NO20200360A1

NO20200360A1 - Fixing Apparatus for a Roof

Info

Publication number: NO20200360A1
Application number: NO20200360A
Authority: NO
Inventors: Gudmund Fløysand
Original assignee: Lonevag Beslagfabrikk As
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2021-08-30
Also published as: NO345841B1; SE2150346A1

Description

Fixing Apparatus for a Roof

The present invention relates to a fixing apparatus for a roof, and especially to a fixing apparatus for mounting external structure on a roof.

The most important considerations when designing and installing a roof structure are whether the structure will be capable of supporting any loads to which it may be subjected, and whether and for how long the structure will remain waterproof. These considerations are relevant to domestic and commercial buildings alike, and have shaped development in the field of roof construction and mounting mechanisms for use on roofs.

More recently, the desire to mount external structures in addition to the traditional components of a roof has also increased. Solar panels, for example, are now widely used even in domestic settings. These need to be fixed securely enough to a roof to prevent damage or loss of the panels in bad weather and in a manner which will not damage the roof itself. So far, it has not been possible to successfully mount such external structures in a way which will not jeopardize to some extent the integrity of the waterproof layer, or will not place a substantial load on the underlying roof structure.

Traditional roof structures are formed from a number of layers having different properties and providing different benefits to the overall structure. In a typical roof, a corrugated steel base structure commonly called a deck sits directly below a layer of insulation, possibly with the addition of an intervening vapor layer. A cover board protects the insulation layer and is held flush thereto using plates and fasteners.

A waterproof membrane then often covers the entire roof. It is crucial that the waterproof layer is completely impenetrable to water. To this end, where a thermoplastic membrane is used, any seals are heat treated to ensure that water cannot reach the internal roof layers. Waterproof layers may be formed from asphalt or tar, other bituminous waterproofing, rubber, polyvinyl chloride, or other water impermeable substances. In some cases, liquid substances are painted or sprayed onto the roof and allowed to harden to provide the waterproof layer.

When it is desired to attach additional external structures, such as lighting or photovoltaic panels, walkways, decorative panels, ventilation systems, heating pumps, electrical equipment to a roof this is traditionally achieved by the use of rail mounting systems which support the structures. Rail free systems also exist in which panels or lighting, for example, are attached directly to the roof surface. Where a folded metal outer roof layer is present, rails can be attached to the ridges forming part of the outermost surface of the roof as shown in JP5551800B1. Here, rails are coupled to the upwardly extending ridges of the corrugated outer roof surface using a bolt and additional supporting structure. Such a method will not require penetration of the waterproof layers of the roof but will not provide a particularly strong coupling and may not be suitable for use in windy conditions, for example.

More recently, the attachment of solar panels to flat or slightly sloped roofs has been achieved using ballast systems which also do not require penetration of the waterproof layer. Some such systems are described in WO-A-2015/110254 and WO-A-2013/056101. These, however, involve large loads being placed on the roof in order to provide the required support and this may cause damage or may be unsuitable for use in the case of more modern buildings where the load will exceed structural capacity. Such mechanisms may also be dangerous in situations where adverse weather can be expected.

The rails may in some circumstances be attached to the roof via fixing plates placed on top of the waterproof layer. Bolts running through the rail, waterproof layer, and fixing plate hold the rails in place and the fixing plate itself is attached to the roof using a number of additional bolts. This will usually allow the external structure to be attached securely enough to prevent damage either to the roof layers or to the external structure. However, because the waterproof layer must necessarily be penetrated in order to attach the bolts there is a risk of leaking, and this can cause major damage not just to the roof but to the whole of the building over time. In addition to this, the external structure will tend to bend and move under load or in high winds. This will transfer forces to the join and will cause rubbing and wear of the waterproof layers as well as other parts of the roof and the fixings.

Some attempts have been made to limit leakage through holes made in the waterproof membrane of the roof in order to accommodate coupling to external structures. In US-A-16/160,370 a hole is made through the waterproof layers of the roof to support a rail-less structure. Some protection is provided from water leaking through the hole around the edge of the bolt by a waterproof sealing cap which fits over the bolt head. In US-A-12/661,379 a protective raised cover section is provided over the joint, again in order to limit leakage of water through the joint. These methods are fairly complex, limit access to the joint, and cannot completely exclude the possibility of leaking and/or rusting.

