Floor System, a Coupling Insert and a Floor Covering Comprising Such a Floor System

The present invention relates to a floor system, a coupling insert and a floor covering comprising such a floor system.

More particularly, the invention is related to a floor system for forming a floor covering, wherein the floor system comprises a floor element, wherein this floor element comprises a decorative layer made of a brittle material such as natural stone, glass or sintered ceramic materials like porcelain, earthenware or the like. The decorative layer can, for example, be a ceramic tile.

Traditionally, ceramic tiles are installed by laying them side by side on a surface such as a floor or wall. Typically, an adhesive compound is used to attach the tiles to the surface. Seams between the tiles are grouted. In this way, the tiles are bonded to a rigid surface, for example a concrete subfloor, thereby improving their impact strength. The bound with the subfloor, and thus also with the structure of the dwelling, also leads to a high attenuation of walking sounds, both in the room where the floor is installed, and in quarters below the respective room. The tiled surface is water impervious and hygienic, since it can be cleaned in a very wet manner. The step of installing the tiles with an adhesive is, however, labor intensive and represents a significant portion of the labor involved in a typical floor covering installation. Moreover, this installing technique requires a high professional competence in order to obtain a well levelled floor covering. Thus, due to the time and labor involved in the installation, it is typically quite costly to have tiles professionally installed. Further, expansion gaps need to be provided in the tiled surface in accordance with the expected expansion of the subfloor. Installing on a wooden subfloor may lead to failure due to the different expansion mechanism of the subfloor and the ceramic tile.

To substitute an existing floor covering made of tiles, it is often necessary to break the tiles, regenerate the surface by removing the residues of adhesive and then install a new floor covering. Thus, the demolition of a floor covering made of tiles is a labor and time-consuming operation. If the aim of the restoration is to substitute only one or a few damaged tiles, this operation becomes also difficult, since the substitution of one tile preferably does not damage the adjacent tiles.

In recent years, manufacturers have attempted to produce do-it-yourself tiling solutions that are easier to install. Some examples of these attempts are shown in WO 2004/097141 and WO 2008/097860. The floor elements disclosed in those documents can be laid on a surface and mechanically coupled together to form a floor covering without the use of an adhesive, thereby reducing the labor and time of the installing phase. Such kind of floor covering is known as a floating floor covering. In particular, in these documents, a ceramic tile or natural stone slab is fixed to a support layer that comprises coupling elements, in the form of tongue and groove, configured to realize a coupling with coupling elements of an adjacent floor element, thereby forming a floor covering. Due to its floating nature, the floor covering can be laid over expansion gaps foreseen in the subfloor.

On the other hand, since such floor elements are not bonded to a common rigid surface, the impact strength and, consequently, the fatigue strength is significantly reduced. The floating installation may also give rise to louder walking noise. The joints between the tiles of WO 2008/097860 may be prone to water penetration especially upon wet cleaning. According to some embodiments of WO 2004/097141, grout may be applied in the joints available between adjacent floor elements, which may lead to water imperviousness of the respective joint.

Nevertheless, floor elements with mechanical coupling elements and a hard decorative layer, like the one disclosed in WO 2004/097141, can be heavy and complicated to handle during installation to achieve the mechanical coupling. Moreover, this kind of coupling elements can allow lay down of the floor elements in a limited number of configurations.

WO 2015/005860 discloses ceramic tiles that are connected at adjacent edges by means of separate coupling inserts. Hereto the edges of the ceramic tiles have been provided with profiled edges. Intricate machining of edges of ceramic tiles is difficult, and the required grooves and/or undercuts may render the edges vulnerable to damage on impact load, or even with localized static loading.

The present invention aims in the first place to provide an alternative floor system, which, in accordance with several of its preferred embodiments, is directed to solving one or more of the problems arising in the state of the art.

