GB2374878A

GB2374878A - Composite panel for curved roofs or walls

Info

Publication number: GB2374878A
Application number: GB0110165A
Authority: GB
Inventors: Holdings Limited Talfab; Peter Taylor
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-04-26
Filing date: 2001-04-26
Publication date: 2002-10-30
Also published as: GB0110165D0

Abstract

A composite panel (10) for curved roofs or walls comprises a first (outer) sheet member (30), a second (inner) sheet member (50) and an insulating material (70) disposed between the sheet members. The second sheet member includes a plurality of transverse recesses or grooves (52) which accommodate the curvature of the panel and prevent delamination of the second sheet member.

Description

Composite Panel for Curved Roofs and Walls The present invention relates to roof panels, and more particularly to composite roof panels which can accommodate a degree of curvature. Although described herein as roof panels, the panels of the invention can also be suitable for wall construction.

Composite roofing panels for the construction of roofs are well known and have many advantages, such as ease and speed of application at the building site, and excellent insulation properties. Generally the panels comprise an inner (often nonstructural) liner, which may be a metal (e. g. steel) sheet and an outer (structural) sheet metal web which may be of steel or aluminium, for example. In the void between the inner liner and the outer sheet metal web, an insulating material is provided. The insulating material is provided during the manufacture of the panels and commonly comprises an insulating foam such as a polyurethane or a polyisocyanate foam which is adherent to the liner and the sheet metal web. The outer sheet metal web may be profiled for increased strength and rigidity and normally includes connecting means, such as interlocking formations, by which adjacent panels are joined together to provide a watertight outer roof surface.

Individual panels are fixed to an underlying support structure, such as roof purlins, by suitable fixing means, such as self tapping screws.

An earlier technique of providing insulated roofs comprised mounting liner sheets directly onto the underlying support structure, attaching fixing brackets (through the liner sheets) to the underlying support structure, applying insulation material onto the liner sheets and around the fixing brackets and finally attaching exterior metal sheeting to the fixing brackets. This technique is disadvantageous, as compared with composite panels, because of the number of construction operations which are required on-site. In contrast, composite panels are manufactured to include all three layers (liner, insulation, exterior sheet) so that fewer on-site operations are required.

For modern buildings, there is an increasing demand for so-called barrel-vault roofs in which the roof takes the form of a continuous arc, rather than flat or plane sloping surfaces. The radii of such curved barrel-vault roofs can, in some applications, be as little as 6m or 7m, although larger radii are more typical. However, the applicant is not aware of any composite panel which is properly suitable for use in barrel-vaulted roofs, in particular where the radius of the roof is less than about 150m, since manufacturing processes do not allow the panels to be suitably curved during manufacture, unless produced in very small hand-made batches, which is uneconomic.

Curving of conventional composite panels on site is also not possible because the introduction of curvature to the panel causes delamination of the liner from the insulating material. Therefore, the existing method of providing barrel-vault roofs relies on the above-described technique of building up individual layers on-site-i. e. first applying liner sheets, then fixing brackets, then insulation and finally the exterior metal sheeting.

In view of the above, the present invention seeks to provide composite roofing panels suitable for use in barrel-vaulted or otherwise curved roof structures having a radius of curvature typically of less than 150m and even of 30m to 40m, or less.

According to a first aspect of the present invention there is provided a composite panel for a curved roof or wall structure comprising a first sheet member, a second sheet member having first and second opposed marginal edges, the first and second sheet members forming the major external surfaces of the panel, and an insulating material disposed between the sheet members and adherent to at least the second sheet member, wherein the second sheet member includes a plurality of recesses, each recess extending substantially between the first and second marginal edges, said recesses acting to accommodate deformation of the panel with respect to a direction transverse to the recesses from a substantially planar condition to a curved condition.

Preferably, the recesses are substantially v-shaped grooves and particularly preferably the recesses have a depth of from about 2mm to about 25mm.

In preferred embodiments of the invention, the recesses are located at intervals of from about 2mm to about 300mm, with respect to the longitudinal direction of the panel.

Preferably the insulating material is an insulating foam.

Preferably also the second sheet member is a steel or aluminium sheet member.

It is further preferred that the first sheet member is a steel or aluminium sheet member.

The panels of the invention will desirably accommodate a radius of curvature of 150m or less, preferably 50m or less and especially 30m or less.

In another aspect, the present invention also relates to a roof or wall structure including a panel as defined above.

In a further aspect, the present invention relates to a method of constructing a curved wall or roof structure comprising providing an underlying support structure defining a curvature of the wall or roof, applying a part of the panel as defined above to said support structure and deforming the panel into conformity with the defined curvature.

I 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, in which: Figure 1 is a schematic cross-section through a prior art composite panel;

Figure 2 is a schematic illustration of the failure mode of the prior art panel of Figure I when caused to adopt a curved configuration.

Figure 3 is a schematic cross-section through a panel according to the invention, and Figure 4 is a schematic cross-section through the panel of Figure 3, in a curved condition.

