GB2345705A

GB2345705A - Insulated cladding panel with sealing means

Info

Publication number: GB2345705A
Application number: GB9900647A
Authority: GB
Inventors: Peter Taylor
Original assignee: TALFAB HOLDINGS Ltd
Current assignee: TALFAB HOLDINGS Ltd
Priority date: 1999-01-13
Filing date: 1999-01-13
Publication date: 2000-07-19
Anticipated expiration: 2019-01-13
Also published as: GB2345705B

Abstract

Panels 61, 61a for roofing or cladding comprise first and second external sheet members 62, 64 and an intermediate thermally insulating layer 66 located between first and second external sheet members. Co-operating formations 72, 74a engage for assembling the panels. Resilient sealing material 78 is disposed along the panel. On assembly, sealing material 78 is compressed to form a seal between second external sheet members of adjacent panels.

Description

IMPROVEMENTS IN OR RELATING TO PANELS The present invention relates to panels, sheeting and cladding members, and in particular to inter-engaging composite panels for roofing and cladding of buildings.

Panels for cladding and roofing are well known and in general comprise a sheet of material (which may include strengthening ribs), which is attached to a roof supporting structure or similar by suitable fasteners such as nails, bolts, screws or clips. Adjacent panels may be joined together to form a single structure and formations may be provided at the edges of the panel to achieve this, such as by seaming the panels together. It is also known to provide interlocking panels wherein first and second interlocking formations are formed along opposed edges of the panel. The first interlocking formation of one panel is constructed to co-operate with the second interlocking formation of an adjacent panel to join the panels together. It is desirable that the fasteners are concealed in order to protect them from the atmosphere and to avoid corrosion.

Although simple roofing sheets may provide a weathertight covering, it is typically required to insulate the roof so produced. This is achieved by means of a multi-layer roof structure which commonly comprises an internal nonstructural supporting layer (which is often visible from the interior of the building) which is overlaid with a vapour barrier layer. A layer of insulating material is provided over the vapour barrier layer, and the structural external roofing sheets are fixed in place over the insulating layer. Since the exterior will often be colder than the interior of the building, steps must be taken to stop moist air inside the building from causing condensation on the roof, which can then drip back inside the building. In this sort of roof structure, this is achieved by the provision of the above insulation and vapour barrier layers.

Roof structures which comprise separate component layers have disadvantages in complexity of construction and installation as further described below. In order to overcome some of these disadvantages, roof structures comprising composite panels have also been provided. These panels are generally in the form of integral units composed of three layers: a first sheet member forming the external face (with respect to the building) of the panel when in place, an insulating layer, and a second sheet member forming the internal face of the panel when in place. Each of these parts has a particular function, as outlined below.

The first sheet member must protect against the weather.

It must also provide mechanical strength to the panel so as to be able to withstand, for example, a heavy snow fall laying on the roof, and occasional foot traffic for maintenance purposes.

The insulating layer must provide thermal insulation between the interior of the building and the first sheet member. The first sheet member will be exposed to outdoor temperatures and conditions. Since it is typically made of metal, the first sheet member is highly thermally conductive and the insulating layer serves to minimise heat transfer into or out of the building through the roof. The interior of the roofed building is likely to be heated, at least in winter, and in these circumstances the first sheet member will be relatively cold with respect to the second sheet member. In the summer, or in hotter climates, the first sheet member may be heated by the sun so that it is relatively warmer than the second sheet member and it is usually desired to protect the interior of the building from such heating.

The second sheet member is required to protect the insulating layer, which is often of fragile, lightweight material, to improve the aesthetic appearance of the internal surface of the roof, which will often be exposed to the occupants of the roofed building, and also to provide a vapour barrier to protect the insulating material from moisture originating inside the building.

The insulating layer is often composed of a foam or fibrous material. Such material must be kept dry in order to function effectively as a thermal insulator.

A particular problem with composite panels is that relatively warm moist air from inside the building (of which the panels form the roof or wall) is able to enter any gap formed at the joint between adjacent panels. In cold weather, the first sheet members of the panels are colder than the interior of the building. This causes the moisture in the air which has penetrated into the joints to condense onto the panels and to drip back into the building. Also, if the condensed vapour penetrates into the insulating material, the insulating material may lose its insulating properties.

It is therefore essential to provide an effective vapour barrier or seal, in order to prevent moisture from inside the building from reaching the insulating layer or from penetrating towards the first (external) sheet member.

Although various methods have been suggested to provide vapour seals between adjacent panels to prevent the ingress of warm, moist air, many have not been sufficiently effective and this is one problem addressed by the present invention.

The conventional method of securing composite panels to a supporting structure has been to drill through the panel and to leave the fixing exposed to the environment where it is subject to corrosion. A cover piece, such as a metal cap may be fitted over the particular area where the fixings are located, in order to conceal them. Although the metal cap may protect the fixings from the environment, an additional on-site operation is required in fitting the cap and the cap has a tendency to fall off over time. The improved appearance of the panel achieved by concealing the fasteners and the protection of the fixings from the weather depend on the integrity of attachment of the metal cap and this is not wholly reliable.

