This invention is concerned with improvements in a roof system and is particularly concerned with improvements in a roof system comprising through the roof insulation panels and roof tiles for use therewith.

Roof systems incorporating through the roof insulation panels are well known and have been used extensively in Germany and Italy, such panels being conveniently moulded from foamed polystyrene of varying densities depending upon the performance required from the products when installed on a roof of a building.

The roof insulation panels may include means for attachment thereof to roof decks; they may be attached to the purlins and rafters of a roof structure or they may be located on conventional roof battens. In addition, the roof insulation panels may incorporate means for the retention of roof tiles,- such means may be provided by metal battens . Such battens may be affixed to the roof insulation panels and extend across a roof thereby providing means for engagement by hanging nibs of the roof tiles laid overlying the panels as aforesaid.

In further arrangements provided by the prior art, the roof insulation panels may incorporate recesses for receiving the hanging nibs of roof tiles laid thereon, such recesses being aligned as between sideways adjacent roof insulation panels across a roof.

The roof insulation panels may be laid in full bond or half bond relationship and may include configured side edge portions for mutual overlapping and/or interlocking in use. Also, the roof insulation panels may be laid in single lap or double lap

relationship to enhance the water tightness and strength of a roof structure .

The degree of overlap of the roof insulation panels is normally chosen according to the distance between an eaves and a ridge of a roof structure while maintaining the water tightness and integrity of a roof .

A roof comprising the roof systems as hereinbefore described may also include underlay and vapour control layers, all of which adds to the complexity of the roof structure giving high investment costs in plant for the production of all of the component parts together with the high labour costs incurred in assembling the roof structure.

It is therefore an object of the present invention to provide an improved roof system that overcomes or at least mitigates the disadvantages of the prior art roof systems.

Consequently, the present invention conveniently provides a roof system comprising a roof tile and an insulation panel for being supported on a roof structure, the roof tile being formed with an integral hook-like protuberance on an underside, in use, thereof, characterised in that the dedicated insulation panel is provided with a channel for location of the hook-like protuberance of the roof tile, the channel comprising a reentrant wall for receiving in close proximity a re-entrant wall portion of the hook-like protuberance of the roof tile.

The channel may be defined between ribs or walls extending across the width of the insulation panel, the walls constituting means for supporting the roof tile in use. Alternatively, the support means for the roof tile may be

constituted by a non-integral member, such as a batten secured across the width of the insulation panel, the re-entrant wall being formed on the batten.

The integral hook-like protuberance is preferably located on the roof tile intermediate a top edge portion and a bottom edge portion thereof.

In one preferred embodiment provided by the present invention the insulation panel may be moulded from an expanded foam material such as polystyrene, polyurethane or polyisocyanurate. The panel may be provided with a radiant barrier on its surface formed, for example, of an aluminium foil film or coating.

Conveniently, the insulation panel may be provided with a toughened upper surface portion wherein the toughened upper surface portion may be provided by a dense layer of polystyrene co-moulded with a body of the insulation panel . The insulation panel may also have a sandwich structure, with top and bottom layers of cardboard or wood and an intermediate layer of an insulating material. A fire-resistant insert, formed for example of wood or metal, may be provided in the projecting walls of the insulation panel, to reduce the risk of tiles falling from the roof in the event of a fire hot enough to melt the insulation material .

In another preferred embodiment provided by the present invention, the roof structure comprises conventional rafters and the insulation panel may be secured directly to the rafters . The insulation panel may be secured to the rafters by clips, brackets or similar fasteners, preferably of a type that do not penetrate the full thickness of the insulation panel so as to prevent cold bridges . In an alternative embodiment the

insulation panel may be provided with integral fastening features moulded within the insulation material .

In a further preferred embodiment provided by the present invention, the roof structure comprises a decked roof and the insulation panel may be secured directly to the decked roof.

The present invention also conveniently includes an embodiment wherein a plurality of insulation panels, roof tiles and a roof structure comprising rafters and purlins may be pre-assembled prior to being attached in situ overlying a building, so the panel can be mounted directly on the building with a minimum of structural elements underneath (such as a ridge beam and possibly a purlin mid way between eaves and ridge) .

