AU2004241359B2

AU2004241359B2 - Building block

Info

Publication number: AU2004241359B2
Application number: AU2004241359A
Authority: AU
Inventors: Graham Glasspool
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-21
Filing date: 2004-05-21
Publication date: 2008-01-10
Anticipated expiration: 2024-05-21
Also published as: AU2004241359A1; US20070022708A1; EP1625260A1; GB0411379D0; GB2402141A; WO2004104312A1; GB2402141B

Description

WO 2004/104312 PCT/GB2004/002195 BUILDING BLOCK Field of the Invention The present invention relates to a building block, especially for the construction of swimming pools.

Background to the Invention When building a swimming pool there are various methods that can be used.

Generally, a common method of making a swimming pool is to form a wall using concrete and/or blocks, and then to finish off the surface of the wall using two or more coats of render, plus a finishing marbled coat or tiles. This process of rendering causes difficulties to the pool builder, and to the pool owner, and the procedure involved is very labour intensive, specialised, skilled and hazardous, especially the application and polishing (grinding) of the marbled finish.

One of the most common methods of building the shell of a pool is via the use of a standard hollow breezeblock, whereby the tradesman builds the walls of the pool using the blocks like large bricks. As he cements them together, he adds steel reinforced bars, both horizontally and vertically into the blockwork. When the cement between the joints is dry, he pours concrete into the cavities and the structure is complete and ready for waterproofing and the application of the internal finishes. In order to fill the cavities with concrete the tradesman must fill each individual cavity, which can be very time consuming.

An alternative construction method uses solid concrete blocks which are constructed to form inner and outer walls leaving a cavity between them into which the steel is fixed and the concrete poured. However, this construction method is time consuming as it requires building separate walls.

A third construction method called the Gunnite/Shotcrete method is by far the most expensive but structurally most sound. It involves the use of a compressed air concrete' machine. This shoots concrete onto a pre-formed background and steel re- :bar,frame where the concrete builds up into a mass to form the walls and floor of thepool. It is then tiled or marblited like other pools.

CONFIRMATION COPY WO 2004/104312 PCTiGB2004/002195 2 The process is highly skilled and expensive in terms of labour, materials and machinery. Weather conditions during construction and drying out are also critical.

All three construction methods then require various further treatments to be applied before the pool can be filled with water.

When the shell is sufficiently dry, (ten days for the Gunnite method) the builder will need to waterproof it and apply a decorative finish. This is done by first applying a layer of cement render to the most uneven areas, the corners and edges (several coats may be necessary as no more than 12 mm can be applied at a time). A waterproofing scratch coat is then applied over the entire area. This has an admix in the cement to make it waterproof and the surface is scratched to aid adhesion of the next coat (adhesion to a waterproofed surface is difficult).

After a few days when the scratch coats are dry, the finish coat is applied. This commonly consists of a mixture of marble chips, marble dust and white cement.

Special stainless steel tools are required for its application to prevent rust staining.

Great care must be taken to prevent contamination and suitable curing conditions are essential. Two to four days after application, depending upon the curing circumstances, the surface is then ready to be polished.

The drying out process for both the scratch and finish coats is crucial for the prevention of shrinkage cracks (it must not be allowed to dry too quickly). Frequent supervision is required in the form of covering and uncovering with polythene sheeting or a wet fabric together with light sprinkler hosing, dependent upon the prevailing weather conditions.

Polishing is a very hazardous practice consisting of grinding with an electric angle grinder to expose and polish the marble chips and obtain a smooth surface. The process is extremely skilled and dangerous to the person doing the job, as the safety guard to the grinder has to be removed. It also causes huge amounts of air pollution and needs to be carried out at a precise time in the drying out process.

WO 2004/104312 PCT/GB2004/002195 3 A number of alternative and combination finishes are available using renders, tiles, paints, plastic liners, etc. However, they virtually all still rely on a good rendered surface upon which to apply them.

All the methods of construction listed above require two or more coats of render plus a finishing coat. This process causes enormous difficulties to the pool builder, as the procedure involved is very specialized and hazardous, especially the application and polishing of the marbled finish. Inclement weather, dirty site conditions and drying out delays add to the difficulties involved.

