The present invention concerns a method for the laying and anchoring of pantiles on rafters on roof constructions with sub roof. The invention also concerns a tile binder of stiff material for use in the execution of the method, of the kind which is used for the laying and anchoring of pantiles on roof constructions with sub roof, and comprising an inser- tion part for insertion in the binding boss on the underside of the tile, and in extension herewith a part standing in connection with a gripping end part.

Roof-tile binders are used in connection with the laying of roofs consisting of tiles or other materials (in the fol- lowing mutually called tiles), with the view to achieving a certain anchoring of the tiles to the underlying rafters in the event of outwardly-directed wind forces as a result of the influence by wind on the roof construction.

The underside of the tile, cf. fig. 1, comprises a bind- ing boss 5 and a laying boss 7 at the front edge. The binding boss, which consists of a projection on the underside of the tile, is provided with a through-going hole 3, cf. fig. 3, disposed in the longitudinal direction of the tile for the accommodation of the straight end part 4 of a wire-formed tile binder, the other end of which is staggered in relation to said end part, and which in the laying of the tile is in- troduced in behind the rafter closest to the foot (lower part) of the tile, or that rafter (10) on which the upper end of the underlying tile 22 is supported, where the staggered end of the binder is in contact with that side of said rafter which faces towards the sub roof (not shown). The laying boss 7 consists of a projection on the underside of the tile at the top 24 (upper end) of the tile. In the correctly laid out position of the tile, the under edge 9 of the laying boss is in abutment with the upper edge 11 of an underlying rafter 30, so that the tile is held and secured by the rafter (for the sake of clarity and understanding, in figs. 1 and 3 a

clearance is shown in between the under edge of the laying boss and the upper edge 11 of the rafter 30).

The known tile binders typically consist of a stiff piece of round wire of steel with a strength of 16-1800 N/mm2, and they are shaped as shown in fig. 1. The known tile binder 2 comprises a straight free insertion part 4 for insertion from the lower end of the tile into the hole in the boss 5 of a tile 6, and a gripping end part 8 for anchoring in abutment against a rafter 10, and a slightly curved intermediate length 12 in between said parts, beginning with an approxi- mately right-angled bend 14 followed by two consecutive 45° bends 16,18, and ending with a bending-over 20 of the wire in towards itself to form the gripping end part 8, whereby the tile binder 2 is able to be placed extending around the underlying tile 22 and the rafter 10. It must be noted that in the mounted state, the obtuse extending end of the bend is not intended to engage with the side of the rafter 10, but serves merely to stabilise the tile binder in the event of possible influence by outwardly-directed, transverse forces on the tile 6, and to prevent damage to the sub roof when the tile binder is mounted. The tile binder is secured in its po- sition partly by friction which arises by the abutment pres- sure of the staggered end part against the rafter 10, and partly due to the fact that the laying boss 7 of the underly- ing tile prevents the straight insertion part 4 from sliding out of the hole 3 in the binding boss 5, cf. fig. 1.

The known tile binders, however, have certain disadvan- tages, e. g. they are very sensitive to incorrect rafter di- mensions, which means that the anchoring becomes poor if the rafters are too narrow, and rafters which are too large in dimensions can cause wear damage to arise on the sub roof, and further that the straight free insertion end 4 placed in the boss 5 can give rise to an undesired, outwardly directed force on the upper end 24 of the tile 6 (indicated by the ar- row 26 in fig. 1), for the reason that the gripping end part 8 is placed at a greater distance from the underside 28 of the tile. This outwardly-directed force arises in that the insertion part placed in the tile's boss is turned, whereby

the outer end of the insertion part exercises an outwardly- directed pressure on the boss, and herewith on the tile, which results in a considerable reduction in the abutments pressure of the upper end of the tile on the underlying raf- ter. All in all, the latter disadvantage can give rise to an inexpedient effect of the tile binders when the rafters and binders do not correspond with each other. The known tile binders are thus delivered in different dimensions, corre- sponding to a rafter of a given size, which thus means that a craftsman should/must hold a stock of tile binders of differ- ent dimensions.