One design of composite panel is illustrated in US 4 196 554 in which a first formation on a first panel is deformed into engagement with a second formation of an adjacent panel, to join the panels together. Sealing material is provided between the formations. Also complementary mating elements are also provided along the sides of the panels in the form of a projecting tongue on a first panel which enters a corresponding channel of an adjacent second panel. A particular problem with the design of US 4 196 554 lies in the way in which the adjacent panels are secured to the structural support since the fastening means act directly on the exposed insulating material in the region of the joint between the panels. This construction cannot achieve the required strength to combat uplift on the panels caused by wind since the fixing is reliant on the strength of the insulating material only, which will tend to shear from the region of the fixing.

Accordingly, the present invention seeks to provide a composite panel, in particular for roofing or cladding, having one or more of the following advantages, that is: providing excellent weather-proofing, allowing concealed fixing to the supporting structure, requiring the minimum of on-site operations during installation of the panel and providing an effective vapour seal to prevent moisture penetration between adjacent panels from within the building.

According to a first aspect of the present invention there is provided a panel comprising: -first and second sheet members forming respective major external surfaces of the panel; -an insulating layer located between the first and second sheet members, -first and second minor faces extending respectively between the first and second sheet members, -first and second engagement formations formed along opposed marginal portions of the first sheet member, -each of the first and second formations being of a first type or a second type, -a securing surface formed integrally with the first or second engagement formation, which surface may operatively cooperate with securing means to secure the panel to a supporting structure, -a resilient sealing material disposed along the length of the panel adjacent a corner formed between the second sheet member and a minor face, wherein -on placing first and second panels adjacent one another such that their respective first and second minor faces are in juxtaposition, a first-type formation of the first panel may operatively be deformed into engagement with a second-type formation of the second panel and wherein the sealing material is thereby brought into compression between the second sheet members of the adjacent panels, to form a seal between the panels.

In a particularly preferred form of this aspect of the invention, the first and second co-operating formations of adjacent panels, when engaged, define a closed void including a securing surface.

In another preferred form of this aspect of the invention the first type of formation comprises a wall portion upstanding from the first sheet member and an enlarged head part formed at the end of the wall portion distant from the first sheet member.

In a particularly preferred construction according to this aspect of the invention, the second type of formation includes a concave portion adapted to receive and retain the enlarged head portion of the first type of formation.

In one form of this construction, on engagement with the enlarged head portion, the concave portion is resiliently deformed by the enlarged head portion from a rest condition to an expanded condition and resiliently returns substantially to the rest condition when the enlarged head portion is fully received therein.

In another form of this construction, the concave portion is adapted to receive the enlarged head portion is operatively non-resiliently deformable from a relatively expanded condition to a relatively contracted condition in order to retain the enlarged head portion.

In particularly preferred embodiments of this aspect of the invention, the panel further comprises: -an outwardly extending lip formed continuously along the length of the panel at each marginal portion of the second external sheet member which is adjacent a formation of first type; and -a lip receiving portion extending continuously along the length of the panel at each marginal portion of the second external sheet member which is adjacent a formation of the second type; and wherein the resilient sealing material is disposed continuously along the outwardly extending lip and/or along the lip receiving portion.

According to a second aspect of the present invention there is provided a panel comprising: -first and second sheet members forming respective major external surfaces of the panel; -an insulating layer located between the first and second sheet members; -first and second minor faces extending respectively between the first and second sheet members; -first and second engagement formations disposed along opposed marginal portions of the first sheet member -a resilient sealing material disposed along a length of the panel adjacent a corner formed between the second external sheet member and a minor face, whereby -a resilient sealing material disposed along a length of the panel adjacent a corner formed between the second external sheet member and a minor face, whereby -on assembly of first and second panels adjacent one another such that their respective first and second minor faces are in juxtaposition, a first engagement formation of the first panel and an adjacent second engagement of the second panel may respectively be brought into engagement with corresponding formations of a cover piece and the sealing material is brought into compression between the second sheet members of the adjacent panels, thereby to form a seal.

In particularly preferred forms of this aspect of the invention the panel further comprises a securing surface formed integrally with the first or second engagement formation which surface may operatively cooperate with securing means to secure the panel to a supporting structure. Most preferably, the first and second engagement formations of adjacent panels and the securing surface define, together with the cover piece, a closed void.

In particularly preferred embodiments of this aspect of the invention the panel further comprises an outwardly extending lip formed continuously along the length of the panel at a first marginal portion of the second external sheet member and a lip receiving portion extending continuously along the length of the panel at a second marginal portion of the second external sheet member opposed to the outwardly extending lip and wherein the resilient sealing material is disposed continuously along the outwardly extending lip and/or along the lip receiving portion.

In the first and second aspects of the invention, it is especially preferred that the outwardly extending lip projects in a direction substantially parallel to the second sheet member. It is also preferable that a face of the outwardly extending lip is contiguous with the second external sheet member.

