EP0463933B1 - Underlayer to lay slabs or tiling - Google Patents

Abstract

Underlayer, capable especially of being disposed between a slab or support, made of concrete or prestressed concrete, and a covering surface formed by contiguous and juxtaposed flagstones of a tiling or the like. According to the invention, the underlayer in question is characterised in that it consists of a material (8, 12) having a low modulus of elasticity, suitable for constituting a zone of fracture or of weakness in order to transmit the stresses from the slab (1) to the tiling (2). The material of the underlayer may be especially a bitumen or a bonding mortar incorporating a polymerisable resin to which cement has been added. <IMAGE>

Description

The present invention relates to an underlay suitable for the direct laying of tiles on a support slab, in particular in prestressed concrete.

When building premises, in particular for residential or other use, it is common to equip the ground floors of buildings on all or part of their surface with tiling.

However, experience shows that, without any particular precaution, in particular if the removal of the concrete after pouring of the slab forming the support, is not completely completed, disorders appear. They consist of detachment or cracking of the tiles.

It is frequent that, fixed again, the tiling is detached once again from its support thus bringing the proof that it occurs at the tiling interface slab of the physical phenomena that the tiling mortar cannot absorb. Even if the slab is covered with a thick mortar screed in which the tiles are sealed, it is demonstrated by a mathematical model that the shrinkage of the concrete results in the interface between the screed and the tiling by a stress of shear.

This harmful effect is less noticeable when the tiles are sealed in a mortar screed, but the construction does not always make it possible to have an acceptable free thickness above the slab.

The detrimental effect is more noticeable when the tiles are no longer sealed but simply glued, in particular by means of a bonding layer, in adhesive mortar placed above the concrete slab, and all the more so since the tiles are larger.

The installation of the tiles by gluing would constitute a more satisfactory process because of the speed of laying that it provides. However, in the current state of the art (Technical specifications), installation by gluing is prohibited on many concrete or prestressed concrete substrates, in particular on the slabs of individual houses to limit almost systematic damage .

However, when the size of the tiles increases, sealing becomes an impossible practice, one cannot, in fact, obtain a perfect seating of the large tile by threshing, without the risk of breaking it, which makes it even more necessary to point of a bonding technique as proposed by the present invention.

British patent GB-A-445,811 illustrates a bonding sub-layer between a concrete slab or support, if necessary prestressed, and a covering surface formed by tiles or the like, in which the concrete surface is arranged and tiles a composite thickness consisting of bituminous felt, an asphalt coating, a thin layer of bitumen and finally a dispersion of particles of cork or similar material, with a granular coating of the sand type or other, realizing hanging of cork particles on the lower surface of the tiles.

Such an embodiment aims to ensure a better connection between the concrete support and the layer of tiles by providing a more resistant and better insulating assembly, in particular from an acoustic point of view. However, such a structure is complex, difficult to implement and does not make it possible to withstand the shear stresses at the interface between this support and the layer, making it possible to eliminate the drawbacks which arise from the inevitable withdrawal of the support from concrete.

FR-A- 2,378,918 also describes an underlay between a concrete support slab and a covering surface formed of tiles, with a bonding mortar incorporating a certain amount of resin between these two elements. . Nevertheless and here again, the result obtained is not perfectly satisfactory, the phonic and thermal improvement created not making it possible to limit the shear stresses created, the modulus of elasticity of the intermediate layer being non-negligible.

The subject of the present invention is a sub-layer for laying tiles or the like, which avoids the drawbacks of conventional solutions, by allowing both easy laying of this tile by means of an appropriate bonding substance. and a satisfactory weakening of the shear stress at the interface between the underlay and the tiling.

To this end and in a first embodiment, the considered underlayer, suitable in particular for being disposed between a concrete or prestressed concrete slab or support and a covering surface formed by the adjoining tiles and juxtaposed with a tiling or the like, consisting of a bituminous material on which is laid a thin layer of a bonding mortar, on which the tile is then directly laid, is characterized in that the bituminous material is a fluxed bitumen having a low modulus of elasticity, suitable for constituting a zone breaking or weakening for the transmission of stresses from the slab to the tiling and is coated on its face receiving the thin layer of bonding mortar with a dispersion of a mineral granule, of the diorite, quartzite, silica or similar type .

According to an additional characteristic, the bituminous material has in its face coming into contact with the concrete slab, a thin adhesive layer, facilitating its connection with the surface of the slab.

Furthermore and in a manner known per se, the thin adhesive layer can be coated with a non-stick protective protective film of plastic, of the polyethylene type or of silicone paper, capable of being removed from the adhesive layer before application. of the layer of bituminous material on the concrete slab. If necessary, an intermediate layer can be placed between the slab and the layer of bituminous material.

In another embodiment, the material of the underlay consists of a bonding mortar incorporating in a suitable proportion an emulsion of a resin, the latter comprising cement in a given proportion, allowing the absorption of the excess water by hydration reaction of this cement, thus facilitating the laying of tiles. Advantageously, the resin used is a resin formed from an acrylovinyl copolymer.

• La Figure 1 est une vue en coupe et en perspective partielle d'une dalle de béton recouverte d'une surface en carrelage, celui-ci étant mis en place selon la pratique habituelle.
• Les Figures 2 et 3 sont des vues également en coupe et en perspective partielle de sous-couches résilientes selon l'invention, correspondant à deux variantes de réalisation de cette dernière.

Other characteristics of an underlay for laying tiles on a prestressed concrete slab will become more apparent from the following description of two exemplary embodiments, given by way of non-limiting indication, with reference to the appended drawing in which:

• Figure 1 is a sectional view in partial perspective of a concrete slab covered with a tiled surface, the latter being put in place according to usual practice.
• Figures 2 and 3 are views also in section and in partial perspective of resilient underlayers according to the invention, corresponding to two alternative embodiments of the latter.

