Roof underlay and manufacturing method

Abstract

The invention relates to a roof underlay (100) comprising: a first metal layer (102) having an inner face (102a) and an outer face (102b) and perforations (102c) extending through the layer; a second breathable and waterproof layer (104) with a second face (104b) bonded to the inner face (102a) of the first layer (102); and a third resistant layer (106) with a second face (106b) bonded to a first face (104a) of the second layer (104), wherein the first layer (102) is perforated prior to the first layer (102) being bonded to the second layer (104), by means of spikes that penetrate the layer from the inner face (102a) to the outer face (102b).

Description

[0001] ROOF UNDERCOVER AND MANUFACTURING METHOD

[0002] TECHNICAL FIELD

[0003] The present invention relates to a roof underlayment and to a method of manufacturing such a roof underlayment.

[0004] STATE OF THE PRIOR ART

[0005] A roof underlay typically comprises a first layer made of a metallic material, and different layers which are glued successively from one side of the first layer.

[0006] The first layer and possibly other layers are perforated to create a waterproof and breathable screen.

[0007] Even if such an under-roof screen is efficient, it may happen that the micro-perforations are not optimal and breathability is degraded.

[0008] STATEMENT OF THE INVENTION

[0009] An object of the present invention is to provide a roof underlayment whose breathability is guaranteed.

[0010] For this purpose, a roof underlay is proposed comprising:

[0011] - a first layer made of a metallic material having an inner face and an outer face and crossed by perforations,

[0012] - a second layer made of a material ensuring water impermeability and water vapour permeability and having a first face and a second face bonded to the inner face of the first layer, and

[0013] - a third layer made of a third material constituting a coating of woven or non-woven glass fibers and having a first face and a second face bonded to the first face of the second layer, where each perforation of the first layer takes the form of a tube with a wider base on the inner face side and a narrower top on the outer face side, where the tube has at its base, a lower orifice, and at its top an upper orifice and where the lower orifice has a diameter greater than the diameter of the upper orifice.

[0014] Advantageously, the first layer is an aluminum foil. Advantageously, the second layer is a layer containing calcium carbonate mixed with polyethylene and / or polypropylene.

[0015] Advantageously, the diameter of the perforations is 0.125 ± 0.02 mm for a density of 80 perforations per cm 2 .

[0016] The invention also proposes a method of manufacturing a roof underlay according to one of the preceding variants, characterized in that it comprises:

[0017] - a step of providing a first layer made of a metallic material and having an inner face and an outer face,

[0018] - a step of perforation of the first layer by penetration of points from the inner face to the outer face,

[0019] - a step of providing a second layer made of a breathable and waterproof material and having a first face and a second face,

[0020] - a first bonding step during which the second face of the second layer is bonded to the inner face of the first layer,

[0021] - a step of providing a third layer made of a resistant material and having a first face and a second face, and

[0022] - a second bonding step during which the second face of the third layer is bonded to the first face of the second layer.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above-mentioned and other features of the invention will become more clearly apparent from the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among which:

[0025] Fig. 1 is an enlargement of a section of a perforated metal sheet implemented in a roof underlay according to the invention, and

[0026] Fig. 2 is a schematic representation of a roof underlayment according to the invention.

[0027] DETAILED PRESENTATION OF EMBODIMENT METHODS

[0028] Fig. 1 shows a first layer 102 made of a metallic material, and in particular takes the form of an aluminum sheet. The first layer 102 is implemented in a roof underlay 100 shown in Fig. 2.

[0029] The first layer has an inner face 102a and an outer face 102b and is traversed by perforations 102c. The under-roof screen 100 also comprises a second layer 104 made of a breathable and waterproof material and having a first face 104a and a second face 104b bonded to the inner face 102a of the first layer 102. A material is waterproof and breathable when it ensures impermeability to water and permeability to water vapor.

[0030] The under-roof screen 100 also comprises a third layer 106 made of a third resistant material and having a first face 106a and a second face 106b bonded to the first face 104a of the second layer 104.

[0031] When installing the under-roof screen 100 under a roof of a building, the first layer 102 is oriented towards the roof, i.e. towards the exterior of the building, while the third layer 106 is oriented towards the interior of the building.

[0032] The first layer 102 serves as a reflective thermal barrier to external heat wanting to penetrate into the building.

[0033] To make the perforations 102c prior to bonding the first layer 102 with the second layer 104, points 50 penetrate into the first layer 102 from the inner face 102a towards the outer face 102b.

[0034] According to a particular embodiment, the first layer 102 passes between a first rigid roller 52a carrying the spikes 50 and a second flexible roller 52b. When the first layer 102 passes between the rollers, the inner face 102a is pressed against the first roller 52a and the outer face 102b is pressed against the second roller 52b.