According to a first aspect of the present invention, there is provided a fixing apparatus for mounting external structure on a roof, the fixing apparatus comprising a fixing plate and a connector for coupling to the external structure and to the fixing plate at a joint, wherein the fixing plate has a convex surface and the connector has a corresponding mating concave surface such that when the connector and fixing plate are coupled together at the joint the concave and convex surfaces interlock. This interlocking function may act to form a seal between the two surfaces, and may act to form a seal between the two surfaces when a waterproof membrane is pressed between the two surfaces. The upper surface of the fixing plate may comprise a flat portion surrounding the convex surface and the convex surface itself, which may be located in the center of the plate. Interlocking refers to the fact that the surfaces correspond in shape, however intervening layers such as a waterproof layer may be present between the two mating surfaces when the fixing apparatus is assembled. External structure refers to any structure that might be required to be mounted to a roof, usually outward of an external surface of the roof. Examples of external structure include external lighting, solar panels, walkways, ventilation systems, heat pumps, decorative panels, or electrical units. Coupling between the connector and the external structure may or may not be direct, so that intervening fixings may be provided therebetween.

The fixing apparatus avoids the usual problems in terms of water leakage through a joint while still providing a strength enough to withstand heavier loads and more severe weather conditions. The raised or convex portion, which may be located around the joint on the fixing plate, prevents water from reaching the joint without the requirement of additional structure as used in some of the existing solutions discussed above. The joint is also strong enough to support heavy loads and additional attachments or extensions can be included as discussed in more detail below. Additional attachments can be used, for example, in order to enable the fixing apparatus to be used to support harnesses during installation of the external structure.

Convex refers to the fact that at least a part of the surface of the fixing plate is raised with respect to the rest of the plate when it is set on a flat surface. Similarly, the concave surface of the connector must include at least a part of the surface which is indented in order to mate with the convex surface of the fixing plate. The entirety of one end surface of the connector may be configured to match, mate, or interlock with a part of the surface of the fixing plate. Concave and convex do not therefore necessarily refer to a hemispherical shape, although this may be the case. The concave and convex surfaces may be hemispherical surfaces, or may be shaped so as to form part of the surface of a sphere. The convex surface may be interrupted at the position of the joint between the fixing plate and connector. A hole forming a part of the joint may be present in the convex surface of the fixing plate and the concave surface of the connector. Where a dome-shaped concave and convex surface is described, therefore, this will most often include a portion in the center of the surface which is cut-out for a threaded screw to pass through for the purposes of attaching the plate and connector together.

The above features also provide a strong joint without the need for additional structure. A waterproof layer can sit directly between the convex and concave surfaces and because the shapes of the two surfaces there will be no gap between the waterproof layer and the concave and convex surfaces of the connector and plate respectively.

In embodiments, the convex surface and the concave surface are mating domeshaped surfaces. In embodiments, the convex surface and the concave surface are mating frustoconical surfaces. In both cases positioning and joining of the fixing plate and connector are facilitated because the two can be turned in relation to one another while the two surfaces are mating. Both shapes also provide no pathway for water to pass to the join.

In embodiments, the convex surface of the fixing plate and the concave surface of the connector are positioned such that they each surround the joint when the fixing plate and connector are coupled together. Again, this means that the join is raised with respect to the surrounding plate, preventing the ingress of water to the join and into the roof structure beneath.

In embodiments, the fixing plate and connector are configured to be coupled together to hold a layer of waterproof material between the two surfaces. The waterproof layer is part of existing roof surfaces and by pressing it between the plate and connector leaking can be more effectively prevented. Only one hole is required to be made in the waterproof layer and this will be raised (as for the hole in the fixing plate) above the level of the rest of the fixing plate and the roof structure.

In embodiments, the layer of waterproof material is flexible and of uniform thickness and can be held in place between the two surfaces so as to form a tight seal with each surface. In embodiments, the fixing apparatus comprises the flexible waterproof layer. Clearly, where the two surfaces press tightly against the waterproof layer a better seal is provided to prevent leakage through the join.

In embodiments, the whole of each of the concave and convex surfaces is in direct contact with the waterproof layer when the apparatus is assembled. It is preferred that once assembled the two mating surfaces of the plate and connector will press together against the waterproof layer over the whole of their respective areas to provide the best possible seal against water ingress.

In embodiments, the fixing plate and connector are configured to be joined together by a bolt extending through the convex surface of the fixing plate.

In embodiments, the connector comprises joining means in an end surface opposite the concave surface for attachment of the external structure or additional units.

In embodiments, the fixing apparatus comprises a suspension unit configured to couple the connector to the external structure, the suspension unit being formed at least partially from a flexible material such that the extension unit can bend in response to movement of the external structure when the apparatus is mounted on the roof and the external structure is mounted thereto. Inclusion of a suspension unit which can act as a vibration damper will prevent rubbing against the waterproof layer which may threaten its integrity over time. Damage to the rest of the fixing apparatus and the roof structure itself by movement of the external structure in the wind, for example, can also be avoided.

In embodiments, the flexible material is rubber. Rubber is a convenient, waterproof, and cheap material which is effective in absorbing shock impacts or vibrations.

