Abstract:
The invention relates to a paving system for tiles, especially flagstones, for paving ceilings, walls, or floors, in which each tile ( 2 ) is provided with a paving frame ( 1 ) on which the tile rests over at least part of its area. The paving frames ( 1 ) comprise, on each of two adjacent (intersecting) limbs ( 1   c   , 1   d ), a fin ( 6 ) for the accommodation of a rubber-elastic sealing profile ( 8 ) that defines the width of the seam.

Description:
BACKGROUND OF INVENTION  
         [0001]    a. Field of Invention  
           [0002]    The invention relates to a paving system for floor tiles and is particularly suitable for stoneware tiles, flagstones, and blocks of wood.  
           [0003]    b. Description of Related Art  
           [0004]    Floor tiles, when in the form of stoneware or ceramic tiles, are usually laid by means of a suitable adhesive on an appropriately prepared surface, eg, a smooth coat, the width of the seams being usually determined by the insertion of cross-shaped gap definers, and the resulting seams must be subsequently pointed. Paving or tile-laying is comparatively elaborate both as regards the tools required and with respect to the necessary materials, and, in addition, it demands relatively high mechanical skill on the part of the paver. Furthermore, the time lapse required before the paving may be walked on is long. Another drawback may be seen to be the fact that paving laid by this method cannot be readily removed, ie not without destroying the tiles.  
           [0005]    In the case of blocks of wood, for example parquetry or laminated blocks, such as are used for floor coverings, is it known to provide a groove on one pair of the intersecting sides of the block and a matching tongue on the other two sides of the block. During the paving operation, the blocks are pushed together so that a groove is engaged by a tongue, in which position they are then adhesively joined. Here again, the floor covering cannot be removed at a later date without destroying the blocks.  
           [0006]    DE 199 62 812 and DE 200 09 717 U1 disclose stone tiles having a laying frame and a gasket.  
           [0007]    DE 199 62 812 A1 discloses the provision of the edges of tiles for paving floors and walls with an edge profile, which can be bonded to the tiles. The edge profiles are formed such that a first limb is provided for the tile to rest on and a second limb is provided to bear against the all-round edge surface of the tile. Furthermore, a projection is provided on the side of the tile remote from the limb extending along the edge of the tile, which, together with the projection on the adjacent tile, governs the specified minimum width of the seam. Into the seam formed by two mirror-symmetrically disposed edge profiles there is inserted a topping profile. This topping profile is prevented from slipping out by the engagement of teeth. A non-slip damping layer can be provided on the tile, the marginal area of the underside of the tile being left free, however, because the edge profiles bear against the tile over this area all round the tile. The tiles, which are supplied with the edge profiles already in position, are laid out on a floor surface in such a manner that the projections abut each other.  
           [0008]    According to DE 200 09 717 U1 it is known to provide a substantially T-shaped supporting profile, between two abutting tiles, which profile has two lateral supporting webs for supporting a tile and a middle retaining section with a groove for holding a gasket. The retaining section extends along a portion of the edge of the tile and the gasket is formed such that it presents a number of consecutive sealing faces toward the top surface of the tile. Between the tile and the lateral supporting web there is provided a sealing tape, which prevents any water that may have passed through the gasket from escaping at the underside of the tile. Furthermore, a guide web can be provided in the region of the supporting web for the formation of effluent channels.  
           [0009]    It is an object of the present invention to provide a paving system which enables paving to be carried out relatively easily, ie by unskilled persons if necessary. The paving system is intended to be particularly suitable for natural flagstones of, say, granite, marble, etc. or for wooden blocks or tiles of ceramics or other materials. Moreover, it is intended to ensure that the paving can be removed, if required, without causing damage to the individual tiles.  
         SUMMARY OF INVENTION  
         [0010]    The aforementioned drawbacks can be avoided with the paving system proposed by the invention. Each tile rests, at least over part of the surface of its underside, on a paving frame exhibiting supporting profiles having paving areas, and the paving frame exhibits a fin projecting beyond the paving surface toward the top side the tile, which fin extends along at least part of the edge of the tile toward the top side of the tile. The paving frames can be interconnected. The fin is provided on only two adjacent supporting profiles whereas the other two supporting profiles have a paving area having no fin. The first supporting profiles exhibit at least one locking extension extending beyond the tile, whilst the other two supporting profiles exhibit at least one locking extension situated underneath the tile, and in each case one supporting profile cooperates with a different supporting profile.  
