Apparatus for Covering a Roof

Cross Reference to Related Applications

This application claims priority from United Kingdom Patent Application No. 06 105 525.8, filed 26 May 2006, the entire disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to apparatus for covering a roof.

Background of the Invention A typical roof consists of a metal framework having a profiled deck supported on purlins. This deck supports an insulation layer of typically compressible mineral wool. A weatherproof outer layer can be provided by the application of a membrane laid on top of the roof and attached using mechanical fasteners or other means. The membrane is typically constructed from a number of strips which are laid down the roof slope and welded together at the overlaps between strips to form a weather-tight layer.

It is desirable to facilitate the attachment of solar energy collection devices to such roofs.

Many known solar energy collection systems have been attached to buildings and on the whole the collection panels are effectively treated as part of the building, being in common ownership such that an occupant or owner may be responsible both for the solar energy collection systems and the fabric of the building itself.

Increasingly, in the future, it is likely that alternative relationships may be developed in which a separate organisation is responsible for the ownership, maintenance and operation of solar energy collection systems, without having any direct relationship with the ownership or control of the building on which the devices are situated. Consequently, under these circumstances, it is preferable for solar energy devices to be installed and maintained on a roof

while at the same time minimising the actual physical impact upon the roof itself. Consequently, the roof should not be damaged and opportunities for mechanical attachment to the roof may be limited.

Brief Summary of the Invention According to a first aspect of the present invention, there is provided apparatus for covering a roof, comprising a waterproof membrane, wherein: said membrane has a lower surface contactable with an uncovered roof; and said membrane has an upper surface with an integrated surface fastener system configured to facilitate the subsequent attachment of solar energy collection devices.

According to a second aspect of the present invention, there is provided apparatus for collecting solar energy mountable on the roof of a building, comprising: an upper surface displaying a solar energy collection surface; and a lower surface carrying a surface fastener system, wherein said fastener system is fastenable to a roof membrane having a co-operating fastener system.

According to a third aspect of the present invention, there is provided a method of producing a roof covering membrane having a lower surface contactable with an uncovered roof, comprising the steps of: producing a waterproof membrane material; forming said material into an appropriate membrane shape; and processing said membrane shape so as to include an integrated surface fastener system in an upper surface of the membrane to facilitate the subsequent attachment of solar energy collecting devices.

According to a fourth aspect of the present invention, there is provided apparatus for attachment to a roof in order to derive electrical energy from sunlight, comprising: a membrane attachable to the exposed surface of a roof; a web of solar energy collection material attachable to an upper surface of said membrane and including electrical connections; and an elongate trunking configured to be installed on said roof and to be attached to an edge of said web, so as to locate said web and to house said electrical connectors.

Brief Description of the Several Views of the Drawings

Figure 1 shows an embodiment of the present invention in use on a roof;

Figure 2 shows the first procedure for manufacture of membranes or webs;

Figure 3 shows a second procedure for manufacture of membranes or webs;

Figure 4 shows detail of an example of the surface fastener; Figure 5A shows a building with a uncovered roof; Figure 5B shows the application of membranes;

Figure 6 a cross-section through a roof; Figure 7 shows a roof with membranes applied; Figure 8 shows the arrangement of a trunking base on a roof; Figure 9 shows the fitting of webs; and Figure 10 shows alternative configurations of trunking.

Description of the Best Mode for Carrying out the Invention

Apparatus for covering a roof in accordance with an embodiment of the present invention is shown in Figure 1. The apparatus is also suitable for use on other outer surfaces, for example walls. A building 101 is shown which in this embodiment is a commercial building, having a substantial roof area. In alternative embodiments, residential or other building types may also be used. It can be seen in Figure 1 that membrane such as in regions 102 and 103 has been applied to the modestly sloping roof of building 101. In this example, the membrane is laid down the slope of the roof. This apparatus may also be applied to a building with a flat roof.

Examples of processes for manufacture of a membrane such as that in regions 102 and 103 are described with reference to Figures 2 and 3. The procedures described in Figures 2 and 3 also are applicable to the manufacture of webs shown at 104, 105 and 106 etc. Webs such as 104 are examples of a carrier of solar energy collection devices. In an embodiment, the

webs are flexible. The application of membrane such as that in regions 102 and 103 is described with reference to Figures 6 and 7. An example of a surface fastener system which can be used to attach, for example, web 104 to membrane 102 is shown in Figure 4. The attachment procedure is described with reference to Figure 9.