In embodiments, the connector has a height of at least 4cm such that the external structure is supported at a distance of at least 4cm from the roof surface once it is mounted on the fixing apparatus. Ensuring a gap of a certain size between the roof surface and any externally mounted equipment makes access to the roof easier.

This may be required particularly in a fire, but also for repair and replacement of roof parts, of the external structure, or of the fixing mechanism itself. The connector may have a height of at least 2cm to 6cm, preferably at least 3cm to 5cm, and preferably at least 4cm. The standard height for the connector of 5cm therefore provides for a gap between the roof surface and the mounted external equipment which makes repair and access easier and can make drying out of the roof more straightforward if this is needed at any time. Some example dimensions for parts of the plate and connector are provided in figures 11 and 12 and the associated description.

According to a second aspect of the present invention, there is provided a method for mounting external structure to a roof, the method comprising: coupling a fixing plate to the roof and attaching a connector to the fixing plate at a joint such that a convex surface of the fixing plate interlocks with a mating concave surface of the connector, wherein the connector is configured to be coupled to the external structure.

In embodiments, the method comprises: attaching the fixing plate to the roof; providing a waterproof layer over at least a part of the fixing plate; and attaching a connector to the fixing plate such that the waterproof layer is pressed between the convex surface of the fixing plate and the interlocking concave end surface of the connector.

In embodiments, the method comprises mounting the external structure to the connector.

In embodiments, the method comprises mounting the external structure on the connector via a flexible suspension unit which is configured to bend in response to movement of the external structure.

According to a third aspect of the present invention, there is provided a fixing apparatus for coupling external structure to a roof, the fixing apparatus comprising a fixing plate and a connector configured to couple the fixing plate to the external structure, wherein the connector is formed at least partially from a flexible material such that the connector can bend in response to movement of the external structure once mounted.

In embodiments, the flexible material is rubber.

In embodiments, the connector comprises a first metal portion for coupling to the fixing plate and second portion at least party formed from the flexible material for coupling to the external structure.

In embodiments, the first and second portions of the connector are configured to be removably coupled together.

Embodiments of the present invention will now be described, by way of example only, with reference to the following diagrams wherein:

Figure 1 shows a section of a roof structure and a fixing apparatus mounted thereto;

Figure 2A is a plan view of a fixing plate and pins for attachment to a roof;

Figure 2B is a side view of the fixing plate of figure 2A;

Figure 2C is a view from above of the fixing plate of figure 2A showing the surface which faces upwards when mounted on a roof;

Figure 3A is a side view of the fixing plate;

Figure 3B is a cross-sectional view through the fixing plate and connector along the line A-A shown in figure 3A;

Figure 3C is a view of the top surface of the fixing plate and bolt for attachment to the connector;

Figure 3D is a view of the connector showing the concave surface for interlocking with the convex surface of the fixing plate;

Figure 4A is a plan view of a cross-section through a fixing apparatus;

Figure 4B is a side view of the cross-section shown in figure 4A;

Figure 5 shows a connector with safety ring attached;

Figure 6A is an exploded view of a fixing apparatus including a rubber suspension unit;

Figure 6B is a side view, partially exploded, of the fixing apparatus of figure 6A;

Figure 6C is a view from below of the fixing apparatus of figure 6A;

Figure 6D is a view from above of the fixing apparatus of figure 6A;

Figure 7 shows a connector, suspension unit, and safety ring on the left and a connector and suspension unit on the right;

Figure 8 shows a portion of a roof with external structure mounted via a plurality of fixing apparatuses;

Figure 9A shows a plan view of a roof section with walkway, solar panels, and heating pump or ventilation system attached using a fixing system comprising a fixing plate and connector;

Figure 9B shows a view from above of the roof section shown in figure 9A;

Figure 9C shows a plan view of the roof section shown in figure 9A;

Figure 10 shows detail of a mounting system for angled equipment

Figure 11 shows a plate and connector from the side and above with example dimensions;

Figure 12 shows a cross sectional view of a connector with example dimensions.

The fixing apparatus described herein is intended for use in coupling external or additional structure to a roof. This external structure may comprise solar panels, railings, walkways, cladding, railings or any similar structure required to be supported externally to a building. Figure 1 illustrates the position of a fixing apparatus 1 on the underlying roof structure in one example. The fixing plate 3 sits directly on top of a layer of insulation 5 or on top of an additional cover layer for the insulation. The fixing plate 3 will usually, as in this case, be attached to the underlying roof layers using some type of mechanical fixing mechanism such as screws or plugs 6 as shown to provide sufficient strength to the fixing. In certain cases, it may be that no fixing mechanism is required, and the fixing plate can simply be placed on the roof, or the fixing plate can be attached to the roof by means of adhesive portions or an adhesive layer on the back surface. Including one or more additional mechanical fixings 6 between the plate and the roof is of course preferable. This provides extra strength and helps with alignment of the various parts of the apparatus during the installation process. The additional fixings are also particularly useful if installation on a sloped roof is required. Fixings may pass through the insulation layer 5 and couple to structures below this such as a corrugated support layer or deck 7 shown in figure 1.