From DK 25298 there is known a tile binder for use for under-pointed roof constructions, where there is access to the undersides of the tiles after they have been laid. The tile binder comprises an upper bent-over end for insertion in the hole in the tile's binding boss from above, and a lower end which is of rectangular U-shape and intended to grip around the whole of the underlying rafter with the free end in between the rafter and the underside of the front end of the underlying tile. The tile binder also comprises an inter- mediate length with a spirally-wound flexible part which makes it possible to stretch the binder during insertion of the upper bent-over end in the tile's binding boss. The tile binder is intended for mounting after the tiles have been laid. After the tiles have been laid, an under-pointing (sealing) of the spaces in between the tiles is carried out with mortar, after which the binders are mounted in that the rectangular U-shaped lower end is led around the rafter, and the bent-over end of the binder is subsequently inserted in the hole in the binding boss, which is possible due to the good possibilities of access to the underside of the tiles.

The inventor has acknowledged that the anchoring of the tile in accordance with the known technique (disclosed in DK 25298), which has previously been used in connection with un- der-pointed tiles, is even particularly expedient, in that the binder exercises a resulting downwards-directed force on the tiles, so that these hereby lie in a firmer manner against the underlying roof construction. The configuration

of this known binder, whereby this is secured around the whole of the underlying rafter, results however-due to in- adequate space conditions when laying tiles on roof construc- tions with sub roof, and the lack of possibilities for access to the under side of the tiles for the subsequent mounting of the insertion end of the known tile binder-that this binder can not be used in the laying of tiles on roof constructions with sub roof.

The object of the invention is thus to provide a method for the laying and anchoring of tiles on roof constructions of the kind disclosed (with sub roof), which ensures an ef- fective and more durable securing of the tiles than with the known method which is used for roof constructions with sub roof, and also a binder for use in the execution of the method.

This object is achieved by the introduction of the inser- tion part of a tile binder with a substantially inverted U- shaped insertion part, an intermediate length with a part which provides flexibility, and a gripping end part with a U or V-shaped bend, into the through-going hole in the tile's binding boss or similar insertion opening from the upper end of the binding boss, followed by the placing of the tile on the upper side of the underlying tile, after which the tile is tilted down so that the tile's laying boss is placed on top of the rafter at the top of the tile, whereby the free end of the gripping end part is turned in behind the under- side of the rafter at the foot (lower end) of the tile, upon which the tile is pushed upwards, whereby the free end of the gripping end part is brought into abutment with the underside of the rafter at the foot of the tile, and by continued dis- placement of the tile, stretching (tensioning) of the flexi- ble part of the tile binder, with the laying boss sliding on the outer side of the rafter at the top of the tile, until the front end of the tile falls down on the outer side of the rafter and rests on this with the back of the laying boss in abutment with the upper side of the rafter, whereby the tile is secured.

There is hereby achieved a considerably improved securing of the tile in comparison with the known method, in that the tile is secured in its correct position by a downwards-di- rected force brought about by the stretching of the flexible part of the tile binder as a consequence of the anchoring of the gripping end part in the underside of the underlying raf- ter, which results in both the front edge and the rear edge of the tile being drawn respectively against the foremost rafter and the upper edge of the preceding/underlying tile.

A tile binder for use in the execution of the method ac- cording to the invention comprises a body (a length) of stiff but outwardly-flexible material comprising a substantially reversed U-shaped insertion part for insertion from above in a tile's binding boss or similar insertion opening, said in- sertion part, via an intermediate length comprising a part which provides elasticity in both the tile's longitudinal and transverse directions, standing in connection with an anchor- ing part, characterised in that the anchoring part comprises a substantially straight length having a free end which is concluded with a U-or V-shaped bend for engagement in the underside of the rafter nearest to the foot (lower end) of the tile extending in substantially the same plane as the re- versed U-shaped insertion part.

Out of regard for the achieving of an expedient anchoring of the free end of the bent-over part, it can be mentioned that the directional deviation of the bend in relation to the straight extent of the anchoring part forms an angle within the interval of 90°-225°, typically between 110°-200°, and preferably within the interval 120°-190°.