In this example webs 104 and 105 are both attached to membrane 102. Elongate trunking 107 is also provided. This is, in this embodiment, installed at the apex of the roof of building 101. In alternative configurations it may be installed at different locations. Trunking 107 is attachable to an edge of web such as 104, as is illustrated in Figures 9 and 10. The installation of trunking

107 is shown in Figures 8 and 9. Trunking 107 also houses electrical connectors as shown in Figure 9 which connect with multiple energy collection devices webs such as 104, to form a DC circuit.

A junction box 108 is provided which in this example is shown on the end wall 109 of building 101. In alternative examples junction box 108 may be located on the roof and connected to the trunking 107. Junction box 108 is connected in a DC circuit with solar energy collection devices on webs such as 104.

Figure 2 shows an example of a lamination process which can be utilised to manufacture a membrane such as 102 or a web such as 104. The process shown in Figure 2 either applies a material which is pre-prepared as a surface fastener, or a material suitable for formation into a surface fastener, to an active layer of either a membrane or a web.

A first roll 201 is shown which comprises the active layer of either the membrane such as membrane 102 or the web such as web 104. The active layer of the membrane comprises a waterproof portion and the active layer of the web comprises the solar collection device. The active layer of a membrane may comprise, for example, thermoplastic olefin (TPO) material. The active layer of a web may comprise, for example, a photovoltaic layer such as amorphous thin-film silicon. A second roll 202 is shown which comprises an

integrated surface fastener system. The procedure described with reference to Figure 2 is an example of the manufacture of a membrane or web. Alternative methods may be used including that shown in Figure 3. In Figure 2, the roll 202 of material which comprises a surface fastener system may be for example hook and loop fastener such as Velcro®. Further examples of surface fastener systems include mushroom fasteners as illustrated in Figure 4, or strip fasteners. The fasteners allow the material to flex and roll. The addition of fasteners does not typically significantly alter the weight or other properties of the material. The fasteners may be provided across a whole surface or in patches. Strip fasteners may comprise strips of hook and loop fastener or may for example comprise a slot configured to receive a ridge and seal around it, in the way that seals are known for plastic bags used in food storage etc.

The surface fastener system may be such that it is applied to a surface or it may be embossed or moulded in a surface. The term integrated is used to mean attached, moulded, embossed or any other way of integrating a surface fastener.

Roll 202 has an upper surface 203, which may be fully covered by a surface fastener system or may have portions of surface fastener system material incorporated therein. For example, the surface may be entirely covered by hook or loop-side Velcro®, or it may have strips of Velcro® or another surface fastener system incorporated therein.

Rollers 204 and 205 are used, along with, in this example, the application of heat, to push the materials from rolls 201 and 202 together and laminate them to form a product shown at 206. Adhesive may also be applied if required. The product shown at 206 is either membrane or web, depending upon which active layer was used at 201.

In an example, a web active layer is used at 201 with loop-side Velcro® at 202 to form a web. Thus the upper surface of the web is formed by the active layer, and can carry solar energy collection material, whilst the lower surface of the web carries a fastener system. A corresponding membrane is therefore formed by use of a membrane active layer at 201 with hook-side

Velcro® at 202. Thus the lower surface of the membrane is formed by the active layer, and is waterproof, whilst the upper surface of the membrane has an integrated surface fastener system. The fastener systems of the web and the membrane are configured to co-operate to facilitate the subsequent attachment of them together. In an embodiment of the present invention, both the membrane and the web are formed by this process. Alternatively, one or both of the membrane and web are formed by a different process, such as that shown in Figure 3. In an alternative embodiment, roll 202 comprises a material which is suitable to be formed into a surface fastener, as described in the process of Figure 3.

Figure 3 shows a roll 301 of material. This material may be a membrane such as 102 or a ^" web such as 104. The material on roll 301 is configured to allow a surface fastener to be formed. For example, roll 301 of material may have undergone the procedure of Figure 2, and been laminated with a material which can be moulded or embossed etc to form a surface fastener.

A press 302 is provided which embosses upper surface 303 of the material. In this example upper surface 303 is heated prior to reaching press 302. Press 302 moves up and down as it presses a portion of the material, and then the material is moved through and press 302 presses on a further portion, etc. The material at 304 which has been acted on by press 302 has, in this example, patches of mushroom fasteners moulded into its surface, such as patch 305. Mushroom fasteners are shown in detail in the cross-sectional view of Figure 4. The step of processing the material to include a surface fastener system may take place after the membrane has been formed, such that the membrane material is still in a semi-cured state.