Thereto, the present invention, according to its first independent aspect, relates to a floor system comprising a floor element, wherein said floor element comprises a top layer, preferably comprising a ceramic tile, and a support layer, wherein said support layer comprises edges provided with coupling elements, wherein the system comprises at least one coupling insert adapted to interact with one coupling element of the floor element. In this way, it may be possible to simplify the lay down of the floor elements as by using an insert a new and easier coupling movement can be available to an operator. As the support layer is provided with edges having coupling elements, intricate profiling of the top layer edges can be omitted. The support layer may further provide stabilizing, levelling and/or sound attenuating effects to the floor covering. The floor system is preferably suitable for floating installation. The floating installation leads to an easy removal or even a temporary, possibly repeated, use of the same floor elements or parts thereof. Existing expansion gaps in the subfloor may be bridged.

Additional cushioning and/or sound attenuation may be attained by an underlayment available between the subfloor and the floor element, more particularly the support layer of the floor element. It is noted that the floor elements, in particular the support layers of the floor elements, may be loosely installed over such underlayment or may be glued onto such underlayment. The glue may be factory applied on the underlayment and/or on the bottom of said support layer and, for example, shielded by means of a removable foil. Glueing the floor elements to an underlayment may create additional stability to the floor covering, while maintaining the floating nature of the floor covering, inclusive the underlayment.

Preferably, said top layer, e.g. ceramic tile, is reinforced by means of reinforcing means. Said reinforcing means can comprise one or more of a resin material, a glue, a glass fiber sheet and a steel sheet available in between said support layer and said ceramic tile. Preferably, said top layer, preferably a ceramic tile, is at its bottom or downward oriented side impregnated by means of a resin material having one or a combination of two or more of the following properties:

The application of such resin material may bring about a floor element having an impact resistance greater than 5 J, also when said top layer is a brittle material, such as a ceramic tile. Preferably, the resin material at the same time functions as a glue adhering said top layer to said support layer. WO 2021/225808 and WO 2021/055260 disclose suitable resin materials for reinforcing top layers of brittle material and are incorporated herein by reference in their entirety.

Preferably, the material of said top layer is porous at the lower or downward oriented surface thereof. Such porosity allows for glue and/or resin material to impregnate the bottom of said top layer. In that way a reinforcing effect can be obtained. Preferably said top layer is a ceramic tile having a porosity as measured by means of the boiling method described in ISO 10545-3:2018 of 0.01% to 10%, or 0.1% to 10% or 0.01% to 6%, or 0.1% to 6%. In a special embodiment, the top layer is a ceramic tile having a porosity as measured by means of the boiling method described in ISO 10545-3:2018 is from 0.01% to 0.5%. In the latter case, the ceramic tile is of porcelain quality. Generally speaking, a minimum amount of porosity is desired to obtain some penetration of glue and/or resin material into the lower or downward oriented surface of the ceramic tile. Too high a porosity is preferably avoided in order to economize on the resin material, as well as to maintain an acceptable impact resistance of the floor element. A preferable amount of glue for obtaining the desired reinforcing effect can be above 150 gm/sqm.

In accordance with said first aspect, said support layer comprises edges provided with coupling elements. Said coupling elements can be the same on opposite edges of the support layer, and preferably on all the edges of the support layer. In this way, manufacturing the support layer, and consequently the floor element, can be simplified. Additionally, installation can be simplified as one coupling insert, and possibly the same coupling movement, can be used on all the edges of the support layer.

