WO1997034061A1

WO1997034061A1 - A roof panel, an anchoring member for a roof panel and a method of constructing a roof cladding

Info

Publication number: WO1997034061A1
Application number: PCT/DK1997/000104
Authority: WO
Inventors: Jørgen Rask JENSEN
Original assignee: Icopal A/S
Priority date: 1996-03-12
Filing date: 1997-03-11
Publication date: 1997-09-18
Also published as: AU2022197A

Abstract

A roof panel (1) comprises a membrane (23) and reinforcing profiles (4) arranged in connection with and protruding from the underside of the membrane, said reinforcing profiles comprising rest surfaces allowing the roof panel to be supported, and anchoring surfaces allowing the roof panel to be secured against lifting forces. An anchoring element (4) for anchoring the roof panel comprises means which may be caused to engage with the anchoring surfaces of the reinforcing profiles, and are arranged for being secured to a supporting structure (14). The invention further comprises a method of constructing a roof cladding.

Description

A roof panel, an anchoring member for a roof panel and a method of constructing a roof cladding

This application is based on application No. 290/96 filed in Denmark, the contents of which are incorporated herein by reference.

Field of the Invention

The present invention relates to a roof panel and an anchoring member for a roof panel, and in particular roof panels and anchoring members to be used in the construction of light-weight roof coverings. The invention also relates to a method of constructing a roof.

In particular, the invention relates to such roof panels which may be mounted without direct surface support, since the roof panel proper spans the distance between the supporting points, and wherein the roof panel is not necessarily dimensioned to be walkable. The only requirement made to roofs of this type is that they are able to tolerate the expected snow and wind loads, e.g. the Danish Building Codes prescribe that they should be designed for a snow load of 800 N/m² and for a wind lift of a similar magnitude.

Such roof panels may be implemented as thin-walled plates of metal or plastics which are typically corrugated or profiled which enhances their bending strength in a direction along the corrugations. Such plates are suitable for mounting on lathes arranged transversally to the corrugations.

Prior Art By the constructional method known in the art for mounting corrugated roof panels, the roof panels are mounted on a pattern cf suitably arranged lathes and are anchored with screws through the roof panels. The screws are positioned at the crests of the corrugations and are screwed tightly to the lathes. Positioning in the valleys of the corrugations is impossible due to the risk of substantial amounts of the water flowing along the corrugation valleys seeping through the screw holes. Immobilisation by means of screws at the corrugation crests involves the problem that the roof panel has no solid abutment in the region around the screw which means that only a fairly modest force can be applied to screw the screw into its final position in order to avoid deformation of the roof panel. Displacements due to thermal expansions cannot be absorbed. The securing in points of plates of a thin material means that the tensions in the roof panel are concentrated around the securing points which may very easily result in asterisk- shaped cracks in the roof plate initiated the securing points. It is a further drawback of this method of mounting roof claddings that complications may arise due to the fact that the work involved therewith has to be performed from the roof top side with an ensuing risk of causing damage to the roof.

DK patent No. Ill 461 features a roof panel having a particular design and which permits mounting with no walking on top of the roof. This is made possible by providing a roof panel having an elongated profile with a wide central portion which is flat or slightly upwardly arched in a flattened arch, and a marginal portion along each edge which is arched sharply upwards to a bead having the shape of three fourth of a cylinder with the opening facing downwards. The two marginal beads differ in sizes and are matched to allow the roof panels to be combined with the respective marginal beads of two neighbouring panels in a snap-locking engagement. Owing to their cylinder form, the panel beads are able to pivot relative to each other about their cylinder axes.

For this roof panel a particular anchoring member has been developed which is made of a flat metal plate specimen die-cut to a configuration with a head and a neck indentation or a waist indentation and matched to allow the head of this anchoring member to be inserted from below into the downwardly opening key in the open marginal bead (i.e. the smaller of the two marginal beads), whereby the head engages with the cylinder key following a 90° pivoting of the member about an axis perpendicular to the roof surface, following which the anchoring member is nailed into the side of a roof lathe. Hereby a roof constructed from these roof panels may be anchored without any work being performed from the roof top side.

