GB2227034A - Roof construction - Google Patents

Abstract

A roof construction comprising overlapping formed plastics sheets (11) for retaining tiles or slates (19), the sheets incorporating shaped formations arranged to receive and locate corresponding formations on the underside of roofing tiles or slates (19). The sheets (11) are fixed to roof beams (12) prior to location of tiles or slates (19), which is then achieved without the use of external fixing means such as nails or clips.

Description

Roof Construction Ihis invention relates to roof construction and particularly to roof construction in which separate tiles or slates (hereinafter called panels) are carried in side-by-side and partly overlapping relationship on a roof structure, such as roof beams.

Current roofing and cladding practice utilises panels comprising traditional natural slates, clay tiles or simulated materials such as concrete or polyester resin filled with slate dust. Such panels are conventionally fixed in position by nails passing through respective holes near the upper edge of each panel, the bottom edge thereof being free.

The disadvantage of this method is that when the nails deteriorate the panels becomes loose and can fall out of place.

Similar techniques can be used for wall cladding purposes.

Wire nails, aluminium clips, or copper disc rivets have also been used, which engage and restrain the bottom edge of the panels, but such arrangements are visible and unsightly.

Panels have been devised having edge chennels within which a nail or clip may be covered by an adjacent, overlapping panel, but this constraction has the disadvantage that it is very labour intensive.

In traditional constructions, roof beams are first covered by transverse overlapping strips of bituminous felt, nailed to the beams. Parallel spaced wooden battens are then nailed transversely across the roof beams, over the felt, the spacing between the battens depending on the panel dimensions. Finally the panels are secured to the battens by one of the above-mentioned constructions.

It is an object of the present invention to alleviate the disadvantages of traditional constructions.

According to one aspect of the present invention, a roof construction includes parallel roof beams, a sheet of panel-retaining material fastened across the beams, and a plurality of panels (as hereinbefore defined) retained by and on said sheet, the sheet incorporating shaped formations each arranged to receive and locate a complementary shaped formation provided on the undersurface of each panel.

Preferably the sheet is unperforated, except by any fastenings thereof to the beams, and is impermeable to water. For this purpose, the sheet may be of a synthetic plastics material and may be shaped by vacuum forming.

Conveniently the sheet is formed with longitudinal and/or transverse stiffening grooves or ribs.

The shaped formations provided in the sheet advantageously comprise depressions in an upper surface thereof and the shaped formations provided in the undersurface of the panel comprises protrusions, each of which is a mating fit in a corresponding depression so as to retain the corresponding panel.

In order to enhance retention of each protrusion in a corresponding depression, the lower face of each protrusion may be inclined to the undersurface of the panel at an acute angle, the face of the depression against which the inclined lower face of the protrusion bears being correspondingly inclined, so that each protrusion hooks into a respective depression.

The depressions for retaining a plurality of the panels are preferably in the form of transverse parallel grooves.

The upper face of each panel may have a transverse ridge or groove adjacent the top edge thereof, and the lower face of the panel may have a respective transverse groove or ridge adjacent the bottom edge thereof, to engage with the adjacent ridge or groove of the adjacent panel.

The upper wall of each transverse retaining groove of the sheet is conveniently in the form of a rib, to engage into a further transverse groove in each panel, adjacent the bottom edge thereof.

The undersurface of the sheet may be provided with a layer of thermal insulation material, such as foamed or expanded plastics. In a preferred embodiment of the invention, such insulation material may substantially fill ribs in the sheet, so as to contribute both towards the structural strength of the sheet as well as the insulating qualities thereof. It is in any case preferred that the sheet should have substantial rigidity.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a longitudinal section through part of a roof construction according to a first embodiment of the invention; Figure 2 is a view, in the direction of the arrow A in Figure 1, of part of a sheet of material included in the roof construction of Figure 1; Figure 3 is a longitudinal section through part of a roof construction according to a second embodiment of the invention; Figure 4 is a view, in the direction of the arrow B in Figure 3, of part of a sheet of material included in the roof construction of Figure 3; Figure 5 is a perspective view of parts of two adjoining sheets of the type shown in Figure 4; Figure 6 is a perspective view of parts of two adjoining sheets which are a modification of the type shown in Figure 4;; Figure 7 is a perspective view of a hip tile used in a roof construction according to the invention; and Figure 8 is a perspective view of a valley tile used in a roof construction according to the invention.

In the drawings (in which like parts are labelled by like numerals), a roof construction includes a plurality of spaced wooden roof beams 10, covered by rigid lengths of vacuum formed synthetic plastics sheet material 11. The sheets 11 are fastened to the beams 10 by nails or screws 12. Each sheet 11 is formed with longitudinal and transverse stiffening ribs 13,14 respectively. When installed, the sheets 11 are covered all over by a series of panels, such as tiles 19, which are laid side-by-side in edge overlapping relationship. A layer of thermally insulating material 24, such as a foam plastics material, of suitable thickness, is, in the illustrated embodiment, applied to the undersurface of the sheet 11.