Figure 1 also illustrates connector 9 coupled to fixing plate 3. A waterproof layer 11 covers at least a part of the roof structure. This layer may be sprayed onto the surface or may comprise a separate layer of material that is placed onto the roof and held in place between the fixing plate and the connector. In some examples the waterproof layer is also fixed to the rest of the roof surface as usual by way of heat treatment or similar means. In the figure, the waterproof layer is shown with a portion removed in order to make visible parts of the fixing apparatus lying below. The waterproof layer may cover only a small section of the fixing plate near to the position of the join with the connector 9 as shown or may cover an area slightly larger than the fixing plate. In such a case the fixing plate may sit on top of an additional waterproof layer covering all or the majority of the roof surface. There will then be two waterproof layers present, one of which will be clamped between the fixing plate and the connector and will help to prevent leakage of water at the position of the fixing plate. The waterproof layers may be formed from a flexible sheet material made from, for example, PVC, rubber, synthetic rubber such as EPDM rubber, bitumen, or asphalt.

In some cases, the waterproof layer will be clamped between the fixing plate and the connector around the join but will also extend over a large area at least the size of the fixing plate in order to extend over the edges thereof, and possibly over the whole of the roof surface. As set out below in more detail, a number of fixing apparatuses will usually be coupled to the same roof in order to support the required external structure, and the same waterproof layer may extend between these and be held in place between the fixing plate and connector of each apparatus.

The present fixing system requires very little interruption of the waterproof layer which reduces the likelihood of leaking. The waterproof layer 11 extends above the fixing plate. A hole is required to be made in the waterproof layer to allow a device such as a bolt to pass through to couple the fixing plate to the connector, however this hole is raised in relation to the rest of the roof surface as explained below.

Leaking through the joint is prevented both because the water is stopped from travelling upwards towards any hole in the waterproof layer by gravity and due to the tight fit provided between the mating surfaces of the plate 3 and connector 9 (with a waterproof layer compressed between the two surfaces in most cases).

In some embodiments, fixing between the connector 9 and plate 3 may not require a hole to be made in the waterproof layer. Fixing may be magnetic, for example. This will provide a good seal, but the fixing point will not be strong and may only be usable where small loads or bending forces are expected.

In figure 2A, a plan view of the fixing plate is shown. Here, 4 plugs 6 are used to hold the fixing plate 3 to the roof. This means of fixing is typical where a flat plate of this type is used as part of a roof structure. The plate 3 includes additional fixing holes 13 to provide an option to fix the plate at additional or different points. A connector 9 is shown coupled to the fixing plate 3 with a waterproof layer 11 held between. Figure 2B shows a side view of the fixing apparatus of figure 2A, and figure 2C is a view from above of the same apparatus.

In this case the plate 3 includes a number of fixing holes 13 which provides some adaptability in terms of how the plate is attached to the underlying roof surface. Here four nails, screws, or other fixers 6 are shown and eight additional fixing holes 13 are present, however this configuration is not limiting and there is the option of fixing the plate using any number of fixers or no fixers as mentioned above. Any number of fixing holes can also be provided in the plate and the exact number will depend on the surface configuration and the strength of the material that the plate is to be fixed to. In some cases, it is possible to install the system without anchoring the plate to the roof using additional mechanical fixing means, and the plate can be held in place by the waterproof layer itself extending over the plate. This will be possible where the additional strength from fixings is not required, such as when the fixing system is providing extra support for mounted structure or apparatus. Fixing means for coupling the plate to the roof may not be required, for example, when the fixing system is being used to provide additional support for heating pumps.

Figure 3B shows a cross-section through the apparatus along line A-A shown in the side view of figure 3A. In figure 4A the cross section of figure 3B is blown up and is shown in plan view and a side view of the same cross section is shown in figure 4B. The fixing plate 3 includes a convex portion 15 in its upper surface which mates with a similarly shaped concave 17 portion forming at least part of an end surface of the connector 9 (in this case the whole of the end surface of the connector mates with a corresponding surface of the fixing plate).

The convex 15 and concave 17 surfaces of the plate 3 and connector 9 may be frustoconical or dome shaped, although any shape for the surfaces can be used provided that the surfaces of the plate and connector correspond to one another in order to provide a mating fit. The mating surfaces of the plate and connector therefore represent the inverse version of one another or are complementary.