By use of the tile binder according to the invention in combination with the method according to the invention, there is hereby achieved a particularly effective anchoring of tiles laid out on roof constructions with sub roof, in that in the correctly laid position on the rafters, by stretching of the elasticity-providing part, the tiles are drawn respec- tively in against the underlying tile and against the outer side of the rafters which support the front end of the tile.

With the tile binder according to the invention, there is

thus achieved the same effective anchoring of tiles laid out on roof constructions with sub roof, than has hitherto been possible only when using the previously-mentioned tile bind- ers for use with roof constructions with under-pointed tiles, where subsequent mounting of tile binders is possible as a result of unhindered access to the underside of the roof af- ter the laying of the tiles.

Laboratory tests have also shown that roof constructions with sub roof provided with tiles anchored with tile binders according to the present invention have been considerably more resistant to wind effects than roofs where the tiles are anchored with the commonly-known tile binders for anchoring of tiles laid on roof constructions with sub roof.

The configuration of the insertion part as the free end of a U-shaped insertion part makes it possible for the inser- tion part to be inserted from the upper end of the binding boss (unlike the known tile binders which are inserted in the through-going hole in the boss from below), and in combina- tion with the gripping end part which is brought into abut- ment with the rafter at the foot of the tile, as already men- tioned this results in a considerable improvement of the an- choring of the tile to the underlying roof construction. The reason for this is that when the tile binder is mounted, with the altered point of engagement in the boss, an inclined, downwards-directed resulting force on the tile is achieved in relation to the surface of the tile, regardless of deviations in rafter dimensions as well as in the breadth and the height of the rafters and tiles used in the roof construction, in that compensation is made for these deviations by the elas- ticity-providing part of the binder. With rafters which are too large, it is thus achieved, unlike with the known tile binder cf. the above, that the downwards-directed tractive force on the tile is increased with subsequent increase in the stability of the roof. With rafters which are too small, it is achieved merely that the force is reduced, though not more than the said inclined downwards-directed force can be maintained. Consequently, when use is made of the tile binder according to the invention, no outwardly-directed force which

could give rise to the roofing tiles becoming unstable is ap- plied to the upper end of the tile under any positioning/- building-in/mounting conditions whatsoever. Moreover, the tile binder according to the invention has the further advan- tage that it can be used together with rafters of different dimensions. Practical tests with the tile binder according to the invention have thus shown that this can be used together with rafters of three different dimensions (30/50,50/50 and 40/60), which is not possible with the known tile binders where a specific type of binder must be used with rafters of specific dimensions.

With the view to achieving an expedient distribution of pressure in between the obtuse end of the bend and the raf- ter, the obtuse end can be flattened so that there is hereby formed a pressure surface with an area which is greater than the cross-sectional area of the obtuse end.

With the view to providing the tile binder with additio- nal flexibility, its middle section in between the insertion part and the gripping end part can extend in a substantially curved manner.

Without waiving any other configurations, an advantageous configuration of the curved extent of the middle part can be disclosed as being a bend in the plane of the U-shaped inser- tion part oriented towards the insertion part, standing in connection with the U-shaped insertion part, followed by an oppositely-directed (outwards-directed) bending of the middle section and thereafter a substantially straight piece conti- nuing over to the elasticity-providing part which is con- cluded with the gripping end part.

The elasticity-providing part in the middle section can be configured in different ways, but without waiving other configurations, a preferred embodiment hereof consists of at least one zig-zag bending (W-. shaped bending) of the middle section. The possibility is hereby provided for an elastic increase in the length of the middle section when placing the gripping end part of the tile binder on the underside of the nearest rafter, in that a pull on the gripping end part will

result in a stretching at the angle bends in the zig-zag-bent area.

The angles in the tips of the zig-zag bends when the tile binder is not mounted lie within the range of 60-120°, typi- cally within 80-110° and typically between 90-100°.

The length of the tile binder can also with advantage be adapted so that the angles of the angle bends in the elastic- ity-providing part when the tile binder is mounted are greater than 90°. It is hereby achieved that the tile binder according to the invention exercises an adequate downwards- directed force on the tiles, whereby the necessary anchoring of the roof is ensured.

