Background Art It is known to construct buildings with cavity walls having an inner leaf of breeze block and an outer leaf of brickwork. The spacing between the two leaves is for thermal insulation purposes. The constructional cost of cavity walls can be reduced substantially by constructing the wall as just a single leaf of breeze blocks having a U- value (a thermal insulation measure) equivalent to that of a cavity wall, the outer face of the wall being sealed and rendered and then coated with masonry paint to improve the wall's weather resistance. However the appearance of a rendered wall is generally less aesthetically pleasing than that of a brick wall, and this is especially so when the paint coating cracks or peels.

Suggestions for building elements to represent a plurality of stones or bricks have been made in the past including, for example, the disclosures in GB-2312010, GB-2197005, GB- 2124675, GB-1014140, EP-0442863, US-4644719, US-4183188 and US-2819495.

Summary of the Invention According to a first aspect of this invention there is provided a coating material to be applied to a building element, said material being characterised by having as constituents: (a) a first adhesive comprising styrene butadiene, (b) a second adhesive comprising polyvinyl adhesive, (c) a cementitious powder, and (d) particulate material to be scattered onto a mixture of the constituents (a), (b) and (c) after the latter have been applied as a coating to the building element.

Preferably the coating material includes, as a constituent, a colouring pigment-advantageously in powdered form.

Advantageously, the cementitious powder comprises ordinary Portland cement or high-fired Portland cement or a mixture thereof.

Preferably, where the coating material includes the colouring pigment as a constituent, the cementitious powder comprises a mixture of 20% to 80% ordinary Portland Cement and 80% to 20% high-fired Portland Cement, the proportions being dependent upon the colour of the pigment.

Advantageously the constituents (a), (b) or (c) are in substantially equal parts by volume, preferably mixed with a substantially equal part of water.

In one preferred arrangement the constituents are provided in separate receptacles within an outer packaging member.

According to a second aspect of this invention there is provided a method of applying to a building element a coating material according to the first aspect of this

invention and with a colouring pigment added to the mixture of constituents (a), (b) and (c) prior to the scattering thereon of the particulate material.

According to a third aspect of this invention there is provided a method of applying to a building element a coating material according to the first aspect of this invention, said material further comprising-as a constituent-a colouring pigment, characterised in that said colour pigment is mixed with the particulate material prior to scattering both the particulate material and the colouring pigment together onto the said mixture of constituents (a), (b) and (c) applied as a coating on the building element.

Preferably, with either method, the building element has an interrupted surface and the said mixture of constituents (a), (b) and (c) is applied as a coating on the surfacially-interrupted face of the building element by a roller and such that there is little or no entry of said mixture into the surfacial interruptions. Advantageously the surfacial interruptions comprise elongate indentations extending in mutually perpendicular directions to represent mortar between adjoining bricks.

According to a fourth aspect of the present invention there is provided a building element having a brick-simulated surface provided by a method according to a said method.

The building element is preferably characterised in that the brick-simulated surface has the appearance of a plurality of bricks in superimposed courses with at least one brick in one course being in staggered relation to a brick in an adjoining course.

Preferably the building element is characterised in that at least one pair of superimposed courses has the two opposed side edges of one course staggered laterally with respect to the two opposed side edges of the other course.

In a preferred embodiment the building element is characterised in that the said bricks and courses are bounded by simulations of mortar which, away from a perimeter of the building element, have a nominal mortar width and which, at the perimeter of the building element, have a width of half the nominal mortar width (such that two such elements placed edge-to-edge can simulate a mortar course of said nominal width).

Advantageously the building element comprises a formation formed from settable material, e. g. a plaster or render.

According to a fifth aspect of this invention there is provided a casting of settable material to form a brick- like facing having a front face and a rear face in registry with one another, the front face having the appearance of a plurality of bricks in superimposed courses with at least one brick in one course being in staggered relation to a brick in an adjoining course, the bricks and courses being bounded by simulations of mortar which, away from a perimeter of the building element, have a nominal mortar width and at the perimeter of the building element have a width of half the nominal mortar width.

Advantageously said brick-like appearance is provided by one or more coatings of an adhesive upon which sand and/or other particulate material is scattered.

According to a sixth aspect of the present invention there is provided a casting of settable material to form a brick- like facing having a front face and a rear face in registry

with one another, the front face having the appearance of a plurality of bricks in superimposed courses with at least one brick in one course being in staggered relation to a brick in an adjoining course, said brick-like appearance being provided by at least one coating of an adhesive upon which sand and/or other particulate material has been scattered.

Conveniently (and for building elements according to either of the last two paragraphs), said coating, or the last of said coatings, may include a brick-coloured pigment which, advantageously, is applied by a roller.

In one preferred embodiment according to this invention the building element comprises a set (i. e. self-supporting) casting adhered by its rear face to a support member. Said support member may be a tile or like article of fired clay.

Alternatively (and preferably) said support member may be a breeze block.

Advantageously the support member has forward and rearward faces in registry with one another and with the front and rear faces of the casting.

