ROOF TILE AND A ROOF COVERING

Abstract

A roof tile comprising a ceramic body and a reinforcing element attached to a lower surface of the ceramic body.

Claims

1. A roof tile comprising a ceramic body and a reinforcing element attached to a lower surface of the ceramic body.

2. The roof tile according to claim 1, wherein the reinforcing element comprises a resin.

3. The roof tile according to claim 2, wherein the resin comprises a viscosity less than 1000 mPas at 20° C.

4. The roof tile according to claim 2, wherein said resin comprises a tensile strength between 50 and 90 MPa.

5. The roof tile according to claim 2, wherein said resin comprises a hardness above 50 Shore D.

6. The roof tile according to claim 2, wherein said resin is provided in an amount above 50 g/sqm.

7. The roof tile according to claim 2, wherein said resin comprises epoxy, polyurethane, acrylic and/or polyester resin.

8. The roof tile according to claim 1, wherein the reinforcing element comprises a metal plate.

9. The roof tile according to claim 8, wherein the metal plate is attached to the bottom of the ceramic body in a stretched state so that after releasing the stretch the metal plate compresses the ceramic body.

10. The roof tile according to claim 8, wherein the metal plate comprises a thickness below 1 mm, preferably less than 0.5 mm, more preferably below 0.2 mm.

11. The roof tile according to claim 1, wherein the roof tile comprises a support layer attached below the reinforcing layer.

12. The roof tile according to claim 11, wherein the support layer is made of a solid polymer composite (SPC).

13. The roof tile according to claim 11, wherein the roof tile comprises at least an attachment hole provided in the support layer.

14. The roof tile according to claim 11, wherein the support layer comprises a thickness below 4 mm.

15. The roof tile according to claim 11, wherein the support layer comprises coupling parts adapted to provide a mechanical coupling with the coupling parts of an adjacent roof tile.

16. The roof tile according to claim 15, wherein the coupling parts are configured to prevent vertical movement between the roof tile and said adjacent roof tile.

17. The roof tile according to claim 1, comprising at least an attachment hole provided in the ceramic body.

18. The roof tile according to claim 1, wherein the ceramic body comprises a thickness below 8 mm, preferably below 6 mm.

19. The roof tile according to claim 1, wherein the roof tile comprises a weight below 20 kg/sqm.

20. The roof tile according to claim 1, wherein the roof tile comprises a rectangular shape and a top décor imitating a plurality of roof tiles.

Description

[0108] With the intention of better showing the characteristics of the invention, in the following, as an example without any limitative character, several preferred forms of embodiments are described with reference to the accompanying drawings, wherein:

[0109] FIG. 1 represents a perspective view of a roof tile according to a first embodiment of the present invention, with a view on the front face of the roof tile;

[0110] FIG. 2 represents an enlarged cross-section according to line II-II in FIG. 1;

[0111] FIG. 3 represents an enlarged view of the section that is indicated with F3 in FIG. 2;

[0112] FIG. 4 represents an enlarged view of the section that is indicated with F3 in FIG. 2, according to a second embodiment;

[0113] FIG. 5 represents a cross-sectional side view of part of an installed roof covering with roof tiles according to FIG. 1;

[0114] FIG. 6 represents a perspective view of a roof tile according to the present invention, with a view on the front face of the roof tile;

[0115] FIG. 7 represents an enlarged cross-section according to line VII-VII in FIG. 6;

[0116] FIG. 8 represents an enlarged view of the section that is indicated with F8 in FIG. 7;

[0117] FIG. 9 represents an enlarged cross-section according to line VII-VII in FIG. 6, in an alternative configuration.

[0118] FIG. 1 represents a perspective view of a roof tile 1 according to the present invention, with a view on the front face of the roof tile 1.

[0119] The roof tile 1 is mainly rectangular and, in the represented example, rectangular and oblong. It has an upper surface 2 and a lower surface 3, whereby, in the installed condition of the roof tile 1, the upper surface 2 is directed upwards, whereas the lower surface 3 is directed downwards. The upper surface 2 forms the decorative surface of the roof tile 1.

[0120] Furthermore, the roof tile 1 has an upper edge 4 and a lower edge 5, whereby, in the installed condition of the roof tile 1, the upper edge 4 is directed towards the top of the roof, whereas the lower edge 5 is directed towards the bottom of the roof. Also, the roof tile 1 has two opposite side edges 6-7.

[0121] In the illustrated embodiment, the roof tile 1 comprises a ceramic body 8, which is made of porcelain, and a glaze coating 9, which is situated above said ceramic body 8.

