WO2005031084A1

WO2005031084A1 - Installation method for coverings of natural or agglomerated stones by assembling preformed regular elements

Info

Publication number: WO2005031084A1
Application number: PCT/EP2004/010536
Authority: WO
Inventors: Giuseppe Godi
Original assignee: Rover S.P.A.
Priority date: 2003-09-26
Filing date: 2004-09-20
Publication date: 2005-04-07
Also published as: ITMI20031844A1

Abstract

The invention relates to a method for the installation of coverings, in particular floors, of natural or agglomerated stones, or other materials. The method consists in the dry installation of a plurality of tiles (1, 2) on a suitable screed or mortar bed, and is characterized in that modules of proper shape and dimension are pre-assembled before installation by joining at least two tiles together.

Description

INSTALLATION METHOD FOR COVERINGS OF NATURAL OR AGGLOMERATED STONES BY ASSEMBLING PREFORMED REGULAR ELEMENTS

Description of the invention The present invention relates to a method for the dry installation of coverings -in particular floors- made from natural materials (marble, granite, or stone), agglomerated stones, or other. In the following description, the terms "installation" and "laying" mean all the operations performed to lay a covering onto a pre-existing structure, either internal or external, using appropriate products or fixing systems. Installation methods based on metallic anchorage of slabs, which anchoring systems can play a role of simple fixing to the supporting wall, or can act as bearing structure, and methods based on an air space between slabs and walls of the structure (ventilated facade) are known and are not part of the present invention. It is also known that the problems of these installation methods are completely different from those related to methods based on backfilling with various adhesives; in fact, the problems encountered in the installation of ventilated fa ades with fixing systems and raised access floors are of technical type and are directly connected to the design of the fixing units. Conversely, in the traditional installation technique with mortar or adhesives, further to objective difficulties due to the fact that the whole sequence of operations is time-consuming, physical and chemical problems related to the structure of the laying material and adhesive used may arise. To understand the problems related to the choice of the installation system and/or the most suitable binder, in the different applications, it is necessary to take into account the structure to be covered and the environmental stresses it must be able to withstand. In particular, it should be borne in mind that floors and walls are complex (multi-layer) building systems and that these systems as a whole, not only the coverings, are environment- sensitive and must be able to withstand mechanical, chemical and hygrometric stresses. The considerations to be taken into account during installation are therefore linked to a classification of the surfaces to be covered. The significance of this classification lies in the fact that to each environmental typology corresponds a different stress level. Moreover, a correct choice of the installation system cannot leave out of consideration the characteristics and the behaviour of the structure to be covered. In particular, it is at least necessary to know: the present state of the surfaces to be covered and to evaluate the need for any pre-treatments; the dimensional variations the structure components might undergo; the physical- mechanical properties of the structure-forming materials and the composition and distribution of joints. The surface shape is also important, because it can influence the choice of the size of the covering material, its arrangement and installation technique (open joint/closed joint). Moreover, the surface size may require the insertion of some dilatation joints and the overall thickness of the covering may influence the choice of the installation system (thick or thin layer). Two fundamental aspects should also be considered when choosing the covering materials: first, they must have physical-mechanical properties that allow to withstand environmental stresses; second, they must be compatible with one another; in fact, since each layer is made of a different material, it would react to environmental stresses according to its own behaviour if it were alone, but when a layer is joined to the others, the behaviour of each of them is mutually affected. These constraints give rise to stretch or compression states inside each layer, and creeps and tensions at the interface between the layers. Under certain circumstances these stresses can be higher than those the materials are able to withstand, with consequent cracks, detachments and bending. Moreover, the way and the quality of the installation may give rise to dangerous conditions due to an incorrect evaluation of the properties of the covering materials in respect of the environment, or to problems due to tensional states between covering and screed. The presence of a binding layer makes it possible to chose the material and the installation system only after having defined all the data of the project. The choice of the covering material must be made not only on the basis of aesthetic characteristics, but also of the performances declared by the manufacturer; these performances affect the covering size, which, in turn, gives elasticity or stiffness to the covering layer. In the case of installation by adhesive, the binding material must meet the following requirements: allow firm and tight anchorage between the upper and lower layer, have a compact structure, have elastic/plastic characteristics able to withstand any movements or deformations of the supporting layer. Moreover, the binding layer affects all the characteristics of the covering. The dimensional variations the covering may undergo primarily depend on the linear thermal expansion coefficient and on the water absorption coefficient of the materials of which it is made. It is therefore necessary that the dimensional variations of the covering materials are compatible with those of the materials of the supporting structure. Any tensional states due, for example, to temperature changes, could cause dilatation, with consequent compression of the covering layer and risk of lifting and detachments of the covering. As a consequence, the system might result unstable due to the presence of layers made of different materials not compatible with one another. The numerous installation methods by adhesives can be divided into two main categories: the so called traditional installation methods with cement mortar (which require laying a mortar bed 4-5 cm thick) and installation methods with adhesive (which require applying a thin layer about 2-5 mm thick). The latter can be further subdivided into two categories, depending on whether adhesives based on cement or adhesives based on organic substances are used. Traditional installation methods with cement mortar require the use of a binding material (cement) and an inert fraction (sand), thoroughly mixed and added with water. The problems experienced with these methods depend in general on high water/cement ratios, incorrect amounts of cement and use of lime in partial or total replacement of cement. The resulting drawbacks are poor adhesion and elasticity, high amounts of free water, poor dimensional stability of the screed, high thickness of the mortar bed and prolonged settling times after installation. Another drawback is that walking on the covering is possible only after a long time following installation. As an alternative to cement mortar, cement-based adhesives can also be used, i.e. pre-dosed cement mortars marketed in the form of powder, to be mixed with water upon use. They are made of cement, sand, resin and other additives, whose main function is to increase both water retention power and adhesion. In general, from the technical point of view, these types of adhesives are not very different from traditional mortars and share the same mechanical brittleness. Other drawbacks are poor elasticity and limited adhesion. Organic-based adhesives are of two types: ready-to-use paste adhesives, i.e. premixed water dispersions of various type (acryl, vinyl, etc.), mineral