In Figure 1, the reference 1 designates the upper part of a reinforced or prestressed concrete slab intended in particular to constitute the floor of a dwelling house or a similar room, with placement on top of the slab of a covering of tiling 2 consisting, in itself quite classic, of contiguous and juxtaposed tiles 3. According to the usual practice for the laying of such a tiling, a thick layer 4 is deposited on the slab 1 a mortar screed, in which the tiles are sealed by being placed one by one on the surface of the screed, juxtaposing them according to the design of the tiling to be produced and the relative dimensions of these tiles. Conventionally, the tiles have in their face coming into contact with the sealing mortar an uneven and in particular non-planar surface 5, in order to facilitate the creep of the mortar in the hollow parts thus presented and perfectly secure each tile of the screed ensuring perfect horizontality of the coating.

However, it is noted, for the reasons already specified, that if the removal of the concrete from the slab 1 is not completed in a substantially complete manner, occurs at the interface between the tiling 2 and the mortar screed 4, constraints of shear which are all the more important as the thickness of the screed is lower and especially that the compressive forces created in the concrete slab following the withdrawal of the latter, are greater. However, depending on the requirements of the construction, it is not always possible to reserve above the slab a threshold height sufficient for the installation of a thick screed. In addition, for the sake of profitability of the operation, it is preferable to proceed with the installation of the tiling using a technique of gluing the tiles, all the more so since the dimensions of the latter are themselves important. . Under these conditions, the shear stresses occur at the interface 6 between the screed and the tiling 2 and become such that they exceed the resistance of the bonding mortar used in such a technique, inevitably producing uplifts or cracks in the tiling. which comes off the mortar, the release of stresses which can also be accompanied by a particularly annoying explosion noise.

According to the invention, the tiling is carried out on the concrete slab by interposing between them a resilient underlay 7, on which the tiles 3 can be directly bonded according to the usual technique, and of which Figures 2 and 3 respectively illustrate two alternative embodiments.

In the example illustrated in FIG. 2, the resilient sub-layer 7 is constituted by a bituminous material 8 and in particular an appropriate fluxed bitumen, presented in plates or in rolls and which can thus be directly placed on the concrete slab 1. Advantageously, the bitumen layer comprises in its surface directed towards the tiling a coating 9 of a mineral granule, of the diorite, quartzite, silica or other kind, allowing good adhesion on the thin layer 10 of a conventional adhesive mortar, on which the tiles 3 of the tile 2 are then arranged, in accordance with usual practice. Preferably also, the sub-layer 7 comprises, under the bitumen layer 8, an adhesive coating 11 which facilitates the placing on the concrete slab 1 and the joining with the latter of the deposited layer. Usually, the adhesive coating can be protected by a plastic film (not shown) made of polyethylene or silicone paper, this film being removed before the bitumen layer is placed on the slab.

In the variant illustrated in Figure 3, the sub-layer 7 consists of a thickness 12 of a flexible bonding mortar within which is dispersed an appropriate quantity of a polymerizable resin, in particular of the acrylovinyl copolymer type, to which is also added a certain amount of cement, the latter contributing on the one hand to the absorption of excess water in the underlay by hydration of the cement, and also to the fixing of the tiling. Indeed, the installation of the latter using only resin, would pose a problem of the evacuation of the emulsion water which would remain trapped between the support and the tiling and could not be evacuated until the end. a very long time, not compatible with the usual implementation constraints.

A resilient underlay is thus produced allowing the easy and safe installation of a tile on a concrete slab, the characteristics of which make it possible to significantly weaken or even eliminate the shear stresses at the interface between this tile. and the undercoat, and consequently to overcome the disadvantages which result from an indefinite withdrawal of the concrete. Such an undercoat has a reduced cost price and is very easy to use at the same time as it makes it possible to fix the tiles using the faster and more efficient gluing process, especially when the size of the tiles becomes large.

Claims (5)

1. Connecting substrate capable of being arranged, in particular, between a concrete or prestressed concrete slab or base and a covering surface formed by the joined juxtaposed tiles of tiling or the like, consisting of a bituminous material (8) on which there is arranged a thin layer (10) of an adhesive mortar, on which the tiling (2) is then placed directly, characterised in that the bituminous material is a fluxed bitumen having a low modulus of elasticity capable of forming a breakage or weakened region for the transmission of stresses from the slab (1) to the tiling (2) and is covered on its face receiving the thin layer of adhesive mortar with a dispersion of mineral pellets (9) of the diorite, quartzite, silica or similar type.
2. Connecting substrate according to claim 1, characterised in that the fluxed bitumen (8) contains, in its face coming into contact with the concrete slab (1), a thin adhesive layer (11) facilitating its connection to the surface of the slab.
3. Connecting substrate according to claim 2, characterised in that the thin adhesive layer (11) is covered with a non-adhesive protective film of polyethylene-type plastic or of silicone-coated paper capable of being removed from the adhesive layer before application of the substrate of bituminous material to the concrete slab.
4. Connecting substrate capable of being arranged, in particular, between a concrete or prestressed concrete slab or base and a covering surface formed by the joined juxtaposed tiles of tiling or the like, consisting of a flexible adhesive mortar (12) incorporating an emulsion of a polymerisable resin, characterised in that the resin contains, in part, cement allowing the absorption of supernatant water in the substrate by a hydration reaction.
5. Connecting substrate according to claim 4, characterised in that the resin is an acrylovinyl copolymer.

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