In further preferred constructions of the first and second aspects of the invention, the lip receiving portion comprises a rebate along an edge of the second external sheet member. Most preferably, the rebate is so sized as to allow the second external sheet members of adjacent panels to lie flush when the outwardly extending lip of a first panel lies in the rebate of a second adjacent panel.

The insulating material preferably comprises a flexible cellular foam such as EPDM, polyurethane foam, or suitable polyethylene foams.

In preferred embodiments of the present invention, the first and second sheet members are composed of one or more of steel, aluminium, a plastic or a plastics composite, or a resinous composite.

According to a third aspect of the invention, a roof structure comprises a plurality of panels as hereinabove defined.

Preferably, the roof structure of the invention comprises a plurality of panels secured with fasteners to form a roof surface. Each fastener has a head portion which engages a respective securing surface of a panel and an engagement portion which engages a supporting structure thereby to retain the panels in position. Each head portion is preferably disposed within a closed void.

According to a fourth aspect of the invention, a wall cladding structure comprises a plurality of panels as described.

Preferably the wall cladding structure of the invention comprises a plurality of panels secured with fasteners to form a wall surface. Each fastener has a head portion which engages a respective securing surface of the panel and an engagement portion which engages a supporting structure thereby to retain the panels in position. Each head portion is preferably disposed within a closed void.

A particular advantage of the panel of the present invention is that the sealing material can be applied to the panel in the factory and so an additional on-site operation is avoided. This can ease installation and provide a more reliable vapour seal. Furthermore, because the sealing material is resilient and is placed in compression, a greatly improved seal is achieved, which does not deteriorate over time.

For a better understanding of the invention and to show how the same may be carried into effect, reference will be made, by way of example only, to the following drawings (which are not drawn to scale), in which: Figure 1A is a schematic cross-sectional view of an example of a prior art fastening technique for conventional panels; Figure 1B is a cutaway perspective view of a part of a roof structure, including roof panels as shown in figure 1A ; Figure 1C illustrates a prior art panel as described in US 4 196 554; Figures 2 and 3 are schematic cross-sectional views of examples of prior art fastening techniques for composite panels; Figures 4A and 4B are transverse sections through panels according to a first embodiment of the first aspect of the invention; Figures 5A and 5B are transverse sections through panels according to a second embodiment of the first aspect of the invention; Figures 6A and 6B are transverse sections through panels according to a first embodiment of the second aspect of the invention; Figures 7A and 7B are transverse sections through panels according to a second embodiment of the second aspect of the invention; and Figures 8A and 8B are transverse sections through panels according to a third embodiment of the second aspect of the invention.

Referring now to Figure 1A, the panels 11, lla include complementary hook-like formations 12,12a and 14,14a which are adapted to engage around clips 16. The clip 16 includes an enlarged head portion 18 about which formations 12,14a (in the embodiment illustrated) are seamed. That is, the formations 12,14a are deformed into tight engagement around the head portion 18. Each clip has a short length of, say, 5cm and several clips are provided along the length of each panel 11, lla. The clips 16 are attached to the supporting structure 20, such as spaced apart purlins, by fasteners 22, such as nails, bolts and screws.

Figure 1B shows a roof structure including such panels. In addition to roof panels 11, lla the roof structure requires an insulating material 24 and a vapour barrier layer 26. A non-structural supporting layer or liner sheet 28 is required to support the insulating material and vapour sealing layer. Such a roof construction has numerous disadvantages. Many separate components are required, which have to be assembled on top of the building being roofed, often in adverse conditions. In particular, for cost and weight considerations, the supporting layer 28 is not strong enough to support a person's weight. However, accidents can occur due to construction workers stepping onto the liner sheet while assembling the roof.

The vapour barrier layer 26 takes the form of a plastic sheet applied over the supporting layer 28. Problems with this include difficulty in handling when on top of a building, but more importantly, in order to form the barrier layer numerous individual sheets of vapour sealing liner material need to be joined together in situ in a watertight manner. This involves applying a waterproof adhesive tape to attach the sheets together. Such a method is unsatisfactory, since it relies upon manual application of the tape in difficult circumstances. It is not uncommon for such taped seals to be incorrectly applied or to become unstuck after a short service life, rendering the vapour barrier layer 26 ineffective.

Next, clips 16 are attached with fasteners 22. Again, this operation must be carried out with only the supporting layer 28 and the vapour barrier layer 26 covering the roof.

These layers will not support a person's weight, but the need to attach clips 16 over the surface of the roof structure invites accidents and damage to the vapour barrier layer by workers stepping on the liner sheet 28.

Insulating material 24 must then be applied to the roof.

This is commonly in the form of either foam blocks or strips, or a felt or fibrous material. In either case, large pieces of lightweight material are hard to handle in situ if there is any wind. Also, felt type insulating material has a tendency to compact, and slip, reducing its thermal insulation properties over a period of years.

Finally, the roofing panels 11 are applied. This must also be performed without stepping on the adjacent thermal insulation, vapour seal and liner sheet structure. Panels need to be"zipped"together by deforming the hook portions 14 as described with reference to figure 1A.