fillers and additives; two-components adhesives to be mixed upon use, based on synthetic resins (epoxy or polyurethane resins or other) with suitable hardeners. All organic-based adhesives are characterized by good elasticity, therefore they are necessary for applications where differential movements between screed and covering are expected, or in environments particularly subjected to hygro-thermal variations (for example in outdoor coverings). The main drawback is their high cost. It will be understood from the above recalled state of the art that installation problems derive from the need to hold together in a long-lasting and dimensionally stable way layers of materials that are often poorly compatible with one another. Moreover, not only the project, but also the execution is troublesome, and if the operations are not carried out properly, defects may arise over time, mainly deformations in the planarity of the covering, often together with cracks and detachments. Object of the present invention is to overcome the above mentioned drawbacks; in more detail, the object of the invention is to provide an installation method for coverings that does not require continuity among the layers and at the same time makes the covering stable and long-lasting after installation. A further object of the invention is to provide an installation method that can be carried out easily and in short times, without skilled workers. These objects are reached by the invention claimed in independent claim 1. Preferred embodiments are claimed in dependent claims 2-11. The invention also concerns the elements used in the installation method, in particular the tiles of independent claim 13, and the module comprising several tiles of claim 12. In particular, according to the invention, more tiles are joined together to form a panel before laying them onto the screed. This assembling is possible because, after cut-to-size operations, the four tile sides are worked so as to create grooves and protrusions that allow permanent locking. The dimension of the tiles is not subject to limitations; the only limit is imposed by the need to handle the panel once the tiles are assembled. The thickness of the tiles can range from 8 to 30 mm, but is preferably not lower that 12 mm, in order to allow perimeter finishes. The tiles can be bevelled or not and their upper surface can be either polished or honed. The invention further relates to a process for the dry installation of coverings of pre-assembled modules, which does not require the use of cement mortars, organic-based adhesives, or inorganic binders. The main advantages of the process are savings in adhesives, easy installation (skilled workers are not required), and short installation time, which is reduced to the mere positioning of panels prepared in advance by inter-locking more tiles until reaching the desired surface dimensions. However, dilatation joints are still necessary to release the covering from the fixed elements of the building and allow small relative movements, divide large surfaces in smaller ones and interrupt the covering in correspondence of discontinuities in the supporting layer. It is also evident that, to overcome the planarity problems often encountered in buildings, the screed must be prepared properly, by covering it with a compensative layer which could be made of a thin polyurethane mattress, a non-woven polyester fabric, a suitable bituminous membrane, or else. To increase adhesion between joint profiles, an insert or a pin of a suitable material can be introduced in the tiles. As an alternative, or in addition, a thin layer of a suitable adhesive can be applied to tile sides. The panels can be of different dimension and shape, according to the expected thermal stress from the environment; dimension and shape should also allow easy handling. Further to the above mentioned economical advantages, namely savings in adhesive costs and installation times, as well as possibility to immediately step on the covering, also technical advantages are provided, as detachment of the covering from the screed or unwanted reactions between the cement mortar or the adhesive used and the covering material components do not occur. Such reactions could cause not only a structural degradation (with consequent warping and/or cracking), but also a remarkable aesthetic degradation of the covering (mainly stains on the covering surface). It must also be pointed out that the method of the invention, i.e. the dry installation of coverings wherein single tiles are worked on their sides and placed onto a mattress of suitable elasticity, allows the system "floor + covering" to gain the necessary mechanical resistance to walking and withstand mechanical stresses, because the covering is continuous, even without the application of a binding layer. The covering can be finished with conventional methods, by filling the joints with suitable materials having sufficient elasticity to allow it to settle after installation. As an example, the attached drawings show some possible embodiments of tiles suitable for carrying out the installation method of the invention. In the drawings: fig. 1 (A) and (B) schematically show two possible interlocking couplings between tiles; fig. 2 (A) and (B) schematically show two possible tiles junctions using inserts or coupling pins; fig. 3 shows, with size references, an example of covering made with the tiles of fig. 2 (A). In the drawings, reference numbers 1 and 2 indicate tiles which fit together to form a covering panel of appropriate dimensions. The figures show the interlocking coupling between two sides or faces of two adjacent tiles, but it will be understood that such an interlocking coupling extends along the whole tile perimeter, i.e. on the four side of each tile 1, 2. In fig. 1 (A) tile 1 has a triangular protrusion 3 along the whole perimeter, which inserts into a groove or complementary hole 4 of tile 2, while in fig. 1 (B) protrusion 3 and groove 4 have a rectangular shape. However, other shapes of the interlocking elements 3 and 4 are possible and each tile can have protrusions 3 and grooves 4 on either adjacent or opposite sides. In fig. 2 (A) and (B), each tile has a groove or hole 3, 4, of rectangular, in particular square, or semi-cylindrical shape, suitable for housing an insert 5, of rectangular or circular section, respectively, which allows to join the tiles together. Also in this case the fitting elements may have different shapes. In all the represented cases, a bevel 6 is cut on the upper edge of the tiles. EXAMPLE As an example, and with reference to fig. 3, we will refer to a covering made with tiles measuring 30 x 30 cm, or 60 x 60 cm, having a nominal thickness of 12 mm. In this case, adopting the perimeter finishes schematically shown in fig. 2 (A), tiles 1 and 2 should be worked on their sides so as to form grooves 3, 4 having a depth of 4 mm and a height of 4 mm. The distance between the groove and the tile edge could also be of 4 mm. In the case of a bevel 6 having an inclination of 45° and 0.5 mm deep, the distance between the groove and the lower bevel is 3.5 mm. Interlocking between tiles is secured by a strip-shaped insert 5, for example in polyurethane material, 10 mm large and 3.6-3.8 mm thick (anyway smaller than 4 mm). The longer size of the strip should allow the tiles to settle onto the supporting layer at a reciprocal distance of 2 mm. This gap between the tiles should be filled, up to the depth of the strip 5, with a suitable filling material, chosen among those available on the market. In this way, modules formed by two or more tiles can be pre-assembled and laid down without the use of adhesives, over a mattress positioned on the screed. The modules can have different dimensions, and can measure one square metre or more, according to the number of dilatation joints to be inserted in addition to those present along the tile perimeter, for example near the walls, according to the expected temperature changes in the room in which the covering is to be installed. The invention is not limited to the particular embodiments described above and shown in the drawing; various changes and modifications can be made by the skilled in the art, which are covered by the scope of the invention, as defined by the appended claims.