Work cannot be carried out in wet conditions, or if rain is imminent, due to the possibility of slumping. If it is windy or sunny then the render can dry too quickly, causing shrinkage that result in cracks and poor adhesion to the underlying surface.

Debris, too, can blow onto the surface and stain or contaminate the finish.

The pool owner is often unaware of the problems, especially if the builder fills the swimming pool with water quickly after construction (a common practice). A few seasons down the line, when algae has grown in the cracks or frost acts on the water in the hollows behind the render, the customer has an unsightly pool and imminently, some large maintenance bills.

The builder's reputation may also be tarnished, by his production of a pool with an inferior finish, long-term maintenance problems and warranty call outs. At the very least, he risks upsetting his customer with delays in construction due to inclement weather and non-availability of skilled labour at the required times.

Surface finishes are potentially a major maintenance problem in all pools anyway.

Even if all the above difficulties have been overcome it is possible for perfectly-built tiled pools (the most expensive) to suffer from breakdown of their adhesives and grouts by the effect due to chemicals in the pool.

It is therefore an object of the present invention to overcome some or all of the problems outlined above.

Summary of the Invention According to the present invention there is provided a swimming pool building block comprising a first panel and a second panel together with spacer means adapted to space the first panel from the second panel to create a cavity therebetween, said building block further comprising means to allow a filling material to flow through the cavity such that, in use, said filling material can pass through the building block in both horizontal and vertical directions, said building block further comprising interlocking means to join adjacent blocks together to form a mortar-less joint comprising a projecting rim on two adjacent edges of each panel and corresponding recessed shoulders on opposing adjacent edges of each panel whereby the projecting rims on one block engage with the recessed shoulders on abutting blocks, wherein an outward face of at least one of the first or second panels comprises a finished surface such that, in use, the finished surface does not require further finishing, including further rendering or tiling.

Building block is taken to mean any unit which is capable of being used in construction to form a structure, for example a wall. Known building blocks include bricks, breeze blocks and concrete blocks. The building block comprises a front panel, a rear panel and spacer means to space the front panel from the rear panel. This includes a building unit which has an inner and an outer face which are held apart either by specific supports, or alternatively a one piece building block which comprises a front and a rear face.

An important aspect of the present invention is that the building block or building unit has a specifically designed cavity between the two faces. This allows a filler material to be poured into the cavity and the block is designed so that the filler material pours or flows through the cavity into adjacent blocks both vertically and horizontally.

Preferably the spacer means comprises passageways in said means to space N \Mclboumc\Cases Patent\9000-59999\P593O5 AU\Spccis\P9305.AU Spccification 2007-8-16doc 23/ 1/2007 the front panel from the rear panel. This allows a filling material such as concrete to pass through the sides of the block (in a horizontal direction) when 0 z the blocks are in use. This forms what is, in effect, a concrete membrane t' between the inner and outer faces of the blocks.

o Preferably the building block is adapted to allow the cavity of one building block Sto be open to the cavity of an abutting building block in both vertical and horizontal axes.

Typically, the filler material will be concrete in a liquid or slurry form but it is also possible to pour a light, dry mix of concrete into the cavity and add water.

In the context of this invention vertical and horizontal are to be determined in relation to a building block in its normal orientation during construction. That is, horizontal is considered to be in line parallel with the ground and vertical is given its normal meaning.

To further explain the terms horizontal and vertical in this context, a building block can be said to have two major axes that can allow a filling material to flow through the building block. The first major axis is from the top face of the block to the bottom face of the block. The second major axis is through the sides of the block. In the case of a rectangular block this would be the top and bottom, and left side and the right side. In the case of a polygonal block the second major axis is considered through at least some of the side faces. In the case of a curved block the second major axis would be through the side ends of the block. The major axes can therefore be considered analogous to the vertical and horizontal directions outlined in the present invention. The object is to allow a fill material, such as concrete, to flow substantially freely from one block into all blocks adjacent to that block, to form a substantially continuous membrane of fill material.