This known roof system presents certain drawbacks and limitations for its use. The marginal finishing of a roof constructed of such panels requires some extra precautions since, for practical purposes, the roof lathes must extend beyond the edge of the outermost roof panel, whereby they are exposed to rain. Furthermore, the anchoring members only fit into the smaller of the marginal beads of the roof panels and consequently an edge is formed at the one lateral edge of the roof where the anchoring members cannot readily engage. The engagement of the anchoring member is not particular resistant to the lifting forces which may occur as a consequence of wind lifts since the contact surfaces that exist between the anchoring member and the key insides are inclined in a relatively acute angle. In order to allow the anchoring member to enter the key, the inclined sides of the key make it necessary to provide it in the shape of a thin plate which bears only on the edges; it is not presently possible to provide the anchoring member with an extended area of the contact surfaces. Displacement due to thermal expansions is absorbed only with difficulty since, due to the narrow edge and the wedging effect, the member is susceptible to chip firmly into the key rather than slide. This may result in spikes of tension, jumpy movements and optionally permanent material deformations with ensuing play in the engagement areas.

The fact that the marginal beads are upwardly arched relative to the interjacent portion of the roof panel means that narrow grooves will be formed at the marginal beads on the roof top side which are very difficult to clean. Dirt collects in these grooves due to the water being conveyed towards the marginal beads of the upwardly arched interjacent portion of the roof panel. Further the anchoring points have to be arranged in the roof panel edges. Therefore it is necessary to manufacture relatively narrow roof panels in order to avoid wide spans and allow the anchoring points to be positioned close enough to each other to allow for even the most adverse influences which may occur.

In particular, it is a drawback of the known roof that it is unsuitable for mounting with transversal overlaps. The marginal beads have to be fairly large in order to provide a satisfactory joining, and mounting with overlaps will therefore result in a substantial vertical offset in the joint between the two overlapping roof panels and hence the air gap therebetween becomes unacceptably large. At the overlapping area it is not practically possible to anchor the overlapping portion of the uppermost roof panel which is thereby caused to be cantilevered over a part of the length. The known roof panel is not suitable therefor since its shape means that the underlying roof panel does not in any way assist in the controlling of the overlapping portion. At the same time the option of pivoting the individual roof panels relative to each other makes support and anchoring even more important.

Summary of the Invention

The invention provides a roof panel comprising a weatherproof membrane with substantially C-shaped structural profiles arranged integrally with the membrane with leg portions extending away from the membrane and with lip portions defining the openings of the C- profiles, wherein the lip portions are spaced from the membrane and provide rest surfaces and anchoring surfaces, which roof panel is characterized in that the rest surfaces and the anchoring surfaces extend along respective parallel planes.

Hereby a roof panel is provided which may be supported and anchored in a very convenient manner where the transfer of force at the securing points is effected indirectly via reinforcing profiles in connection with the underside of the roof panel membrane proper, and wherein said membrane is unbroken. Hereby the loads on the membrane are distributed thereby eliminating the risk of stress cracking which allows for meeting a given requirement to dynamic strength with smaller material dimensions. Moreover a roof panel is provided which may be anchored without any work being performed from the roof top side. This roof panel may be secured to a supporting structure through the use of an anchoring member which is provided in accordance with a further

suBsππjTE SHEET embodiment of the invention and which may be caused to engage with a reinforcing profile by a simple rotating movement, and which obtains a solid engagement which may transfer large forces without any risk of the engagement being torn loose.

According to a preferred embodiment, rest surfaces and anchoring surfaces are arranged opposite each other in order to allow them to be secured by means that clamp the respective surfaces towards each other while simultaneously permitting a movement along the respective surfaces. Hereby deformation of the membrane portion of the roof panel by the securing forces is avoided, and consequently it is possible to operate with stronger securing forces. The securing forces do not give rise to a wedge effect and therefore the securing may be adjusted to allow the surfaces to slide parallel with the surfaces, e.g. during thermally induced dimensional changes .

According to a preferred embodiment the roof panel is corrugated and the reinforcing profiles are so designed and arranged that by mounting on a plane support, the roof panel will be caused to bear on the rest surfaces. The supporting force on the roof panel is thereby transmitted indirectly to the reinforcing profiles and from there to the membrane portion of the roof panel whereby a convenient distribution of forces is obtained without ensuing deformation of the membrane portion.