           [0011]    In the case of square or rectangular tiles, the paving frame has a total of four supporting profiles, our special embodiment of the connection between them making it possible to move parallel rows of paved tiles. By this means it is possible to pave the tiles in staggered relationship to each other. In this case, a corner of one tile will not meet three other corners of other tiles but instead two corners will abut the side edge of the adjacent row of tiles.  
           [0012]    The rubber seam sealant used to seal the individual tiles gives a precise and consistent seam pattern, and the resulting impermeability thereof to water is very convincing.  
           [0013]    The invention dispenses with the need for expansion joints even when large areas are being paved since with this floating paving there is no fixed anchorage to the substrate. Thus the risk of cracks forming in the floor covering or in an individual tile, such as can occur when tiles are adhesively bonded to plaster floors, does not exist. Furthermore, adhesives are no longer necessary for paving.  
           [0014]    Special advantages arise when paving with high-quality tiles, such as granite flagstones or similar tiles, since the additional cost of the paving system is less significant in terms of the price per unit, and a much more important advantage is that mistakes during paving are avoided even by poorly trained paving personnel. Moreover, the paving costs are considerably lower.  
           [0015]    On account of the floating paving method, it is possible, when restoring old buildings containing boarded floors, to pave granite floors quickly and cheaply on the existing wooden constructions without much preparatory work. In addition, the invention makes it possible to pave the floors of prefabricated timber houses with granite and natural stone.  
           [0016]    The very frequently occurring problem of insufficient footfall-sound-insulation in existing plaster floors, with which acoustic refraction frequently occurs as a result of improper paving, no longer occurs when use is made of the paving system of the invention in conjunction with footfall-sound-insulating material, and optimal insulation is guaranteed. To this end, the underside of the paving frames is provided with footfall-sound-insulating material.  
           [0017]    In addition to the paving system itself, the invention relates to a tile for use in the paving system and also to the floor covering produced with the aid of the paving system or by the use of said tile. Another object of the invention is a paving frame for a tile. Advantageous developments are described in the respective sub-claims.  
           [0018]    Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate preferred embodiments of the invention and together with the detail description serve to explain the principles of the invention. In the drawings:  
         [0020]    [0020]FIG. 1 shows a pre-formed frame to accommodate a tile,  
         [0021]    [0021]FIG. 2 a  shows a cross-section of a floor covering with a tile in position,  
         [0022]    [0022]FIG. 2 b  shows another cross-section of a floor covering with two tiles in position,  
         [0023]    [0023]FIG. 3 is a top view on a corner of a paving frame,  
         [0024]    [0024]FIG. 4 shows a (male) part of the profiled frame element in cross-section,  
         [0025]    [0025]FIG. 5 shows a (female) part of the profiled frame element in cross-section,  
         [0026]    [0026]FIG. 6 is a cross-section of a gasket for fitting into one part of the profiled frame element,  
         [0027]    [0027]FIG. 7 shows another locking joint in cross-section,  
         [0028]    [0028]FIG. 8 shows yet another locking joint in cross-section,  
         [0029]    [0029]FIG. 9 shows another working example of a pre-formed frame for accommodation of a tile,  
         [0030]    [0030]FIG. 10 is a cross-section through the floor tile shown in FIG. 9,  
         [0031]    [0031]FIG. 11 shows another cross-section of the floor covering with two floor tiles to be laid,  
         [0032]    [0032]FIG. 12 is a cross-section of a partial enlargement of FIG. 9 with holes in the supporting surface,  
         [0033]    [0033]FIG. 13 is a partial enlargement of FIG. 9 as viewed from below,  
         [0034]    [0034]FIG. 14 a  is a cross-section through a partial enlargement of FIG. 9 showing a first supporting profile,  
         [0035]    [0035]FIG. 14 b  is a cross-section of a partial enlargement of FIG. 9 showing a second supporting profile,  
         [0036]    [0036]FIG. 15 a  shows a variant of the design of the gasket, and  
         [0037]    [0037]FIG. 15 b  shows the gasket in detail. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]    Working examples:  
         [0039]    The working examples illustrated involve floor coverings comprising a number of flagstones, eg, granite flagstones, that abut each other in rows laid out on a substrate, eg, a smooth coating or boarded flooring, so as to float on intermediate spacing material.  
