Method for functionalizing a roofing device and resulting roofing device

Abstract

Method for functionalizing a roofing system and resulting roofing system. The invention relates to a method for functionalizing a roofing system (1), with at least maintenance and preferably an increase in its fire resistance, said roofing system (1) comprising, at least, a waterproofing membrane or similar waterproofing system (2), previously or recently installed either directly onto a roofing support or substrate (3), or onto a functional layer (4) installed on this support or substrate (3), this waterproofing membrane or similar waterproofing system (2) forming a first layer. The resulting system is characterized in that it consists of applying at least one base bonding layer (5) which comprises at least one intumescent material (6), and then applying at least one additional layer (7) onto said at least one base layer (5), constituting, after drying, a functional top layer (7').Figure to be published with the abbreviation: Fig. 2.

Description

Title of the invention: Method for functionalizing a roofing device and resulting roofing device

[0001] The present invention relates to the field of roofing systems and functionalized roofing devices, more specifically in relation to complex layered systems incorporating a liquid waterproofing or a functionalized top layer of another type, and has as its objects a method of functionalizing a roofing device with preservation, or even increase, of its fire resistance, as well as a resulting functionalized roofing device.

[0002] The protection of buildings, houses and similar structures against fire, particularly against fire from external sources, is a constant concern for builders and is subject to strict regulations. Specifically for roofs, there is a classification system in Europe in accordance with standard EN 13501-5:2016.

[0003] In the field of construction, the use and operating method of an intumescent material, or one that expands under the effect of heat, to protect a support that it covers, are well known to those skilled in the art.

[0004] This type of material is for example incorporated into paints or varnishes that can coat structural elements made of wood, metal or concrete, or for example incorporated into a top protective coating layer applied to roofing products, as disclosed by document WO 2005 / 067470.

[0005] It is also known, for example from document WO 03 / 006109, to incorporate such an intumescent material into a product forming a fire-resistant barrier, such as a curtain intended to subdivide the interior space under a roof structure, or possibly to cover it. This curtain is fixed, with an adhesive also incorporating an intumescent material, to structural elements of the roof structure.

[0006] From document WO 2017 / 197136, a prefabricated, multilayer, composite thermoplastic membrane is further known, comprising two sheets of thermoplastic material between which a reinforcing layer is sandwiched and to which are attached a layer of expandable graphite and a support layer.

[0007] US patent 11,060,290 further discloses a multilayer construction panel with a central layer made of paper and polypropylene fragments bonded with polyethylene, this central layer being covered on one side by a fiberglass felt incorporating an intumescent material and on the other side by a sheet of paper (the two outer layers being laminated with a base-based adhesive). made of polyethylene. To create a watertight system on site, this panel is covered with a waterproofing membrane.

[0008] The prefabricated products disclosed by these two documents are complex and expensive, are tedious to install on site and are generally "oversized", in terms of number of layers, for restoration work or additional work (aimed at providing fire resistance properties) on existing roofs already equipped with waterproofing.

[0009] In addition, roof sealing processes are also known, in the context of new roof constructions or restoration projects, by implementing a liquid sealant in association with a layer of primer laid beforehand, which allows obtaining continuous sealing without surface joints, possibly in addition to the existing initial sealing, possibly deficient or at least with joints.

[0010] Furthermore, methods are known for giving the visible surface of the roof an additional functionality, whether technical or not, by adding an extra functional layer (for example, with surface radiative properties, a decorative or informational purpose, or increased resistance to climatic agents and / or the effects of pollution). However, the addition of such a surface layer may, particularly given the often at least partially organic nature of its constituent material, lead to a reduction in the fire resistance of the roofing system in question.

[0011] Taking into account the prior art set out above, a person skilled in the art, faced with the problem of preserving or even (preferably) improving the fire resistance of a roofing system comprising a liquid waterproofing layer or an otherwise functionalized surface layer, might be encouraged to integrate such an intumescent material either i) in the surface layer, or ii) in at least one underlying layer in combination with another component having particular fire resistance properties, or iii) in all the layers of the stratified complex formed by these layers.

[0012] However, the first option i) is likely to compromise the sealing performance or other functionality, and also to degrade the visual appearance, of the apparent top layer.

[0013] The second option ii), and even more so the third option iii), entail the need to provide two / three components / layers with fire resistance properties, which complicates and increases the cost of the roofing system, and also limits the range of usable products, as well as the conditions of implementation, in particular in relation to an existing waterproofing.

[0014] Furthermore, there is also a constant demand and search, particularly on the part of manufacturers, for processes and systems that, in terms of resources and costs, meet the requirements of applicable standards as closely as possible, namely, in the given context, to obtain or at least maintain a required (possibly minimum) classification in relation to the aforementioned standard, without compromising sealing or other functional properties, or impacting the final appearance of the top layer. Moreover, additional operations should be avoided and modifications to existing products should be limited.

[0015] Thus, the present invention aims to propose a method of functionalizing a roofing device with preservation or improvement of its fire resistance (compared to the same device without the functionality) and simultaneously making it possible to overcome the disadvantages of the three options considered above, while being able to easily meet the stated requirement.

[0016] This objective is achieved by the invention through a method of functionalizing a roofing device, with at least maintaining and preferably increasing its fire resistance, said roofing device comprising, at least, a waterproofing membrane or a similar waterproofing system, previously or recently installed either directly on a roofing support or substrate, or on a functional layer installed on this support or substrate, this waterproofing membrane or similar waterproofing system forming a first layer,

[0017] process characterized in that it comprises the steps of:

[0018] - apply, on at least part of the surface of said waterproofing membrane or said similar sealing system, at least one base or bonding layer which comprises at least one intumescent material

[0019] as an additive, this base layer forming a second intermediate layer;

[0020] - then apply at least one additional layer on said at least one layer base, this or these additional layer(s) constituting after drying a functional top layer, or third layer, and preferably not exhibiting increased or special fire resistance properties, the first, second and third layers together forming a multilayer stratified complex and the base layer forming an intermediate layer between the aforementioned first and third layers, and it alone, comprising at least one intumescent material as an additive.

[0021] Indeed, the inventors unexpectedly and surprisingly found that incorporating intumescent material exclusively into the single intermediate primer layer conferred external fire resistance properties to the entire multilayer laminate complex, regardless of the characteristics of the at least two other layers of the laminate complex, which may not exhibit no particular fire resistance properties and must be made in particular from existing unmodified materials.

[0022] The inventors also found that despite the addition of such an intumescent material, in just enough quantity to obtain the intended regulatory performance, the performance of the other functions of the primary of such a system, namely promoting the adhesion of the functionalized upper layer to the first lower layer and preventing migrations between this lower layer and the functionalized upper layer (barrier function), were substantially preserved (compared to the same unmodified primary).