[0035] With such an arrangement, each tip 50 pierces the first layer 102, forming a tube 110 which generally has the shape of a volcano with a wider base on the side of the inner face 102a and a narrower top on the side of the outer face 102b. The tube 110 thus has at its base a lower orifice 110a, and at its top an upper orifice 110b and a channel 110c between the two orifices 110a-b. The lower orifice 110a has a diameter greater than the diameter of the upper orifice 110b.

[0036] Thus, each perforation 102c of the first layer 102 takes the form of a tube 110 where the widest base is on the side of the inner face 102a and the narrowest apex is on the side of the outer face 102b. The tube 110 has at its base, a lower orifice 110a and at its apex an upper orifice 110b and the lower orifice 110a has a diameter greater than the diameter of the upper orifice 110b.

[0037] Due to the presence of the lower orifice 110a with a larger surface facing the second layer 104, the breathability of the under-roof screen 100 is improved compared to a reverse installation where the smaller diameter orifice is towards the second layer 104. During manufacturing by passing between the rollers, a depression 112 is formed around the tubing 110 by depression of the outer face 102b.

[0038] According to a particular embodiment for obtaining a waterproof under-roof screen 100 on the side of the first layer 102 and breathable, the diameter of the upper orifice 110b of each perforation 102c is 0.125 ± 0.02 mm and for a density of 80 perforations 102c per cm 2 .

[0039] According to a particular embodiment, the second layer 104 is a layer containing calcium carbonate mixed with polyethylene and / or polypropylene. This second layer 104 is produced for example by stretching in order to produce a network of micro-channels allowing water vapor to pass through.

[0040] According to a particular embodiment, the second layer 104 is a breathable layer based on polyethylene or polypropylene of the Aptra 715© or Aptra W type 40001© type from the company RKW©.

[0041] According to a particular embodiment, the third layer 106 is a coating of woven or non-woven glass fibers, such as a tablecloth or a fabric.

[0042] The bonding of the different layers 102, 104 and 106 together can be carried out by heat bonding. For example, polyethylene can be used to constitute the glue between the different layers 102, 104 and 106.

[0043] The various layers are stored in roll form and a method of manufacturing the under-roof screen 100 comprises:

[0044] - a step of providing the first layer 102,

[0045] - a step of perforating the first layer 102 by penetration of points 50 from the inner face 102a towards the outer face 102b,

[0046] - a step of providing the second layer 104,

[0047] - a first bonding step during which the second face 104b of the second layer 104 is bonded to the inner face 102a of the first layer 102,

[0048] - a step of providing the third layer 106, and

[0049] - a second bonding step during which the second face 106b of the third layer 106 is bonded to the first face 104a of the second layer 104.

Claims

1)     Roof-deck screen (100) comprising:- a first layer (102) produced from a metal material having an interior face (102a) and an exterior face (102b) and with perforations (102c) passing through it,- a second layer (104) produced from a material providing impermeability to water and permeance to water vapour and having a first face (104a) and a second face (104b) bonded to the interior face (102a) of the first layer (102), and- a third layer (106) produced from a third material constituting a coating of glass fibres, woven or nonwoven, and having a first face (106a) and a second face (106b) bonded to the first face (104a) of the second layer (104),wherein each perforation (102c) of the first layer (102) takes the form of a tube (110) with a wider base on the interior face (102a) side and a less wide top on the exterior face (102b) side, where the tube (110) has, at the base thereof, a bottom orifice (110a), and, at the top thereof, a top orifice (110b), and where the bottom orifice (110a) has a diameter greater than the diameter of the top orifice (110b).2)     Roof-deck screen (100) according to claim 1, characterised in that the first layer (102)is an aluminium sheet.3)     Roof-deck screen (100) according to one of claims 1 or 2, characterised in that thesecond layer (104) is a layer containing calcium carbonate mixed with polyethylene and / or polypropylene.4)     Roof-deck screen (100) according to one of claims 1 to 3, characterised in that thediameter of the perforations (102c) is 0.125 ± 0.02 mm for a density of 80 perforations (102c) per cm2.5)     Method for manufacturing a roof-deck screen (100) according to one of claims 1 to 4,characterised in that it comprises:- a step of providing a first layer (102) produced from a metal material and having an interior face (102a) and an exterior face (102b),- a step of perforating the first layer (102) by the penetration of spikes (50) from the interior face (102a) towards the exterior face (102b),- a step of providing a second layer (104) produced from a breathing and impermeable material and having a first face (104a) and a second face (104b),- a first bonding step during which the second face (104b) of the second layer (104) is bonded to the interior face (102a) of the first layer (102),5   - a step of providing a third layer (106) produced from a strong material and having a first face(106a) and a second face (106b), and- a second bonding step during which the second face (106b) of the third layer (106) is bonded to the first face (104a) of the second layer (104).

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