[0122] The glaze coating 9 comprises a décor, which here simulates wood. In particular, the décor shows wood nerves and wood pores. It is to be noted that the décor 10 may represent any desired graphic, for example natural stone, slate etc. It is also to be noted that the décor 10 is printed, more preferably digitally inkjet printed using ceramic pigments.

[0123] In the represented example, the front face of the roof tile 1 represents or forms an image of a plurality of roof tiles 1A-1B-1C-1D. The borders or transitions between the roof tiles 1A-1B-1C-1D are formed by depressions 12, which form part of the relief at the upper surface 2 of the roof tile 1. Alternatively, said transition can be simulated by the printed décor 10.

[0124] Although, in the represented example, the front face 2 of the roof tile 1 represents or forms an image of four roof tiles 1A-1B-1C-1D, it is contemplated that less than four roof tiles are represented, such as two or three roof tiles, and it is contemplated that more than four roof tiles are represented.

[0125] The thickness T of the roof tile 1 is less than 10 mm, for example less than 8 mm, more preferably less than 6 mm. The thickness T is greater than 1 mm, preferably higher than 3 mm.

[0126] The length L of the roof tile 1 is larger than its width W. The length L of the roof tile 1 may be at least 250 mm and preferably at least 500 mm. it is to be noted that the length L of the roof tile 1 correspond to the upper edge 4 and the lower edge 5, and defines that dimension that is destined to be placed horizontally in use.

[0127] The roof tile 1 is provided with at least one attachment hole 13. Here, the roof tile 1 is provided with a plurality of attachment holes 13. The attachment holes 13 are present in at least the ceramic body 8 of the roof tile 1. They are situated closer to the upper edge 4 of the roof tile 1 than to the lower edge 5 of the roof tile 1. In particular, the attachment holes 13 are situated at a distance D from the upper edge 4, measured in the width direction of the roof tile 1, which is smaller than 0.25 times the width W of the roof tile 1. The minimal width or diameter of the attachment holes 13 is smaller than the thickness T of the roof tile 1. The attachment hole 13 is a through hole that passes through the entire thickness T of the roof tile 1.

[0128] FIG. 2 represents an enlarged cross-section according to line II-II in FIG. 1.

[0129] The glaze coating 9 comprises a décor 10, said décor comprising a print 14, a glaze layer 15 of uniform color, which is situated below the print 14, and a transparent or translucent glaze layer 16, which is arranged over said print 14. It is noted that according to alternative examples the glaze coating 9 may be free from said transparent or translucent glaze layer 16 and/or from said print 14. In further alternative embodiments a glaze coating may absent and the print 14 and the relief may be provided at the upper surface 2 of the ceramic body 8. It is also noted that the glaze coating 9 may comprise a print 14 at least partially provided above said transparent or translucent glaze layer 16.

[0130] The upper surface 2 of the roof tile 1 is provided with a relief, which, in the represented example, is formed by a plurality of excavations 18 present in said upper surface 2. According to the present embodiment the relief is formed in the ceramic body 8 and manifest itself through the glaze coating 9, although according to non-showed embodiments the relief may be at least partially formed directly in the glaze coating 9.

[0131] Here, the relief is also used to represent the borders or transitions between the roof tiles 1A-1B-1C-1D, which, as aforementioned, are formed by the depressions 12 in the upper surface 2 of the roof tile 1.

[0132] In the example, the relief is performed in register with the print 14.

[0133] FIG. 2 further shows that the roof tile 1 comprises a reinforcing layer 20 attached to the lower surface 3 of the ceramic body 8.

[0134] FIG. 2 shows the reinforcing layer 20 in a first preferred embodiment wherein it comprises a resin material, for example a thermosetting resin or thermoplastic resin. Examples of thermosetting resin are epoxy, polyurethane, cyanoacrylate, unsaturated polyester, vinyl ester or acrylic resin. It is to be noted that in this example the reinforcing layer 20 is constituted by the resin. Examples of thermoplastic resin are reactive hot melt, hot melt, polyester thermoplastic, vinyl etc. Preferably the resin is a rigid resin. In particular, according to a preferred embodiment of the invention the reinforcing layer 20 comprises an epoxy resin. It is also preferred that the epoxy is a bicomponent resin, i.e. a thermosetting resin obtained by curing at low temperature (for example at room temperature) a mixture of two components, namely a resin and a hardener.

[0135] The resin preferably comprises a tensile strength between 50 and 90 MPa, more preferably between 60 and 80 MPa, for example 75 MPa. Moreover, the resin preferably comprises a compressive strength between 90 and 130 MPa, more preferably between 100 and 120 MPa, for example 110 MPa. It is also preferable that the resin shows a hardness value of at least 50 measured on a Shore D scale.