N:\Melboumc\Cases\PaleL\59000-59999\P59305 AU\Spccis\P59305AU Spccfcaicaion 2007-8-1 6doc23/1 /2007 When constructing a wall a plurality of building blocks will be used, in the same manner as standard building units. Once the wall is formed, concrete can be 0 z poured into the cavity. Because all of the cavities of the individual blocks are Cc interlinked they will all be filled with concrete in a single pour. This is because a given block has passageways or open cavities in both a vertical and horizontal direction so a material entering through the top of the block can exit Cthrough both the bottom and the two sides. Obviously, the material cannot exit through the front and rear faces.

Preferably the building block is further adapted to permit reinforcing bars to N pass through the cavity.

More preferably the reinforcing bars pass through the cavity in both a vertical and horizontal direction.

The reinforcing bars, typically made of steel, can rest on the spacer means within the cavity in a horizontal direction and also pass through the cavity in a vertical direction. This adds strength to the concrete and the methods of doing this are well known to those skilled in the art.

The building block further comprises interlocking means to join adjacent blocks together.

Preferably the interlocking means comprise a projecting rim on adjacent sides of each panel and corresponding recessed shoulders on opposing adjacent sides of each panel whereby the projecting rims on one block engage with the recessed shoulders on abutting blocks.

It is possible to envisage other ways in which the blocks can be interlocked. By interlock, it is meant that the blocks engage with each other to hold them in place whilst the structure is being built. This removes the need for mortaring the blocks in place.

The interlocking means, in use, are substantially fluid tight. This can either stop water seeping between the blocks or stops liquid or slurried concrete from N MeIbourme\CasePatenz\59000-59999\PS93OSAU\Spccis\P59305 AU Speciication 2007-8-16doc23/ 1/2007 escaping through the joints while it sets. During use, the concrete membrane ensures the pool is watertight.

0 q Optionally the building block is of unitary construction. For example, the block could be formed from a mould using concrete, plastic or any other mouldable material.

q In this context, unitary construction is given a broad meaning. It is taken to cover any building block according to the present invention whether constructed o by a multi-stage process or a single moulding whereby the block is delivered to site as a unitary construction.

Optionally the building block further comprises an insulation layer.

The insulation layer can optionally be on the front and/or rear panel.

In use, the building block is used to build a structure by laying rows of blocks one above another and pouring a filling material into the cavity formed between said front and said rear faces of each of the blocks.

Preferably horizontal reinforcing bars are laid in the cavity of each row before the next row is formed. The vertical bars can be laid at the start or afterwards.

Preferably said filling material is concrete. The filling material is needed to give support to the structure. Liquid, slurry or dry mix concrete can be used. Indeed the invention covers any filing which acts to support the structure.

Preferably when the concrete is poured into said cavity it forms a continuous concrete block between said front and said rear panels.

Generally, said structure is a wall.

Preferably, said structure is a swimming pool.

An outward face of at least one of said front panel or said rear panel is adapted to form a finished surface.

N \MlboumcCes\Patenl\59000-59999\P593OSAU\Spcis\P593OSAU Spccification 2007-8-16doc 23/1 /2007 O In this context, finished surface is taken to mean a surface which is the final surface to be used in the swimming pool. Prior art constructions required 0 z various render layers plus smoothing. The finished surface in this invention does not require these same steps.

C~ More preferably the outward face of said front panel comprises a pool wall finish.

Preferably the pool wall finish comprises one or more tile shapes formed thereon wherein said tile shapes are so sized, shaped and configured so as to abut against tile shapes on an adjacent abutting block to create a continuous N tile effect. This allows, for the first time, the building unit to fully comprise the finished surface which saves an enormous amount of time, energy and money.

is Optionally the outward face of said rear panel is adapted to comprise a brick or stone effect.

Optionally the building block further incorporates drainage channels.

In one embodiment the building block is manufactured out of a cement based material such as pumice, marblite or resin concrete or combinations thereof.

Alternatively the building block is manufactured out of a non-cement based material including plastics, wood, metal, fibreglass, stainless steel, ceramic tile, Shipboard, MDF (cardboard), solid marble or combinations thereof.

This list is not meant to be limiting but rather to show the breadth of the range of possible materials.