In Figure 4, two sheets of material 401 and 402 are shown. Sheet 401 has moulded to it a plurality of mushrooms such as 403, 404 and 405. Sheet 402 has moulded to it a plurality of similar and co-operating mushrooms such as 406, 407 and 408. Sheet 401 represents a membrane such as 102 and sheet 402 represents a web such as 104. Each mushroom interacts with

neighbouring mushrooms to form a removable but secure bond. For example, Mushroom 404 interacts with mushrooms 406 and 407. The mushrooms are an example of protrusions which co-operate to removably fix the two sheets together. Alternatively shaped protrusions could also be used, for example saw-toothed protrusions. In addition, although a sheet of mushrooms cooperates with another sheet with similar mushrooms, the two sheets may have co-operating different shaped protrusions, as is the case with Velcro®.

Covering the whole of one of the surfaces with surface fasteners allows flexibility of positioning of webs such as 104 onto membranes such as 102. A further example to provide flexibility is the provision of surface fasteners in strips in a first orientation on a first surface, and strips in a second, possibly substantially perpendicular orientation on a second surface.

Procedures have now been explained for the manufacture of membranes and webs. The application of these materials to produce the result shown in Figure 1 is described below.

Figure 5A shows building 101 with an uncovered roof 501. This view is before the application of a deck, insulating material and membranes such as 102. Beams such as 502 and 503 are shown forming a primary framework to give the structure of roof 501. The building framework is typically made from metal or concrete. Purlins such as 504 and 505 run in a substantially perpendicular orientation to beams such as 502 and 503.

On top of purlins (504,505), a profiled metal deck is applied. A layer of insulation (511,512) typically mineral wool or closed cell foam, is laid. The layers are illustrated in Figure 6. As shown in Figure 5B, panels of membrane (102) are applied over a roof such as roof 501 , contacting with the insulating material (511 ,512). The lower surface of membrane 102 is shown in contact with uncovered roof insulation (511 ,512). In this embodiment, membrane 102 has on its upper surface a plurality of strips of Velcro®, such as strips 508, 509 and 510. In alternative embodiments, the entire upper surface may be covered by a

surface fastener such as Velcro®, mushroom fasteners, inter-digitated rubber etc, or patches of fastener may be present. Further alternative fastening mechanisms such as metallic or hard plastic mechanical devices may also be used. Mechanical fasteners are provided along edge portions 506 and 507 of membrane 102. In this embodiment the mechanical fasteners are embodied as self-drilling (TEK) screws that may penetrate through membrane 102 and secure it to the underlying deck, as shown in Figure 6. Alternative mechanical fixings may also be used, for example gripping strips similar to those used for fitted carpets, which can be located above the insulation layer and secured to the underlying profiled deck, and the membrane pressed thereto. Different quantities or types of mechanical fixings may be appropriate for use on buildings in different locations, for example due to varying wind and general weather conditions. As each membrane is applied, it is overlapped with the preceding membrane (and its fasteners).

The surface fastener embodied by Velcro® strips 508 to 510 is provided to facilitate the subsequent attachment of webs comprising solar collection devices, the attachment of which are illustrated in Figure 9. Thus, solar collection devices can be attached, and, if necessary removed in a simple and efficient manner.

The embodiment shown in Figure 5B incorporates the fitting of membranes with integrated surface fasteners. Alternatively, surface fasteners may be retro-fitted to existing roof covering membranes to allow the attachment of webs comprising solar collection devices. In addition to the provision of surface fasteners, covers may also be provided. Thus, for example, cover strips of complementary Velcro® may be provided attached to the membranes. This allows the membranes to be installed and remain in place for a period of time before webs are attached. In this way, membranes may be fitted to buildings in order to make them suitable for receiving solar energy collection devices, whether or not the installation of the solar energy collection devices is performed as part of the same process.

The provision of covers for surface fasteners may be necessary if webs are not to be attached straight away, in order to prevent the degrading of the surface fasteners, or the presentation of an undesirable appearance. An alternative to individual covers to attach to fasteners is the provision of shields. A shield could be of similar dimensions to a web and would attach to the surface fasteners. The shields can then be removed when webs are to be installed.

Each membrane is attached in turn until the desired area is complete. An example of membranes applied to a roof surface is shown in Figure 7. In this example only one side 701 of roof 501 has membranes with surface fasteners applied thereto. Depending upon the location of the building 101 and other constraining factors, both sides may be treated similarly or differently.