The invention further provides an anchoring member for securing a roof panel which anchoring member comprises a T-shaped head which is so designed that the crossbar portion of the T may enter the key while oriented substantially along the key's longitudinal direction, and wherein the ends of the crossbar engage the lips of the C-key when the crossbar is rotated transversally to the key. Such engagement allows the reinforcing profile to slide longitudinally and, provided allowance is made in the dimensioning for a certain play, transversally without ensuing weakening of the engagement of the anchoring member.

The anchoring member may be made from a sheet which is die-cut to a suitable shape, and wherein the T-shaped head is formed by an angular folding. However, it is considered to be within the scope of the invention to manufacture the anchoring member from other materials and in other shapes, provided the member is matched to allow firm engagement with the reinforcing profile of the roof panel.

The invention makes it economically viable to provide a roof panel with sinusoidal or trapezoidal corrugations and with structural profiles being arranged on the bottom surfaces of all corrugation valleys of the profile. The additional material needed to form the reinforcing profiles is fully balanced by the reduction of the membrane portion dimension of the roof panel permissible with the design according to the invention. Consequently it does not involve any substantial cost to provide the roof panel with a very large number of relatively closely spaced reinforcing profiles which allow for a high degree of flexibility in the positioning of the anchoring points. Therefore, the anchoring points may be positioned fairly freely, observing, of course, design parameters such as the number of anchoring points needed per area unit and the maximum distance allowed between the points, which parameters will be calculated as part of the structural design procedure. The reinforcing profiles may be made with a fairly modest height and thereby it is possible to provide the roof with overlapping joints, tne reinforcing profiles allowing for a corresponding gap in the joint which, if necessary, may be sealed with sealant. Owing to the modest height of the gap the sealant may readily be secured. If the roof panels are so adapted that the reinforcing profiles are arranged at the wave valleys, it is obtained that in case of an overlapping joint the roof panels are guided relative to each other whereby the reinforcing profiles of the overlapping roof panels support the valley areas of the subjacent roof panel.

The invention also provides a method of constructing a roof cladding, the method comprising selecting a roof panel which comprises a weatherproof membrane together with substantially C-shaped structural profiles, which profiles comprise leg portions extending away from the membrane and lip portions defining the openings in the C- profiles, which lip portions are spaced from the membrane and provide rest surfaces and anchoring surfaces which extend along respective parallel planes, the method further comprising placing the roof panel on top of structural members of a roofing substructure, whereby the rest surfaces take support on top of the structural members, introducing anchoring members into at least some of the C-profiles and engaging them by twisting them, and securing the anchoring members to respective structural members .

This method very provides a convenient roof construction wherein the roof panels are secured effectively and m such a manner that the risk of stress-induced cracks is avoided, wherein the membrane has not been perforated, and wherein the anchoring may be carried out without any work being carried out from the roof top side. According to preferred embodiments this method is used to build roof coverings wherein at least two roof panels are positioned in a bonded arrangement and wherein any gap between the bonded panels is optionally scaled by filling the gap with sealant.

Brief Description of the Drawings

Further characteristic features and advantages of the invention will appear from the following detailed description made with reference to the drawings, wherein

Figure 1 is a partial, sectional view of a roof panel according to the invention sectioned by a plane transversally to the wave axes, mounted on a support lathe and anchored by means of anchoring members according to the invention,

Figure 2 illustrates a detail of the roof panel seen in Figure 1 in an enlarged scale,

Figure 3 is a side view of the anchoring member according to the invention,

Figure 4 is a side view of the anchoring member seen in

Figure 3 in a direction perpendicular to the view seen in Figure 3,

Figure 5 is a top plan view of the anchoring member seen in Figure 3, and

Figure 6 is a vertically sectional view of a detail of a roof with a longitudinally overlapping joint, sectioned by a plane extending along a valley area of the respective roof panels. All figures are schematic and not to scale and illustrate only details relevant to the understanding of the invention while further details have been omitted for the sake of clarity. In all figures identical reference numerals are used to designate identical or corresponding elements.