Claims

1. Installation method for coverings of natural or agglomerated stones, or other materials, particularly for walking floors, comprising dry installation of a plurality of tiles (1, 2) on a suitable screed or mortar bed, characterized in that at least two tiles (1 , 2) are pre-assembled before installation to form modules of suitable shapes and dimensions.

2. Installation method according to claim 1, characterized in that the tiles (1 , 2) are mutually interlocked by means of protrusions (3) and complementary grooves (4) the opposite sides of two adjacent tiles.

3. Installation method according claim 2, characterized in that said protrusions (3) and grooves (4) have a triangular, rectangular or other geometrical shape.

4. Installation method according to claim 2 or 3, characterized in that said protrusions (3) and grooves (4) extend along all the perimeter of the tiles (1 ,

2).

5. Installation method according to claim 2 or 3, characterized in that each tile has protrusions (3) and grooves (4) on its opposite or adjacent sides.

6. Installation method according to claim 1, characterized in that the tiles (1, 2) are interlocked by means of connecting pins (5) inserted into substantially identical grooves (3, 4) of the same shape present on the opposite edges of adjacent tiles.

7. Installation method according to claim 6, characterized in that said grooves (3, 4) have a depth x and a height also x centred on a nominal thickness of the tiles of about 3x and in that said connecting pins are strips made of polyurethane material having a with higher than 2x and a thickness smaller than x.

8. Installation method according to anyone of claims 1-7, characterized in that said a bevel (6) is provided on the upper edges of said tiles (1, 2).

9. Installation method according to any one of claims 1 -8, characterized in that said screed or supporting layer comprises a thin mattress made of a polyurethane, a non-woven polyester fabric, a bituminous membrane, or other material.

10. Installation method according to any one of claims 1-9 characterized in that said tiles (1, 2) are positioned at a short reciprocal distance, so as to form a gap which is filled with a material of enough elasticity to allow for small settling movements.

1 1. Installation method according to any one of claims 1-10 characterized in that a thin layer of adhesive is applied onto the sides of adjacent tiles forming a module.

12. A module comprising two or more interlocked tiles (1, 2), for carrying out the dry installation method of coverings according to any one of claims 1- 1 1.

13. Tiles (1, 2) suitable for being mutually interlocked to form a module for the execution of the dry installation method of coverings according to any one of claims 1 to 1 1.