Referring now to Figures I and 2, the prior art composite panel 1 comprises an outer (first) sheet member 3 which may be of steel or aluminium, an inner (second) sheet member 5 which may, for example, be made from steel and an insulating material 7 disposed between the sheet members 3,5. The insulating material may be a polyisocyanate foam or a polyurethane foam. Figure 2 illustrates a typical failure of a prior art panel when deformed into a curve. Thus, as the panel I is deformed to introduce the curvature, the second sheet member 5 forming the inner liner is placed into greater and greater compression. Ultimately, the compression of the liner 5 exceeds the strength of the adhesive bond between the second sheet member (liner) 5 and the insulating material 7. The liner 5 then becomes locally detached from the insulating material as indicated at 9, generally at a point towards the middle of the panel 1. The liner 5 buckles outwardly from the insulating material so that the panel then loses its strength and so that the aesthetic appearance of the panel is damaged.

As can be seen from Figures 3 and 4, the present invention overcomes this problem.

Figure 3 illustrates schematically a panel 10 according to the invention in its substantially planar condition as manufactured. The panel 10 will typically have a width of from about 500mm to 1000mm and a length of several metres, e. g. up to 20m or more. The panel 10 includes an outer (first) sheet member 30, and an inner (second) sheet member 50 and an insulating material 70. The insulating material is preferably an insulating foam as noted above. The outer sheet member 30 will preferably be of steel or aluminium and the inner sheet member 50 will preferably also be of steel or aluminium. The second sheet member (liner) 50 includes a

plurality of transverse recesses 52 which in the embodiment illustrated are in the form of v-shaped grooves or notches. The recesses may take other forms, provided that they consist of a concavity extending generally transversely with respect to the panel. For example, the recesses may be generally U-shaped. The recesses 52 can alternatively be regarded as inwardly directed ribs in the liner 50. Where the recesses 52 are more closely spaced, the liner 50 may have a corrugated or concertina construction having little or no plane surface 50a between the recesses 52. As can be seen especially from Figure 4, the recesses 52 accommodate the compression of the liner 50 when the panel is caused to adopt a curved condition. Therefore, the problem of delamination caused by compression of the liner is eliminated as the compression forces are accommodated by gradual closure of the recesses 52.

Moreover, when the recesses 52 are present, compression of the liner 50 on curvature results in a force which acts to urge the liner more firmly against the insulating material, contrary to the direction which would cause delamination. The spacing of the grooves or recesses 52 along the panel will vary in accordance with the design requirements and required use of the panel. For example, for a greater degree of curvature, the spacing between the grooves or recesses 52 will generally be less.

Typically, the grooves or recesses 52 will be located at intervals of from about 2mm to about 300mm, more especially about 10mm. Similarly, the depth of the grooves or recesses 52 will vary with the design requirements of the panel. Typically, the depth of the recesses 52 will be from about 2mm to about 25mm.

By means of the present invention, roofs can be constructed with a radius of curvature of 150m or less. Even a radius of curvature of 30m or less is achievable.

Such a curvature is entirely unachievable with the prior art panels known to the applicant.

In use, the building to be roofed or walled is constructed to provide a support structure (eg the roof purlins) for the panels of the invention, to which the panels of the invention are fixed by conventional means. The support structure defines the curvature of the final roof (or wall). The panels of the invention are substantially

planar as manufactured and are brought to bear against the support structure and deformed into conformity with the curvature of the structure to provide the final curved roof or wall. This technique is more efficient (in terms of labour costs and ease of use) than manufacturing panels already having the required degree of curvature (if this is possible) and transporting such curved panels to the site of use.

Claims

CLAIMS 1. A composite panel for a curved roof or wall structure comprising a first sheet member, a second sheet member having first and second opposed marginal edges, the first and second sheet members forming the major external surfaces of the panel, and an insulating material disposed between the sheet members and adherent to at least the second sheet member, wherein the second sheet member includes a plurality of recesses each recess extending substantially between the first and second marginal edges, said recesses acting to accommodate deformation of the panel with respect to a direction transverse to the recesses from a substantially planar condition to a curved condition.
2. A panel as claimed in claim 1 wherein the recesses are substantially v-shaped grooves.
3. A panel as claimed in claim 1 or 2 wherein the recesses have a depth of from about 2mm to about 25mm.
4. A panel as claimed in any of claims I to 3 wherein the recesses are located at intervals of from about 2mm to about 300mm, with respect to the longitudinal direction of the panel.
5. A panel as claimed in any preceding claim wherein the insulating material is an insulating foam.
6. A panel as claimed in any preceding claim wherein the second sheet member is a steel sheet member.
7. A panel as claimed in any preceding claim wherein the first sheet member is a steel or aluminium sheet member.

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8. A panel as claimed in any preceding claim which can accommodate a radius of curvature of 150m or less.
9. A panel as claimed in claim 8 which can accommodate a radius of curvature of 50m or less.
10. A panel as claimed in claim 8 or 9 which can accommodate a radius of curvature of 30m or less.
11. A panel substantially as hereinbefore described with reference to Figure 3 or Figure 4.
12. A roof or wall structure including a panel as claimed in any preceding claim.
13. A method of constructing a curved wall or roof structure comprising providing an underlying support structure defining a curvature of the wall or roof, applying a part of the panel of any of claims I to 11 to said support structure and deforming the panel into conformity with the defined curvature.