         [0040]    [0040]FIG. 1 is a perspective view of a square frame  1  to accommodate a tile (not shown in this figure), eg, a granite flagstone. Frame  1  is of a plastics material and is pre-formed; it may consist of an undivided injection molding or, alternatively, of individual elements made from extruded profiled material. The material used may be recycled plastics material.  
         [0041]    Of the four limbs  1   a  to  1   d  of frame  1 , two adjacent limbs  1   c ,  1   d  have a plug-type profile  3  which is shown in FIG. 4 in cross-section. The other two limbs  1   a ,  1   b  have a socket-type profile  4  as shown in FIG. 5 in cross-section. All four limbs  1   a  to  1   d  have a paving strip  5 , on which the tile  2  to be placed in the frame rests in the paved state.  
         [0042]    [0042]FIG. 2 a  illustrates such a tile  2  resting on paving strip  5  with the socket-type profile  4 . The width the paving strip  5  is, for a tile width of 305 mm, advantageously 20 mm.  
         [0043]    The distance between the paving substrate (floor coating) and the paved tile  2 , as specified by the height or thickness of the paving strip  5  of the frame  1 , may advantageously be utilized for the insertion of footfall-sound-insulating material  12 . The thickness of the footfall-sound-insulating material  12  must be such that it is equal to said distance between tile and paving substrate only when under load. The footfall-sound-insulating material  12  is advantageously stuck to the underside of the tile. In this way the problem of reverberation, as is met in the parquetry trade, is reliably avoided.  
         [0044]    [0044]FIG. 2 b  shows two tiles in paved position, of which, however, the right-hand tile  2  has been moved back for illustration purposes. The underside of tile  2  rests, in its marginal area, on the paving strip  5  and is adhesively bonded thereto.  
         [0045]    Unlike FIG. 2 a  the footfall-sound-insulating material  12  extends not only to near the paving strip  5  but also beneath this, so that insulation takes place in the region of the paving strip  5  itself. This is indicated by broken lines, the area below paving strip  5  being designated by the reference numeral  13 .  
         [0046]    If slight unevenness or roughness in the surface of the paving substrate has to be taken into consideration, eg, in the case of a very rough plaster floor, it may be advantageous to additionally stick a resilient foamed underlay (not shown) to the underside of frame  1 . This underlay can be attached by adhesive applied in spots or over the entire area.  
         [0047]    As is evident from the illustration according to FIG. 4, the plug-type profile  3  of limbs  1   c  and  1   d  has a fin  6  extending vertically upwardly, against both sides of which the tiles  2  bear when paved. The fin  6  is provided with a groove  7 , into which a rubber gasket  8  is inserted, as shown in FIG. 6 in cross-section. If required, the gasket  8  may be glued to the fin  6  of the limb in the region of the groove to prevent emergence of said gasket. Furthermore, provision is made for the gasket  8  to be manufactured in a color which goes well with the colors in the tiles. It is therefore not necessary for the frame itself to have a color suited to the color of the tiles.  
         [0048]    The rubber gasket  8  is mushroom-shaped, the stem  8   a  of the gasket  8  being formed such that it fits in the groove  7  of the fin  6 . The cap  8   b  is preferably trapezoidal and its height is such that its top edge approximately coincides with the top edge of a tile  2  when in its paved position in the frame, as illustrated in FIG. 2 b.    
         [0049]    The width of the rubber gasket  8  is greater than that of the fin  6  at least toward the upper end of the gasket, as a result of which the rubber gasket is pressed together when the tiles are in their paved position so that the gasket forms a gap seal. At the corners,  1   e  at the point of intersection of the tiles, the rubber gasket  8  is mitered at angles of 45° (FIG. 3), so that a seal is also obtained at the point of intersection.  
         [0050]    The plug-type profile  3  (FIG. 4) has an extension  9 , which cooperates with a snap-in groove  11  of corresponding shape in the socket-type profile  4  (FIG. 5). The two profiles  3  and  4  thus form a plug-and-socket framework by means of which a number of frames can be readily put together and, if desired, later readily separated from each other. To avoid problems which could occur when putting the parts together on site without the necessity of cutting, the extensions  9  of each frame with their locking cams  10  are disposed at a distance X from the outer edge of the frame.  