[0136] As illustrated the reinforcing layer 20 covers the 100 percent of the lower surface of the ceramic body 8. The resin is preferably provided onto the lower surface 3 of the porcelain layer 8 in an amount above 150 g/sqm, more preferably above 200 g/sqm, for example 220 g/sqm.

[0137] FIG. 3 on a larger scale shows a view on the area F3 indicated on FIG. 2. As illustrated in FIG. 3 the ceramic body 8 comprises, at least in correspondence of its lower surface 3, an open porosity 21 adapted to be permeated by the resin of the reinforcing layer 20.

[0138] Thus, according to a preferred embodiment of the invention, the ceramic body 8 comprises an apparent porosity between 0.1% and 10% determined according to ASTM C373, more preferably between 2% and 8%, for example 6%. Furthermore, the ceramic body 8 may preferably have a volume of the open pores 21 comprised between 0.01 cc (cubic centimeter) and 1 cc, more preferably between 0.10 cc and 0.90 cc, for example 0.60 cc.

[0139] Preferably, in order to properly flow into said open pores 21 the resin of the reinforcing layer 20 comprises a viscosity at 20° C. less than 1000 mPas, preferably less than 800 mPas, more preferably less than 600 mPas, for example approximately 400 mPas. Within the scope of the invention “viscosity” means the viscosity of the uncured resin, for example the viscosity of the mixture of the two components before the completion of the curing, i.e. during the so-called pot life.

[0140] FIG. 4 represents a second embodiment of the roof tile 1 wherein the reinforcing layer 20 comprises a metal plate 22.

[0141] Preferably, the metal plate 22 is made of steel. The metal plate 22 is configured to produce a compressive state in the ceramic body 8 starting from the lower surface 3 thereof. In this way, since the ceramic body 8 is in a compressive state, a major improvement in the impact resistance is obtained. In order to achieve this goal, the metal plate 22 is firstly tensioned (stretched or elongated) by means of a mechanical or thermal stretching action and is then arranged underneath the ceramic body 8 while it is still in the elongated state. Then the stretched condition is released, by interrupting the mechanical stress or cooling the metal plate 22, so as to cause compression of the ceramic body 8.

[0142] According to a preferred embodiment, the metal plate 22 has a thermal expansion coefficient greater than the thermal expansion coefficient of the ceramic body 8. Owing to this solution the metal plate 22 may be stretched by means of heating so as to expand in a substantially uniform manner in every direction. After the metal plate 22 has been arranged underneath the ceramic body 8 it may be cooled down so as to contract and cause compression of the ceramic body 8.

[0143] Furthermore, the metal plate 22 comprises one or more protective coatings 23, each designed to cover at least partially, or better entirely, the metal plate 22 so as to protect it from corrosion. In particular, according to the example shown, the metal plate 22 is of the PPGI (Pre-Painted Galvanized Iron) or PPGL (Pre-Painted GlavaLume) type. This abbreviation is understood as meaning metal (not necessarily steel) plates which are galvanized (covered with a zinc or aluminium layer) and painted. Preferably, the metal plate 22 is lined on one or both its surfaces with a first layer of zinc, optionally a chrome-plated layer, and one or more protective coatings 23 of paints or sealing membranes, for example polymer material consisting of epoxy resin, polyesters, polyurethanes, polyvinyls or polyolefins.

[0144] According to a preferred embodiment shown in FIG. 4, the metal plate 22 has a thickness A less than 1 mm, preferably less than 0.5 mm even more preferably less than 0.2 mm. The metal plate 22 has a thickness A greater than 0.05 mm, preferably greater than 0.1 mm.

[0145] The metal plate 22 is attached to the lower surface of the ceramic body 8 by means of an adhesive. Said adhesive can is preferably a polyurethane or a hot melt glue.

[0146] FIG. 5 represents a cross-sectional side view of part of an installed roof covering 25 with roof tiles 1 according to FIG. 1.

[0147] The roof tiles 1 are attached or fastened to a framework 26 by means of nails 27, which are put in the attachment holes 13.

[0148] The roof tiles 1 are installed in subsequent rows, of which only a few are represented in FIG. 7, namely the subsequent rows 25A-25B-25C. In particular, the roof tiles 1 are installed such that the roof tiles 1 of one row partially overlap the roof tiles 1 of a previous row. For example, the roof tiles 1 of row 25C and 25B respectively overlap the roof tiles 1 of previous row 25B and 25A.