The coupling elements can be configured such that in a coupled condition with the coupling insert, relative movement between the coupling insert and the floor element in one or more vertical and/or horizontal direction is limited or prevented. Preferably, said coupling elements can comprise one or more first contact surfaces adapted to contact respective first contact surfaces of the insert to thereby prevent or limit said movement in one or more vertical directions. Said first contact surfaces preferably extend horizontally or substantially horizontal, i.e. parallel or substantially parallel to the plane of the support layer, or extend at an angle of less than 45° with the horizontal plane or the plane of the support layer. Preferably, said coupling elements can comprise one or more second contact surfaces adapted to contact respective second contact surfaces of the insert to thereby prevent or limit said movement in one or more horizontal directions. Said second contact surfaces preferably extend vertically or substantially vertical, i.e. perpendicular or substantially perpendicular to the plane of the support layer, or extend at an angle of less than 45° with the vertical plane or the plane of the support layer. It is also possible that said coupling elements and insert prevent or limit the mutual movement in one or more vertical directions only, or in one or more horizontal directions only. According to an alternative, said coupling elements and insert prevent or limit the mutual movement in one or more horizontal directions by means of a friction connection. Preferably said friction connection in itself prevents or limits the mutual movement in one or more vertical directions. For example said coupling insert may clamp a portion of said coupling elements. The clamping may be brought about by means of a tightened mechanical connection, such as by means of a screw connection or a snapping connection, preferably comprising one or more hooks and undercuts.

In a preferred embodiment of the invention, the coupling elements are disposed partially, preferably entirely, at a horizontal level below said top layer, more particularly below the bottom or downward oriented side of said top layer. In this way, it may be possible to limit the distance between adjacent edges of the top layer of the floor elements, and/or the length of said distance can be determined mainly, whether or not exclusively, by the shape and dimension of the coupling insert. For example, said coupling element can project inwardly with respect to a respective edge of the top layer for a major portion or in its entirety. Preferably, said first contact surfaces, when available, and/or said second contact surfaces, when available, extend at least partially, and preferably wholly, vertically below said downward oriented surface of said top layer.

Anyway, in alternative embodiments, said coupling elements can partially or entirely extend beyond a respective edge of the top layer. For example, it is possible that said coupling elements are partially or entirely formed in or by respective portions of the support layer that extend beyond respective edges of the top layer.

In the most preferred embodiment, the coupling elements are configured to allow coupling with the coupling insert in an angling, horizontal and/or downward, e.g. vertical, movement. Downward or vertical movement is preferred above the other as it is more similar to the movement required in traditional installation of ceramic tiles. A horizontal movement can also be executed quite naturally and intuitively, and is therefore also an advantageous embodiment.

Preferably, the coupling of the coupling insert with the coupling element is purely mechanical, i.e. obtained by the geometry of the insert and element. Alternatively, the coupling may comprise an adhesive that may or may not be pre-applied to said coupling insert or said floor element, in particular to said coupling element.

In the most preferred embodiment, the coupling elements can be present substantially continuously along the entire length of the respective edge. In this way, multiple installation configurations can be achieved. Furthermore, continuous profiling of such edge to form said coupling elements may be executed fluently in an industrial manner, for example by using so- called end-tenoners, wherein the support layer, whether or not already connected to the top layer, is transported with the respective edge in a continuous manner past rotating milling cutters.

Preferably said coupling elements are at least in part, preferably integrally, formed in said support layer. In particular, the coupling elements can be milled in the support layer, for example as stated above using an end-tenoner. In alternative embodiments, the coupling element can be partially formed by the top layer, for example the coupling elements can be in the form of a recess, or can comprise a recess, between a downward oriented surface of the top layer and an upward oriented surface of the support layer. In accordance with such alternative embodiment, obtaining a sturdy coupling remains possible even in thin support layers, for example in support layers having a thickness of 2 to 3.5 mm.

In the most preferred embodiment, the support layer is in the form of a panel, or a board, attached, for example laminated, to a lower surface of the top layer. As stated above, the lamination can be obtained by means of a resin material or a glue that for example impregnates the downward oriented surface of the top layer.