[0023] The invention will be better understood from the following description, which relates to preferred embodiments, given by way of non-limiting examples, and explained with reference to the accompanying schematic drawings, in which:

[0024] [Fig-1] is a schematic cross-sectional and elevational view of a stratified complex multilayer (here three-layered) obtained by implementing the process according to the invention and forming part of a functionalized roofing system, and,

[0025] [Fig.2] is a stepped cross-sectional and perspective view of a functionalized roofing device according to an embodiment of the invention, comprising a multilayered laminated complex as shown [Fig.1].

[0026] Thus, the present invention relates to a method of functionalizing a roofing device 1, with at least maintaining and preferably increasing its fire resistance, said roofing device 1 comprising, at least, a waterproofing membrane or an analogous waterproofing system 2, previously laid or having just been laid either directly on a roofing support or substrate 3, or on a functional layer 4 laid on this support or substrate 3, this waterproofing membrane or this analogous waterproofing system 2 forming a first layer.

[0027] In accordance with the invention, this method is characterized in that it comprises the steps of:

[0028] - apply, on at least part of the surface of said waterproofing membrane or said similar sealing system 2, at least one base or bonding layer 5 which includes at least one intumescent material 6 as an additive, this base layer 5 forming a second intermediate layer;

[0029] - then apply at least one additional layer 7 on said at least one base layer 5, this or these additional layer(s) 7 constituting after drying a functional top layer 7', or third layer, and preferably not exhibiting enhanced or special fire resistance properties, the first, second and third layers 2, 5, 7' together forming a multilayered laminate complex 8 and the base or bonding layer 5 forming intermediate layer between the first and third layers mentioned above, and it alone, comprising at least one intumescent material as an additive.

[0030] Thanks to these different arrangements taken in combination, the invention makes it possible to meet the demand expressed above and to achieve the stated goal.

[0031] The multilayer laminated complex 8 obtained by implementing the process according to the invention, as seen by way of example in [Fig.1], is designed for any type of roofing device 1 to be functionalized, such as a pitched roof or a flat roof known as a terrace, in particular also roofs of residential buildings or establishments open to the public.

[0032] According to the invention, the term "fire resistance properties" refers to the fact that the spread of an external fire on a multilayer laminated system of the type concerned remains limited to the surface and depth of the material(s) constituting the multilayer laminated system, for a sufficiently long period to prevent the fire from reaching adjacent areas and entering the dwelling. For the purposes of the invention, the "fire resistance property" is governed by standard NF EN 13501-5 by implementing one of the four test methods described in NF EN 1187 to determine an external fire performance class defining fire resistance over time, over a distance of fire propagation in the depth and on the surface of the system.For example, the BROof t3 class is given using test method 3 and for a system where the external fire propagation time (TE) is > 30 minutes, and the fire penetration time (TP) is > 30 minutes.

[0033] The value of TE, defined by the standard NF EN 13501-5, corresponds to the external propagation time of the fire during the test upwards and downwards, expressed as the maximum length burned, from the edges of the projection of the embers on the exposed surface.

[0034] The value of TP, defined by the standard NF EN 13501-5, corresponds to the time of penetration of the fire until the appearance of flaming elements on the lower layer of the entire system.

[0035] When the roofing system 1 already possesses, before application of the functionalization process according to the invention, sufficient fire resistance due to its own covering layers, the invention may aim to at least maintain this level of resistance (and thus compensate for the loss or decrease in fire resistance resulting from the functionalization), or even to improve it to meet the aforementioned standard. However, in the event of the absence of any particular fire resistance of the roofing system before application of the functionalization process, or of insufficient fire resistance, the functionalization process according to the invention may advantageously contribute to increasing this resistance, in particular so that the functionalized roofing system has a fire resistance that meets the standard.

[0036] As illustrated by way of example in [Fig.1], the multilayer laminate complex 8 according to the invention, obtained by means of the process mentioned above, comprises: a first lower layer 2 of the type of sealing membrane or similar sealing system, a second intermediate layer 5 of the type of base or bonding layer and a third functional upper layer 7'.

[0037] In the present application, the term "sealing system 2" refers in particular to a system consisting of at least two superimposed sealing layers, in particular two superimposed membranes, whether identical or not.

[0038] The base layer 5 is of the type capable of providing the desired adhesion to the surface of the first layer 2 for the upper layer 7'. It may consist of a so-called primary bonding material, advantageously also having barrier functions to migration between the first and third layers 2 and 7'.

[0039] Although not mandatory, it may be provided, within the framework of an application fully exploiting the advantages of the invention, that the functional upper layer 7' advantageously does not have a physico-chemical constitution or composition conferring upon it enhanced or special fire-resistance properties. This layer 7' may even, on the contrary, be readily combustible and thus, where applicable, tend to degrade any potential fire-resistance properties of the roofing device 1, this potential degradation being largely compensated, or even overcompensated, by the beneficial effects resulting from the provisions of the method of the invention.

[0040] Preferably, the sealing membrane or similar sealing system 2 – forming the first lower layer of the multilayer laminate complex 8 – is provided that, on the one hand, and the third upper functional layer 7', on the other hand, have mutually different physicochemical compositions or are predominantly made of materials having mutually different physicochemical compositions. Furthermore, the two aforementioned layers 2 and 7', as well as, where applicable, the functional layer 4, advantageously do not have a physicochemical composition or composition that confers enhanced or special fire-resistance properties. Alternatively, the functional layer 4 may, however, have fire-resistance properties, for example, if it is a rock wool insulation layer.

[0041] According to the invention, the term "physico-chemical composition" of a layer means all the compound(s) / material(s) that chemically and physically constitute said layer. Furthermore, the term "majority" means in it presents at least 50% by weight of the composition of the materials forming layers 2 and 7' respectively. Furthermore, and in any event, layer 7' does not consist of a layer of prefabricated material of a thermoplastic nature (for example a synthetic waterproofing membrane based on plasticized PVC or polyolefins), and preferably none of the materials of layers 5 and 7' are thermoplastic materials, nor based on such materials.

[0042] The third upper functional layer 7' may have a physical structure resulting from the application of a single layer 7 in one piece, or a multilayer structure in a stratified form resulting from the application of several unit layers 7. In other words, the third upper functional layer 7' may consist of a single layer or a succession of strata physically arranged one on top of the other resulting from layers 7 applied successively with intercalated drying phases (for example, to obtain shorter drying times).

[0043] Furthermore, the third functional upper layer 7' can be obtained by applying one or more liquid products of identical or different chemical natures. Said or each applied liquid product may consist of a single compound or a multi-component composition. The application of the liquid product(s) may be carried out in a single application step or in several successive and distinct steps.