Domed or frustoconical convex and concave surfaces on the plate and on the connector end surface respectively will provide a good seal and allow for turning of the connector relative to the plate to fix the two together by means of a bolt 19. A dome or bowl-shaped protrusion in the upper surface of the plate is shown in figures 3B and figure 3C. The end of the connector 9 configured to sit over this once assembled will comprise a corresponding dome or bowl-shaped indent 17 into which the protrusion can fit as shown in figure 3D. The connector will generally include a threaded borehole 21 through which a bolt 19 can be inserted to fix the connector 9 and plate 3 together. Figure 3D shows a cross section 50 through line C-C in the figure, a bird’s eye view 51 of the concave surface and a plan view 52 of the connector in which the concave surface is visible.

The connector 9 shown in the figures is cylindrical and thus has a circular crosssection, however this need not be the case. The connector may have a square, rectangular, hexagonal, or triangular cross-section, or may have a cross section or any other shape. Including edges (rather than the smooth surface of a cylinder) may help with installation or replacement, for example, if it is required to screw and unscrew the connector from the fixing plate 3.

As can be seen in figure 3B, a hole 23 extends through the fixing plate in the centre or apex of the convex surface 15 and through a waterproof layer 11 located between the fixing plate and the connector. A threaded bore 21 also extends part of the way into the connector through the centre of the concave end face. A bolt 19 can be passed through the hole in each of the plate and the waterproof layer for coupling to the connector via the threaded bore. In this way, the connector can be screwed into proper connection with the fixing plate and tightened until a tight seal is formed.

The connector 9 also includes a bore 25 in the end surface opposite the concave surface for fixing to rails or other external structure, or for coupling with additional modules as set out in more detail below. The threaded bore 21 for receiving a bolt 19 to attach the fixing plate 3 to the connector 9 and the bore 25 in the opposite end face of the connector should not meet. There should be provided a solid region 27 between the two within the connector such that there is no pathway for water from one end of the connector to the other. Preferably, this region should be at least 0.5cm to 5cm, more preferably 1cm to 3cm, and most preferably around 2cm, in height so that the ends of the two bores are separated by at least this distance. The depth of the bores may be around 1.5cm each to allow for the use of standard bolts or may be different if the connector is to be used with non-standard bolts. The total height of the connector may therefore be between 3cm and 7cm, preferably between 4cm and 6cm, and most preferably around 5cm. A height of 5cm is most preferable because this allows the use of standard 1.5cm bolts at both ends of the connector with a 2cm solid portion in the centre, or a 2cm distance between the ends of the two boreholes required for the bolts. The connector may have a diameter of between 3cm and 10cm, more preferably between 4cm and 8cm, more preferably between 4cm and 6cm and most preferably around 5cm. Larger sizes (for example a diameter of 20cm or larger) may be used if additional support is required. Corresponding measurements can be used for a largest distance across the connector in the case where the cross section is not circular.

The presence of the connector, being associated with a certain height, therefore also ensures that there is at least a small gap between the roof and any external structure. This provides easier access to the roof during a fire and means that holes can easily be made in order to allow hot and noxious gases to escape. An air gap may also be beneficial in terms of access to the external structures for replacement and maintenance and to allow airing of the same structures where necessary.

The connector and the fixing plate may each be formed from stainless steel which will provide the required level of strength without rusting. The fixing plate can also be galvanised (i.e. with a coating of zinc) for additional strength or can be formed entirely from a zinc or magnesium-based material. The connector may also be galvanized or can be formed completely or partly from plastic. Plastic will generally be acceptable when this component is not required to be particularly strong.

As can be seen in figures 3B, 4A, and 4B in particular, the waterproof layer 11 extends between the convex surface 15 of the plate 3 and the concave surface 17 of the connector 9 and extends right up to the edge of the hole 23 formed through the plate for the bolt. This will preferably be the case in order to provide a better seal, however the waterproof layer can in some examples extend only part of the way up the convex surface 15 if desired or may extend only up to where the convex 15 and concave 17 surfaces begin such that once assembled the convex and concave surfaces are in direct contact with one another. The waterproof layer 11 may be flexible such that it will bend to conform to the surfaces of the plate and connector and may be pressed between the two once the apparatus is installed. In some examples, the waterproof layer may be sprayed onto the roof and fixing plate after the fixing plate or a number of fixing plates have been positioned. Once the waterproof layer is present, the connector can be coupled to the plate to form the seal and provide the required framework for mounting external structure such as solar panels.

The convex surface 15 of the fixing plate may be formed by bending of the plate or the plate may be formed in the desired shape by moulding. In either case, there may be a corresponding concave surface 29 on the underside 31 of the plate corresponding to the convex surface 15 on the top side 33. If this is the case, as shown in figures 4A and 4B, the head of the bolt 19 or the nut 35 fixing the plate and connector will not protrude above the underside of the plate and will not prevent the plate from being placed flush with the roof surface. The nut or bolt head may be fixed in place at the underside of the plate by welding or similar means to provide additional strength and leak resistance to the join. There may also (or instead) be a sealing ring provided between the bolt head or separate nut and the fixing plate.