Detailed Description of the Preferred Embodiments

Reference is first made to Figure 1 wherein a roof panel according to the invention which has been mounted on a roof lathe is shown in a view perpendicular to the waves in the roof panel. The roof panel 1 shown comprises a membrane portion 23 undulated sinosoidally upwards and downwards, the upwardly arched portions being designated wave crests 7, and the downwardly arched portions the wave valleys 8. Underneath the valleys 8, reinforcing profiles 4 are shown which are permanently secured to the underside of the membrane portion. The top surface of the membrane (as seen relative to the service position intended for the roof panel) is designated by the reference numeral 2, the underside by the numeral 3. Reinforcing elements 15 engage with some of the reinforcing profiles and are secured to the lathe 14 with nails 22.

Figure 2 illustrates the encircled detail shown in Figure 1 in an enlarged scale. Figure 2 more clearly illustrates how the reinforcing profile at the valley 8 in the profile comprises two portions which are symmetrical around the symmetry plane 12 which is also the symmetry plane for a part of the roof panel. Each portion of the profile comprises an L-profile with a web 10 connected to the roof panel membrane 23 and a horizontal flange 11. The underside of the horizontal flange forms the rest surface 5. The top side of the horizontal flange constitutes the securing surface 6. Two symmetrical L- profiles together form a reinforcing profile 4 with a C- profile having a downwardly oriented opening 9.

Figure 2 illustrates that, although the L-profiles are arranged somewhat to the side of the lowermost point centrally of the valley 8, they have such magnitude that the roof panel will be caused to bear on the rest surfaces if arranged on a planar surface.

According to the invention the roof panel is conveniently made of a plastics material by extrusion thereby imparting an identical cross section to the roof panel across the entire length thereof. The widths may typically be comprised within the range of from 60 to 120 cm, the typical modular length of the waves being 70 mm. Typical roof panel lengths may range from 250 to 800 cm, optionally as much as 1200 cm, as may be convenient for the particular application. The wall thickness of the membrane 23 proper may be e.g. from 0.5 to 1.0 mm, and preferably from 0.6 to 0.8 mm. The wall thickness of the L-profile may typically range from 1.0 to 1.5 mm.

Reference is now made to Figures 3, 4 and 5 for description of the anchoring member. The anchoring member is preferably made of an elongate metal plate specimen, of e.g. stainless steel in a thickness of 1.2 mm, which is die-cut or recessed with waist indentations 18 and folded perpendicularly at the folding line 19 to obtain an L-shape as will appear from Figure 4. The folded portion constitutes the head 16 of the anchoring member, whereas the portion which is vertical in Figure 4 is designated the shank 17. The shank is preferably provided with apertures 21 for nailing. The head is preferably rounded at the corners 20. The length of the head 16 of the anchoring member is adapted to allow the head to be introduced into the opening 9 of the C-profile (cf. Figure 2) . The width of the head 16 is adapted to provide firm engagement with the anchoring surfaces 6 of the reinforcing profile (cf. Figure 2) following pivoting of the anchoring member about an axis perpendicular to the rest surface 5 of the reinforcing profile.

Preferably, the height of the body 10 in the L-profiles is adapted to allow an anchoring member which is introduced into and rotated to its final position in the key to be in engagement without play, optionally with an ensuing slight elastic deformation of the L-profiles and/or the valley 8.

Figure 6 illustrates a detail from a roof where panels according to the invention are mounted to be overlapping. The skilled person would construct the supporting structure of the roof with a number of lathes 14, one of which being shown in Figure 6. The lathes are arranged horizontally, mutually parallel and inclined whereby the upwardly inclining outside of each of the lathes together define a plane 13 with a suitable inclination or slope. The lathes may e.g. be arranged at a mutual spacing of 60 cm whereby a roof panel of e.g. 240 cm spans five lathes.