[0149] The overlap O between the roof tiles 1 of the respective rows is less than 50%, preferably less 35%. Or, in other words, the roof tiles 1 of row 25C and 25B respectively overlap the roof tiles 1 of previous row 25B and 25A, whereby the overlap O is such that less than 35% of the upper surface 2 of the roof tiles 1 of row 25A and 25B is covered by the roof tiles 1 of row 25B and 25C respectively.

[0150] The roof covering 25 comprises a plurality of under layers 29, in form of strips placed beneath a row 25A-25B-25C of roof tile. In particular, each strip of under layer 29 is placed beneath one row 25A-25B-25C. Said under layer 29 is made of a material different from ceramic or porcelain. In particular, said under layer 29 is be made of one or more of the materials selected from the group consisting of: a thermoplastic polymer, such as polyvinylchloride, polyethylene, polypropylene and/or polyethylene terephthalate, a thermosetting polymer, such as polyurethane, and/or an elastomer, such as rubber or a thermoplastic elastomer. In case polyethylene is used as a material for said under layer 29, low-density polyethylene or HDPE is preferred, although the use of high-density polyethylene or LDPE is not excluded.

[0151] FIG. 6 represents a perspective view of an alternative roof tile 1 according to the present invention, with a view on the front face of the roof tile 1.

[0152] The roof tile 1 comprises a support layer 30, which is situated below the ceramic body 8 so that the reinforcing layer 20 is disposed between the ceramic body 8 and the support layer 30.

[0153] Said support layer 30 is preferably made of a material different from ceramic or porcelain. In particular, it is preferred that said support layer 30 is made of one or more of the materials selected from the group consisting of: a thermoplastic polymer, such as polyvinylchloride, polyethylene, polypropylene and/or polyethylene terephthalate, a thermosetting polymer, such as polyurethane, and/or an elastomer, such as rubber or a thermoplastic elastomer.

[0154] In the illustrated example the support layer 30 is PVC, in particular rigid PVC. The support layer 30 may also comprise a high amount of filler materials, such as talc, limestone, chalk, e.g., more than 30 wt % or more than 60% wt.

[0155] Preferably the rigid PVC may comprise a flexural modulus between 1.5 and 3.5. GPa, for example, approximately 2.6 GPa. The support layer 30 may also comprise a flexural strength between 60 and 90 MPa, for example approximately 76 MPa.

[0156] The support layer 30 has a part 31 which extends beyond the ceramic body 8. In the represented example, the part 31 extends beyond the upper edge 4 of the ceramic body 8. Further, in the present embodiment the ceramic body 8 extends beyond a lower edge 32 of said support layer 30.

[0157] The support layer 30, at least at two opposite edges, in this case an upper edge 33 and the lower edge 32, is provided with coupling parts 34-35, which allow that two of such roof tiles 1 can be coupled to each other.

[0158] In fact, as illustrated in FIG. 7, the support layer 30 and the ceramic body 8 are offset with respect to each other in the width and/or length direction of the roof tile 1, in this case in the width W.

[0159] In this embodiment the attachment holes 13 pass through the thickness of the support layer 30 and are preferably entirely realized in the support layer 30.

[0160] The support layer 30 and the ceramic body 8 may be laminated or press laminated together, for example by means of an adhesive.

[0161] In a preferred embodiment wherein the reinforcing layer 20 comprises a resin as illustrated in FIG. 3, said resin of the reinforcing layer can act as the adhesive to bond together the ceramic body and the support layer, as illustrated in FIG. 8.

[0162] In a preferred embodiment wherein the reinforcing layer 20 comprises a metal plate 22 as illustrated in FIG. 3 the support layer 30 is attached to the metal plate 21 via an adhesive that can be the same used to attach the metal plate 21 itself to the ceramic body 8.

[0163] Coming back to FIG. 7, the ceramic body 8 forms between 25% and 75% of the thickness T of the roof tile 1 and preferably between 40% and 60% of the thickness T of the roof tile 1. The support layer 30 forms between 25% and 75% of the thickness T of the roof tile 1 and preferably between 40% and 60% of the thickness T of the roof tile 1.

[0164] In a preferred illustrated embodiment, the support layer 30 has an upper surface 36 and a lower surface 37 that converge towards each other. In particular, they converge towards each other in the direction towards the upper edge 33 of said support layer 30 so that the thickness of the support layer 30 is higher in proximity of the lower edge 32 than in proximity of the upper edge 33.