         [0051]    Each tile  2  to be laid is provided with a frame such as is shown in FIG. 1. Preferably, the frame is adhesively bonded to the underside of the tile so that the tile and frame form a unit. This adhesive bonding has the further advantage that the tiles are firmly fixed in the paving and cannot emerge therefrom even when the finished paving is walked on for a long period of time.  
         [0052]    Paving is carried out by placing the tiles and the frames adhering thereto on the prepared substrate to be paved (in the present case the floor coating) in such a manner that the limbs having the snap-in grooves  11  abut the limbs having the locking cam  10 . The parts are forced (snapped) together to give a mechanical joint which can, if required, be disconnected later. When the parts are put together, the rubber gasket  8  is also pressed together, as described above, so that a certain degree of prestress is produced. This prestress ensures that an adequate seal against the penetration of dirt and moisture is obtained. It also compensates for tolerances in the paved tiles.  
         [0053]    [0053]FIG. 7 shows another locking joint, in which the locking cam  10  extending beyond the limb  1   c  has undercuts on its top and bottom sides, which engage a groove  11  on the receiving limb  1   a  that also has two undercuts. When the locking cam moves into the snap-in groove, the latter is forced apart and snaps back into its original position after the locking cam has been completely introduced and the side edge of the limb  1   a  has come to rest against the side edge or fin  6  of the limb  1   c . The elasticity of the material used is such that this can be carried out non-destructively.  
         [0054]    In FIG. 8, the locking joint is itself free from undercuts in the region of a projection  14  and a groove  15  so that these parts are provided merely for guidance purposes. The parts are mechanically locked together via a locking cam  10  on the underside of the projection  14  and a locking groove  11  in the surface of the lower side wall of socket-type profile  4 . For the purpose of facilitating assembly, an insertion bevel  16  can be provided, as indicated by the dashed line.  
         [0055]    In FIGS. 4, 5,  7 , and  8  it is particularly apparent that the female socket-type profile  4  engages under the male plug-type profile  3  on the underside thereof over a certain distance, which is equal to the width of the fin  6 .  
         [0056]    [0056]FIG. 9 shows another embodiment of the invention. In this case, a paving frame  21  consists not only of edge profiles  21   a, b, c , and d at the edges but also of stiffening ribs  22 ,  23 , of which a first group  22  runs parallel to the sides and a second group  23  diagonally thereto. The ribs  22 ,  23  intersect so that points of intersection  24  are formed. These points of intersection can be of different sizes.  
         [0057]    On the edge profiles  21   a  to d there are formed top and bottom projections  25 ,  26  each of which represents one half of a locking joint, namely the upper or lower half respectively. This is described in greater detail below. Each paving area  27  bordered by ribs, edge profiles  21   a - d , and the field delimited by  22 ,  23  has holes, indicated by dotted lines, whose function will be explained below.  
         [0058]    [0058]FIG. 10 is a cross-section through the paving frame shown in FIG. 9 and shows the lateral profiles  21   b ,  21   d  in the border area. Furthermore, it illustrates the course of fin  28 . Starting from the profiles  21   a  to d, the fin  28  extends over almost the entire length or width of the tile frame  21 , but only on two adjacent sides. This may be seen in FIG. 9 from the fin  28  disposed on the profile  21   a  and the fin  29  disposed on the adjacent profile  21   b.    
         [0059]    [0059]FIG. 10 likewise illustrates the holes  30  and also the inward ribs  22 . Also visible are a top and bottom part  25 ,  26  of a locking joint.  
         [0060]    The left-hand part of FIG. 11 is a cross-section taken along the line AA of FIG. 9, and the right-hand part of FIG. 11 corresponds to a neighboring tile according to the invention. First of all, the profiled frame element  21  having the edge profile  21   a  is illustrated, on which a tile  2  rests, this being fixed in position by the fin  28  acting as a stop.  
         [0061]    The paving frame  21  is provided with holes  30 , which will be explained below.  
