GB2326437A

GB2326437A - Roof covering

Info

Publication number: GB2326437A
Application number: GB9712875A
Authority: GB
Inventors: Michael John Crabb; John Tycho Heslewood
Original assignee: ARMADEK Ltd
Current assignee: ARMADEK Ltd
Priority date: 1997-06-18
Filing date: 1997-06-18
Publication date: 1998-12-23
Anticipated expiration: 2017-06-18
Also published as: GB2326437B; GB9712875D0

Abstract

A method of covering or re-covering a roof. Anchoring bars (4) are fixed at spaced intervals across the existing roof surface, a layer of filler material (8) is applied to the roof surface between the anchoring bars, and a waterproof membrane layer (5) is fixed over the anchoring bars and filler material. The method does not require skilled labour to effect, and does not require the expense and trouble of disposal of the existing roof materials.

Description

ROOF COVERING The present invention relates to roof coverings. More particularly the invention relates to coverings for flat or substantially flat roofs.

Flat roofs are widely used on many types of buildings, for example, garages, schools, prefabricated buildings and extensions to other buildings. The flat nature of the roof can mean that drainage of water is a problem; water trapped on a roof together with other prevailing conditions such as frost or sunlight can result in damage and it is generally necessary to repair flat roofs more often than other roofs.

Known methods of repairing flat roofs are expensive, time consuming and can be hazardous. The old roof cover must be removed before the new roof is added; this requires the use of expensive skilled labour and can also result in damage to the building interior if inclement weather occurs while the roof is being removed. The cost of removal and disposable of the old roof materials can be expensive.

Known methods of covering flat roofs include the following: layers of asphalt, layers of felt and hot bitumen or felt applied using a blow torch for sealing. These processes of applying such roofs are known as "hot work" due to the necessity of using heat to melt bitumen or pitch. As well as being hazardous and requiring skilled labour "hot work" on buildings may soon be forbidden. Other methods of covering flat roofs without "hot work" include glass fibre covers, single ply roofing, concrete or zinc panels. All of the above roofs can only be applied when the existing roof has been removed.

A preferred embodiment of the present invention provides a method of re-covering a roof which does not require removal of the existing roof covering. It requires less skilled labour to fit the new roof as no heat or heavy tools are used, it does not require the removal of existing materials and it does not require the use of water, electricity or gas supplies.

According to the present invention there is provided a method of covering a roof comprising the steps of: a) fixing anchoring bars at spaced intervals across the roof surface; b) applying a layer of filler material to the roof surface between the anchoring bars; c) fixing a waterproof membrane layer over the anchoring bars and filler material.

Preferably the method also includes the additional step of first removing loose debris from the existing roof surface in the areas where anchoring bars are to be fixed.

It is not necessary to remove loose debris from the whole roof as the filler layer can be laid directly to the existing roof.

Preferably the anchoring bars, which can also be referred to as battens, are long thin rods made of wood, plastic, UPVC, composite or metal which have been treated where necessary to be waterproof by a method such as plating in the case of metal or tanalising in the case of wood.

Preferably the waterproof membrane layer is made of poly butyl rubber sheets. Such sheets are considered "environmentally friendly" by conservation organisations.

Preferably the poly butyl rubber sheets are made sufficiently thin so they can be rolled when not in place and flat when laid in place. The waterproof membrane layer may also be made of flexible composite plastic sheeting or bitumen sheeting with or without a fleece backing or any other waterproof material.

Preferably the waterproof membrane layer is a vapour permeable material. In this case any water contained in the old roof layers can escape through the new roof covering by, for example, evaporation.

Preferably the anchoring bars are laid parallel to each other on the roof at a distance of 0.6m apart or less apart.

Preferably the equipment for covering the roof by the method according to the invention can be supplied as a kit of parts comprising the anchoring bars and the means for fixing these to the existing roof; the filler material; the waterproof membrane layer; and the means to fix the waterproof membrane layer to the anchoring bars and covers for these fixing means.

Preferably the filler material is an insulating material. Preferably the insulating layer will be of thermal benefit to the property and/or will act as a barrier between the surface of the existing roof and the underside of the waterproof membrane layer. Suitable filler materials include fibre glass and expanded polystyrene sheeting.

The present invention will now be described in detail by way of example with reference to the accompanying drawings in which; FIGURE 1 is an elevated view of a roof covering applied to a flat roof by a method embodying the invention; FIGURE 2 is a sectional view alongside line i-i of figure 1; FIGURE 3 is an expanded view of the components of Figures 1 and 2; and FIGURE 4 is a sectional view of a roof covering applied to a flat roof by a further method embodying to the invention.

Figures 1-3 show a roof covering applied to a flat roof by a method embodying the invention. The drawings show a flat roof of a building such as a garage. The original flat roof is provided by joists (1) covered with surface layer (2), weather protection and waterproofing being provided by a layer of felt, bitumen and loose chippings (3).

To provide a new roof by this embodiment of the invention the area (9) is cleared of the loose chippings (3) down to the level of layer (2) in an area of sufficient width and length so that the full length of anchoring bar (4) can be placed and fixed in direct contact with layer (2). The anchoring bar is preferably provided with predrilled holes and is firmly fixed, for example, with screws or toggle bolts. At a distance, for example 0.6m away, from anchoring bar (4) another area (9) is cleared and a further anchoring bar (4a) is fixed; this process is continued until the roof is provided with a series of several spaced parallel anchoring bars disposed across the full surface of the roof. The anchoring bars provide the fixing point for attachment of the new roof covering to the existing roof.