The bolt 19 in other embodiments may be integral with the fixing plate. The plate with its convex surface 15 and the bolt 19 extending from the top of the convex surface can then be integrally formed by moulding or by a similar method. There will be no hole in the fixing plate 3 where it joins to the connector 9 in this embodiment, which will be beneficial in terms of preventing leakages.

Once the fixing plate 3 and connector 9 are coupled to the roof, external structure such as a framework of rails for supporting solar panels or cladding can be coupled directly to the connectors, for example via the threaded borehole in the upper end surface. Alternatively, additional units may be included between the connector and any external structure or instead of any external structure. A hook or a ring 37 may be coupled to the connector 9 as shown in figure 5 to provide an anchor point for safety gear during installation of the external structure. This may be done by screwing a bolt extending from the base of the ring into the borehole 25 of the connector. When a plurality of fixing apparatuses are mounted on a roof during installation such rings may be useful for clipping harnesses to as an additional safety measure for workers. Because the rings are simply screwed into the existing structure and are able to be unscrewed, these can be mounted when necessary and can be removed for replacement with some other structure at any time. Coupling via screw and thread provides a strong and easily removable fixing, however any method for fixing the ring to the connector may be used.

In some cases, it may be desirable for the external structure to be able to be mounted at an angle. Rather than including a ring, an extension portion may be coupled to the connector as an additional unit in order to increase the gap between the roof and the external structure where needed. The extension portion may simply screw into to end face of the connector as for the safety ring 37 described above. The extension portions may be different heights in order to allow for the mounting of angled panels and other external structures, or may provide for adjusting the angle of the mounted structure. Mounting one side of a panel, for example, using a short extension portion and another side using a taller extension portion is an easy way to achieve an angled mounting. Rather than including extension portions of different heights, the connector portion itself may be available in a number of different heights for use in mounting a sloping external structure. Connectors may be available, for example, with a standard height of 5cm and in larger sizes having heights of 7cm, 10cm, 15cm, and so on.

Any size of extension can be provided to give maximum flexibility in terms of the configuration, or such extension portions can be adjustable so that their height can be adapted as needed even after attachment with the connector and/or the external structure. Adjustment may be achieved by means of a screw which extends into the connector further or less far as desired. In order to provide an adjustable height for the external structure without compromising on strength an additional adjustment mechanism may be provided. The extension portion may be coupled to the connector by screwing it all of the way in as usual, but an extendable leg may instead be provided by another screw (or a different mechanism) to achieve the desired height adjustment.

Different sizes of connector may alternatively or additionally be provided to allow some flexibility in the positioning of the mounted structures. If a number of angled panels, such as solar panels, are to be mounted then this can be achieved by including a first size of connector for fixing one side of the panel and a second, taller, connector for fixing a second side. This will then automatically result in the panel being mounted at an angle.

Rather than a safety ring or extension portion, a rubber suspension unit 39 may be fixed between the connector and the external structure. Figures 6A to 6D illustrate a fixing apparatus 1 including an additional rubber suspension unit 39. In this case, the suspension unit 39 screws into the borehole 25 in the upper end of the connector 9 as for the safety ring 37 described above with reference to figure 5. The external structure, which may include supporting rails, is attached to the rubber suspension unit for example by way of an additional borehole in the uppermost end thereof. The rubber suspension portion damps vibrations which would otherwise transfer to the roof structure causing wear and damage. Such a rubber suspension unit may be between 2cm and 6cm in height, preferably around 4cm in height. The unit may have around the same diameter as the connector portion where cylindrical connectors and suspension units are used or may have the same cross section. In embodiments, the connector itself may be formed entirely, mostly, or partially from rubber in order to provide the damping function of the rubber suspension unit without the requirement of an additional coupling or additional height. An upper portion of the connector may be formed from rubber, for example. The whole or substantially the whole of the connector portion may be formed from rubber, however this will mean sacrificing strength to an extent. The suspension unit 39 may be formed of rubber with metal end faces thereon for additional strength where coupling to other parts of the fixing is required. The rubber suspension unit may be formed from rubber with steel or stainless steel plates glued or fixed to both ends to provide additional strength.

The additional units described above can be used alone or together. A safety ring 37 can be coupled to the top of a rubber suspension unit 39, which is in turn coupled to a connector 9 as shown in figure 7A (left hand side), for example. This can provide extra flexibility to the join when a worker is moving around on the roof and is coupled to the ring via a harness, preventing wear to the connector and the rest of the fixing.

