregate provides the upper surface of that layer 23 with suitable solar reflective properties, whilst also meeting local authority fire regulations. The aggregate may be embedded in at least the upper surface of that upper waterproof layer 23, although it may be embedded throughout the thickness thereof.

Further, the aggregate may be applied to the upper surface of the upper laminate layer 23 after installation thereof but, preferably, during manufacture of the laminate 21, thereby providing an integral part thereof. It is to be appreciated that this arrangement may be used in the laminate 21 of any of the embodiments of roofing system 1, 31 and 41 described above, as well as any other roofing systems falling within the scope of the invention.

Referring now to Figure 6 of the drawings, a socalled "cross-bonding" arrangement for, say, the laminate 21 and a lower layer of, say, bituminous roofing felt 35, such as that shown in the roofing system of Figure 3, is illustrated. Hence, the approximately 1 meter wide lengths of laminate 21 and roofing felt 35 are laid at right angles to each other, with the lengths of laminate 21 overlying those of the roofing felt 35. However, the lengths of laminate 21 and roofing felt 35 need not necessarily be at right angles to each other but may be inclined to each other at any other suitable angle.

In this arrangement, the cross-bonding of the lengths of laminate 21 and roofing felt 35 disperses the load and stresses applied to the roofing system when the upper waterproof layers 23 of the lengths of laminate 21 are peeled back from the lengths of the roofing felt.

It is to be appreciated that, in a conventional manner, a suitable adhesive layer, such as a bituminous adhesive layer, may be provided between adjacent lower layers of the roofing systems described above.

Claims

1. A roofing system comprising a supporting roof structure on which are laid a plurality of layers of sheet material of which the upper layer is waterproof and is arranged to be or is capable of being removed readily from the lower layer beneath it, without disturbing or causing any substantial damage to that lower layer.

2. A roofing system according to claim 1, wherein the upper layer of the roofing system comprises a bituminous material for rendering that layer waterproof.

3. A roofing system according to claim 1 or 2, wherein, between the upper waterproof layer and the lower layer beneath it, there is provided an intermediate layer which is adhered to or is integral with the upper layer and which enables that upper layer to be removed readily from the lower layer.

4. A roofing system according to claim 3, wherein the intermediate layer comprises a web or sheet of frangible elements, such as filaments or fibres, which are capable of being broken, to enable the upper layer to be removed readily from the lower layer beneath it.

5. A roofing system according to claim 3 or 4, wherein the intermediate web or sheet is woven from frangible fibres or filaments.

6. A roofing system according to claim 3, 4 or 5, wherein the intermediate layer of frangible elements is adhered to the lower layer beneath it.

7. A roofing system according to claim 6, wherein such adhesion is sufficient to provide the system with good uplift strength.

8. A roofing system according to any preceding claim, wherein the individual frangible elements are sufficiently weak to provide ready removal of the upper layer.

9. A roofing system according to claim 3 or any of claims 4 to 8 when dependent upon claim 3, wherein the removable, upper layer and the intermediate frangible layer are formed as a laminate.

10. A roofing system according to any preceding claim including an uppermost or top layer of waterproof material overlying the upper waterproof layer.

11. A roofing system according to claim 10, wherein the uppermost or top waterproof layer is provided with a mineral aggregate on the upper surface thereof.

12. A roofing system according to any preceding claim, wherein the upper waterproof layer includes mineral aggregate on at least the upper surface thereof.

13. A roofing system according to any preceding claim, wherein lengths of material of the upper waterproof layer are inclined at an angle, preferably normally, to lengths of material of the lower layer beneath.

14. A roofing system substantially as hereinbefore described with reference to the accompanying drawings.

15. A laminate for refurbishing a roofing system, comprising a layer of frangible material provided on only one side thereof with a layer of waterproof material.

16. A laminate according to claim 15 wherein the waterproof material is a bituminous material.

17. A laminate according to claim 15 or 16, wherein the frangible material layer comprises a web or sheet cf irangible fibres or filaments.

18. A laminate according to claim 17, wherein the web or sheet of frangible fibres or filaments is woven therefrom.

19. A laminate according to any of claims 15 to 18, wherein the layer of waterproof material is provided on at least its outer surface with mineral aggregate.

20. A laminate substantially as hereinbefore described with reference to the accompanying drawings.

21. A method of refurbishing a roofing system, which method comprises applying to the upper surface of an existing roofing system a first, layer of frangible material and a second upper layer of a waterproof material, such as a bituminous material.

22. A method according to claim 21, wherein the first, frangible material layer is applied to the upper surface of the existing roofing system prior to the subsequent application of the second, upper layer of waterproof material.

23. A method according to claim 21, wherein the first, frangible and second, upper layers are applied simultaneously.

24. A method according to claim 21, wherein the first, frangible and second, upper layers are in the form of a laminate.

25. A method according tc claim 24, wherein the laminate is applied to the upper surface of the existing rooting system using a suitable adhesive, such as, a bituminous adhesive.

26. A method according to claim 24 or 25, wherein the laminate is one in accordance with any of claims 15 to 20.

27. A method according to claim 25 or 26, wherein the adhesive is applied to the upper surface of the existing roofing system prior to the application of the laminate thereto.

28. A method according to any of claims 21 to 27, wherein an uppermost or top layer of waterproof material is applied to the second, upper waterproof layer.

29. A method according to any of claims 21 to 28, wherein lengths of material of the first frangible and second, upper waterproof layers are applied at an angle to lengths of material constituting an upper layer of the existing roofing system.

30. A method of refurbishing a roofing system in accordance with any of claims 1 to 14, which method comprises removing the upper waterproof layer from the lower layer beneath it, without disturbing or causing any substantial damage to that lower layer, and then applying to that lower layer another upper waterproof layer which is arranged to be or is capable of being removed subsequently from the lower layer, again without disturbing or causing any substantial damage to that lower layer.

31. A method according to claim 30, wherein the replacement upper waterproof layer is one in accordance with any of claims 15 to 20.

32. A method according to claim 31, wherein the frangible material layer of the replacement upper layer is applied to the exposed lower layer of the existing roofing system using a suitable adhesive, such as a bituminous adhesive.

33. A method according to claims 30, 31 or 32, wherein an uppermost or top layer of waterproof material is applied to the other upper waterproof layer.

34. A method of refurbishing a roofing system substantially as hereinbefore described.