Thus, a preferred embodiment of the present invention is a prefabricated system, wherein an insulation panel is supplied to the user with a number of roof tiles already supported thereon, ready to be positioned on the building. In one such embodiment, no tiles should overlap the side edges of the insulation panel in such a prefabricated system, to enable adjacent panels to be joined together on the roof. A set of separate covering roof tiles may then be provided to cover the joins between the insulation panels. Where the roof tiles are of the type having underlocks and overlocks on their side edges, it will be convenient if the separately supplied covering roof tiles have double overlocks, the roof tiles carried on the insulation panel including at least one double underlock tile in each row. In another such embodiment, the pre-fitted tiles do overlap the edges of the insulation panels.

In a preferred embodiment, a plurality of the roof tiles are associated with each insulation panel. For example, a single

insulation panel may be provided to carry from 100 to 180 roof tiles, arranged with from 4 to 12 roof tiles in each row.

Conveniently, the roof tile may be moulded from a cementitious composition, viz. concrete mortar or the roof tile may be moulded from a ceramic composition, a reconstituted slate composition, metal or a plastics material.

There now follows, by way of exemplification of the invention, a detailed description, which is to be read with reference to the accompanying drawings in which:

Figure 1 is a left-hand upper perspective view of parts of a roof system provided by the invention,-

Figure 2 is a plan view of the parts shown in Figure 1;

Figure 3 is diagrammatic side view in the direction of the arrow III in Figure 1;

Figure 4 is a right hand upper perspective view of a roof insulation panel;

Figure 5 is a side elevation of the roof insulation panel shown in Figure 4;

Figure 6 is a plan view of the roof insulation panel of Figure 4;

Figure 7 is a view in the direction of the arrow VII in Figure 4;

Figure 8 is a plan view of a first roof tile provided by the present invention;

Figure 9 is an underside view of the roof tile shown in Figure 8;

Figure 10 is a left-hand upper perspective view of the roof tile shown in Figure 8;

Figure 11 is a view in the direction of the arrow XI in Figure 8;

Figure 12 is a view in the direction of the arrow XII in Figure 8;

Figure 13 is a plan view of a second roof tile provided by the present invention;

Figure 14 is an underside view of the roof tile shown in Figure 13 ;

Figure 15 is a right-hand upper perspective view of the roof tile shown in Figure 13;

Figure 16 is a view in the direction of the arrow XVI in Figure 15; and,

Figure 17 is a view in the direction of the arrow XVII in Figure 15.

In overcoming the disadvantages of the prior art roof systems referred to herein, the present invention provides a novel roof system, which generally comprises a plurality of roof

insulation panels 4 arranged in overlapping relationship, the roof system also comprising a plurality of roof tiles 6 supported by the panels 4, see Figures 1, 2 and 3.

Each roof insulation panel 4 is moulded from foamed polystyrene and may have several layers of different densities and strength depending upon the specification therefor, i.e. the load that the panel 4 has to support in use. Thus, a typical insulation roof panel 4 may have a thick lower layer of a first density and an upper layer of less thickness but of a greater density thereby providing a stronger upper layer to the panel 4 and an overall strength thereto.

The roof insulation panel 4 is rectangular in plan and comprises opposite side edges 8 and 10 and opposite ends 12 and 14, see Figures 1 and 6. The panel 4 also comprises an under surface 16 and an upper surface 18 as shown in Figures 1 to 6.

The under surface 16 is provided with a depending wall portion 20 extending across the width of the panel 4 for a purpose to be described hereinafter, the portion 20 being provided toward the end 12 of the panel 4, see Figure 1, 3, 4 and 5.

On its upper surface 18, the panel 4 is provided with first and second upwardly projecting ribs or walls 22 and 24 extending across the width of the panel 4 defining a channel 25 therebetween. The wall 22 comprises a front surface 26, a top surface 28 and a stepped rear surface 30 including a re-entrant surface 32, see especially Figures 1 to 7, the purpose for the re-entrant surface 32 being explained hereinafter.

The wall 24 comprises a rearward sloping front surface 34, a top surface 36 and rear surface 38, the top surface 36 being in

substantial alignment with the top surface 28 of the wall 22, see especially Figures 4 and 5, the purposes of which top surfaces 28 and 36 being made clear hereinafter.

The roof tile 6 of Figures 8 to 11 is a conventional 'bold roll' roof tile, which is generally rectangular in plan, see Figure 8, and comprises a downward facing side lock 40 at a right hand side 42 and an upward facing side lock 44 at a left hand side 46, see especially Figures 10 and 12.

The roof tile 6 also comprises conventional hanging nibs 50a and 50b at a head portion 52 thereof, see especially Figures 9 and 11.