Where a number of fixing apparatuses are mounted on a roof, different additional units can be mounted to each depending on requirements. In figure 7A, the left image shows a fixing plate with connector, rubber suspension unit, and safety ring fitted. Obviously, once the apparatus is mounted on a roof an additional waterproof layer will in most cases be present between the connector and plate. On the right, the safety ring has been removed and a threaded borehole 41 is visible in the top end surface of the rubber suspension unit for coupling to other units or to external structure.

Figure 8 shows how external structure 43 may be mounted on a roof using a plurality of fixing apparatus. In this case a frame 45 formed from several metal bars is fixed to a number of fixing apparatuses 1 mounted every meter or so on a roof. Solar panels 47 are coupled to this frame. In this way some space can be maintained between the panels, the frame structure, and the roof which is beneficial in terms of access and in case of fire as explained above.

The fixing plate 3 in an embodiment is installed such that it sits on top of a waterproof layer 11 covering the whole roof. An additional waterproof layer may be provided in order to cover the plate and this can be sealed to the uppermost surface of the roof outside of the perimeter of the plate in order to provide further protection from the ingress of water. Installation of the fixing plate above the waterproof roof covering allows the system to be installed easily at any time, even after the roof has been completely assembled and waterproofed. As explained above, the fixing plate can also sit underneath the waterproof layer 11 in which case no additional waterproof layer is required (although this can be provided if desired).

The structure of the interlocking portions of the fixing plate and connector themselves may be enough to prevent the ingress of water or waterproofing may not be required (for example if used on concrete flooring) in which case no waterproof layer may be provided therebetween. A waterproof layer may also be provided prefixed to the concave or convex surface of the connector or plate, or prefixed to both such that coupling of the plate and connector causes the waterproof layer or layers to be held tightly between the interlocking surfaces of the two parts.

In figure 9A, some examples of external structure are shown mounted to a roof section (in this case a flat roof) using fixing plates and connectors. In this case, a walkway 53, solar panels 55, and a ventilation system 57 are shown. Obviously, many different types of external structure can be mounted as desired. The configuration and the type of equipment shown in figure 9A is by way of example only. The walkway is supported by rails 59 separated along the length of the structure and each fixed to the roof at two fixing points. All fixing points in the figure are provided with rubber suspension units 39 to help to prevent damage to the roof, although this need not necessarily be the case. Solar panels 55 are supported at each corner by fixing apparatuses 1, with central fixing points being shared between two panels as described in more detail below. The ventilation system 57 is supported at each corner.

The same mounted external structure is shown in each of figures 9B and 9C. In 9C, some of the fixing plates are equipped with an additional waterproof layer 49 in the vicinity of the joint between the fixing plate and connector and others are not. This may depend on whether the fixing plate 3 is already provided underneath a waterproof covering, or whether it is desired to add additional waterproofing. External equipment is mounted with minimal additional supporting structure being required. This is beneficial during mounting of the equipment because workers do not run the risk of tripping over mounting rails prior to mounting the panels or walkway. Rails generally extend in one direction only in a particular section of roof for the configuration shown in figures 9A to 9C, which further reduces the risk of tripping because workers are able to simply walk between the rails.

In figure 10, some detail of a mounting mechanism for angled solar panels 55 is provided. Although the mounting mechanism is used to mount solar panels in this example it is suitable for mounting any sloping panel or object, such as decorative panels. Lower angled support members 61, shown in detail as image D, are coupled either directly to the connector 9 or, as in this case, to a suspension unit coupled to the connector. Each support member comprises a bolt 63 and two angled bars 65 for coupling to one side of each solar panel. The angle of the bars may be fixed, for example at between 2° and 45° to the roof, preferably between 5° and 20° to the roof, and most preferably at around 10° to the roof surface. It is also possible to include support members for which the angle of the bars can be adjusted by way of a hinged joint to provide greater flexibility. Upper angled support members 67, shown in detail as image E, are used to mount the higher end of the sloping panel. The structure of the upper support members is slightly different and comprises two upwardly extending bars 69 as shown which form the apex of a triangle for stability. Two additional support bars 71 are then coupled to this triangular section. The angles of the two additional support bars 71 from the horizontal is configured to match the angle of the support bars of the lower support member (and the desired angle of the solar panels) from the roof. The coupling between the support bars and the solar panel may use any fixing means providing the required level of strength. Clip fixings, and screw fixings are both suitable examples.

Figure 11 illustrates some preferred measurements for the plate and connector. Measurements are shown in the figures in millimeters. The height of the connector may be between 30mm and 80mm, preferably between 40mm and 70mm, more preferably between 50mm and 60mm and most preferably around 58mm. The length of a side of the plate may be between 30cm and 50cm, preferably between 35cm and 40cm, and most preferably around 390mm (or 39cm). The plate shown in the figure is square in this case, but it may alternatively have sides of different length or may be of a different shape, such as a circular plate. For a circular plate the diameter of the plate may be between 30cm and 50cm, preferably between 35cm and 40cm, and most preferably around 390mm (or 39cm).