Preferably the side contour of the building element is of modular form, preferably of castellated modular form to enable a plurality of such elements to interfit, preferably interdigitate, with one another.

According to a seventh aspect of this invention there is provided a method of making a building element, said method comprising the steps of casting or molding a plurality of support members of a uniform modular outline shape enabling them to interfit with one another, casting or molding a plurality of brick-like facings of corresponding outline shape, and adhering respective facings and support members

to one another either before or after applying to the facings-on their surfaces (to be) away from the support members-one or more coatings of a material according to said first aspect of the invention.

Brief Description of the Drawings By way of example embodiments of this invention will now be described with reference to the accompanying drawings of which: Figure 1A is a perspective front view of a building element according to a first embodiment of this invention, Figure 1B is a front elevation of the element of Fig 1A, Figure 2 is a perspective rear view of the building element of Figs 1A and 1B, Figure 3 is a perspective front view of a building element according to a second embodiment of this invention, Figure 4 is a perspective front view of a building element according to a third embodiment of this invention, Figure 5 is a plan view of a building element according to a fourth embodiment of this invention, Figure 6 is a perspective front view of a building element according to a fifth embodiment of this invention, and Figure 7 is a perspective front view of building elements providing a modification of the arrangement suggested in Fig 6.

Detailed Description of Example (s) of the Invention The building element 10 shown in Figs 1 and 2 comprises a breeze block 12 and a pre-formed facing element adhered to one another.

The breeze block 12 is pre-formed as by casting of conventional materials (e. g. compressed ash) to have a toothed or castellated modular shape with substantially flat front and rear surfaces 16,18. Following its removal from the casting mold, the block 12 has its pores sealed by submerging it in a suitable sealant. The sealant may be a solution comprising a mixture of pva and styrene butadiene.

The pre-formed facing element 14 is separately cast or molded in a mold of similar toothed or castellated outline shape from a render material comprising, for example, sand, portland cement and water. One surface of the wet, impressionable render is embossed with a 3-dimensional surface patterning representing three courses of staggered brickwork 20 with two simulated bricks 22 per course, the simulated bricks 22 being separated horizontally and vertically by elongate indentations 24 (e. g. of triangular or semi-circular cross-section) to represent pointing and/or mortar between the simulated bricks 22 (see Fig 1).

The embossing may be provided on the lower surface of the render in the mold by the mold's bottom face. Alternatively the embossing may be provided on the upper face of the render in the mold by a separate, suitably shaped tool or a mold piston plate pressed onto the render mixture's upper surface.

When the cast render material has set, it is removed from the mold and its embossed surface is coated with first, second and third layers of adhesive, each adhesive layer having sand loosely and randomly scattered thereon and being allowed to dry before the next adhesive layer is applied. This ensures that the simulated brickwork representation 20 has a very realistic texture.

The adhesive employed may comprise a mixture or blend of a styrene butadiene copolymer adhesive and a polyvinyl adhesive, together with ordinary Portland cement or high- fired Portland cement (white) or a mixture of these cements, water and, if wanted, a suitable colouring pigment (e. g. a coloured stone dust such as that known as"Jahn") to provide a desired texture and consistency (and colour).

To prepare the adhesive, the styrene butadiene copolymer is mixed with the cement, and the polyvinyl adhesive added thereto prior to adding the water and any desired colour pigment.

The adhesive may comprise substantially equal parts by volume of (a) styrene butadiene, (b) ordinary Portland cement or high-fired Portland cement (white) or a mixture thereof, and (c) polyvinyl adhesive.

Typically, the adhesive may have the following approximate composition: 25 parts by volume styrene butadiene, 25 parts by volume of a cementitious powder such as ordinary Portland cement or high-fired Portland cement (white) or a mixture thereof, 25 parts by volume polyvinyl adhesive, and 25 parts by volume water.

Each adhesive coating is applied by a roller to avoid or minimise the application of adhesive in the grooves 24 and, following sand being scattered thereon, a resultant brick- like effect for those grooves which are to provide a simulation or represention of inter-brick mortar.

Also, at least the last coating of adhesive includes a suitable pigment to provide a suitable brick-like colouration to the front face 26 of the facing element 14 (except across the inter-brick mortar simulations or representations of grooves 24). With advantage, the pigment utilised is an organic, non-oil-based, powder colourant.

Preferably the cementitious powder is a mixture of between 20% to 80% of ordinary Portland Cement and 80% to 20% of high-fired Portland Cement (white), the precise proportions of these two depending on the colour desired for the coating and the colour of the pigment powder included in the mixture with the two adhesives.

The two separately formed elements 12 and 14 are then bonded to one another by a suitable adhesive between the front face 16 of the breeze block 12 and the flat rear face 28 of the facing element 14. The adhesive employed may be similar in composition to that used for coating the embossed surface of the element, but omitting any colour pigment and at least some of the added water.