On an under surface 54 of the roof tile 6, toward a tail end portion 56 thereof, the roof tile 6 is provided with two hook- like protuberances 60a and 60b, which are provided with reentrant surfaces 62a and 62b respectively, see especially Figures 9 and 11, the purpose of which surfaces 60a and 60b being made clear hereinafter.

In use, insulation panels 4 are assembled on a roof structure, not shown, the panels 4 being located on or between the purlins and/or the rafters of a roof structure or on the decking of a decked roof .

In the present example the roof insulation panels 4 are oriented in the relationship shown in Figures 1, 2 and 3 by being located on battens, not shown, the battens being received between front surfaces 20a of respective depending wall portions 20 and ends 12 of the panels 4 adjacent thereto, see Figures 1, 3, 4 and 5.

The panels 4 may be provided with mutually overlapping and/or interlocking side portions to ensure the water tightness of the roof structure. In addition, the panels may also include clipping arrangements as necessary for mutual attachment one to another and for attachment of the roof insulation panels 4 to the roof battens, purlins or the rafters of a roof structure.

When the roof panels 4 are attached to the roof structure, roof tiles 6 are located thereon, as shown in Figures 1 to 3 , with the re-entrant surfaces 62a and 62b of their hanging nibs 60a and 60b being located in mutual juxtaposition with the respective re-entrant surfaces 32 of the walls 22. When located in this way the under surfaces 54 of each tile are supported on associated top surfaces 28 and 36 of the walls 22 and 24.

It will be appreciated that the tiles 6 are securely mounted on the roof insulation panels 4 and that the roof system provided by the present invention is not as labour intensive as prior roof systems, especially because of the mutual interlocking relationship between the roof tiles 6 and the panels 4.

Figures 13 to 17 illustrate a second configuration of roof tile 6a provided by the present invention, which tile 6a is generally similar to the roof tile 6; thus like parts thereof are accorded the same numerals for identification purposes with the exception of the two hook-like protuberances 61a and 61b, which are of different configuration as shown in Figures 14 and 16. However, the further nibs 61a and 61b of the roof tile 6a are also provided with a re-entrant surfaces 63a and 63b for engagement, in use, with the re-entrant surfaces 32 of the walls 22 provided on the roof insulation panels 4.

The roof tiles 6 and 6a described herein may be formed: a) from tile mortar by the well know extrusion process; or, b) from a ceramic composition in a clay tile press; or, c) from a castable cement composition in moulds formed as complimentary half-moulds; or, d) from any other suitable moulding composition, for example, a plastic material or a reconstituted slate composition.

The roof insulation panels 4 of the present invention may be provided with a series of channels, not shown, in the walls 22 and 24 for facilitating the egress of any water that may pass through the roof tiles 6 or 6a to the underside thereof; in addition, such channels will provide ventilation to the underside of the tiles 6 and 6a whereby any residual condensation is evaporated thereby avoiding damage to the roof insulation panels 4 and the other elements of the roof structure .

Whereas the panels 4 and tiles 6 and 6a have been described herein as a roof system, it will be fully appreciated that the combination of panel and tile provided by the invention may find use as a wall cladding system. In such an embodiment, it would be useful to provide the tiles with additional hook-like protuberances adjacent the top edge portion of the tile, to provide improved security.

Irrespective of the use made of the panels 4 and the roof tiles 6 and 6a, it is envisaged within the scope of the present invention that the panels 4 may be provided with a vapour barrier and underlay material to further enhance the integrity of a roof structure or a wall clad with the panels 4 and hanging tiles provided with the hook like protuberances of the roof tiles 6 and 6a.

The vapour barrier, where provided, may take the form of a film or a coating material applied to the surfaces of the panels 4 or it may be provided by a sealant composition applied to the joints between sideways adjacent panels on a roof or a wall.

Although it is envisaged that the roof insulation panels 4 will have sufficient strength for purpose, further reinforcement may be provided within the structure of the panels 4 or the panels 4 may be moulded with reinforcing rib configurations.

Whereas the present invention has been described as a roof system comprising a plurality of roof insulation panels 4, which are laid in overlapping relationship from the eaves to the ridge of a roof, it is envisaged within the scope of the present invention, that the roof insulation panel may be moulded as a single unit that stretches between the ridge and the eaves of a roof. It is to be appreciated that the use of a plurality of roof insulation panels will allow for any inconsistency in the length of the roof between the ridge and the eaves thereof. Such a panel could also be laid from gable to gable.