         [0062]    On the outside of the tile frame  21  there is visible an upper projection  25 , which possesses downwardly directed catch teeth  31 . The transition region of projection  25  toward the profiled frame element  21   a  is of resilient material so that the projection  25  can give way slightly.  
         [0063]    In the right-hand part of FIG. 11, an adjacent floor tile is shown, whose marginal structure corresponds to the cross-section taken along line BB in FIG. 9. The tile  2 ′ rests on the edge profile  21   c , which possesses a lower projection  26  having catch teeth  32 . The tile  2 ′ extends over the lower projection  26  so that when the floor tiles  21 ,  21 ′ are put together, the tile  2 ′ overlaps the upper projection  25  of the edge profile  21   a . On the left-hand side of FIG. 11, this state of installation is illustrated for the tile  2 ′, in which case the lower projection  26  of the supporting profile  21   c  is beneath the upper projection  25  of the profiled frame element  21   a . The upper projection  25  is thus enclosed on both sides. To enable the upper locking projection  25  to nevertheless slide over the catch teeth, it is positioned at a distance from the tile  2 ′ such that the top side of the locking extension  25  is lower than the underside of tile  2 ′ or the paving surface of tile  2 .  
         [0064]    The tiles  2 ,  2 ′ are kept at a predefined minimum distance from each other by means of fin  28 , whilst a gasket  33  mounted on fin  28  seals the tiles at their top surface. For this purpose, the gasket  33  is upwardly broadened in the form of a wedge and has sealing lips  34 ,  34 ′ in the region of its shaft and extending toward the tiles  2  and  2 ′ respectively. When the tiles are placed together, the inclined surfaces of the wedge-shaped end of the gasket  33  come to bear against correspondingly formed inclined surfaces on the tile  2 ,  2 ′ and thus create a seal. If, however, moisture coming from, say, cleaning fluid, should penetrate beyond these seal faces, the sealing lips  34 ,  34 ′ will prevent it from leaking down further.  
         [0065]    In addition, the paving frame is provided on its underside with a groove  35 , in which an insulating profile  36  is positioned. The insulating profile  36  projects beyond the lower edge of the profiled frame element  21   a  and can possess lateral compensating spaces  37 ,  37 ′, which allow for deformation of the insulating profile  36  under load. Not only the supporting profiles  21   a  but also the stiffening ribs  22 ,  23  are provided with an insulating profile embedded in a groove so that good footfall-sound insulation is achieved.  
         [0066]    [0066]FIG. 12 is likewise a cross-section taken along the line AA, but in this case the arrangement of the holes  30 ,  30 ′ and the interposed supporting webs  38  of the paving region  27  is apparent. Of special significance is the inclination of the side walls of the webs  38  such that the hole  30  widens in the direction from the paving area for the tile toward the underside of the tile frame  21 . This makes mechanical anchorage of the tile in the paving frame  21  possible by means of adhesive exuding through the hole  30 . The tile (not shown) is by this means also mechanically fixed to the paving frame  21  since a pseudo-dovetail joint is formed.  
         [0067]    The underside of the supporting webs  38  or the holes  30  is in spaced relationship to the underside of the supporting web  21   a . The application of adhesive to the top side of the supporting web  38  is carried out, for example, mechanically by means of a doctor blade. Alternatively, only the rear side of the tile can be coated with adhesive, or both possibilities may be employed. It is not always necessary to glue the entire surface of the tile. In some cases it is sufficient to coat only partial areas with adhesive, and the adhesive may, if desired, be applied in the form of a bead of adhesive.  
         [0068]    The adhesives used can be thermoplastic adhesives, so-called hot-melt glues, or else single-component or multicomponent reactive adhesives, particularly polyurethane (PU) adhesives showing slight initial foaming.  
         [0069]    In addition, FIG. 12 shows the upper and lower projections  25 ,  26  respectively, but the projections  25 ,  26  on the supporting profile  21   a  are not opposite to each other but are staggered back into the plane of the drawing by a certain distance, as is visible in FIG. 9. However, the interrelationship of the catch teeth is clearly shown here. At this juncture, reference may be made to the fact that the lower projection  26  also exhibits elasticity, to enable the catch teeth to slide past each other. An additional space for deflection is not provided in this case, however, since it is assumed that when it is desired to disconnect the joint it will be possible to lift the tile completely. Thus disconnection of the joint would even be possible if the upper locking projection should bear directly against the underside of the tile.  