Preferably said support layer can be made of thermoplastic material, for example PE (poly ethylene), PP (poly propylene), PVC (poly vinyl chloride), PET (poly ethylene terephthalate). It can be preferable that the material forming the support layer is rigid as it may contribute in improving the impact resistance of the top layer. For example, the material forming the support layer can comprise a high content of mineral filler, for example above 50%, more preferably equal or above 60%, based on the weight of the support layer itself. Said mineral filler can comprise chalk or calcium carbonate. For example, the material forming the support layer can comprise low or no content of plasticizer, for example a content of plasticizer lower than 15 phr, or lower than 5 phr. Preferably, the PVC, for example PVC with a plasticizer content of 5 phr or lower, comprises a thermal expansion coefficient below 85 μm/m per° C., preferably below 60 μm/m per° C. for example 50 μm/m per° C. For example, thermal expansion coefficient of the support layer can be comprised between 20 μm/m per° C. and 85 μm/m per°° C., preferably between 40 μm/m per° C. 60 μm/m per° C. In such case, the differential expansion between the support layer and a typical brittle top layer, such as a ceramic tile, can be limited and warping effects, as well as the risk for subsequent failure of the flooring elements can be minimized.

Alternatively, said support layer may comprise wood-based material, such as an MDF or HDF board, or, comprise mineral-based material, such as a cement fiber board, a gypsum board, or a magnesium oxide board, or, comprise thermosetting plastic material, for example unsaturated polyester or a copolymer of unsaturated polyester. In the latter case, the material described in WO 2022/224086 and/or WO 2023/144744, both incorporated herein in their entirety, may be applied.

The top layer can preferably be made of a ceramic tile, more preferably of the kind having a ceramic body and one or more glaze coatings covering the upper surface of the tile. A decorative pattern can be present in said glaze coatings. Preferably, the ceramic body is made of porcelain stoneware, but alternatively can be made of other ceramic materials like, for example, red body ceramic.

Preferably, the top layer comprises a lower, i.e. bottom or downward directed, surface which is substantially flat, i.e. free from any relief structure or comprising a relief structure showing a depth below 1 mm. Preferably, said top layer has a flat, or nearly flat bottom surface over at least 85%, or at least 95%, of the area of said bottom surface. Preferably the maximum deviation of said bottom surface from a least squares plane defined by said bottom surface, or defined by at least 85% or at least 95% of said bottom surface, is less than 500 μm, or less than 250 μm. For example, said top layer is a ceramic tile that has been produced using a continuously operated powder scattering line with subsequent continuously or semi-continuously operated pressing. An example of a continuously operated pressing is disclosed in EP 1 356 909 which is incorporated herein in its entirety by reference.

Preferably, said top layer has a thickness larger than the thickness of said support layer, for example a thickness that is at least 150% or at least 200% of the thickness of said support layer. The top layer can for example be a ceramic tile with a thickness of at least 7 millimeter, while the support layer can have at thickness of 4.5 millimeter or less, for example 3.5 mm. Such support layer may be an extruded board material, for example mainly comprising a thermoplastic material, such as PVC, and filler material, preferably inorganic filler material, such as CaCO3, sand and/or talcum.

Preferably, said support layer has a thickness of at least 2 mm, or at least 3 mm. Such thickness of support layer allows forming coupling elements at the edges of the support layer, while offering a sufficient levelling ability.

The floor elements can comprise an intermediate layer between the top layer and the support layer. The intermediate layer can preferably comprise a resin material bonding together the tile and the support layer. Preferably this concerns a resin material as described above, that may impregnate the downward oriented surface of said top layer. Alternatively, the intermediate layer comprises a sheet of metal and/or a textile layer, such a glass fiber layer, either woven or non-woven, or a complex of a woven and non-woven textile or glass fiber layer.

