The present invention relates to a method for casting a covering tiling formed by concrete tiles in such a way that moulds are placed as a set of moulds on the surface to be covered, fresh concrete is brought into the set of moulds and it is allowed to set. The invention also relates to a mould for casting the covering tiling formed by the concrete tiles.

It is known to use concrete tiles for tiling yards and footpaths. A problem in the tiling is that the tiles move in connection with the frost heaving of the gound such that the edges and corners of adjacent tiles position on different levels at the seam points. For preventing this, a so-called bondstone tile has been developed, in which the flanks of the tile are formed such that they lock in the tiling onto the flanks of adjacent tiles. However, such bondstone tiles are relatively expensive.

The purpose of this invention is to provide a method and a mould, by means of which a frost resistant concrete tiling is achieved in a very simple and economical way. The inventive method is characterized in that before bringing the concrete into a set of moulds, a reinforce¬ ment is fitted through holes in the mould walls, which reinforcement binds the adjacent tiles together. The inventive mould is characterized in that the mould walls have holes for reinforcing bars passing through adjacent walls of the tiling.

The inventive method is very simple and adapts also well for do-it-yourself builders. The inventive method may be adapted in such a way that the corners of the moulds are fixed to the corners of the other moulds in the set of moulds such that the mould walls are located at a distance from the walls of the adjacent moulds. Then, rectangular

moulds may be used such that intermediate spaces of the size and form of the moulds remain between the moulds, whereby the total surface area of the moulds needed for the tiling equals approximately half of the whole surface area to be covered. In this way, the costs for the moulds remain low, although the moulds are disposable and remain in place in the completed tiling. An economical mould material is plastic.

The invention is next described in more detail with reference to the accompanying drawings, in which

Fig. 1 shows an inventive mould seen from the top,

Fig. 2 is a partial view of a corner of a tile on a larger scale,

Fig. 3 is a section A-A of Fig. 1,

Fig. 4 is a section B-B of Fig. 2,

Fig. 5 is a section C-C of Fig. 2,

Fig. 6 shows, seen from the top, a set of moulds formed by the inventive moulds, one mould as well as sections cut from the mould,

Fig. 7 is a perspective view showing the joining-together of the corners of two moulds, and

Fig. 8 shows the casting of the tiles.

In the application shown, the mould is square and intended for casting tiles of e.g. 500 x 500 mm. The mould has four walls 1, below which are located support flanges 2 projecting on two sides of the wall. Between the walls and the support flanges are placed stiffening ribs 3. On the

corners of the mould, the outer support flange 2 is bevelled at the corner at an angle of 45°.

Each corner of the mould has joining members provided with a hole 4 and a pin 5. The hole is formed on an ear 6 projecting from the bevelled end of one outer support flange 2. The pin projects upwards from a recess 7 formed at the bevelled end of a second outer support flange located in the same corner. From the upper surface of the pin extends a V-slot 12, by means of which it is achieved that the pin made of a flexible plastic may be compressed, when it is pushed into the hole of the second mould. Furthermore, the upper edge of the pin has a projecting flange 13, which prevents the pin pushed into the hole from coming out of the hole.

The mould walls 1 have at equal intervals e.g. three holes 8 such that the hole of the opposite walls abut.

Two moulds may be placed mutually cornerwise at a line of 45° such that in each mould the bevelled ends of the flanges of one corner are located opposite to each other (Fig. 7) . Then, the pin 5 of the first mould fits into the hole 4 of the second mould and the ear 6 of the first mould fits into the recess 7 of the second mould, whereas the pin 5 and the ear 6 of the second mould fit into the hole 4 and the recess 6 of the first mould. In this way, a set of moulds formed by moulds fixed together may be built on the surface to be covered. Such a set of moulds is schematically shown in Fig. 6. The moulds are fitted as an integral latticework such that an intermediate space 9 of the size of the tile remains between four moulds fixed together at their corners. The set of squares in the latticework thus has a mould in every second square of each line and also of each row and every second square has an intermediate space as a formation resembling the squares of a chessboard.

The mould may be sawed at its corners at an angle of 45° into four sections 10 such that one wall 1 remains in each section and one hole 4 remains at one end and one pin 5 at the other end. The intermediate spaces that remained open on the edges of the set of moulds may be closed by means of these sections. A set of moulds is thus achieved for an integral set of tiles, whereby the number of the moulds needed equals only half of the number of tiles to be cast.

When casting the tiling, a set of moulds is first formed on the surface to be covered in the manner described above. The joining members 4, 5 ensure that the corners of the moulds remain on the same level during the casting. The reinforcing rods 11 (Fig. 8) are then pushed via the holes 8 such that the rods extend into the set of moulds through several moulds both longitudinally and laterally. Fresh concrete is brought into the set of moulds, the surface is levelled and the concrete is allowed to dry.