An adjustment of the flexibility and tractive force of the tile binder can also with advantage be effected by short- ening/lengthening the straight section in between the bends in the zig-zag part in the elasticity-providing area.

The tile binder according to the invention can with ad- vantage consist of a piece of stiff, round wire, with a yield stress within the interval of 1400-1800 N/mm2.

The tile binder can also with advantage consist of a piece of stiff, round wire with a diameter lying within the range of 1.0-4.0 mm, typically within the interval 1.5-3.0 mm, and typically within the interval 1.7-2.2 mm.

With the tile binder according to the invention, savings can be achieved in wire due to the increased, better anchor- ing ability which is achieved by changing the engagement point of the tile binder in the boss. In accordance with fu- ture EU standards, the presently prescribed wire diameter of 3.0 mm for tile binders of the known type can thus be reduced to a diameter of between 1.8-2.2 mm, whereby a saving in wire right up to 50% could be achieved.

In the following, the invention will be explained in more detail with reference to the drawing, where Fig. 1 is a side view of a tile binder of the kind used in roof constructions with sub roof, where the same is shown inserted in a roof construction, Fig. 2 is an end view of a pantile,

Fig. 3 is a side view of a tile binder according to the invention, and the same inserted in a roof construction with sub roof, and Fig. 4 illustrates the laying of a tile provided with a tile binder according to the invention.

Fig. 1 shows one of the tile binders which are typically used for anchoring tiles on roof constructions with sub roof (not shown, but cf. fig. 3). Such a binder consists of a piece of stiff, round steel wire with a strength of 16-1800 N/mm2, and which typically has the shown configuration.

The shown, known tile binder 2 comprises a straight, free insertion part 4 for insertion from the lower end of the tile in the hole 3 (cf. fig. 2) in the binding boss 5 of a tile 6, and an end part 8 for anchoring to a rafter 10, and an ap- proximately curved middle section 12 in between said parts, beginning with an approximately right-angled bend 14 followed by two successive 45° bends 16,18, and terminated with a bending-over 20 of the wire end in against itself to form an end part 8 which will not be able to damage the sub roof by penetration. With this configuration, the roof-tile binder 2 can thus be mounted extending around the laying boss 7 on the underlying tile 22 and the rafter 10. Moreover, the laying boss 7 will be able to prevent the tile binder from falling out, in that with a downwards-directed displacement of the binder 2, the right-angle bend 14 will abut up against the front edge of the laying boss 7 before the insertion part is displaced out of the boss 5.

However, the shown, known tile binder 2 is very sensitive to incorrect rafter dimensions, which means that the anchor- ing becomes poor if the rafters are too small, and rafter di- mensions which are too great can result in wear damage occur- ring on the sub roof. Moreover, rafter dimensions which are too great can result in the straight free insertion end 4 of the binder placed in the boss 5 giving rise to an undesired, outwards-directed force being applied to an upper end 24 of the tile 6, indicated by the arrow 26, this being a conse- quence of the gripping end part 8 being placed at a greater distance from the underside 28 of the tile than the displace-

ment which is provided by the bends 14,16,18 in the middle section 12. The outwards-directed force 26 arises by the in- sertion part 4, which is housed in the hole 3 (cf. fig. 2) in the tile's boss 5, being turned so that the outer end of the gripping end part 4 exercises an outwards-directed pressure on the boss 5 and herewith the tile 6, the lower underside 28 of which is hereby pressed more firmly against the underlying tile 22, whereby the contact pressure of the tile's upper end on the overlying rafter 30 is considerably reduced as a re- sult of the outwards-directed influence 26 from the roof-tile binder.

Fig. 3 shows a roof-tile binder 40 according to the in- vention, respectively before and after insertion in a roof construction with sub roof 102. The roof construction also comprises underlying rafters 100, on the upper side of which the sub roof 102 is laid, for example in the form of a strong plastic foil. The sub roof is secured by a spacing batten 104 which is fastened to the outer side of the rafters. In fig.