In figure 12, preferred dimensions for the connector are provided. The height of the connector may be between 30mm and 80mm, preferably between 40mm and 70mm, more preferably between 50mm and 60mm and most preferably around 58mm (as shown above with respect to figure 11). The diameter of the connector if a circular connector is used, or the width of a cross section through the center of the connector if not, may be between 20mm and 80mm, preferably between 40mm and 60mm, and most preferably around 50mm. The depth of the borehole extending into the connector from its upper surface may be between 10mm and 30mm, preferably between 15mm and 25mm, and most preferably around 25mm. The height of the concave portion in the base of the connector (and correspondingly of the convex portion of the plate) may be between 5mm and 15mm, preferably between 8mm and 13mm, and most preferably around 11mm. The concave portion if dome shaped may then have a diameter of around 50mm and height of around 11mm.

Claims

1. A fixing apparatus for mounting external structure on a roof, the fixing apparatus comprising a fixing plate and a connector configured to be coupled to the external structure and to the fixing plate at a joint, wherein the fixing plate has a convex surface and the connector has a corresponding mating concave surface such that when the connector and fixing plate are coupled together at the joint the concave and convex surfaces interlock.

2. The fixing apparatus of claim 1, wherein the convex surface and the concave surface are mating dome-shaped surfaces.

3. The fixing apparatus of claim 1, wherein the convex surface and the concave surface are mating frustoconical surfaces.

4. The fixing apparatus of any of claims 1 to 3, wherein the convex surface of the fixing plate and the concave surface of the connector are positioned such that they each surround the joint when the fixing plate and connector are coupled together.

5. The fixing apparatus of any of claims 1 to 4, wherein the fixing plate and connector are configured to support a layer of waterproof material between the two interlocking surfaces when they are coupled together at the joint.

6. The fixing apparatus of claim 5, wherein the fixing plate and connector are configured to support a layer of waterproof material that is flexible and of uniform thickness such that the layer of waterproof material is held in place between the two surfaces so as to form a tight seal with each surface.

7. The fixing apparatus of any of claims 5 and 6, comprising the layer of waterproof material.

8. The fixing apparatus of any of claims 6 or 7, wherein the concave and convex surfaces are configured such that the whole of each of the concave and convex surfaces are in direct contact with the waterproof layer when the apparatus is assembled.

9. The fixing apparatus of any of claims 1 to 8, wherein the fixing plate and connector are configured to be joined together by a bolt extending through the convex surface of the fixing plate.

10. The fixing apparatus of any of claims 1 to 9, wherein the connector comprises joining means in an end surface opposite the concave surface for attachment of the external structure or additional units.

11. The fixing apparatus of any of claims 1 to 10, comprising a suspension unit configured to couple the connector to the external structure, the suspension unit being formed at least partially from a flexible material such that the extension unit can bend in response to movement of the external structure when the apparatus is mounted on the roof and the external structure is mounted thereto.

12. The fixing apparatus of claim 11, wherein the flexible material is rubber.

13. The fixing apparatus of any of claims 1 to 12, wherein the connector has a height of at least 4cm such that the external structure is supported at a distance of at least 4cm from the roof surface once it is mounted on the fixing apparatus.

14. A method for mounting external structure to a roof, the method comprising: coupling a fixing plate to the roof and attaching a connector to the fixing plate at a joint such that a convex surface of the fixing plate interlocks with a mating concave surface of the connector, wherein the connector is configured to be coupled to the external structure.

15. The method of claim 14 comprising: attaching the fixing plate to the roof; providing a waterproof layer over at least a part of the fixing plate; and attaching a connector to the fixing plate such that the waterproof layer is pressed between the convex surface of the fixing plate and the interlocking concave end surface of the connector.

16. The method of claim 15, comprising coupling the external structure to the connector.

17. The method of claim 16, comprising mounting the external structure to the connector via a flexible suspension unit which is configured to bend in response to movement of the external structure.

18. A fixing apparatus for coupling external structure to a roof, the fixing apparatus comprising a fixing plate and a connector configured to couple the fixing plate to the external structure, wherein the connector is formed at least partially from a flexible material such that the connector can bend in response to movement of the external structure once mounted.

19. The fixing apparatus of claim 18, wherein the flexible material is rubber.

20. The fixing apparatus of any of claims 18 and 19, wherein the connector comprises a first metal portion for coupling to the fixing plate and second portion at least party formed from the flexible material for coupling to the external structure.

21. The fixing apparatus of claim 20, wherein the first and second portions of the connector are configured to be removably coupled together.