Overall, construction of such a roof is very complex, requiring intensive labour, and providing many opportunities for failure. The likelihood of faults developing in such a roof is increased by the adverse conditions that may be experienced during assembly of the roof, and possible errors committed by unskilled workers assembling the roof.

Many of the disadvantages of the roofing structure of figure 1B can be alleviated by the use of composite roofing panels.

The applicant has considered adapting a separate clip of the type illustrated in Figure 1A for use with composite panels. However, in order to accommodate a vapour seal it would be necessary to make the clip 18 continuous along the length of the panel 11, lla. Two adhesive vapour seals could then be manually applied, one between each respective side face of the upright portion of the clip and the side face of the adjacent panel. It is believed that such a solution would be prohibitively expensive and impractical in use and unlikely to provide an adequate vapour seal.

In Figure 1C, the panel as described in US 4 196 554 has first and second outer skins F, S and insulating material I.

Adjacent panels are secured together by means of formations E, tongue T and channel C. Panels are secured to the structural support (not illustrated) by fastening means N.

In Fig. iC, the general direction of wind uplift is indicated by arrow W. As indicated, because of the nature of the fastening of the panels to the structural support, the panels will shear, under wind uplift, in region X.

In Figure 2 there is shown a fastening technique for composite panels in which a vapour seal is provided. Each panel 41,41a includes a formation 42 which is adapted to overlap an adjacent panel. A vapour seal 44 is provided between the adjacent panels. The panels 41,41a are secured to the supporting structure 46 directly by fasteners such as screws, nails or bolts illustrated at 48.

The fasteners remain exposed to the atmosphere and are commonly subject to corrosion. Also, the vapour seal achieved by this technique is often inadequate, since the vapour seal is applied as a separate component, and accuracy of on-site installation cannot be guaranteed.

Further, the vapour seal component may work loose, or shrink, over several years'use. Any of these effects will spoil the effectiveness of the vapour seal.

Figure 3 illustrates a further prior art technique for attaching composite panels in which the panels 51,51a lie adjacent one another but do not overlap. The panels 51, 51a are secured to the supporting structure 52 directly by means of fastenings 54 which may suitably be screws, nails or bolts. The fasteners 54 are covered by a metal cap 56 and a vapour seal 58 is provided between adjacent panels.

The metal cap 56 may become dislodged over time, exposing the fasteners 54 to the atmosphere so that they may corrode, and the vapour seal 58 is, again, often inadequate at least for the reasons discussed with reference to figure 2.

Figures 4A and 4B illustrate panels according to a first embodiment of the first aspect of the invention. Panel 61 comprises first and second sheet members 62,64 and an insulating layer 66 between the sheet members. Insulating layer 66 terminates at or close to respective edges 68,70 of the panel. First and second co-operating formations 72, 74 depend from the first sheet member 62 at opposed marginal portions thereof, that is, towards opposite side edges and extend continuously along the length of the panel 61.

Insulating layer 66 may comprise a polyurethane foam. The sheet members may be made from any suitable material, although steel or aluminium is preferred. The thickness T of the major portion of the panel may be selected as desired in accordance with the panel's desired use.

Similarly, the effective width W of the panel may be selected as desired.

An outwardly extending lip 75 is formed along a marginal portion of the second sheet member 64 of the panel 61 and extends continuously along the length of the panel 61. The lip 75 includes a face 77 which is contiguous with second sheet member 64 and an opposite face 76 along which a layer of resilient sealing material 78 is formed. At a marginal portion of the second sheet member 64 opposite the lip 75, a lip receiving portion 80 is formed. The lip receiving portion 80 will generally have a width Wlr of between 10mm and 40mm and be in the form of a rebate along the edge of the second sheet member 64. The lip receiving portion 80 is sized to accommodate the lip 75 of an adjacent panel, such that the face 77 of the lip 75 of a first panel may, in use, be substantially flush with outer surface 82 of the second sheet member 64 of the adjacent panel.

The first co-operating formation 72 comprises a post 84 and an enlarged head portion 86. The post 84 includes upstanding wall portions 88b, 88c which extend approximately at right angles to the first sheet member 62, and the enlarged head portion 86 forms an approximately cylindrical hook receiving formation.

The first co-operating formation 72 further includes a valley 94. The floor 96 of the valley 94 is approximately parallel to the first sheet member 62, effectively forming part of first sheet member 62. The floor 62 may optionally continue to form an upwardly directed part 98.

The second co-operating formation 74 comprises a hook part 90 and an upstanding wall part 92 which is approximately at right angles to the first sheet member 62.

The second co-operating formation 74 further includes a fastening cover part 100. In the embodiment illustrated, the fastening cover part 100 comprises an upstanding wall part 100b and a laterally extending part 100c. Upstanding part 100b is so sized as to ensure that extending part 100c is at or above the height of end 98e of upwardly directed part 98. Laterally extending part 100c effectively extends the width of the upper surface of the first sheet member 62 for a distance approximately equal to the width of the valley 94. The fastening cover part 100 may take the form of a step, as shown in Figure 4A, or a slope, an arc or any suitable form. The fastening cover part 100 is shaped to cover the valley 94 and any upwardly directed part 98 of an adjoining panel when assembled, as will be described below in relation to Figure 4B.