Reference now being made to the detail shown in Figure 6, the lowermost panel is first mounted so as to cause its uppermost edge to be positioned on the lathe 14, and the panel is immobilised in this position by anchoring to subjacent lathes (not shown in Figure 6) in the same manner as shown in Figure 1. Then the top panel is mounted in such a manner that its lowermost edge is caused to overlap the subjacent panel to a certain extent. Figure 6 illustrates how an anchoring member 15 is inserted into the first panel, said anchoring member being secured to the lathe with nails 22. The top panel is anchored to lathes positioned at a higher level (not shown in Figure 6) . Such overlapping means that the support of the top panel is somewhat elevated relative to the roof plane 13 defined by the top sides of the lathes. The roof panel absorbs this departure from a perfect plane by elastic deformation.

The lowermost roof panel is kept in place and guided by the superposed roof panel. Although not shown in the Figure, it is possible, of course, to anchor the subjacent roof panel to the lathe during the mounting in the same manner as the superposed one.

Although specific preferred embodiments have been described above, they serve only to exemplify and explain the invention and not to limit the scope of protection conferred which is defined exclusively by the appended claims.

Claims

C l a i s

1. A roof panel comprising -a weatherproof membrane -substantially C-shaped structural profiles arranged integrally with the membrane, with leg portions extending away from the membrane and with lip portions defining the openings of the C-profiles, wherein the lip portions are spaced from the membrane and provide rest surfaces and anchoring surfaces, c h a r a c t e r i z e d in that

-the rest surfaces and the anchoring surfaces extend along respective parallel planes.

2. The roof panel according to claim 1 c h a r a c t e r i z e d in that the anchoring surfaces are arranged adjacent the rest surfaces in order that the structural profiles may be secured by means which urge the surfaces together while permitting displacement in directions along their respective planes.

3. The roof panel according to claim 1 c h a r a c t e r i z e d in that the structural profiles extend along mutually parallel directions, in that the membrane is corrugated, and in that the structural profiles are arranged adjacent the lowermost portions of the corrugated membrane as referred to the service position.

4. An anchoring member for securing a roof panel, which panel comprises a downwardly open dovetail key on its lower side, said anchoring comprising a T-shaped head adapted to the key in such way that the crossbar portion may enter the key while oriented substantially along the key longitudinal direction while, upon twisting the anchoring member through approximately 90 degrees, the ends of the crossbar engage the key, c h a r a c t e r i z e d in that the T-shape is matched to the key in such a way, that the mutual engagement is maintained with no substantial play but with the possibility of sliding the panel along the key's longitudinal direction.

5. The anchoring member according to claim 4, c h a r a c t e r i z e d in that it comprises an elongate plate specimen, wherein a neck portion delimiting the head is formed by cutting a pair of opposite recesses and wherein the neck portion is angled through approximately 90 degrees.

6. The anchoring member according to claim 5 c h a r a c t e r i z e d in the plate specimen comprises stainless steel.

7. A method of constructing a roof cladding, comprising

- selecting a roof panel, which comprises a weatherproof membrane together with substantially C-shaped structural profiles, which profiles comprise leg portions extending away from the membrane and lip portions defining the openings in the C-profiles, which lip portions are spaced from the membrane and provide rest surfaces and anchoring surfaces, which extend along respective parallel planes,

- placing the roof panel on top of structural members of a roofing substructure, whereby the rest surfaces take support on top of the structural members,

- introducing anchoring members into at least some of the C-profiles and engaging them by twisting them, and

- securing the anchoring members to respective structural members .

8. The method according to claim 7, c h a r a c t e r i z e d in that a respective anchoring member is manipulated to engage the key of a structural profile by introducing into the key a head of the anchoring member and subsequently twisting the anchoring member to make the head tightly engage the key, whereafter the engagement is secured by the immobilization obtained once the anchoring member has been secured to the structural member.

9. The method according to claim 8, wherein at least two roof panels are positioned on a sloping roof substructure in a bonded arrangement, wherein an uppermost border region of a first panel is covered by a lowermost border region of a second panel, c h a r a c t e r i z e d in comprising,

- selecting for the roof panels which comprise membranes with sinusoidal, trapezoidal corrugations and with the structural profiles being arranged adjacent the lowermost portions of the corrugations,

- positioning and securing the first panel,

- positioning the second panel with the rest surfaces registering with the valleys of the corrugations, and

- securing the second panel.

10. The method according to claim 9, c h a r a c t e r i z e d in comprising sealing the gap between the bonded border regions by filling the gap with sealant.