[0044] The entirety of the third upper functional layer 7' can be of a single chemical composition with a single liquid product.

[0045] The entirety of the third upper functional layer 7' may alternatively have a chemical composition formed by several liquid products, of different chemical natures, which are structurally arranged in a single mixture or superimposed in layers.

[0046] According to a first embodiment of the process according to the invention, the additional layer or each layer 7 applied is of the liquid sealing material type, the resulting functional upper layer 7' having after drying a continuous surface and a thickness structure (seen in cross-section) of one piece or laminated.

[0047] According to a second embodiment of the method according to the invention, the additional layer or each layer 7 applied consists of a liquid coating material and the resulting functional top layer 7' has surface radiative properties, particularly in the wavelengths of sunlight (in particular visible and IR), and advantageously features a continuous surface and a single-piece or layered thickness structure.

[0048] Preferably, the additional layer or each additional layer 7 applied consists of a light-colored liquid coating material, for example white, the layer superior functional 7' resulting, which shows a single-piece or layered structure, exhibiting a solar reflectance index (SRI) greater than 90, preferably greater than 100.

[0049] According to a third embodiment of the process according to the invention, the functional upper layer 7', with a one-piece or laminated structure, is a light-colored, or even white, sealing layer and has a solar reflectance index greater than 90, preferably greater than 100.

[0050] Also in accordance with the invention, and as is apparent from the process mentioned above, the second intermediate layer 5, and only it, comprises at least one intumescent material 6 and the fire resistance properties of said multilayer laminate complex 8 are conferred solely by the second intermediate layer 5, none of the first and third layers 2 and 7' having a physico-chemical constitution conferring particular fire resistance properties.

[0051] In relation to the invention, the term "intumescent material 6" refers to any material that, under the action of heat, is capable of expanding and swelling, forming a charred or carbonized layer that delays the spread of ignition to the underlying layers. This charred layer forms a protective barrier that limits the combustion of the material itself by suppressing the "activation energy" element of the fire triangle. According to the invention, the presence of this "intumescent material 6" within the intermediate layer 5 does not alter, under normal conditions (outside the presence of fire), the functions and physicochemical properties of this intermediate layer 5, nor of the adjacent layers. In particular, the presence of said "intumescent material 6" does not alter the sealing properties of said first lower layer 2, nor the functional properties of said third upper functional layer 7'.It also does not affect the functions, for example of snapping and barrier, of the intermediate layer 5.

[0052] Thus, in a particularly advantageous manner, the multilayer laminate complex 8 for roofing has the advantageous property, by its specific structural configuration (incorporating in the intermediate layer at least one intumescent material 6) of being, as a whole, resistant to fire and to a rise in temperature of the underlying layers, in order to protect the construction bearing said multilayer laminate complex 8 (as well as the roofing device 1 comprising it) and the neighboring constructions over a sufficiently long period of time to allow, for example, the evacuation of people and the activation of other means of extinguishing fire, such as the intervention of firefighters.

[0053] According to a preferred embodiment of the invention, and since the fire resistance properties are conferred solely by the second intermediate layer 5, the layers 2 and 7' can be traditional existing layers, unmodified and devoid of any specific fire-resistant properties.

[0054] Indeed, the judicious integration of an intumescent material 6 solely and exclusively in the second intermediate or base layer 5 makes it possible to impart fire-resistant properties to the entire multilayer laminate complex 8. In addition to not deteriorating, before combustion, the respective properties, particularly the sealing properties, of the first layer 2 and the third functional layer 7', the integration of an intumescent material 6 specifically in the second intermediate layer 5 advantageously allows the fire-resistant properties to be deployed across the entire multilayer laminate complex 8.

[0055] Thus, the structural configuration of the layers of the multilayer laminate complex 8 of the invention, obtained by the above process, allows the fire resistance properties to be distributed throughout the entire multilayer laminate complex 8, through a synergistic effect between the second intermediate layer 5, comprising at least one intumescent material 6, and the adjacent lower layer 2 and upper functional layer 7', which are not fire-resistant. The intumescent material 6 of the intermediate layer 5 impacts the entire multilayer laminate complex 8, and therefore the roofing device 1, and extends its fire resistance properties over it.

[0056] According to a preferred embodiment of the invention, the intumescent material 6 present in the base layer 5 consists of exfoliating graphite or expandable graphite, preferably present in the form of grains or particles, incorporated into the base material forming predominantly said second intermediate layer 5.

[0057] Expandable graphite is preferred because it contains intercalating agents between its layers, which, under the effect of heat, decompose, generating gases. This causes the layers to separate and the graphite particles to expand up to 300 times their initial volume. Thus, when exposed to a flame, the expandable graphite advantageously produces an insulating layer of expanded graphite on the surface, which provides protection against heat and prevents the diffusion of gaseous decomposition products and fuels that could feed the flame.

[0058] According to a first particular embodiment, the second intermediate layer 5 is made up of said base material which by itself forms the entirety of said layer, such as for example a polyurethane resin, or an epoxy resin, or a PMMA (Poly Methyl Methacrylate) based resin, or a latex composed of an aqueous dispersion of copolymers, or a silane modified polymer resin.

[0059] According to another embodiment, the second intermediate layer 5 comprises a base material such as a polyurethane resin, or an epoxy resin, or a PMMA-based resin, or a latex composed of an aqueous dispersion of copolymers, or a silane-modified polymer resin mixed with one or more other material(s), including, for example, solvent-type, plasticizer, rheology additive, antifoaming agent, leveling effect additive or mineral filler.

[0060] According to a particular embodiment, the selected base material is a single-component or two-component material.

[0061] Expandable graphite is preferred as the intumescent material 6 in the context of the invention because it advantageously exhibits an expansion rate of between 30 and 400 ml / g, preferably 250 to 350 ml / g, under the effect of an ignition temperature of between 140°C and 230°C, for a carbon content of between 85% and 99.5% and graphite particle sizes in the second intermediate layer 5 of between 75 and 500 µm, preferably between 100 and 300 µm. Thus, practically from the start of the fire on the surface of the multilayered composite 8, and under the action of heat, the expandable graphite swells and acts as a fire retardant, while also extending its fire-resistant properties to at least the layers located below the second intermediate layer 5.