[0165] In the represented example, the coupling parts 34-35 are formed in the material of the support layer 33. They are provided with a locking system, which, in the coupled condition of two of such roof tiles 1, is only active in the direction V perpendicular to the plane of the roof covering, which means that the moving apart of two of such coupled roof tiles 1 in said direction V is counteracted and preferably prevented. The locking system comprises locking surfaces 38-39, which, in the coupled condition, cooperate with each other to counteract the moving apart of the coupled roof tiles 1 in said direction V.

[0166] The coupling parts 34-35 are configured such that they allow to couple two of such roof tiles 1 by means of a substantially downward movement M1 of one roof tile 1 with respect to the other roof tile 1.

[0167] FIG. 9 represents a variant of the embodiment of FIG. 7.

[0168] In the represented example, the coupling parts 34-35 are provided with a locking system, which, in the coupled condition of two of such roof tiles 1, is active in the direction H parallel to the plane of the roof covering and perpendicular to the coupled edges 32-33 as well as in the direction V perpendicular to the plane of the roof covering, which means that the moving apart of two of such coupled roof tiles 1 in said directions H and V is counteracted and preferably prevented.

[0169] Here, the coupling parts 34-35 provide for a click-type or snap-type coupling. This means that a click or snap action occurs upon coupling two of such roof tiles at the respective edges 32-33.

[0170] The coupling parts 34-35 are configured such that they allow to couple two of such roof tiles 1 by means of a downward movement M2 of one roof tile 1 with respect to the other roof tile 1. In the example, they are of the so-called push-lock or push-down type.

[0171] The present invention is in no way limited to the hereinabove described embodiments, but such system may be realized according to different variants without leaving the scope of the present invention.

[0172] Further, as is clear from the content of the description, the present invention relates to one or more of the items as listed below, numbered from 1 to 20:

[0173] 1. A roof tile comprising a ceramic body and a reinforcing element attached to a lower surface of the ceramic body.

[0174] 2. Roof tile according to item 1, wherein the reinforcing layer comprises a resin.

[0175] 3. Roof tile according to item 2, wherein said resin comprises a viscosity less than 1000 mPas at 20° C.

[0176] 4. Roof tile according to any of the items 2 or 3, wherein said resin comprises a tensile strength between 50 and 90 MPa.

[0177] 5. Roof tile according to any of the items from 2 to 4, wherein said resin comprises a hardness greater than 50 Shore D.

[0178] 6. Roof tile according to any of the items from 2 to 5, wherein said resin is provided in an amount greater than 50 g/sqm.

[0179] 7. Roof tile according to any of the items from 2 to 6, wherein said resin comprises epoxy, polyurethane, acrylic and/or polyester resin.

[0180] 8. Roof tile according to item 1, wherein the reinforcing comprises a metal plate.

[0181] 9. Roof tile according to item 8, wherein the metal plate is attached to the bottom of the ceramic body in a stretched state so that after releasing the stretch the metal plate compresses the ceramic body.

[0182] 10. Roof tile according to any of items 8 or 9, wherein the metal plate comprises a thickness less than 1 mm, preferably less than 0.5 mm, more preferably less than 0.2 mm.

[0183] 11. Roof tile according any of the preceding items, wherein the roof tile comprises a support layer attached below the reinforcing layer.

[0184] 12. Roof tile according to item 11, wherein said support layer is made of SPC.

[0185] 13. Roof tile according to any of items 11 or 12, wherein the roof tile comprises at least an attachment hole provided in the support layer.

[0186] 14. Roof tile according to any of the items from 11 to 13, wherein said support layer comprises a thickness less than 4 mm.

[0187] 15. Roof tile according to any of the items from 11 to 14, wherein the support layer comprises locking elements adapted to provide a mechanical coupling with the locking elements of an adjacent roof tile.

[0188] 16. Roof tile according to item 15, wherein said locking element are configured to prevent vertical movement between the roof tile and said adjacent roof tile.

[0189] 17. Roof tile according to any of the preceding items, comprising at least an attachment hole provided in the ceramic body.

[0190] 18. Roof tile according to any of the preceding items, wherein the ceramic body comprises a thickness less than 8 mm, preferably less than 6 mm.

[0191] 19. Roof tile according to any of the preceding items, wherein the roof tile comprises a weight less than 20 kg/sqm.

[0192] 20. Roof tile according to any of the preceding items, wherein the roof tile comprises a rectangular shape and a top décor imitating a plurality of roof tiles.

[0193] While several possible embodiments are disclosed above, embodiments of the present invention are not so limited. These exemplary embodiments are not intended to be exhaustive or to unnecessarily limit the scope of the invention, but instead were chosen and described in order to explain the principles of the present invention so that others skilled in the art may practice the invention. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are intended to fall within the scope of the appended claims.