The coupling insert can be adapted to interact with two or more floor elements, for example three floor elements or four floor elements. For example, said insert can comprise a central portion and two or more lateral portions extending laterally from said central portion wherein at least said lateral portions are adapted to interact with respective coupling elements of the floor elements. The central portion can be configured to maintain a desired width, as measured in the plane of the floor covering and perpendicular to the respective edges, between the top layers and/or the support layers of the floor elements concerned. Hereto, the coupling insert, more particularly the central portion, can comprise abutting surfaces for contacting adjacent edges of said top layers and/or support layers. The abutting surfaces may be vertically or substantially vertically oriented. The floor elements, more particularly the coupling elements thereof, may be configured for cooperation with a plurality of differently dimensioned and/or shaped coupling inserts. In particular, the floor elements may be configured for cooperation with at least a first and a second coupling inserts, wherein said first coupling insert maintains a first width as measured in the plane of the floor covering and perpendicular to the respective edges, between the top layers and/or the support layers of the floor elements, and wherein said second coupling insert maintains a second width as measured in the plane of the floor covering and perpendicular to the respective edges, between the top layers and/or the support layers of the floor elements, and wherein said first width is larger than said second width, for example at least 1 mm larger.

In the most preferred embodiment, the coupling insert can be adapted for being coupled to three or four floor elements. Preferably said coupling inserts are adapted to interact with a corner area of the floor elements. For example, the coupling insert can be adapted to interact with one coupling element in an area at an extreme of the respective edge, which is at a corner of the floor element. In some embodiments it may be possible that one coupling insert is adapted to couple with two coupling elements on two different, preferably consecutive, edges of one floor element. Preferably, said two different edges extend perpendicular to one another, and said one coupling insert cooperates with coupling elements on said two edges where the respective edges meet in a corner area of the floor element. By interacting with the corner areas of the floor elements, the coupling insert can provide for a good alignment between the floor elements in the floor covering. For example, said coupling insert can, in a top view, be T-shaped or Y-shaped, for coupling together three floor elements, wherein three lateral portions extend laterally from said central portion. For example, a Y-shaped coupling insert can allow coupling of floor elements having a non-rectangular shape, like hexagonal or chevron shape. For example, said coupling insert can, in a top view, be cross-shaped, for coupling together four floor elements, wherein four lateral portions may extend laterally from said central portion.

In some embodiments, the system can comprise multiple coupling inserts of different types. For example, the system can comprise one or more T-shaped (or Y-shaped) coupling inserts and one or more cross-shaped coupled inserts and/or one or more coupling inserts adapted to cooperate with only two floor elements. For example, for non-offset straight lay down of squared floor elements, i.e. for example in a checkerboard pattern, the system can comprise cross-shaped coupling inserts, for coupling floor elements at the corner areas thereof and, and coupling inserts adapted to cooperate with only two floor elements, for coupling together two floor elements substantially at the mezzanine off the respective edges. In this way, it may be possible to couple floor elements having relatively large dimensions thereby limiting or avoiding lippage in the floor covering. In fact, it is to be noted that floor elements are often not perfectly flat and can show a convex/concave shape. This defect is often irrelevant when the dimensions of the floor element are limited but can become more visible and noticeable in floor elements of large dimensions.

Preferably said central portion can be formed by a body that extends substantially perpendicularly from the lateral portions. Said central portion is adapted, in an installed floor, to stay in between two or more floor elements so that its width can determine, or at least contribute to determine, a distance between the top layers of said floor elements. Preferably, such central portion comprises abutting surfaces for contacting the edges of adjacent support layers and/or top layers.

Preferably, at least said lateral portions comprise first and/or second contact surfaces adapted to contact respective first and/or second contact surfaces of the coupling elements. For example, in some embodiments having second contact surfaces, one lateral portion can be formed by an upper and/or a lower lip having one or more humps or protrusions adapted to define said second contact surface and to interact with respective recesses in the coupling elements (or vice versa, said lip of the coupling insert can have one or more recesses adapted to define said second contact surface and to interact with respective humps or protrusions in the coupling elements). In some embodiments, the central portion of the coupling insert can comprise one or more of said first and/or second contact surfaces adapted to contact respective first and/or second contact surfaces of the coupling elements. For example, said body of the central portion can comprise one or more humps or protrusions adapted to define said first contact surface and to interact with respective recesses in the coupling elements (or vice versa, said body of the central portion of the coupling insert can have one or more recesses adapted to define said first contact surface and to interact with respective humps or protrusions in the coupling elements). It is to be noted that said first contact surfaces formed in the body of the central portion are directed to limit or prevent vertical movements between the coupling inserts and the floor element. Said first contact surfaces may be formed by said lateral portions, in particular by said upper lip and/or lower lip.