It will be appreciated that, due to their formation in similarly shaped and dimensioned molds, the two elements 12,14 lie in registry with one another and form, when fully bonded, a single composite building element of the toothed or castellated modular shape of Figs 1 and 2.

This composite building element 10 may, for example, have an overall length of about 60cms (23"), a overall depth of about 24cms (9.5"), and a height of about 34cms (13.5").

To erect a wall from a plurality of building elements 10, the elements can be readily interfitted with one another (in an interdigitating, mortice-and-tenon fashion with the elements 10 of Figs 1 and 2), with authentic mortar or, as is preferred, a further coating of adhesive, provided

between the adjoining vertical and horizontal contoured surfaces 25,35 of the element's sides. The option of adhesive coating of the contoured sides 25,35 is possible if each composite element 10 is provided at one end with mortar representations to all its vertical edges at 25 (and, optionally, to all its horizontal edges at 35).

Advantageously, as shown in Fig 1B, all the mortar representations 23 at the perimeter of the building element 10 have a width of 5mm, i. e. half the nominal mortar width value of 10mm, so as to provide an overall composite width of 10mm when adjoining building elements are interfitted end to end or are superimposed one upon the other. This enables that the finished structure to have a matching appearance as between the composite mortar representations 23 (provided by two adjoing elements 10) and the inward mortar representations 21 which are all of the nominal 10mm width. This feature, in conjunction with providing the building elements of a uniform modular outline shape enabling them to interfit with one another, also enables the building elements to be non-handed, i. e. they can be placed together either way up, and this eases and speeds up wall assembly from such building elements.

The building element 30 of the embodiment of Fig 3 is constructed in a substantially similar manner to that of building element 10 of Figs 1 and 2, and likewise comprises a breeze block 32 having adhesively bonded thereto a facing 32 representing a plurality of bricks in superimposed courses with at least one brick in one course being in staggered relation to a brick in an adjoining course.

However, building element 30 has the different shape of a series of steps; and a wall built from a plurality of such modular building elements 30 will have them interfit with one another sideways rather than interdigitate with one

another sideways as is the case with building elements 10 of Figs 1 and 2.

For use with the building element 10, in particular, a corner element 40 can be produced substantially as shown in Fig 4. Here again the construction is by joining a pre-cast breeze block 42 and a pre-cast render material facing 44 of similar outline to block 42, the facing 44 extending over two flat faces of the breeze block 42 that adjoin one anther to form an arris.

As an alternative to a single corner element 40, and for a conventional four-inch thick wall, two elements 10'and 10" can be employed which are each substantially similar to the element 10 of Figs 1A and 1B. Element 10' (Fig 6) has its two most laterally projecting side faces 25 provided with a brick-like facing such as that on the element's front face 22. Element 10" (not shown) has its one most laterally projecting side face 35 similarly provided with a brick- like facing such as that on the element's front face 22.

When the two elements 10'and 10"are interfitted with one another at 90° to form a corner construction, the brick- faced representation extends all round the corner.

Where such a two-element corner construction is to be effected for a nine-inch thick wall, the brick facing arrangement for the two elements 110'and 110" (Fig 7) is modified to provide a"half-brick-overlap"or Flemish- brickwork appearance. In this, the two most laterally projecting side faces 25'of corner element 110'have facings which substantially represent two half-bricks, and the one most laterally projecting side face 35"of corner element 110"has a facing which substantially represents two half-bricks. When the two elements 110'and 110"are interfitted with one another at 90° to form a corner

construction, the brick-faced representation extends all round the corner.

The building element 50 of Fig 5 has its pre-cast facing 54 extending over all four sides of the breeze block 52. The latter is centrally apertured at 55 to permit a plurality of elements 50 to be mutually superimposed to form a pillar whilst permitting a gate post, electrical conduit or other rod or pipe to be mounted and secured in the vertically aligned apertures 55.

The embodiments of Figs 1,2,3,6 or 7, may be modified to provide facings such as 20 and/or 30 mounted onto different support members, e. g. shaped tiles or other structures of less depth than the breeze blocks 12 and 32. This will allow the facings to be readily applied to a wooden or metal framework to create a representation of a genuine brick wall, e. g. as a facade around a domestic hearth fire.

Other modifications and embodiments of the invention, which will be readily apparent to those skilled in this art, are to be deemed within the ambit and scope of the invention, and the particular embodiment (s) hereinbefore described may be varied in construction and detail, e. g. interchanging (where appropriate or desired) different features of each, without departing from the scope of the patent monopoly hereby sought. Furthermore the invention is not limited to the coated building element per se but also includes in its scope the coating material-which, for example, may be supplied as its individual constituents in separate receptacles within an outer packaging member-and the method of applying it to a building element.

The illustrated building elements provided with coatings as described above demonstrated (in tests) surprisingly good resistance to weathering and moisture ingress. This is

thought to be due to the substantial sealing of the pores of the element that result from its being coated with the mixture containing the two adhesive materials (which also serve as a binder for the cementitious powder and, in the topmost coating, for the colouring pigment).