         [0070]    [0070]FIG. 13 is a detail showing the right-hand lower corner of FIG. 9. The first point to notice here is the course of the edge profiles  21   a ,  21   d  and also the projecting fin  28  and a diagonal reinforcing rib  23  and also the reinforcing rib  22  running parallel to the supporting profile  21   a . Both the supporting profiles  21   a ,  21   d  and the reinforcing ribs  22 ,  23  exhibit an insulating profile  36 , which can be injection through a central injection feed point  40  in the region of the point of intersection  24  into the grooves  35  provided for this purpose, after the paving frame has been produced in a first injection molding process. The paving area between the edge profile  21   a  and the reinforcing rib  23  is provided with holes  30 ,  30 ′, between which the supporting webs  38  extend.  
         [0071]    [0071]FIG. 14 a  again shows a cross-section through the supporting profile  21   a ,  21   d , in which it is again apparent that exclusively the edge profile  21   a  is provided with the fin  28 , which acts as a stop for the tile, whereas the supporting profile  21   d  exhibits no such fin.  
         [0072]    [0072]FIG. 15 a  shows a special embodiment of the gasket  33 . Instead of the sealing lips illustrated in FIG. 11, sealing beads  34  are provided, which project into a groove in the edge of the tile  2 ,  2 ′. The detailed view shown in FIG. 15 b  illustrates how the groove  41  may indeed be larger than the sealing bead  34  provided that a good seal is produced over at least part thereof. Thus a seal face  42  is obtained.  
         [0073]    As mentioned above, connection of the tile to the paving frame is achieved using, for example, a bonding technique. This may involve applying hot-setting adhesive or a curable adhesive substance such that the adhesive substance passes through the conically widening holes  30  to effect mechanical anchorage. On the paving area between the holes there is a normal adhesive joint so that the tile is fixed in position, after the adhesive has cured, both via the adhesive joint and via said mechanical anchorage similar to a dovetail joint.  
         [0074]    The paving frame can be provided, via a two-component injection molding process, with the thermoplastic elastomer required for the gasket  33  to give the footfall-sound-insulation  36 , and the frame itself can be of a rigid plastics material such as polystyrene or polyurethane, whilst the footfall-sound-insulating material used may be a thermoplastic elastomer TPE.  
         [0075]    In addition, the catch teeth can be in the form of a single projection so that locking is achieved by only one tooth, or, as in the working example, in the form of a plurality of catch teeth so that multilocking is achieved and any dimensional differences can be compensated for. The locking joint should be in such a form that disconnection is possible by reason of the lever action resulting from lifting the tile at the opposite edge. When paved tiles are subjected to a purely tensile load, disconnection thereof should, on the other hand, only be possible after exceeding the load normally employed.  
         [0076]    The one-sided locking joint of the second working example has the advantage that the overall height is even more reduced than when a pin-and-socket connector is used.  
         [0077]    The footfall-sound-insulating material is included in the paving area,  1   e , in the working example, in the reinforcing ribs  22 ,  23  and the edge profiles  21   a  to d. Here again, a low overall height can be obtained. The footfall-sound-insulating material can be such that an antislip action is additionally achieved.  
         [0078]    The floor tile composed of a tile and a paving frame has, due to the adhesive joint, increased static stability, so that the necessary thickness of the tile can, in the case of granite flagstones, be reduced from hitherto 10 mm to 8 mm or even down to 6 mm. This leads to a considerable economy of material and thus to reduced costs for the production of a floor covering.  
         [0079]    As mentioned above, the insulating profile  36  projects beyond the underside of the edge profiles  21   a -d or of the reinforcing ribs  22 ,  23 , and the underside of the supporting profiles or reinforcing ribs also bears against the floor, however, when subjected to extreme load and thus prevents destruction of the footfall-sound-insulating material. Thus the footfall-sound-insulating material let into a groove is protected from damage under extreme load.  
         [0080]    The adhesive used should be one capable of ensuring sufficient thermal stability when use is made of underfloor heating units. When paving is to be carried out outdoors, the adhesive must be weather-resistant.  
         [0081]    Although particular embodiments of the invention have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those particular embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.