In some embodiments, the coupling insert can be made of a material that is different from the material forming the support layer and/or the top layer. In some embodiments, the coupling insert can be made of a material being more elastic than the material forming the support layer and/or the top layer. For example, the material forming the coupling insert can be compressible. Alternatively, said coupling insert can be adapted to deform while coupling with the coupling element of the floor element. For example, said coupling insert may comprise one or more deformable, for example flexible, portions. In this way, the coupling insert can be at least partially inserted into a recess of the support layer and exert an elastic reaction, by means of the material itself or by means of a deformable portion, which holds the coupling insert and the floor element together.

In a first preferred possibility for forming the coupling insert, this is made of a thermoplastic material, for example PE (poly ethylene), PP (poly propylene), PVC (poly vinyl chloride), PET (poly ethylene terephthalate).

In this way the insert can be formed of a relatively economic material and can, for example, be manufactured by means of injection molding which can lead to low manufacturing cost and on the other hand can allow forming of complex geometries. In a second preferred possibility for forming the coupling insert, this is made of metal, for example steel or aluminum, for example by means of stamping. The coupling insert may also be composed of two or more portions of a same or similar material, or of different materials, for example one portion made of metal and one portion made of plastic material, either thermoplastic or thermosetting.

In accordance with a special embodiment, said coupling insert comprises a lower portion and a separate upper portion, wherein the lower portion and the upper portion are preferably connected over a tightened or tightenable mechanical joining system. Said mechanical joining system may comprise a screw connection and/or a snapping connection, preferably comprising one or more hooks and undercuts, for example a ratchet. During installation said first portion can be engaged with the support layer, for example by placing it with a part thereof below said support layer, or by introducing said part in a groove or undercut of said coupling elements. An adjacent floor element may then be placed, preferably also engaging its support layer with an opposite part of said first portion, preferably in a same or similar manner, i.e. by placing the support layer over said opposite part, or by introducing said opposite part in a groove or undercut of said coupling element. Preferably said adjacent floor element can be installed and made to engage with said opposite part by means of a movement substantially in the plane of the installed floor elements. Subsequently said second portion can be tightened by using said tightenable mechanical joining system. Preferably, said second portion, in a tightened condition, contacts the support layer of at least one of, and preferably both of, said adjacent floor elements. Said contact may be a contact under pressure. In the tightened condition said coupling insert and said coupling elements preferably limits at least the motion of said floor elements in a vertical direction perpendicular to the plane of installed floor elements. For example, said first portion and said second portion may clamp adjacent edges of support layers in between them. Due to said clamping first contact surfaces may be formed as described above. According to a preferred embodiment, in said tightened condition, said first and/or said second portion may form second contact surfaces to thereby prevent or limit the movement of adjacent edges of support layers in a horizontal direction in the plane of installed floor elements and perpendicular to said adjacent edges.

In some deviant embodiments, said floor elements and/or said coupling inserts can comprise cavities and/or hollow portions adapted for being partially filled with an adhesive material, for example a grout, filling a space between the top layers of two floor elements in a floor covering so that the adhesive material can contribute to limiting vertical and/or horizontal movements between the floor elements.

It is noted that a floor element and a coupling insert as described in relation to the first independent aspect can both form an invention per se, as well as the pertaining methods for installing a floor covering using such floor elements and coupling inserts.

Therefore, and with the same object as in the first aspect, the invention, according to a second independent aspect, is a floor element comprising a top layer, preferably made of a ceramic material, and a support layer, wherein said support layer comprises edges provided with coupling elements adapted for being coupled with a coupling insert. It is particularly preferable that the floor element has the characteristic that said coupling elements are the same on opposite edges of the support layer, more preferably on all the edges of the support layer. It is to be noted that the floor element of the second independent aspect can comprise one or more of the features described above in relation to the first aspect.