In the embodiment of Figures 1 and 2, parallel transverse locating grooves 15 are formed in the sheet 11, each groove 15 being bounded by upper and lower ribs 16,17, the upper face 18 of the lower rib 17 being inclined to the general plane of the sheet 11 at an acute angle thereto.

Each tile 19 has, on its undersurface, a protrusion 20 which in the embodiment of Figures 1 and 2 is near the top edge (which may extend continuously right across the tile 19, or alternatively across part thereof) and two parallel grooves 21,22 near the bottom edge. A rib 23 extends across the outer face of the tile 19, near the top edge thereof.

As can be seen particularly from Figure 1, when the tile 19 is installed, the protrusion 20 fits snugly in the groove 15, the lower face of the protrusion 20 being inclined at an acute angle to the general plane of the tile 19, to form a hook, which hooks against the face 18 of the sheet 11. The rib 16 engages in the groove 22, and the rib 23 engages in the groove 21. As an alternative, each tile 19 may have a longitudinal rib instead of a groove along one undersurface edge, and a corresponding groove along the opposite upper surface edge, so that adjacent tiles can interlock with each other by means of these mating ribs and grooves.

Referring to Figures 3 and 4, the upper edge 30 of each tile 30 engages with a corresponding shaped rib 31 on the upper surface of sheet 11; there is, furthermore, a transverse protrusion 32 on the undersurface of the tile towards the lower edge 33 thereof. Protrusion 32 locates in a complementary shaped groove 34 in the sheet 11, the groove being bounded by the upper edge of rib 31 and the lower edge of a further rib 35.

Figures 5 and 6 show how the edges of adjacent sheets 11 can be joined by overlapping; the sheet in Figure 5 corresponds to that illustrated in Figure 3 while that illustrated in Figure 6 corresponds to a further embodiment of the invention.

Figure 7 shows the use of hip tiles 25, at the external angle at the junction of two lengths of roof having the ridges thereof at right angles. In this case, two narrow protrusions 20 are provided on each hip tile 25.

Figure 8 shows the use of valley tiles 26, at the internal angle of two lengths of roof at right angles. The longitudinal central part of each valley tile 26 is formed as a depressed gutter 27, the rib 23 and grooves 21,22 extending right across the tile 26 from edge to edge.

The sheets 11 may be formed from any suitable material and by eny suitable method and could, for example be fire-proof. Furthermore, the sheets 11 may be implanted with electrically conducting strips for location of and contact with solar power generating panels.

Figures 7 and 8 show the above-mentioned longitudinal edge ribs 28 and grooves 29 of the tiles 19,25,26.

Claims (12)

CLAIMS:

1. A roof construction which comprises parallel roof beams, a sheet of panel-retaining material fastened across the beams, and a plurality of panels retained by and on said sheet, the sheet incorporating shaped formations each arranged to receive and locate a complementary shaped formation provided on the undersurface of each panel.

2. A roof construction according to claim 1, wherein said sheet is substantially impermeable to water.

3. A roof construction according to claim 1 or 2, wherein said sheet is formed with longitudinal and/or transverse stiffening grooves or ribs.

4. A roof construction according to any of claims 1 to 3, wherein said shaped formations provided in the sheet comprise depressions in an upper surface thereof and the shaped formations provided in the undersurface of the panel comprise protrusions, each of which is a mating fit in a corresponding depression so as to retain the corresponding panel.

5. A roof construction according to claim 4, wherein the lower face of each protrusion is inclined at an acute angle to the undersurface of the panel, the face of the depression against which the inclined lower face of the protrusion bears being correspondingly inclined so that each protrusion can hook into a respective depression.

6. A roof construction according to claim 4 or 5, wherein said depressions for retaining a plurality of the panels are in the form of transverse parallel grooves.

7. A roof construction according to any of claims 1 to 6, wherein the upper face of each said panel has a transverse ridge or groove adjacent the top edge thereof, and the lower face of the panel has a respective transverse groove or ridge adjacent the bottom edge thereof, to engage with the adjacent ridge or groove of the adjacent panel.

8. A'roof construction according to claim 7, wherein the upper wall of each transverse retaining groove of the sheet is in the form of a rib shaped and dimensioned to engage into a further transverse groove in each panel, adjacent the bottom edge thereof.

9. A roof construction according to any of claims 1 to 8, wherein a layer of thermal insulation material is provided on the undersurface of said sheet.

10. A roof construction according to claim 9, wherein said insulation material substantially fills ribs in the sheet.

11. A roof construction according to any of claims 1 to 8, wherein said sheet is substantially rigid.

12. A roof construction substantially as described herein with reference to any of the accompanying drawings.