It is vital that the roof is firmly attached due to the risk of wind uplift -ie. pressure of wind tearing the roof from the building. In some areas wind uplift can be a major problem to flat roof surfaces. In such areas the anchoring bars will be fixed closely together to make the roof fixing more secure. For places where wind uplift is not a significant problem the anchoring bars will be placed a distance of approximately 0.6 metres apart. In locations where wind uplift is a great problem rounded stones can be laid onto the finished new roof surface, i.e. on the membrane layer, to ballast the roof.

The space between the anchoring bars (4 and 4a) is then filled using a filler material (8), for example expanded polystyrene. The space is filled to a level of substantially the same height as the height of the anchoring bars. This provides an additional insulating layer to any insulation in the existing roof. It is not necessary to remove any loose chippings or debris present on the existing roof covering before laying the filler material (8) on top of the existing roof.

A strip of waterproof membrane layer (5), for example, a thin layer of butyl rubber, is then positioned over and along the length of a pair of anchoring bars (4 and 4a) and the filler material (8) provided therebetween and the membrane is then fastened to the anchoring bars (4 and 4a) at intervals along the length of each batten using washers (6) and screws or pins 7. The edge of the membrane (5) is trimmed so that it is flush with the edge of the anchoring bar (4a). The next piece of waterproof membrane (12) is then placed so that it covers anchoring bar 4 and also the washers and pins (6 and 7) that already attach membrane (5) to the batten. The edge between membrane (12) and membrane (5) is sealed. The sealing may be made by a layer of adhesive applied in the region where the membranes (5 and 12) are to be placed in contact, or, for example by the application of a layer of double sided adhesive tape in the region where the membranes are to be placed in contact.

Membrane (12) may then be additionally fixed to anchoring bar (4) using further pins (17) and washers (16) through both membrane layers (5) and (12). The final layers of pins and washers are then covered with butyl rubber patches (13).

Figure 4 shows a further method of covering a roof embodying the invention. Reference numerals referring to objects that have been described in the previous embodiment have been increased by 100. The anchoring bars (104 and 104a) and filler material (108) are laid as with the previous method.

A strip of waterproof membrane layer (105), for example, a thin layer of butyl rubber, is then positioned over and along the length of a pair of anchoring bars (104 and 104a) and - the filler material (108) provided therebetween. The edge of membrane 105 is fastened to the anchoring bar (104) using pressure plates or washers and screws or pins (not shown). The opposite edge of the membrane (105) is loose laid over the next anchoring bar (104a) and is then overlapped by the next sheet of waterproof membrane (112). The layer between membrane (112) and membrane (105) is sealed. The sealing may be made by a layer of adhesive applied in the region where the membranes (105 and 112) are to be placed in contact, or, for example by the application of a layer of double sided adhesive tape in the region where the membranes are to be placed in contact. The overlapping membranes (105, 112) are then additionally fixed to anchoring bar (4a) a using further screws or pins (107) driven through plates and washers (106) and the overlap of both membrane layers (105) and (112). The exposed surface of each fixing point is then sealed with butyl rubber patches (113).

It can be seen in Figure 1 that in this example the existing roof surface contains a chimney or flue (200). The battens are laid either side of such a flue, the filler material is placed around the flue and a collar piece (20) is be laid over the chimney or flue after to the butyl rubber sheet being laid over the whole; the butyl rubber sheet having been cut to form a hole in the location of the chimney or flue. The collar piece will then be sealed to the chimney or flue. It is envisaged that collar pieces will be supplied in various standard sizes. In cases where the chimney or flue to be wrapped is not a standard size it is envisaged that collar material will be supplied in straight lengths that can be cut to size and formed around the chimney in situ.

The main substantially flat area of the roof is thus covered by a series of butyl rubber sheets. In order to seal the edges of the roof covering an additional area of butyl rubber sheet is used. This is fixed to the anchoring bar (4) and the roof edge (25) so that it covers the edge of the roof. Figure 2 shows use of a terminating bar (11) to prevent water finding its way between roof edge (25) and wall (26).

In the example shown the roof ends at a parapet wall (26); where there is no parapet wall the additional butyl rubber sheet will be folded downwards over the edge of the roof and fixed to either an anchoring bar, an edge trim or directly to the supporting wall.

It is envisaged that the equipment for covering a roof according to the invention will be sold as a kit including the membrane material, the anchoring bars and the bulk insulating layer together with pins, screws pressure plates, washers and patches. The method of applying the roof is relatively simple; it does not require skilled labour and it is envisaged that such a roof covering could be applied by a handyman or do it yourself enthusiast. It is also envisaged that the sheets of waterproof membrane such as butyl rubber and insulating material will be provided in rolls of suitable width to enable the minimum amount of trimming of insulating and membrane layer in order to attach the roof covering.

Claims

1. A method of covering a roof comprising the steps of: a) fixing anchoring bars at spaced intervals across the roof surface; b) applying a layer of filler material to the roof surface between the anchoring bars; c) fixing a waterproof membrane layer over the anchoring bars and filler material.

2. A method according to claim 1 which comprises the additional step of first removing loose debris from the roof surface that is already in place solely in the areas where the anchoring bars are to be fixed.

3. A method according to claim 1 wherein the filler material is a thermally insulating material.

4. A method according to claim 1 in which the filler material is expanded polystyrene sheeting.

5. A method according to claim 1 in which the filler material prevents contact between the roof and the membrane layer.

6. A method according to claim 1 in which the waterproof membrane layer is a vapour permeable material.

7. A kit of parts for covering a roof comprising a) a plurality of anchoring bars to fix to the roof b) filler material to apply between anchoring bars c) a waterproof membrane d) means for fixing the anchoring bars to the roof e) means for fixing the membrane to the anchoring bars.

8. A method of covering a roof substantially as hereinbefore described with reference to the drawings.

9. A kit of parts for covering a roof by a method substantially as hereinbefore described with reference to the drawings.