[0062] As an intumescent material 6, exfoliating graphite or expandable graphite is preferred in the context of the invention because, compared to other mineral fire-retardant substances, such as metal oxides like aluminum or magnesium hydroxides, in equal quantities, said graphite exhibits better fire resistance performance and does not alter the mechanical flexibility properties of the intermediate layer 5. Compared to exfoliating or expandable graphites, metal oxides generate undesirable water sensitivity and moisture when combined with a polyurethane resin-type base material. Furthermore, expanded or exfoliating graphite is non-toxic, unlike, for example, known halogenated or melamine fire-retardant compounds.Furthermore, expanded or exfoliating graphite is preferred to liquid fire retardant materials, such as phosphorus, nitrogen or halogen-based compounds, for its low cost and compatibility with the other layers of the multilayer laminate complex (8) of the invention.

[0063] Furthermore, the intumescent material 6 in the form of grains or particles is preferred because this allows its homogeneous distribution in the thickness of the second intermediate layer 5. Indeed, under the effect of heat, the particles disperse instantly in the second intermediate layer 5 and expand so as to produce a protective intumescent layer on the surface slowing down the propagation of fire, gas and smoke.

[0064] A homogeneous distribution of grains or particles promotes a uniform propagation of fire resistance properties within the second intermediate layer 5. Advantageously, the uniform fire resistance properties of the second intermediate layer 5 will be transferred, by synergy, to the whole of the multilayered stratified complex 8, in particular at the level of the third upper functional layer 7'.

[0065] According to a first advantageous arrangement of the invention, the intumescent material 6 constitutes between 5% and 50%, preferably between about 5% and 40%, more preferably between about 10% and 30%, and even more preferably between about 10% and 20%, by weight of the material (or possible mixture of materials) forming the second intermediate layer 5.

[0066] With an amount of intumescent material 6 between 5% and 50% by weight relative to the total weight of the material forming the second intermediate layer 5, the fire resistance properties of the composite are sufficient to meet the requirements of standard NF EN 13501-5 and fall within at least one of the classes (Br00f, CROoh DROof) of that standard. Advantageously, with an amount of intumescent material 6 between approximately 10% and 20% by weight relative to the total weight of the material forming the second intermediate layer 5, the multilayer laminate composite 8 will exhibit a fire resistance property classified as "BROof t3" by test method 3 of NF EN 1187, in relation to standard NF EN 13501-5, which corresponds to the certification required in France.

[0067] According to another advantageous embodiment of the invention, the intumescent material 6 is present in the intermediate layer 5 with a surface mass of between 10 g / m² and 500 g / m², more preferably between 20 g / m² and 250 g / m², and even more preferably between 30 g / m² and 150 g / m². This second embodiment, additional or alternative to the first embodiment, also makes it possible to confer fire resistance properties to the composite that are sufficient to meet the requirements of standard NF EN 13501-5 and fall within at least one of the classes (Br00f, Cr00f, DROof) of that standard. Advantageously, with a presence in the intermediate layer 5 in terms of surface mass of between approximately 50 g / m² and 100 g / m², the multilayer laminate composite (8) will exhibit a fire resistance property that is classified as "BROOF t3".

[0068] In accordance with another preferred feature of the invention, and in particular in relation to the two aforementioned provisions, the intumescent material 6 is in particulate form with an average particle size advantageously between 75 pm and 500 pm, preferably between 100 pm and 300 pm.

[0069] The integration of the particulate or granular intumescent material 6 into the second intermediate or base layer 5 and applied with a very thin thickness (typically between 0.2 mm and 0.7 mm, preferably in the range of 0.4 mm to 0.5 mm), makes it possible to visually verify, during application, the presence of said material and its substantially uniform distribution in this layer 5. This ability is further enhanced when the material of said layer 5 is transparent or at least translucent, at least at the time of its application (avoids non-uniform application, or even absence in areas, of intumescent material - a defect that can be remedied by mixing the loaded liquid / viscous material before application).

[0070] Advantageous choices in terms of types of constituent materials, thicknesses and properties of layers 2, 5 and 7', in relation to variants of the process and the resulting multilayer laminated complex 8 according to the invention, are set out below.

[0071] Thus, according to a feature of the process and the multilayer laminate complex 8 of the invention, the base material forming the second intermediate layer 5 is selected from among 1K or 2K polyurethane resins, PMMA (Polymethyl Methacrylate)-based resins, epoxy resins, silane-modified polymers, and aqueous dispersions of acrylic, methacrylic, urethane, or epoxy polymers, or copolymers of these compounds. The selection of the base material forming the second intermediate layer 5 will be made in accordance with the general knowledge of a person skilled in the art so as to maintain chemical and structural compatibility with the functional top layer 7' of the multilayer laminate complex 8.

[0072] According to an advantageous embodiment of the multilayer stratified complex 8 of the invention and its method of making it, the third upper functional layer 7' of the liquid sealing type is a combustible layer which has a physical structure of one piece or stratified.

[0073] According to a specific embodiment of the aforementioned advantageous embodiment, the third functional upper layer 7' is organic in nature and comprises a composition selected from compositions based on 1K or 2K polyurethane resins, PMMA (Polymethyl Methacrylate) resins, epoxy resins, silane-modified polymers, fluorinated or silicone polymers, or aqueous dispersions of acrylic, methacrylic, urethane, or epoxy polymers, or copolymers of these compounds. The selection of the compositions of the third functional upper layer 7' is made according to the general knowledge of those skilled in the art and the intended end use or application for the multilayer laminate complex 8, in particular the desired functionalization for the roofing system 1.For example, it is possible to choose for the third upper functional layer 7' a composition comprising an aqueous dispersion of elements of fluorine chemistry of the type aqueous polymer dispersion based. of fluorinated latex (such as, for example, polyvinylidene fluoride, known as PVDF) and / or an aqueous latex-based dispersion resulting from the chemistry of the element silicon (for example, a silicone- or silane-based latex).

[0074] In advantageous examples of practical and non-limiting embodiments of the invention, the third upper functional layer 7', preferably of the liquid sealing type and / or with surface radiative properties, in particular with a high solar reflectance index, consists of a combustible organic material which requires the application, in liquid form, of one or more of the aforementioned compositions in one or more steps, so as to obtain a single-layer material or a multi-layer material arranged in strata.

[0075] According to another particular feature of the complex and the process according to the invention, the dry film thickness of this functional top layer 7' is > 0.05 mm and < 3 mm, preferably between 0.3 mm and 2 mm, more preferably between 0.5 mm and 1.5 mm.

[0076] The term "film in the dry state" means the film obtained after complete evaporation of the solvent, or complete crosslinking of the resin, or complete coalescence of the latex, or complete reaction of the reactive species, allowing the physicochemical drying of the third upper functional layer 7', previously deposited in liquid form on the second intermediate or base layer 5.