In a variation of the embodiment, the resilient sealing material 78 may alternatively or additionally be disposed along the lip receiving portion 80. Ribs 102 may be formed in the first and second external sheet members 62,64 for additional strength and rigidity.

Figure 4B illustrates the assembly of two panels such as shown in figure 4A, by the joining together of the first and second co-operating formations. In figures 4A and 4B the same reference numerals have been used except that in Figure 4B for the"adjoining"panel, the suffix"a"has been added to each reference numeral.

As illustrated, the first panel 61 is mounted on a suitable supporting structure 110, such as suitably spaced apart purlins, and is secured thereto by suitable fasteners 112.

The second, adjoining, panel 61a is then mounted adjacent to the first panel with the hook part 90a of the second cooperating formation 74a placed over the hook receiving formation (enlarged head portion) 86 of the first panel.

The hook part 90a is then deformed by use of a suitable tool, thereby to engage the hook receiving formation 86.

First and second panels are thereby assembled together. By this assembly, the sealing material 78 is compressed between second external sheet members of the two panels, forming a vapour seal between the inner sheet members of the panels. Compression of the sealing material may be brought about either by applying pressure during the assembly of the panels, or by careful design of the cooperating formations 72,74a, so as to exert downward pressure by the second panel 61a when the hook part 90a is deformed to engage hook receiving portion 86 of first panel 61.

Thus, the sealing material 78 is compressed between the lip 75 and the recess 80a, thereby forming an effective vapour seal.

As shown in Figure 4B, an enclosed void or space 114 is defined by upstanding wall portion 88b, valley floor 96, upwardly directed part 98, and fastening cover parts 100b and 100c. This space 114 is not open to the atmosphere and accordingly protects the fasteners 112 and joints between panels 61,61a from the effects of the weather. In preferred embodiments of the invention, the panels 61,61a are secured to the supporting structure 110 by fasteners 112 which act on valley floor 96 which serves as a securing surface. In this way, the fasteners are not exposed to the environment and are protected from the corrosion-causing effects of the weather. Also, concealment of the fasteners is aesthetically more pleasing. The fasteners 112 may be any suitable fasteners, although self tapping or self drilling and tapping screws are preferred. Further panels may be assembled adjacent to the second panel 61a, in a similar manner.

Figures 5A and 5B illustrate panels according to a second embodiment of the first aspect of the invention. Panel 561 comprises first and second sheet members 562,564 and an insulating layer 66 between the sheet members. Insulating layer 66 terminates at or close to respective edges 568,570 of the panel. First and second co-operating formations 572, 574 depend from the first sheet member 562 at opposed marginal portions thereof, that is, towards opposite side edges and extend continuously along the length of the panel 561. The panel 561 of the second embodiment is similar in many respects to the panel 61 of the first embodiment.

Accordingly, only differences between first and second embodiments will be described in detail.

The first co-operating formation 572 c

The second co-operating formation 574 further includes a fastening cover part 500. In this embodiment, the fastening cover formation takes the form of a slope, but any suitable form could be used.

Figure 5B illustrates the assembly of two panels such as shown in figure 5A, by the joining together of the first and second co-operating formations. In figures 5A and 5B the same reference numerals have been used except that in Figure 5B for the"adjoining"panel, the suffix"a"has been added to each reference numeral.

As illustrated, the first panel 561 is mounted on a suitable supporting structure 110, such as suitably spaced apart purlins, and is secured thereto by suitable fasteners 112. The second, adjoining, panel 561a is then mounted adjacent to the first panel with the hook part 590a of the second co-operating formation 574a placed over the hook receiving formation (enlarged head portion) 586 of the first panel. A generally downward pressure is then applied to the hook 590a so that it is resiliently deformed during engagement with the first co-operating formation 572. In particular, the hook 590a is deformed by opening somewhat outwardly and engages the first co-operating formation 572 of the first panel 561 by snap fitting around the hook receiving formation 586 so that it regains approximately its original configuration. First and second panels are thereby assembled. By this assembly, the sealing material 78 is compressed between second sheet members of the two panels, forming a vapour seal between the sheet members of the panels. Compression of the sealing material may be brought about either by applying pressure during the assembly of the panels, or by careful design of the cooperating formations 572,574a, so as to exert downward pressure by the second panel 561a when the hook 590a is resiliently deformed to snap fit onto hook receiving portion 586 of first panel 561. Further panels may be assembled adjacent to the second panel 551a in a similar manner.

Thus, the sealing material 78 is compressed between the lip 75 and the recess 80a, thereby forming an effective seal.

As shown in Figure 5B, an enclosed void or space 514 is defined by upstanding wall part 588b, valley floor 596, upwardly directed part 598, and fastening cover part 500a.

Figures 6A and 6B show panels according to a first embodiment of the second aspect of the present invention.

Features corresponding to features of preceding figures carry corresponding reference labels.

