AU688865B2 - Roof cladding panel - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "ROOF CLADDING PANEL" .:"The following statement is a full description of this invention, including the best method of performing it known to the Applicant:- *o a ROOF CLADDING PANEL TECHNICAL FIELD This invention relates to sheet metal roof cladding.

BACKGROUND ART Traditionally such cladding comprises a plurality of corrugated sheet metal panels laid upon supporting purlins or battens. The sheets are laid so that the margins of neighbouring sheets overlap. The sheets may be secured in place by screw or other fasteners piercing the sheets and engaging the purlins or battens. Such fasteners are always positioned so as to pierce the crest of a corrugation, so that rain water tends to drain away from the hole in the panel made by the fastener.

The head of the fastener, and a sealing washer normally provided thereunder, shields the hole from direct precipitation.

The external fastener heads are visible and are regarded as being 15 unsightly. Furthermore, notwithstanding their placement as aforesaid, they destroy the integrity of the panels, and as they loosen with time they become a source of water leaks through the roof.

o Therefore, ribbed cladding panels have been developed, that is to say panels comprising generally flat pans between longitudinally extending, upwardly directed, stiffening ribs, that are adapted to be held by so called concealed fixing.

Concealed fixing is effected by means of clips applied to the purlins or battens. The clips are overlaid by the panels. The clips present upwardly directed male protrusions, of a shape complementary to the cross-sectional shape of the panel ribs. The clip protrusions are adapted to snap engage with the underside of the panel ribs.

Another reason for using ribbed panels is that they are widely regarded as being more aesthetically pleasing than corrugated panels.

DISCLOSURE OF INVENTION Such prior known concealed fixing is not as positive or as secure as that provided by headed fasteners, and is not entirely suitable for use in sites likely to be subjected to cyclones or other high winds. The problem is exacerbated because metal roofs of the kind under discussion are quite air tight, so that very high uplift forces may be generated by high winds blowing over the roof.

Therefore an object of the present invention is to provide a ribbed roof cladding panel enabling the aesthetic and leak free nature of concealed fixing to be obtained while using through fasteners to hold the panel down.

0* 0 The invention consists in a sheet metal roof cladding panel of the 20 kind comprising at least one pan between longitudinally extending upwardly projecting stiffening ribs, characterised in that each said rib has a longitudinally extending crest and two longitudinally extending capping retainer grooves disposed one on each side of the crest and adapted tq, receive and retain respective edge margins of a capping strip extending along the rib and bridging over the crest of the rib.

The invention also consists in an assembly of such a ribbed panel and a said capping strip.

BRIEF DESCRIPTION OF THE DRAWINGS By way of example, an embodiment of the above described invention is described in more detail hereinafter with reference to the accompanying drawings.

Figure 1 is a cross-sectional view through a panel rib and capping strip assembly according to the invention.

Figure 2 is a similar view through overlapping edge ribs of two cladding panels according to the invention.

BEST MODE OF CARRYING OUT THE INVENTION The panel rib shown in figure 1 is an intermediate rib, that is to i say not an edge rib extending along an edge of the panel, but rather a rib parallel to the panel edges and spaced therefrom. As a general rule, 15 ribbed panels, including those of the invention, have ribs along each longitudinal edge and at least one intermediate rib. Neighbouring ribs are separated by substantially flat pans.

Thus in the present instance an inverted channel shaped rib 3 has pans 4 on each side of it. The rib 3 comprises two upwardly converging flanks 5 meeting in a crest 6.

In accordance with the invention two capping retainer grooves 7 are formed in the upper parts of the flanks 5. The grooves 7 are spaced apart and positioned symmetrically about the vertical centre plane of the rib 3. That is to say each groove 7 is spaced by substantially the same distance from the centre line of the crest 6.

Each of the grooves 7 preferably has a relatively gently sloping lower side 8 and a more steeply sloping upper side 9.

An arched, steel, capping strip 10 is applied to the rib 3 and is retained in place by virtue of inturned edge flanges 11, which are respectively located in the grooves 7. The capping strip is sized such that its edges have to be sprung apart to enable the flanges 11 to enter the grooves 7. Thereafter the resilience of the steel from which it is rollformed ensures that the flanges 11 remained lodged below the steeper sides 9 of the grooves.

A conventional fastener 12 may be driven through the crest 6 into a batten or czher underlying support for the cladding. As shown, the 15 capping strip 10 is sufficiently arched to enable it to bridge over the head of the fastener 12 without interference therewith.

In view of the weather proofing provided by the capping strip 10 it is unnecessary to provide a sealing washer under the head of the fastener.

20 In other embodiments the capping strip may be more peaked than shown in the figure to provide clearance under it for a conventional load spreading washer between the head of the fastener and the crest of the rib. Such a washer may comprise a length of steel strip, preferably of shallow inverted channel section with flanges adapted to bear upon the longitudinal edge margins of the crest portion of the panel rib.

As may be seen from figure 2 the capping retainer grooves of the panel's edge ribs may also serve as snap fitting formations between overlapping male and female edge ribs in a finished roof. Thus an edge margin 13 of the male rib may engage against the inner surface of the upper side of a capping retainer groove 7A of the female rib, and the material defining th- retainer groove 7B of the female rib may nest within a similar groove 7C of the male rib.

This provides a firm and weatherproof connection between the two panels and enables the usual degree of overlap to be reduced by the elimination of the rib margin of each rib, which in conventional arrangements lies against a flank of the other rib. This reduces the amount of material in the panels, and at least partly compensates for the additional material of the capping strips.

*.so so*e *°o.oo oe00 s e

Claims (7)

1. A sheet metal roof cladding panel of the kind comprising at least one pan between longitudinally extending upwardly projecting stiffening ribs, characterised in that each said rib has a longitudinally extending crest and two longitudinally extending capping retainer grooves disposed one on each side of the crest and adapted to receive and retain respective edge margins of a capping strip extending along the rib and bridging over the crest of the rib.

2. A pan according to claim I wherein each retainer groove has a sloping lower side and more steeply sloping upper side.

3. A panel according to claim 1 or claim 2 wherein the grooves are formed in a female edge rib of the panel.

4. A panel according to claim 3 wherein the panel further comprises a male edge rib having a groove adapted to receive panel material defining a said retainer groove in a female rib of a second panel according to the invention.

In combination, a panel according to any one of the preceding claims and a capping strip with longitudinal edge margins lodged within the retainer grooves of a rib of the panel and arching over the crest of said rib.

6. A combination according to claim 5 wherein said capping strip is sufficiently peaked to provide clearance between itself and the head of a headed fastener piercing the crest of said rib.

7. reference Applicant Attorney 7 A roof cladding panel substantially as described herein with to the accompanying drawings. BHP STEEL (JLA) PTY. LTD. Date 3 May 1995 ROBERT G. SHELSTON F.I.P.A.A. of CARTER SMITH BEADLE 00*t S. U Un 0* U ABSTRACT A sheet metal roof cladding panel comprises at least one pan (4) between longitudinally extending upwardly projecting stiffening ribs Each rib has two longitudinally extending capping retainer grooves (7) disposed one on each side of the crest of the rib and an arched capping strip (10) covers the crest of the rib with its respective edge margins retained in those grooves. Figure 1. S S* S S S. e I