[0077] According to another possible particular feature of the invention, the third functional upper layer 7' may optionally include (integrate) a reinforcing veil. This additional reinforcing veil is embedded within the third functional upper layer 7'. This additional reinforcing veil is preferably combustible, so as not to impede or significantly limit the expansion of the graphite in the intermediate layer 5 and thus not to reduce the fire resistance performance of the multilayer laminate complex 8. For example, this veil is made of polyester. Thus, this additional reinforcing veil advantageously does not affect the fire resistance properties of the multilayer laminate complex 8, nor does it impact the intumescent properties of the intumescent material 6 in the second intermediate layer 5.

[0078] In accordance with an alternative embodiment already mentioned above, and compatible with most of the possible characteristics described above, the functional top layer 7', whether liquid or non-liquid waterproofing, is light in color, even white, and has specific surface radiative properties. This layer 7' may, in particular, have a solar reflectance index (SRI) greater than 90, preferably greater than 100, typically after drying and before significant aging (a property known as "Cool Roof" in the building sector – see European Cool Roof Council). This SRI is determined from the solar reflectivity and thermal emissivity of the surface considered (here layer 4) according to ASTM E 1980-11 (2013) or EN 17190 (October 2018). The resulting multi-layered laminated complex (8), and therefore the roofing system that incorporates it, combines enhanced fire resistance performance with the fight against the effects of urban heat islands by reducing the surface temperature of roofs.

[0079] Furthermore, it can be noted that the addition of the intumescent material 6, even of dark color, exclusively in the intermediate layer 5, makes it possible to guarantee the quality and uniformity of the light color or whiteness, and therefore the reflectivity performance, of the functional upper layer 7'.

[0080] Furthermore, the absence of granular intumescent material in this upper functional layer 7' does not affect the smoothness of its surface (absence of roughness - good resistance to fouling), regardless of the nature of said layer.

[0081] According to a particular embodiment indicated by Sample No. 10 of the multilayer laminate complex 8 in Table 3 below, when the process for making the multilayer laminate complex 8 provides that the latter comprises a silane-modified polymer as a functional third upper layer 7', a reinforcing veil, in particular of the polyester veil type, may be added.

[0082] Advantageously, the first lower membrane layer 2 consists of a bituminous membrane, preferably cold-adhesive (for ease of installation without the use of a flame). Preferably, this first lower membrane layer 2 is prefabricated in a factory. It can either form part of, and constitute the upper layer of, an existing roofing system, which the method according to the invention aims to make functional during subsequent rehabilitation or improvement work by covering it with the second and third layers 5 and 7', or constitute the first lower layer 2 of a multi-layered laminated system 8 in the construction of a new roofing system. Furthermore, this membrane can also, where appropriate, constitute the upper layer of a waterproofing system formed of two superimposed membranes, whether existing or newly installed.

[0083] In order to meet the regulatory criteria applicable in certain countries, and in particular in France, said multilayer laminate complex 8 is configured, in particular the compositions and thicknesses of the first, second and third layers 2, 5 and 7' forming together a laminate complex 8 are determined, particularly with regard to the second intermediate base layer 5, in such a way that said laminate complex 8 has an external fire performance rating corresponding at least to BROOF t3 according to test method 3 of the standard NF EN 1187 and in accordance with standard NF EN 13501-5. Examples of such compositions and thicknesses are indicated in particular in the tables that follow.

[0084] According to this standard, test method 3 evaluates the performance of a tested roofing system under attack from burning embers, wind, and additional radiant heat, using as classification parameters the external fire spread time (TE) and the time until fire penetration (TP) into the roofing system. For a roofing system, after implementation of test method 3, measured values ​​of TE > 30 min and TP > 30 min result in an external fire performance classification corresponding to BROof t3.

[0085] As illustrated by way of example in [Fig. 2], the present invention also relates to a functionalized roofing device 1, obtained by means of the process described above. This roofing device 1 comprises a waterproofing membrane or a similar waterproofing system 2, laid either directly on a roofing support or substrate 3, or on a functional layer 4 laid on this support or substrate 3, this waterproofing membrane or similar waterproofing system 2 forming a first layer of a laminated complex 8.

[0086] According to an embodiment of the invention visible in [Fig.2], between said roof support or substrate 3 and said functional layer 4, said roofing device 1 may also optionally include, in this order, a bonding coat layer 10, for example a bonding coat (bituminous or not) associated or not with a vapor barrier membrane layer 9.

[0087] According to one embodiment of the invention, the functional layer 4, which may be present, is a thermal insulation layer, preferably of the rigid type, and the first lower layer 2 of the membrane type serving as the base or lower layer of the multilayer complex 8 advantageously consists of a bituminous membrane, preferably cold self-adhesive.

[0088] According to the invention, the roofing device 1 is characterized in that the laminated complex 8 further comprises, on the one hand, present on at least a part of the surface of said waterproofing membrane or said analogous waterproofing system 2 forming first layer, at least one base or bonding layer 5 comprising at least one intumescent material 6 as an additive, this base layer 5 forming a second intermediate layer of said laminated complex, and, on the other hand, a functional top layer 7', or third layer, with a laminated or single-piece structure, resulting from the drying of at least one additional layer 7, possibly of several successive additional layers 7, applied(s) on said at least one base layer 5.This functional top layer 7' does not show any increased or special fire resistance properties and the base or bonding layer 5 forms an intermediate layer between the first and third. the aforementioned layers 2 and 7', and it alone, comprising at least one intumescent material 6 as an additive.

[0089] Preferably, the multilayer laminated complex 8 obtained by means of the process according to the invention corresponds to a complex having most of the characteristics indicated above and, makes it possible to realize a roofing device 1 functionalized according to the present invention, as a new construction or an existing construction renovated or rehabilitated.

[0090] In particular, the invention may advantageously provide that the first 2 and third 7' layers have mutually different physico-chemical constitutions or are predominantly based on materials having mutually different physico-chemical constitutions, and that the fire resistance properties of the laminated complex 8, and advantageously those of the roofing device 1, are conferred solely by the second intermediate or base layer 5, none of the first and third layers 2 and 7' having a physico-chemical constitution conferring particular fire resistance properties.

[0091] In accordance with three possible embodiments of the invention, it may be provided that:

[0092] - that the upper functional layer 7' corresponds to a single layer holding or laminated, resulting from the drying of one or more additional layers 7 of liquid sealing material type;

[0093] - that the upper functional layer 7' corresponds to a single layer single-piece or layered, preferably light-colored, possibly white, exhibiting surface radiative properties, and advantageously a solar reflectance index (SRI) greater than 90, preferably greater than 100, or,

[0094] - that the functional upper layer 7', with a single-piece structure or stratified, consists of a continuous sealing layer of light or white color and has surface radiative properties, and advantageously a solar reflectance index greater than 90, preferably greater than 100.