Panel 661 comprises first and second external sheet members 662,664 and an insulating layer 66 between the sheet members. Insulating layer 66 terminates at. or close to respective edges 668,670 of the panel. First and second engagement formations 672,674 depend from the first external sheet member 662 at opposed marginal portions thereof, that is, towards opposite side edges and extend continuously along the length of the panel 661.

Similarly, the effective width W of the panel may be selected as desired.

An outwardly extending lip 75 is formed along a marginal portion of the second sheet member 664 of the panel 661 and extends continuously along the length of the panel 661.

The lip 75 includes a face 77 which is contiguous with second sheet member 664 and an opposite face 76 along which a layer of resilient sealing material 78 is formed. At a marginal portion of the second sheet member 664 opposite the lip 75, a lip receiving portion 80 is formed. The lip receiving portion 80 will generally have a width Wlr of between 10mm and 40mm and be in the form of a rebate along the edge of the second sheet member 664. The lip receiving portion 80 is sized to accommodate the lip 75 of an adjacent panel, such that the face 77 of the lip 75 of a first panel may, in use, be substantially flush with outer surface 682 of the second external sheet member 664 of the adjacent panel.

In a variation of the embodiment, the resilient sealing material 78 may alternatively or additionally be disposed along the lip receiving portion 80. Reinforcement or strengthening ribs 102 may be formed in the first and second external sheet members 662,664 for additional strength and rigidity.

Each of first and second engagement formations 672,674 comprises an engagement rib in the first sheet member 662, each including an inwardly directed shoulder 622,624 located in the side of the rib furthest from the adjacent edge of the panel.

A valley floor part 696 is formed adjacent to the first cooperating formation 672. The valley floor 696 is approximately parallel to the first sheet member 662 and effectively forms a continuation of the first sheet member 662. The valley floor 696 may optionally continue to form an upwardly directed part 698.

Figure 6B illustrates the assembly of two panels using the first and second engagement formations. In Figures 6A and 6B the same reference numerals have been used except that in Figure 6B for the"adjoining"panel, the suffix"a"has been added to each reference numeral.

As illustrated, the first panel 661 is mounted on a suitable supporting structure 110, such as suitably spaced apart purlins. Lip 75 carrying the sealing material 78 is located above the supporting structure 110. The second panel 661a is then mounted adjacent to the first panel with the lip receiving portion 80a located upon the sealing material 78. The panels are located close together such that one minor surface 670 of first panel is located as close as possible to a minor surface 668a of the second panel. First and second panels are secured to the supporting structure by suitable fasteners 112 and are thereby assembled together. By this assembly, the sealing material 78 is compressed between second external sheet members of the two panels, forming a vapour seal between the inner sheet members of the panels. Compression of the sealing material may be brought about either by applying pressure during the assembly of the panels (tightening of fasteners 112), or by application of downward pressure on panel 661a during tightening of fasteners 112.

A cover piece 128 is then applied over the engagement formations 672a, 674. The cover piece includes a cover portion 130 and hook portions 132. Hook portions 132 engage shoulders 624 and 622a in a snap fit. Small screws 134 may optionally be applied to retain the cover portion 128 in place.

As shown in Figure 6B, the valley floor 696, and engagement formations 672a, 674 form a valley 694. With cover piece 128, they form an enclosed void or space 614. This space is not open to the atmosphere and accordingly is protected from the effects of the weather. In preferred embodiments of the invention, the panels 661,661a are secured to the supporting structure 110 by fasteners 112 which act on valley floor 696 which serves as a securing surface. In this way, the fasteners are not exposed to the environment and are protected from the corrosion-causing effects of the weather. Also, concealment of the fasteners is more aesthetically pleasing. The fasteners 112 may be any suitable fixing means, although self tapping or self drilling and tapping screws are preferred. Further panels may be assembled adjacent to the second panel 661a in a similar manner.

Figures 7A and 7B show panels 761,761a according to a second embodiment of the second aspect of the present invention. Features corresponding to features of figures 6A and 6B carry corresponding reference labels.

In the first embodiment of the second aspect of the invention, as shown in figure 6B, fasteners 112 pierce the sealing material 78. This may be unacceptable in certain cases, dependant on the sealing material and/or the fixing means employed. The second embodiment of the second aspect of the invention avoids these inconveniences. Only differences with respect to the first embodiment of the second aspect will be described.

As shown in Figure 7A, an extension part 797 is formed adjacent to first engagement formation 772 and an extension support part 736 is formed adjacent to second engagement formation 774. The extension part 797 continues beyond the corresponding edges of the second external sheet member 764 and the insulating layer 66, approximately parallel to the first external sheet member 762. The extended part is preferably slightly displaced upward to form a rebate along the edge of the first external sheet member 762. The extended part 797 is sized to accommodate the extended part support 736 of an adjacent panel, and may optionally continue to form an upwardly directed part 798.

Figure 7B illustrates the assembly of two panels as shown in Figure 7A, using the first and second engagement formations. In Figures 7A and 7B the same reference numerals have been used except that in Figure 7B for the "adjoining"panel, the suffix"a"has been added to each reference numeral.