3, these components 100,102,104 are for the sake of clarity shown with spaces between them, but in practice they will be in abutment with one another. Rafters 110 are placed on the outside of the spacing battens at mutual intervals which are selected to suit the tiles 6 which are to be laid on the roof construction. The inner sides 112 of the rafters are in abut- ment with the spacing battens 104, and the outer sides 114 of the rafters are in abutment with the tiles 6. The rafters also have an upper side 116 and a lower side 118.

In the shown embodiment, the roof-tile binder 40 consists of a piece of stiff, round steel wire, typically with a yield stress lying in the range of 1400-1800 N/mm2. The tile binder 40 comprises an insertion part 42 which consists of the free end of an inverted U-shaped bending 44 of the one end of the middle section 46. It is hereby achieved that the insertion part 42 can be inserted in the hole 3 from the upper end 45 of the boss 5. At least a part of the bottom section 46 of the U-shaped bend 44 is hereby brought into abutment with the upper end surface 45 of the boss.

The roof-tile binder also comprises a section 48 which comprises an elasticity-providing part 50 which allows an elastic extension of the distance between the bottom section 46 of the U-shaped bend 44 and a gripping end part 52 which preferably consists of a U-or V-shaped bending over of the free end 54 of the section 48. The gripping end part 52 is intended for fastening to the underside 118 of the rafter 10 at the foot of the tile.

The elasticity-providing part 50 of the section 48 can be configured in different ways, but without waiving other con- figurations, the preferred embodiment shown here can consist of two successive zig-zag bends (W-shaped bending) of the middle section 48. The possibility is hereby provided for an elastic increase in the length of the middle section when placing the gripping end part 52 of the tile binder on the underside 118 of the nearest lying rafter 110, in that a pull on the gripping end part will result in a stretching at the angle bends 56,58,60 in the zig-zag-bent area.

The configuration of the insertion part 42 as the free end of a U-shaped insertion part 44 enables the insertion part 42 to be inserted in the through-going hole 3 in the boss from the upper end 45, whereby at least a part of the bottom section 46 of the U-shaped bend 44 abuts up against the upper end surface 45 of the boss. This, in combination with the gripping end part 52, which when the tile 6 is being laid is brought into engagement with the underside 118 of the rafter 110, results in a considerable improvement of the an- choring of the tile 6 to the underlying roof construction.

The reason for this is that when the tile binder is mounted in the boss 5, with the changed point of engagement in the tile's upwardly-facing side 45, there is achieved a resulting force on the tile 6 which in relation to the surface 62 of the tile is in an inclined downwards direction (indicated by the arrow 64), regardless of deviations in the dimensions of the rafter 110, on the underside 118 of which the gripping end part 52 of the tile binder is anchored, in that compensa- tion is made for these deviations by the elasticity-providing part 50. With use of the tile binder according to the inven-

tion, the upper end 24 of the tile will hereby always be se- cured by the force directed towards an underlying rafter 30.

With rafters which are too large, it is thus achieved, unlike with the known tile binder cf. the above, that the downwards-directed tractive force on the tile is increased with subsequent increase in the stability of the roof. With rafters which are too small, it is achieved merely that the force is reduced, though not more than the said inclined downwards-directed force can be maintained. Consequently, when use is made of the tile binder according to the inven- tion, no outwardly-directed force which could give rise to the roofing tiles becoming unstable is applied to the upper end of the tile under any positioning/building-in/mounting conditions whatsoever.

Moreover, the tile binder 40 according to the invention has the further advantage that it can be used together with rafters of different dimensions. Practical tests with the tile binder according to the invention have thus shown that this can be used together with rafters of three different di- mensions (30/50,50/50 and 40/60), which is not possible with the known tile binders where a specific type of binder must be used with rafters of specific dimensions.