[0095] When the functionalization of the roofing device 1 is aimed, for example, at an advertising, aesthetic or more generally visual purpose, intended for third parties likely to see its surface, it may be provided that the second intermediate or base layer 5 and the upper functional layer 7' only partially cover the surface of the waterproofing membrane or similar waterproofing system 2 corresponding to the first layer and form a pattern of a decorative, representative or informative nature, preferably the upper functional layer 7' having a different color from that of the first layer (2).

[0096] The following tests, carried out by the inventors on different samples (examples 1 to 11, listed in Tables 1 to 3 below) show the properties advantageous, in terms of fire resistance, of a multilayer laminate complex (8) having the characteristics of the invention.

[0097] Sample compositions:

[0098] Tables 1 to 3 below summarize the compositions of the layers, on the one hand, of multilayer complexes 8 according to the invention (examples 1, 4, 7, 9, 10 and 11 above) and, on the other hand, of similar multilayer complexes but with a traditional base layer (examples 2, 3, 5, 6 and 8 above), i.e. devoid of intumescent material in the intermediate layer 5. [Tables 1] SAMPLE NO. COMPLEX 8 COMPLEX 8 1 2 3 BOTTOM LAYER 2 Type of self-adhesive bituminous membrane Self-adhesive bituminous Self-adhesive bituminous INTERMEDIATE LAYER 5 Type of PU 2K resin PU2K PU 2K Primary example Alsan 140 Alsan 140 Alsan 140 Added expanding graphite 10% 0% 0% Application layer 5 (kg / m2) 0.5 0.5 0.5 Graphite dosage (g / m2) 50 0 0 FUNCTIONAL UPPER LAYER T Type of PU 1K resin PU 1K PU 1K Example of Alsan 600 waterproofing resin Alsan 600 Alsan 600 + 4% “Disflamoll® DPK” Application layer 7 (kg / m2) 1.0 1.0 1.0 Thickness + / - 10% (mm) 0.7 0.7 0.7 [Tables 2] SAMPLE NO. COMPLEX 8 COMPLEX 8 4 5 6 BOTTOM LAYER URE2 Type of self-adhesive bituminous membrane Self-adhesive bituminous Self-adhesive INTERMEDIATE LAYER 5 Type of resin PMMA PMMA PMMA Primary example Alsan 172 CR Alsan 172 CR Alsan 172 CR Added expandable graphite 15% 0% 0% Application layer 5 (kg / m2) 0.7 0.7 0.7 Graphite dosage (g / m2) 105 0 0 TOP LAYER 7' Type of resin PMMA PMMA PMMA Example of waterproofing resin Alsan 970 CR Alsan 970 CR Alsan 970 CR + Fleece 1 10P + 50% ATH Application layer 7' (kg / m2) 0.6 0.6 2.9 Thickness + / - 10% (mm) 0.5 0.5 2.3 [Tables 3] SAMPLE NO. COMPLEX 8 COMPLEX 8 7 8 9 10 11 LOWER LAYER 2 Type of membrane Existing self-protected bituminous complex Self-adhesive bituminous Existing self-protected bituminous complex Self-adhesive bituminous Welded bituminous INTERMEDIATE LAYER 5 Type of resin Aqueous dispersion 2K epoxy Aqueous dispersion 2K epoxy PU2K Epoxy 2K PU 1K Primary example Express A+B Express A+B Alsan 140 Alsan EP 120 Alsan H80 Addition of expandable graphite 20% 0% 10% 15% 15% Application layer 5 (kg / m2) 0.5 0.5 0.5 0.5 0.5 Graphite dosage (g / m2) 100 0 50 75 75 SUPER HARD LAYER T type of resin Aqueous acrylic dispersion Aqueous acrylic dispersion PU 1K Silane PU 1K example sealing resin Alsan 320 + Fleece 110P Alsan 320 + Fleece 110P + 5 0% ATH Alsan 902 CR Alsan Fia shing Neo + Fleece 11 0P Alsan 902 CR application layer 7' (kg / m2) 1.6 1.6 1.0 3.2 1.0 thickness + / -10% (mm) 1.2 1.2 0.7 2.7 0.7

[0099] In the examples in Tables 1 to 3 above:

[0100] * for the lower layer 2:

[0101] - the "self-adhesive bituminous membrane" corresponds to the membrane marketed by the company SOPREMA under the reference SOPRASTICK SARKING SABLE;

[0102] - the existing self-protected bituminous complex corresponds to a complex self-protected bituminous waterproofing, for example marketed by the company SOPREMA under the SOPRAFIX HP complex associated with SOPRAFIX AR;

[0103] - the "welded bituminous membrane" corresponds to the commercially available membrane by the company SOPREMA under the reference SOPRALENE FLAM 180;

[0104] * for the intermediate layer 5:

[0105] - “Alsan 140” corresponds to a primary layer of PU (polyurethane) resin 2K applied with a consumption of 500 g / m2, marketed by the company SOPREMA;

[0106] - "Alsan 172 CR" corresponds to a primary layer of poly-(methacrylate of methyl) said PMMA applied with a consumption of 700 g / m2, marketed by the company SOPREMA;

[0107] - "Texprimer A+B" corresponds to a primary aqueous dispersion layer epoxy 2 applied with a consumption of 300 g / m2, marketed by the company SOPREMA;

[0108] - "Alsan EP 120" corresponds to a primer layer of 2K epoxy resin applied with a consumption of 500 g / m2, marketed by the company SOPREMA;

[0109] - “Alsan H80” corresponds to a PU (polyurethane) resin primer layer 1K applied with a consumption of 500 g / m2;

[0110] - the "expandable graphite" added to the 2nd intermediate layer 5 corresponds to the expandable graphite marketed by the company LUH under the reference GHL PX 98 HE. It is expressed as a mass percentage added to the intermediate layer 5 relative to the total mass of said intermediate layer 5, as well as by the parameter "graphite dosage" which corresponds to the surface quantity expressed in g / m2 of expandable graphite present between the lower and upper layers, therefore in the intermediate layer;

[0111] - the intermediate layer 5 is applied on the first lower layer 2 of the sample of the complex taken into account according to a consumption expressed in kg / m2

[0112] * for the functional upper layer 7':

[0113] - "Alsan 600" corresponds to a top layer of 1K PU resin applied with a consumption of 1 kg / m2, this resin being marketed by the company SOPREMA;

[0114] - "Alsan 902 CR" corresponds to a 1K PU resin top layer applied with a consumption of 1 kg / m2, this resin is marketed by the company SOPREMA;