As illustrated, the first panel 761 is mounted on a suitable supporting structure 110, such as suitably spaced apart purlins. Lip 75 carrying the sealing material 78 is preferably located upon the supporting structure 110, with parts of the insulating layer 66 and extended part support 736 also overlying the supporting structure 110. The second panel 761a is then mounted adjacent to the first panel with the lip receiving portion 80a located upon the sealing material 78. The panels are located close together such that one minor surface 770 of first panel is located as close as possible to a minor surface 768a of the second panel. Extended part 797 of the second panel overlies the extended part support 736 of the first panel. First and second panels are secured to the supporting structure by suitable fasteners 112 and are thereby assembled together.

By this assembly, the sealing material 78 is compressed between second external sheet members 764,764a of the two panels, forming a vapour seal between the inner sheet members of the panels. Compression of the sealing material may be brought about either by applying pressure during the assembly of the panels (by tightening fasteners 112), or by application of downward pressure on panel 761a while tightening fasteners 112. The panels are held in this compressive relationship by the fasteners.

Cover piece 128 is then applied over the co-operating formations 772a, 774 as discussed with reference to the corresponding parts in figure 6B.

Figures 8A and 8B show panels 861,861a according to a third embodiment of the second aspect of the invention.

Features corresponding to features shown in earlier figures carry corresponding reference labels.

In the first embodiment of the second aspect of the invention, as shown in figure 6B, first sheet members 662, 662a of the adjacent panels do not overlap. This could lead to mechanical weakness of the final structure, causing the cover parts 128 to become detached from the roof. In addition, the absence of overlap between the first external sheet members could potentially provide a route for infiltration of water from the external roof surface. The third embodiment of this aspect of the invention avoids these inconveniences, and only differences with respect to the first embodiment will be described in detail.

As shown in Figure 8A, an extension part 897 is formed adjacent to second engagement formation 874 and an extended part support 836 is formed adjacent to first engagement formation 872. The extension part 897 continues beyond the corresponding edge 870 of the insulating layer 66, for a distance approximately equal to the width of the lip 75.

The extension part 897 extends approximately parallel to the first sheet member 862, but is preferably offset from the nominal plane of the first sheet member by an amount at least equal to the thickness of the first sheet member.

The extension part 897 is sized and spaced above lip 75 to accommodate the full thickness of an adjacent panel at the lip receiving portion 80, and may optionally continue to form an upwardly directed part 898.

Figure 8B illustrates the interlocking of two panels using the first and second co-operating formations. In Figures 8A and 8B the same reference numerals have been used except that in Figure 8B for the"adjoining"panel, the suffix"a" has been added to each reference numeral.

As illustrated, the first panel 861 is mounted on a suitable supporting structure 110, such as suitably spaced apart purlins. Lip 75 carrying the sealing material 78, and extension part 897 are located above the supporting structure 110. The second panel 861a is then mounted adjacent to the first panel with the lip receiving portion 80a located upon the sealing material 78, and the extension part support 836 located under the extension part 897. The panels are located close together such that one minor surface 870 of first panel is located as close as possible to a minor surface 868a of the second panel. First and second panels are secured to the supporting structure by suitable fasteners 112 and are thereby assembled together.

By this assembly, the sealing material 78 is compressed between second sheet members 864,864a of the two panels, forming a vapour seal between the inner sheet members of the panels. Compression of the sealing material may be brought about either by applying pressure during the assembly of the panels (tightening of fasteners 112), or by application of downward pressure on panel 861a during tightening of fasteners 112.

Cover piece 128 is then applied as discussed with reference to the corresponding part in figure 6B.

In embodiments of the present invention where fasteners 112 do not traverse the sealing material 78, it may be advantageous to apply a sealing compound between the support structure 110 and the second sheet member 64,564, 764 of the first panel, in the region chosen for application of fasteners 112, before mounting the first panel.

All embodiments of the present invention provide a composite panel for roofing or wall cladding applications.

Each panel has a resilient sealing material applied along the length of the panel, which is compressed between second sheet members of adjacent composite panels during assembly of the roof or wall cladding, to provide a simple, effective vapour seal. In all cases, the fixings used to attach the panels to the roof or wall structure are completely enclosed, protecting them and the adjacent parts of the composite panel from corrosion.

The advantages of the invention reside in efficiency of the vapour seal. No unreliable on-site application is required. The seal is under compression, so will not work loose or shrink such that it becomes ineffective.

Furthermore, the protection of the fixing means from corrosion further ensures the long life of roof structures or wall cladding made from such panels.

The invention thereby provides improved roof structures and wall cladding structures, with improved vapour seal properties, and longer service life.

All of the embodiments described have been described in relation to asymmetric panels, having a complementary inter-engaging regions on opposite edges. However, the invention may be applied to symmetrical panels, which have identical inter-engaging regions on opposite edges. In the case of symmetrical panels, at least two different types of panels will be needed to assemble a roof or wall structure.