A cross-sectional view of a roof with a membrane applied is shown in Figure 6. In Figure 5A beam 503 is shown, with a plurality of purlins such as 504 and 505. The purlins are orientated in a substantially perpendicular direction to the beams. In Figure 6 a detailed view is shown of the roof construction. On top of the purlins (504,505), a deck 601 is positioned. This deck is typically made from metal and profiled for rigidity. Insulating material 511 is located on top of deck 601. Membranes such as 102 are applied as shown in Figure 5B and secured by mechanical fixings such as screw 602.

Strips of adjacent membrane overlap mechanical fasteners such as screw 602 as shown at 603. They are each sealed to the next at 604 using, for example, hot air welding or adhesive, to ensure a weatherproof result.

In Figure 7 membrane region 102 can be seen to be fully fitted to roof 501. Further membrane regions 103, 704, 705 etc are also provided to facilitate the attachment of solar energy collection devices.

Figure 8 shows the arrangement of the base 801 of trunking 107 onto roof 501. Depending upon the configuration of the trunking, it may be supplied as two pieces, a base and a top, or may be a single piece. Examples of different configurations are shown in Figure 10.

In an embodiment of the invention, trunking 107 is made from a plastic material. Alternatively, any lightweight suitable material can be used. In this embodiment, trunking base 801 is attached to the upper surface 802 of a membrane. This attachment may use Velcro®, a mechanical fixing or any other suitable attachment method. In this embodiment, trunking base 801 is fitted before fitting webs comprising solar energy collecting devices.

Figure 9 illustrates the fitting of webs comprising solar energy collection devices. Trunking base 801 is shown containing wires 901. In this embodiment, webs are made from a flexible material that may be rolled down the slope of roof 501. In alternative embodiments, rigid material comprising solar energy collection devices may be applied.

A web 902 is shown being applied to roof 501 , on top of a membrane such as 103. In this embodiment, strips of surface fastener (eg 903) such as Velcro® have been applied to a lower surface of web 902, at an orientation substantially perpendicular to that of Velcro® strips such as strip 904 on membrane 103. In an alternative embodiment, a surface fastener is attached to substantially the whole of the lower surface of web 902. Web 902 comprises, in this example, photovoltaic material (for example amorphous thin- film silicon) forming a solar energy collection device. The process of fitting a web therefore, in this example, comprises placing a first edge 905 of web 902 into trunking base 801. Wires such as wire 901 are then connected appropriately to form a DC circuit. In this embodiment, trunking 107 forms a conduit for wires from each solar energy collection device. The wires then connect to junction box 108 to complete the DC circuit. In a preferred embodiment, the electricity generated from the webs is supplied as a dual supply together with mains power received from a grid system. Alternatively, the generated electricity may be supplied directly to a grid system.

Web 902 is then unrolled down the slope of roof 501, attaching to membrane 103 by the interaction of co-operating fasteners such as 903 and

904. Trunking top 906 is then fitted. In this example, it is fixed in place by an interference fit with trunking base 801. In this embodiment, all bases such as 801 of the elongate trunking are fitted before any webs are fitted. Each web is then fitted in turn, and it's respective trunking top added. In alternative embodiments procedures occur in a different order. The process is repeated until the desired area is covered with solar energy collection devices. The appearance of the building 101 will then be as illustrated in Figure 1.

Alternative configurations of elongate trunking such as 107 are shown in cross-section Figure 10. A first example is shown in Figure 10A, having two pieces, and a second example is shown in Figure 10B, having a single piece.

Referring to Figure 10A, a membrane 1001 is shown, having strips of surface fastener such as 1002 applied thereto. Web 1003 is also shown, having strips of surface fastener such as 1004, applied in a substantially perpendicular orientation to strips such as 1002. The top edge 1005 of web 1003 is placed inside trunking base 1006. In this example, trunking base 1006 has a cutaway section at the front, configured to receive edge 1005. Connections with wires are made as shown at 1007. Trunking base 1006 is held in position with surface fastener 1008. Trunking top 1009 is added which is held into trunking base 1006 by a snap fit. In the example shown in Figure 10B, top edge 1010 of web 1011 is placed inside trunking 1012. In this example, the top and base portions of trunking 1012 are attached to each other. They therefore open and close in a jaw-like manner. Once web 1011 has been appropriately positioned, and wires connected at 1013, trunking 1012 is closed. The top portion of trunking 1012 has, in this example, a lip which has an interference fit with a corresponding lip on the base portion.