[0115] - "Alsan 970 CR" corresponds to a top layer of PMMA resin applied with a consumption of 600 g / m2, this resin is marketed by the company SOPREMA;

[0116] - "Alsan Flashing Neo" corresponds to a resin-type top layer of silane modified polymers applied with a consumption of 3.2 kg / m2, in two layers with a reinforcing veil embedded between the two layers, this resin being marketed by the company SOPREMA;

[0117] - "Alsan 320" corresponds to an aqueous dispersion-type top layer acrylic applied with a consumption of 1.6 kg / m2, in two coats with a reinforcing veil embedded between the two coats, this product being marketed by the company SOPREMA;

[0118] - "Fleece 110P" designates an impregnated and integrated polyester reinforcement layer in the upper layer 7' and having a surface mass of 110 g / m2, a veil which is marketed by the company SOPREMA;

[0119] - "50% ATH" refers to the aluminum trihydrate supplemented in the layer upper functional layer 7' as a flame retardant, at a content representing 50% by mass relative to the total mass of the upper functional layer 7';

[0120] - “4% Disflamoll® DPK” refers to diphenyl cresyl phosphate, marketed by Lanxess company, incorporated into the upper functional layer 7' as a flame retardant at a content representing 4% by mass relative to the total mass of the upper functional layer 7'.

[0121] - the products “Alsan 902 CR” and “Alsan 970CR” of examples No. 4, 5, 9 and 11 allow obtaining a functional layer 7' with an SRI index greater than 90 (the so-called "CoolRoof" effect).

[0122] - the products “Alsan 600” and “Alsan Flashing Neo” of examples 1 and 10 provide functional layers 7' of the liquid sealing type.

[0123] - the product “Alsan 320” (RAL 9010) makes it possible to obtain a functional layer 7' Waterproof with an SRI rating greater than 90.

[0124] Tables 1 to 3 also mention, for each functional upper layer 7', the total thickness of the layer in mm.

[0125] The designations “Alsan”, “Texprimer”, “Alsan Flashent”, “SOPRASTICK”, “SOPRALENE” and “SOPRAFIX” are registered trademarks of the company SOPREMA.

[0126] On each of these 11 samples, external fire resistance tests in accordance with test method 3 of XP CEN / TS 1187 and standard NF EN 13501-5 were carried out under the following conditions:

[0127] * The tests were carried out with a slope of 5° (degree of angle) in order to validate the results for multilayer laminated composites 8 intended for roofs installed at slopes of less than or equal to 10° angle,

[0128] * the test support consists of a steel support covered with rock wool ROCKACIER® B » from the Rockwool company,

[0129] * the test support is covered with a complex consisting of the layers according to the Nos. sample described in Tables 1 to 3 above.

[0130] Table 4 below summarizes the significant results in the context of the invention from these different tests: [Tables 4] SAMPLE NO. TES TE according to XP CEN / TS 1187 1 2 3 4 5 6 7 8 9 10 11 External fire propagation time (TE) > 30 min n yes no no yes no no yes no yes yes yes Time to fire penetration (TP) > 30 min yes yes yes yes no no yes yes yes yes BROOF t3 yes no no yes no no yes no yes yes yes

[0131] For sample No. 2 of the complex, identical to sample No. 1 but lacking graphite in the intermediate layer 5, the BROof t3 class is not achieved. For sample No. 3, identical to sample No. 2 with the addition of a "Disflamoll® DPK" type flame retardant in the upper functional layer 7', the BROof t3 class is not achieved. Thus, these results show that only a multilayer laminated complex (8) according to the invention, for example such as sample No. 1, having in its only intermediate layer 5 an intumescent material 6, in particular of the graphite type, makes it possible to achieve the BROof t3 class with test method 3 of XP CEN / TS 1187 applicable according to standard NF EN 13501-5.

[0132] The results obtained for samples No. 4 to 6 also reveal that a modification of the nature and type of the intermediate layer 5 and the functional top layer 7' does not affect the fact that the presence of the intumescent material 6, of the graphite type in the intermediate layer 5, makes it possible to achieve the BROof t3 class. Furthermore, as shown by the result obtained for sample No. 6, the addition of an additional veil and an ATH flame retardant in the layer The superior functional layer 7', with the composition of sample No. 4, does not allow the BROof t3 class to be reached in the absence of graphite in the intermediate layer 5. Neither the veil nor the additional flame retardant has any impact on the complex to reach the BROof t3 class.

[0133] The results obtained for samples No. 7 to 11 show that a modification of the nature and type of the intermediate layer 5 and / or the functional top layer 7', with or without a veil and / or additional flame retardant, does not impact the samples of the tested multilayer laminated complex (8) and the possibilities of achieving the BROof t3 class. Only the presence of expandable graphite in the intermediate layer 5 makes it possible to achieve the BROof t3 class, particularly for samples No. 7 and 9 to 10.

[0134] Consequently, these tests illustrate that the multilayer laminate complex (8) of the present invention meeting the class BROof t3 of test method 3 of standard NF EN 13501-5 is particularly advantageous for increasing resistance to fire and its propagation, in particular in the context of use in a functionalized roofing system 1 of a dwelling or building.

[0135] Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Demands

1. A method for functionalizing a roofing system (1), with at least maintenance and preferably increase of its fire resistance, said roofing system (1) comprising, at least, a bituminous waterproofing membrane or a similar waterproofing system (2), previously or recently installed either directly on a roofing support or substrate (3), or on a functional layer (4) installed on this support or substrate (3), this waterproofing membrane or similar waterproofing system (2) forming a first layer, the method characterized in that it comprises the steps of: - applying, on at least a part of the surface of said waterproofing membrane or similar waterproofing system (2), at least one base or bonding layer (5) which comprises at least one intumescent material (6) as an additive, this base layer (5) forming a second intermediate layer,- then apply at least one additional layer (7) on said at least one base layer (5), this or these additional layer(s) (7) constituting after drying a functional top layer (7'), or third layer, and preferably not exhibiting enhanced or special fire resistance properties, the first, second and third layers (2, 5, 7') together forming a multilayer stratified complex (8) and the base layer (5) forming an intermediate layer between the aforementioned first and third layers (2 and 7'), and it alone, comprising at least one intumescent material (6) as an additive and consisting of an adhesion primer, also exhibiting migration barrier functions between the first and third layers (2 and 7').

2. A method according to claim 1, characterized in that the additional layer or each layer (7) applied is of the liquid sealing material type, the resulting functional top layer (7') having after drying a continuous surface and a thickness structure of one piece or layered.

3. A method according to claim 1, characterized in that the additional layer or each layer (7) applied consists of a liquid coating material and the resulting functional top layer (7') has surface radiative properties, particularly in the wavelengths of sunlight and advantageously exhibiting a continuous surface and a single-piece or layered thickness structure.