In its third independent aspect the invention also relates to a coupling insert for installing floor elements in a floor covering, comprising contact surfaces adapted to cooperate with contact surfaces of a floor element. It is particularly preferred that the coupling inserts comprises one or more of the following characteristics:

It is to be noted that the coupling insert of the third independent aspect can comprise one or more of the features described above in relation to the first aspect.

According to a fourth independent aspect, the invention is a coupling insert for installing floor elements in a floor covering, wherein said coupling insert comprises at least a first portion and a second portion, characterized in that said first and said second portion are connected over a tightened or tightenable mechanical joining system. Preferably, said mechanical joining system comprises a screw connection and/or a snapping connection, preferably comprising one or more hooks and undercuts, for example a ratchet. Preferably said coupling insert comprises a means for tightening said mechanical joining system, wherein said means preferably extends above the horizontal plane defined by the floor covering. Preferably said means is connected to said first and/or second portion over a weakened material portion. Preferably such weakened material portion is available below the horizontal plane defined by the floor covering. In such case, the means for tightening can be easily removed by causing a rupture at said weakened material portion for example by hammering sideways on said means or by giving said means a kick by the foot. Said means may be formed as a knob, or a nut, such as a butterfly nut. In such case, the mechanical connection is preferably tightened by turning said means, for example in case the mechanical connection is a screw connection. Alternatively said means may be tightened by downward pressure and/or by levering action. In such case the means may be formed as a knob as well. It is noted that the floor elements and the coupling insert of the fourth independent aspect can comprise any of the features described in the preceding aspects of the invention.

In its fifth independent aspect the invention also relates to a floor covering comprising a plurality of floor elements and a plurality of coupling inserts, for example as described in relation to any of the preceding aspects.

In particular, in the fifth independent aspect the floor covering comprises a plurality of floor elements, wherein the floor element comprises a top layer, preferably made of a ceramic material, and a support layer, wherein said support layer comprises edges provided with coupling elements; and a plurality of coupling inserts, wherein each of said coupling inserts is mechanically coupled with at least a coupling element of at least two of said floor elements. It is noted that the floor elements and the coupling insert of the fifth independent aspect can comprise any of the features described in the preceding aspects of the invention.

The floor covering can comprise an adhesive material, preferably a grout, at least partially filling a space between the top layers of the floor elements. Said adhesive material can be polymer-based and/or, less preferably, cement-based. In case the grout is polymer-based it can be polyurethan-based, epoxy-based or silicone-based.

The floor covering can comprise an underlayer between said floor elements and a floor basement to be covered, said underlayer can be a sound insulating mat, a moisture insulating mat or a heat insulator. It is to be noted that in alternative embodiments, the underlayer can be integrally formed in, or solidly fixed to, the floor elements, in particular in or to the support layer thereof.

According to a sixth independent aspect, the present invention is a floor covering comprising a plurality of floor elements, wherein the floor elements comprise a top layer, preferably made of a ceramic material, and a support layer, wherein said floor covering further comprises an adhesive material, preferably a grout, at least partially filling a space between adjacent edges of top layers of said floor elements, with as a characteristic that at said space a clearance is available between adjacent edges of support layers of said floor elements. The available clearance can be used to set the desired width of the eventual space, for example groutline, between adjacent top layers in the floor covering. The clearance need not necessary be empty, but can be filled with said adhesive material and/or with an insert. Such insert may be used to set said desired width of the eventual space between the adjacent top layers or the groutline. The clearance may further allow for some expansion of the support layer. Preferably, said clearance is parallel, or substantially parallel to said adjacent edges of top layers. It is clear that with a clearance between adjacent edges of the support layers, it is meant that there are no directly abutting surfaces of said adjacent edges of support layers that would hinder a moving together of the respective support layers.