The present invention relates to a roof comprising an assembled roof element comprising at least one first profiled plate which is manufactured from a composite material and which serves as element supporting the assembled roof element.

In this paragraph a number of examples of known roof elements for skylight barrel vaults are described. A roof element which is common in Belgium is constructed from one or more profiled plates which are manufactured from a polyester resin reinforced with glass fibres. These are referred to as PRV (polyester renforcé de fibres de verre) skylight barrel vaults. In such skylight barrel vaults the U-value is relatively high. The U-value, or coefficient of heat transmission (W/m²K), indicates how much heat is lost per second through 1 m². Therefore, the lower the U-value, the better the roof element insulates.

BE 883519 discloses a roof according to the preamble of claim 1.

Another known skylight barrel vault is constructed from a combination of aluminium curved profiles for supporting multi-walled polycarbonate plates. Such a construction has the drawback that expensive aluminium profiles are necessary.

The present invention has for its object to propose a roof comprising an assembled roof element for which the desired U-value and rigidity can be obtained in simple manner with an inexpensive construction in which expensive aluminium supporting profiles are not necessary.

The invention is distinguished for this purpose in that the roof element comprises the features of the characterising part of claim 1.

The first plate of a composite material functions here as the supporting element, while the U-value can be brought to the desired value by a suitable choice of a multi-walled plate. The second plate is a flexible multi-walled plate.

The composite material is a resin from the group of: polyester resin or other thermoset resins. Glass fibres can optionally be added to further strengthen the material.

The plastic material of the second plate is a material from the group of: polycarbonate, acrylate, PET or other thermoplasts. These materials have the advantage that light-transmitting, flexible and light multi-walled plates can be manufactured, for instance by extrusion. The top side of the second plate must here preferably be given a UV-resistant form.

For an improved strength of the first profiled plate of composite resin, this plate can have a ribbed profile in longitudinal section. The profiled supporting plate preferably describes an arcuate form in transverse direction.

The multi-walled plates are preferably provided on two transverse sides with a connecting profile, whereby the transverse sides of two adjacent second plates can be connected to each other. This can for instance be a protruding transverse part on a first transverse side and a transverse recess on the other transverse side, which can be mutually engaging.

According to a possible embodiment the multi-walled plate is bent close to the longitudinal side for mounting these longitudinal sides on an upstand. This can typically take place by means of a simple bending process.

According to another possible embodiment the first and second plate can be mounted on an upstand by means of a mounting profile, optionally with additional clamping profile.

The invention will be further elucidated on the basis of a number of non-limitative exemplary embodiments of the assembled roof element according to the invention, with reference to the accompanying figures, wherein:

• figure 1 is a schematic cross-section of a roof according to the invention comprising an assembled roof element arranged on upstands;
• figures 2 (A), (B), (C), (D) show four possible variants for mounting of the roof element on the upstand;
• figures 3 (A), (B), (C) show three possible longitudinal sections of the ends of a multi-walled plate of an assembled roof element ;
• figures 4 (A), (B) show two possible longitudinal sections of the first plate of composite resin of an assembled roof element.

The same components are designated in the figures with the same reference numerals.

The assembled roof element shown in cross-section in figure 1 comprises one first curved plate 1 manufactured from a composite resin and one second multi-walled plate 2 of a plastic material. The second multi-walled flexible plate is supported by the first rigid plate 1. This embodiment is typically used in so-called skylight barrel vaults, wherein a number of such assembled roof elements can be arranged adjacently of each other in longitudinal direction on upstands 3.

Figure 2(A) shows a first method of mounting the roof element on upstand 3. The supporting first plate 1 is pushed into a profile 4. Second plate 2 is fixed by means of a clamping profile 5. In the shown embodiment this clamping profile 5 engages behind a protruding rib 17 of profile 4 and in a recess 18 which is provided on the top side of plate 2, close to the longitudinal side thereof.

Figure 2(B) illustrates a second method of connecting the roof element to the upstand. First and second plates 1, 2 are herein mounted on upstand 3 by means of a mounting profile 4 fixed to the upstand and having two longitudinal channels for the respective longitudinal sides of plates 1, 2.

Figure 2(C) shows a third variant in which the second plate is bent along a longitudinal seam 5 and connected to the upstand by means of a screw 6.

Figure 2(D) shows a fourth variant in which plate 1 is connected by means of a screw 8 to an upstand with an oblique top side and plate 2 is connected by means of a screw 7 to the first plate.

Note that these are only a number of examples and that any method known in the art suitable for the roof element can be employed.

Figures 3(A)-(C) show three examples of a second plate in longitudinal section.

According to a first variant, which is shown in figure 3(A), two adjacent second plates are mutually connected in longitudinal direction by an overlapping and snapping connection. In the shown embodiment a first transverse side of a second plate is provided for this purpose with a substantially gutter-like part 20 with a downward directed opening, and the other transverse side is provided with two flexible, upward directed ribs 21, 22. This gutter-like part 20 and ribs 21, 22 co-acting therewith are formed such that the ribs can be snapped into the gutter-like part. This gutter-like part 20 and ribs 21, 22 can be manufactured integrally with second plate 2.

A second variant, shown in figure 3(B), has a protruding transverse part 10 on a first transverse side thereof, and a transverse recess 9 on a second transverse side. In this manner adjacent second plates can be mutually connected in simple manner. According to a second variant, shown in figure 3(C), a transverse side is provided with a vertical flange 12, which can be arranged in a transverse gutter 11 on the other transverse side of an adjacent plate 2. Once again it is possible to envisage many other variants which are known to the skilled person.

Finally, figure 4 shows two examples of a first plate 1 in longitudinal section. According to a possible embodiment, strengthening ribs 13 are provided in transverse direction, wherein one transverse rib 13 overlaps in each case with a transverse rib 13' of an adjacent plate. According to another possibility shown in figure 4(B), the first curved plate is plane and a gutter-flange 15, 14 connection is used to mutually connect adjacent plates.

The invention is not limited to the above illustrated examples, and the scope of protection is defined solely by the appended claims.