For example, a first panel having a first type of interengaging region, on each edge must be placed adjacent to a second panel having a second type of inter-engaging region 74, at least on the adjacent edge. If the second panel is a symmetrical panel, it will have another second type of inter-engaging region on its non-adjacent edge. If the second panel is an asymmetrical panel, it will have a inter-engaging region of the first type on its non-adjacent edge. Provided that adjacent edges of adjacent panels always include one of first type of inter-engaging region 72 and one of second type of formation, symmetrical and asymmetrical panels may be mixed as desired.

Claims

Claims 1. A panel comprising: -first and second sheet members forming respective major external surfaces of the panel; -an insulating layer located between the first and second sheet members, -first and second minor faces extending respectively between the first and second sheet members, -first and second engagement formations formed along opposed marginal portions of the first sheet member, -each of the first and second formations being of a first type or a second type, -a securing surface formed integrally with the first or second engagement formation, which surface may operatively cooperate with securing means to secure the panel to a supporting structure, -a resilient sealing material disposed along the length of the panel adjacent a corner formed between the second sheet member and a minor face, wherein -on placing first and second panels adjacent one another such that their respective first and second minor faces are in juxtaposition, a first-type formation of the first panel may operatively be deformed into engagement with a second-type formation of the second panel and wherein the sealing material is thereby brought into compression between the second sheet members of the adjacent panels, to form a seal between the panels.
2. A panel as claimed in claim 1 wherein the first and second co-operating formations of adjacent panels, when engaged, define a closed void including the securing surface.
3. A panel as claimed in claim 1 or 2 wherein the first type of formation comprises a wall portion upstanding from the first sheet member and an enlarged head part formed at the end of the wall portion distant from the first sheet member.
4. A panel as claimed in claim 3 wherein the second type of formation includes a concave portion adapted to receive and retain the enlarged head portion of the first type of formation.
5. A panel as claimed in claim 4 wherein, on engagement with the enlarged head portion, the concave portion is resiliently deformed by the enlarged head portion from a rest condition to an expanded condition and resiliently returns substantially to the rest condition when the enlarged head portion is fully received therein.
6. A panel as claimed in claim 4 in which the concave portion adapted to receive the enlarged head portion is operatively non-resiliently deformable from a relatively expanded condition to a relatively contracted condition in order to retain the enlarged head portion.
7. A panel as claimed in any preceding claim, further comprising: -an outwardly extending lip formed continuously along the length of the panel at each marginal portion of the second external sheet member which is adjacent a formation of first type; and -a lip receiving portion extending continuously along the length of the panel at each marginal portion of the second external sheet member which is adjacent a formation of the second type; and wherein the resilient sealing material is disposed continuously along the outwardly extending lip and/or along the lip receiving portion.
8. A panel comprising: -first and second sheet members forming respective major external surfaces of the panel; -an insulating layer located between the first and second sheet members; -first and second minor faces extending respectively between the first and second sheet members; -first and second engagement formations disposed along opposed marginal portions of the first sheet member -a resilient sealing material disposed along a length of the panel adjacent a corner formed between the second external sheet member and a minor face, whereby -on assembly of first and second panels adjacent one another such that their respective first and second minor faces are in juxtaposition, a first engagement formation of the first panel and an adjacent second engagement of the second panel may respectively be brought into engagement with corresponding formations of a cover piece and the sealing material is brought into compression between the second sheet members of the adjacent panels, thereby to form a seal.
9. A panel as claimed in claim 8 further comprising a securing surface formed integrally with the first or second engagement formation which surface may operatively cooperate with securing means to secure the panel to a supporting structure.
10. A panel as claimed in claim 9 wherein the first and second engagement formations of adjacent panels and the securing surface define, together with the cover piece, a closed void.
11. A panel as claimed in claim 8,9 or 10, further comprising an outwardly extending lip formed continuously along the length of the panel at a first marginal portion of the second external sheet member and a lip receiving portion extending continuously along the length of the panel at a second marginal portion of the second external sheet member opposed to the outwardly extending lip and wherein the resilient sealing material is disposed continuously along the outwardly extending lip and/or along the lip receiving portion.
12. A panel as claimed in claim 7 or 11 wherein the outwardly extending lip projects in a direction substantially parallel to the second external sheet member.
13. A panel as claimed in any of claims 7,11 and 12 wherein a face of the outwardly extending lip is contiguous with the second external sheet member.
14. A panel as claimed in any of claims 7 and 11 to 13 wherein the lip receiving portion comprises a rebate along an edge of the second external sheet member.
15. A panel as claimed in claim 14 wherein the rebate is so sized as to allow the second external sheet members of adjacent panels to lie flush when the outwardly extending lip of a first panel lies in the rebate of a second adjacent panel.
16. A panel as claimed in any preceding claim wherein the first and second external sheet members are composed of one or more of steel, aluminium, a plastic, a plastics composite, or a resinous composite.
17. A panel substantially as described with reference to, or a panel substantially as illustrated in any of, Figures 4A to 8B.
18. A roof structure comprising a plurality of panels according to any preceding claim.
19. A wall cladding structure comprising a plurality of panels according to any of claims 1-17.