In fig. 4 it is shown how a tile 6 provided with a binder 40 according to the invention is laid on rafters 110. The tile 6 is laid after insertion of the insertion end 42 in the hole 3 in the boss 5, with the binder hanging down under the tile, after which the tile is tilted down so that the laying boss 7 at the upper end of the tile is brought into abutment with the outer side 114 of the overlying rafter 110. In the tilting movement, the obtusely-extending free end 54 of the gripping end part 52 is turned in behind the underside 118 of the rafter 110 at the foot of the tile, after which the tile is pushed slanting upwards in the direction of the arrow 120 until the tile's laying boss 7 passes the edge of the upper side 116 of the rafter, whereby the underside 28 of the tile is brought to rest against the outer side 114 of the rafter 110, and the underside 9 of the laying boss 7 is in abutment with the upper side 116 of the rafter. At the same time with

said displacement of the tile 6, there occurs a displacement of the binder 10, whereby the free end 54 of the gripping end part 52 is now brought into abutment with the underside 118 of the rafter 110 at the foot of the tile. With continued displacement of the tile towards its final position, a trac- tive force in the longitudinal direction is applied to the elasticity-providing part 50, which results in a downwards- directed pull on the tile 6.

Before the roof-tile binder is mounted, the angles A, B, C, D in the zig-zag bends 56,58,59,60 lie within the range of 60-120°, typically within the interval 80-110° and typi- cally between 85-90°.

The length of the tile binder is selected so that when the binder is mounted, the angles A, B, C and D of the bends 56,58,59,60 in the elasticity-providing part 30 are greater than 90°, whereby it is achieved that the tile binder 40 according to the invention exercises sufficient downwards- directed force 64 on the tiles 6, whereby the necessary an- choring of the roof is ensured.

Moreover, in the production of the roof-tile binders 40 according to the invention, it will be possible to effect an adjustment of the flexibility and tractive power of the binder 40 by shortening/lengthening the sections 66,68,70, 72,74 in between the bends in the zig-zag section in the elasticity-providing area 50.

With the view to achieving a suitable anchoring of the bent-over free end 54 at the gripping end part 52, it can be mentioned that the directional deviation of the bend in rela- tion to the straight extent of the anchoring part can form an angle E within the interval of 90°-225°, typically between 110°-200° and preferably within the interval of 120°-190°.

The free end can also be rounded-off, flattened or pointed with the view to providing a preferred grip in the underside 118 of the rafter.

With the roof-tile binder 40 according to the invention, a saving in wire can be achieved due to the increased, better anchoring ability which is obtained by changing the point of engagement of the roof-tile binder in the boss 5. In accor-

dance with future EF standards, a reduction will thus be able to be made in the presently prescribed wire diameter of 3.0 mm for tile binder of the known type to a diameter of 1.8-2.2 mm, whereby a saving in wire of right up to 50% will be able to be achieved.

With the invention, there is thus disclosed a new roof- tile binder which, in addition to eliminating the disadvan- tages connected with the use of roof-tile binders of the known type, is also resource-saving in production and here- with cheaper to produce.

The inventor has acknowledged that the roof-tile binder according to the invention can assume other configurations.

The elasticity-providing element 50 could thus be configured as a spirally-wound spring, and the section between the in- sertion part 42 and the gripping end part 52 could also be of other configurations. Moreover, it is also envisaged that the binders could be configured in materials other than metal (steel wire), and the material could be of cross-sections other than circular (which is that which the steel wire nor- mally has), but which, however will place requirements on the configuration of the tile where the opening for the insertion of the binder is concerned. Combinations of cross-sectional shapes and materials could also be envisaged.

This does not, however, change the basic concept of the invention, which is based on the provision of a roof-tile binder for use in the laying of tiles on roof constructions with sub roof, which has considerably increased the strength of the anchoring of the tiles in comparison to that which has hitherto been possible to achieve with roof-tile binders cur- rently used for roof constructions of this type. This is ef- fected by making use partly of the technique disclosed in DK patent no. 252898, where the insertion of the roof-tile binder's insertion part takes place from the upper side of the boss, combined with the establishing of a suitable grip- ping end part 52 with a free end 54 which can easily be brought into engagement in the underside 118 of the rafter at the foot of the tile, and furthermore by giving the length of the roof-tile binder an elasticity-providing part which, when

the tile is laid, is tensioned and herewith subsequently gives rise to a constantly-applied downwards-directed force on the tile in towards the rafters 110, hereby achieving a considerably better anchoring of the tile to the underlying supporting roof construction.