Patent Description:
Cladding is widely used on buildings to provide an aesthetically pleasing exterior to the building. A wide variety of facing materials can be used to provide a required finish. One type of cladding includes a plurality of facing building members mounted in a required pattern on a cementitious backing layer. The building members are often bricks, though many other types of building members can be used.

With brick facing members, "brick slips" are often used which are relatively thin bricks, which can be formed by cutting conventional bricks for instance into two brick slips. Where bricks are cut this is generally achieved using a diamond tipped saw which inter alia often leaves a layer of dust or slurry upon the cut bricks which can affect their adhesion to the backing layer. Cutting conventional bricks enables any required bricks to be used, such that for instance local bricks can be used to match with existing buildings and structures.

Difficulties can though be encountered in providing a good bond between the brick slips and the cementitious backing layer and also between adjacent brick slips, and especially at the peripheral edges of the cladding where the brick slips may only have two other adjacent brick slips to bond to.

<FIG> diagrammatically shows a plan view of a conventional cladding panel <NUM> with brick slips <NUM> mounted on a cementitious backing layer <NUM>. The brick slips comprise two corner members <NUM> referred to as "pistols", a full length brick <NUM>, a "stretcher", and a half length brick <NUM>, a "header". As can be seen the mechanical key between the cementitious material <NUM> and the brick slips <NUM> is provided between the cementitious material <NUM> on the rear faces of the brick slips <NUM>, and also between the cementitious material <NUM> located between adjacent brick slips <NUM>, where the cementitious material <NUM> has flowed between the brick slips <NUM>. Often the cementitious material <NUM> will not flow as far between the brick slips as is shown diagrammatically in <FIG>.

<FIG> shows a conventional stretcher brick slip <NUM> with a layer of cementitious material therebehind <NUM>.

In the specification the term "mechanical key" on a building member is to be understood as a formation which prevents there being a direct line of sight perpendicularly from the rear of a front face of the building member, to a rear of the building member, at any point.

<CIT> discloses a composite external wall facing panel made up from concrete, using artificial or natural stone with a glass-fibre-reinforced polyester coating, combining rigidity with comparatively light weight and a saving in materials. It can be used for rear ventilated wall cladding. Stone slabs are provided on the rear side with conical recesses, and given the coating of reinforced polyester, and a firm connection is established between these, producing a composite unit. The polyester coating may also comprise the facing sides of the panel, with a frame encompassing it produced by a recess. A peripheral carrier and retainer frame may be applied behind the panel. It may be given a reinforcing profile on the rear side, and anchors, connecting elements and profiled sections may be embedded with the polyester coating. Another prior art assembly of bricks and settable material is shown in <CIT>. A method of forming a cladding panel is known from <CIT>.

Some examples provide a cladding panel formed by a settable material located on the rear of a plurality of facing building members, each facing building member having a front face and a rear side, the rear side being profiled by cutting with a water jet so as to provide at least a pair of mechanical keys provided with edges inclined relative to the front face, with the pair having one edge inclined relative to the front face in a first direction, and a second edge inclined relative to the front face in an opposite second direction, wherein the pair of mechanical keys are provided by a recess with a dovetail profile in plan view relative to the front face, in the rear side of the facing building member, and wherein the settable material extends into the recess of each facing building member and extends into joins between adjacent facing building members of the cladding panel.

The dovetail profile may have rounded edges.

The facing building member may be in the form of a brick facing member, and may be formed by cutting a brick into two or more parts.

The or each recess may extend from between <NUM> and <NUM>% of the thickness of the facing building member, and more particularly between <NUM> and <NUM>% of the thickness of the facing building member.

The rear side of the facing building member may have a regular pattern of recesses, and the recesses may be separated by correspondingly profiled projections.

The rear side of the facing building member may have a recess which extends to one end of the building member, and preferably such a recess only at one end of the facing building member.

The profile of the rear side may be configured with an inclination such that the distance between the rear side and the front face decreases in one or more directions across the building member.

The facing building member may be in the form of a corner member with a front face and a side face, with at least one mechanical key on the rear side from the front face. A mechanical key may also be provided on the rear side of the side face.

According to an aspect of the invention there is provided a method of forming a cladding panel, the method comprising cutting an original facing building member with a water jet to form a facing building member with a front face and a profiled rear side with at least a pair of mechanical keys provided with edges inclined relative to the front face, with the pair having one edge inclined relative to the front face in a first direction, and a second edge inclined relative to the front face in an opposite second direction, wherein the pair of mechanical keys are provided by a recess with a dovetail profile in plan view relative to the front face in the rear side of the facing building member; the method further comprising locating the facing building members in a required pattern in a mould, and locating a settable material onto the rear of the facing building members to form a cladding panel once set, and wherein the settable material extends into the recess of each facing building member and extends into the joins between adjacent facing building members of the cladding panel, as defined in claim <NUM>.

A solid abrasive may be provided in the water jet, which abrasive may be garnet.

The original building member may be cut into two or more pieces so as to provide two or more facing building members, with opposite sides of the original member providing the respective front faces, and the respective rear sides being provided by a cut through the original building member.

The original building member may be cut so as to provide two substantially identical facing building members.

The original building member is a moulded clay brick.

The settable material may be cementitious, may be ultra high performance concrete, which may be fibre reinforced.

Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:-.

<FIG> all show building members according to the invention. These building members are formed by cutting a moulded clay brick to a required profile using a high pressure water jet with a solid abrasive medium such as garnet in the water flow. The water jet may be CNC controlled to permit automatic and accurate profiling.