4. A method according to claim 3, characterized in that the additional layer or each additional layer (7) applied consists of a light-colored liquid coating material, for example white, the resulting functional top layer (7') having a one-piece or layered structure, exhibiting a solar reflectance index (SRI) greater than 90, preferably greater than 100.

5. A method according to claim 2 or 3, characterized in that the functional upper layer (7'), with a one-piece or laminated structure, is a light-colored, or even white, sealing layer and has a solar reflectance index greater than 90, preferably greater than 100.

6. A method according to any one of claims 1 to 5, characterized in that the sealing membrane or similar sealing system (2), on the one hand, and the functional top layer (7'), on the other hand, have mutually different physico-chemical constitutions or are predominantly based on materials having mutually different physico-chemical constitutions, the two aforementioned layers (2 and 7'), as well as where applicable the functional layer (4) possibly present, advantageously not having a physico-chemical constitution or composition giving them increased or special fire resistance properties.

7. A method according to any one of claims 1 to 6, characterized in that the intumescent material (6) present in the base layer (5) consists of exfoliating graphite or expandable graphite, preferably present in the form of grains or particles, incorporated into the base material forming predominantly this layer.

8. A method according to any one of claims 1 to 7, characterized in that the intumescent material (6) constitutes between 5% and 50%, preferably between 5% and 40%, preferably between about 10% and 30%, preferably between 10% and 20%, by weight of the material forming the second intermediate or base layer (5), and is in particulate form with an average particle size particles advantageously between 75 pm and 500 pm, preferably between 100 pm and 300 pm.

9. A method according to any one of claims 1 to 8, characterized in that the intumescent material (6) is present in the base layer (5) with a surface mass of between 10g / m2 and 500g / m2, more preferably between 20g / m2 and 250g / m2, and even more preferably between 30g / m2 and 150g / m2 and is in particulate form with an average particle size advantageously between 75 pm and 500 pm, preferably between 100 pm and 300 pm.

10. A method according to any one of claims 1 to 9, characterized in that the base material forming the second intermediate or base layer (5) is selected from 1K or 2K polyurethanes, PMMA (Poly Methyl Methacrylate) based resins, epoxy resins, silane modified polymers and aqueous dispersions of acrylic, or methacrylic, or urethane, or epoxy polymers or copolymers of these compounds.

11. A method according to any one of claims 1 to 10, characterized in that the functional top layer (7') is of an organic nature and comprises a composition selected from compositions based on 1K or 2K polyurethane resins, PMMA (Poly Methyl Methacrylate) resins, epoxy resins, silane-modified polymers, fluorinated or silicone polymers, or aqueous dispersions of acrylic, methacrylic, urethane, or epoxy polymers or copolymers of these compounds, this layer (7') optionally comprising or incorporating a reinforcing veil.

12. A method according to any one of claims 1 to 11, characterized in that the dry film thickness of the functional top layer (7') is > 0.05 mm and < 3 mm, preferably between 0.3 mm and 2 mm, more preferably between 0.5 mm and 1.5 mm.

13. A method according to any one of claims 1 to 12, characterized in that the first layer (2) consists of a cold self-adhesive bituminous membrane.

14. A method according to any one of claims 1 to 13, characterized in that the compositions and thicknesses of the first, second and third layers (2, 5 and 7') together form a complex

15.

16. laminate (8) are determined, in particular with regard to the second intermediate or base layer (5), in such a way that said laminate complex (8) has an external fire performance classification corresponding at least to BROof t3 according to test method 3 of standard NF EN 1187 and in accordance with standard NF EN 13501-5 of 2016. A functionalized roofing system (1), obtained by means of the process according to any one of claims 1 to 14, said roofing system (1) comprising a bituminous waterproofing membrane or a similar waterproofing system (2), laid either directly on a roofing support or substrate (3), or on a functional layer (4) laid on this support or substrate (3), said waterproofing membrane or similar waterproofing system (2) forming a first layer of a laminated complex (8), roofing system (1) characterized in that the laminated complex (8) further comprises, on the one hand, present on at least a portion of the surface of said waterproofing membrane or said similar waterproofing system (2) forming the first layer, at least one base or tack coat (5) comprising at least one intumescent material (6) as an additive, this base coat (5) forming a second intermediate layer of said laminated complex (8), and, on the other hand,a functional top layer (7'), or third layer, with a stratified or single-piece structure, resulting from the drying of at least one additional layer (7), possibly several successive additional layers (7), applied to said at least one base layer (5), this functional top layer (7') not exhibiting enhanced or special fire resistance properties and the base layer (5) forming a second intermediate layer between the aforementioned first and third layers (2 and 7'), and it alone, comprising at least one intumescent material (5) as an additive and consisting of a bonding primer, also exhibiting migration barrier functions between the first and third layers (2 and 7'). Roofing device (1) according to claim 15, characterized in that the first (2) and third (7') layers have mutually different physicochemical compositions or are predominantly based on materials having mutually different physicochemical compositions, and in that that the fire resistance properties of the laminated complex (8), and advantageously those of the roofing device (1), are conferred solely by the second intermediate or base layer (5), neither of the first and third layers (2 and 7') having a physico-chemical constitution giving it particular fire resistance properties.

17. Roofing device (1) according to claim 15 or 16, characterized in that the functional upper layer (7') corresponds to a layer, in one piece or laminated, resulting from the drying of one or more additional layer(s) (7) of the liquid sealing material type.

18. Roofing device (1) according to claim 15 or 16, characterized in that the functional upper layer (7') corresponds to a layer, in one piece or laminated, preferably light in color, possibly white, having radiative properties, and advantageously a solar reflectance index (SRI) greater than 90, preferably greater than 100.

19. Roofing device (1) according to any one of claims 15 to 18, characterized in that the functional upper layer (7'), with a one-piece or laminated structure, is a continuous sealing layer of light or white colour and has radiative properties, and advantageously a solar reflectance index greater than 90, preferably greater than 100.

20. Roofing device (1) according to any one of claims 15 to 19, characterized in that the second intermediate or base layer (5) and the functional top layer (7') only partially cover the surface of the waterproofing membrane or similar waterproofing system (2) corresponding to the first layer and form a pattern of a decorative, representative or informative nature, preferably the functional top layer (7') having a different colour from that of the first layer (2).

21. Roofing device (1) according to any one of claims 15 to 20, characterized in that the functional layer (4) optionally present is a thermal insulation layer, preferably of the rigid type, the first membrane-type layer (2) advantageously consisting of a bituminous membrane, preferably cold self-adhesive.

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