<FIG> and <FIG> show a first facing building member <NUM> which has a front face <NUM> and a rear side <NUM>. The rear side <NUM> has a profile comprising a complete rounded dovetail shape recess <NUM> in plan view, and a second partial rounded dovetail shape recess <NUM> which extends to one end, the right hand end as shown of the member <NUM>. The two recesses <NUM>, <NUM> are separated by correspondingly profiled rounded dovetail shape projections <NUM>, <NUM>, one <NUM> of which is only partial and extends to the left hand end as shown of the building member <NUM>.

It is to be realised that the building member <NUM> can be cut from a single brick to provide two identical building members <NUM>. This building member <NUM> is suitable for use in half bond brickwork and will provide significantly enhanced bonding between the building member and cementitious material <NUM>, for instance as shown in <FIG>. This is due to the larger contact surface area between the member <NUM> and cementitious material <NUM>, and the mechanical keys formed by the recess <NUM>, <NUM> and respective projections <NUM>, <NUM>.

<FIG> show a further facing building member <NUM> which is similar to the building member <NUM> but is suitable for use in quarter bond brickwork and therefore includes essentially double the number of recesses <NUM> and projections <NUM> relative to the building member <NUM>. As can be seen there are three full dovetail recesses <NUM>, and a further one <NUM> which extends to the right hand end of the building member <NUM>. Similarly, three full dovetail profile projections <NUM> are provided, with a further projection <NUM> extending to the left hand end. Again, this building member <NUM> can be cut from a single brick to provide two identical building members <NUM> as illustrated in <FIG>.

<FIG> diagrammatically illustrates how a brick could be cut into three building members using quarter bond brickwork. The first being the building member <NUM>, a second being a short member <NUM> usable in forming a corner, with a dovetail profiled projection <NUM> at one end, and a dovetail profiled other end <NUM> to permit joining to a dovetail part shape projection <NUM> on another building member <NUM>. A third building member <NUM> is provided which is equivalent to a half brick, i.e. a header. As can be seen this building member <NUM> extends for a little under a half of the length of the building member <NUM>, to provide a space for the cementitious material to extend between adjacent building members. <FIG> shows this building member <NUM>.

<FIG> shows a further building member <NUM> usable as a corner or pistol with two full <NUM> and one part dovetail shape projection <NUM> on the rear of the front face <NUM>, and a side face <NUM> with part of a dovetail shape projection <NUM> at the end thereof.

<FIG> shows a similar corner member <NUM>, but in this instance only two full dovetail shape projections <NUM> are provided such that a dovetail shape recess <NUM> extends to the right hand end as shown.

<FIG> and <FIG> respectively show the corner building members <NUM>, <NUM> connected to the half brick building member <NUM>, with the orientation of the half brick building member <NUM> determined by which of the corner building members <NUM>, <NUM> is used, depending on the orientation of the corner.

<FIG> shows the stretcher building member <NUM> with two half brick building members <NUM> located thereon, illustrating the gap provided between the half brick building members <NUM> to enable cementitious material to locate therebetween in a conventional manner, relative to mortar used to join bricks together.

<FIG> is a similar view to <FIG> but showing use of building members <NUM>, <NUM>, <NUM>, <NUM> according to the invention. This illustrates the significantly increased surface area of the join between the cementitious material <NUM> and the building members <NUM>, <NUM>, <NUM>, <NUM>. As also can be seen the join between adjacent building members <NUM>, <NUM>, <NUM>, <NUM> is provided between a part recess and a part projection which permits cementitious material <NUM> to extend further between the adjacent building members <NUM>, <NUM>, <NUM>, <NUM> to provide a strong bond therebetween.

As can be seen a wide range of profiles or building members can be produced as required, and multiple building members can be provided from each brick. The building members may be cut to suit particular bond types and corner details.

The above described examples therefore provide a system for significantly enhanced bonding between the cementitious material and building members due to the increased surface area of the contact surface therebetween, and the mechanical keys. The use of the water jet cutting permits different profiles to be achieved with a greater surface area of contact faces between the cementitious material and the building members. The water jet cutting exposes the rough nature of the bricks providing a positive keying thereto of the cementitious material. The water jet cutting also removes any slurry from the surface of the brick in contrast to sawing. The rounded edges of the dovetail profile allows the cementitious material to flow around corners to fill voids, and to avoid trapped air which can occur with sharply angled corners. This cutting readily permits computer control for automatic cooperation whilst providing consistent profiles.

It is to be realised that a wide range of modifications may be made without departing from the scope of the invention. A different abrasive such as said may be used. For instance, the building members may gently diverge in one or both directions to provide increased bonding, with the rear side of the building members being cut at an inclination. The recesses and projections may have a different profile. Whilst the above invention is described in relation to bricks, other building members could be cut in this way.

Claim 1:
A method of forming a cladding panel, the method comprising cutting original facing building members to form facing building members each with a front face (<NUM>) and a profiled rear side (<NUM>) with at least a pair of mechanical keys provided with edges inclined relative to the front face, with the pair having one edge inclined relative to the front face in a first direction, and a second edge inclined relative to the front face in an opposite second direction, wherein the pair of mechanical keys are provided by a recess (<NUM>, <NUM>) with a dovetail profile in plan view relative to the front face and projections, in the rear side of the facing building member; the method further comprising locating the facing building members in a required pattern in a mould, and locating a settable material (<NUM>) onto the rear of the facing building members to form a cladding panel once set, and wherein the settable material extends into the recess of each facing building member and extends into the joins between adjacent facing building members of the cladding panel,
and characterised in that the cutting is performed by a water jet and that the original building member is a moulded clay brick.