The building block is used to build a structure said finished surface does not require further finishing, including further rendering or tiling, before use.

Other variations of the invention are also envisaged. For example pool wall finish could be other than tile effect, e.g. a smooth face. The rear panel could N \Mcbome\Cases\Paicn\59000.S9999\P593O ALP\Spccis\PS9305 AU Spccification 2007-8.16 doc 23/11/2007 have a brick or stone effect on its outer face so that it is sightly for "above" or "part above" ground pools. Corner blocks could also be provided to create 0 z corners in a pool wall. The block could be moulded in a polystyrene mould that could double as packaging. The front and rear panels may be formed separately and the spacer means added thereafter whereby a block may be shipped in flat pack form. The block could be of material other than cement based. For example the front and rear panels and spacer means could be formed of plastics, wood or metal or combinations thereof. Drainage channels could be incorporated in the top block for deck level pools or just for natural 1io drainage and cleaning. Blocks could include the necessary fitting to incorporate a pool thermal or protective cover, or a rigid deck. The blocks could form hand or scum rails.

There is also provided a kit for constructing a building block according to the present invention comprising a front panel, a rear panel and means to space the front panel from the rear panel to create a cavity therebetween, whereby said front panel, said rear panel and said spacer means are formed separately and can be assembled to form a building block.

This means that the building block can be bought and transported flat packed and assembled on site. This also opens up the possibility to mix and match the front and rear panels depending on how they are to be used.

Optionally the front panel and said rear panel can be constructed out of different materials.

Preferably the spacer means has interchangeable end fittings appropriate to the front and rear faces.

In this way a standard spacer an be used which has multiple end fittings depending on the panels used, either their material or their shape.

N\Mclboumc\Cas5\Patent\S9OO-5999\PS9O5 ALASpecis\P59305 AU Specification 2007-8-16doc 23 1/2007 Preferably the spacer means is attached to said front and rear panels by clipping, screwing or gluing.

0 Cc There are various ways of attaching the panels to the spaces which would be known to the material specialist and all are intended to be incorporated by this 0o invention. It is possible to have different arrangements of the spacers and q i indeed different numbers of spacers. This will depend on various factors including the shape and material of the panels.

The building block can be used to form a structure comprising building blocks according to the present invention.

The present invention also encompasses a method of forming a structure using building blocks according to any preceding claim.

Preferably the structure is a wall.

More preferably the structure is a swimming pool.

It will be appreciated that the present invention also extends to include structures formed from building blocks according to the present invention. Such structures may take many and varied forms but especially include walls and swimming pools.

N \Mclboume\Cascs\Patnt\59000-59999\P59305 AJSpcis\P59305 AU Spccification 2007-8-16 doc 23/ 11/2007 01 THIS PAGE HAS BEEN INTENTIALLY LEFT BLANK N.Welboume\Cases\Patcnt\59000-59999\P59305 AUISpecis\P59305 AU Spcification 2007-8-16 6doc23/I112007 WO 2004/104312 PCT/GB2004/002195 12 Brief Description of the Drawings Preferred embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, wherein: Figure 1 shows a prior art method of constructing a swimming pool shell using a hollow concrete block method.

Figure 2 and show an alternative prior art method using a solid concrete block method.

Figure 3 shows a third alternative prior art method using a Gunnite Shotcrete method.

Figure 4a shows a perspective first view of a block according to a first aspect of the present invention, from above.

Figure 4b shows a perspective second view of a block according to a first aspect of the present invention, from below Figure 4c shows a wall being built with a plurality of blocks according to a first aspect of the present invention.

Figure 4d shows a perspective end view of a block according to a first aspect of the present invention which shows how concrete can flow around the whole of the inside cavity during construction.

Figure 5a shows a perspective view of an assembled block according to a second aspect of the present invention.

Figure 5b shows a top view of an assembled block according to a second aspect of the present invention.

Figure 5c shows a front view of an assembled block according to a second aspect of the present invention.

Figure 5d shows a end view of an assembled block according to a second aspect of the present invention.

Figure 6a shows a perspective view of one possible connecting means according to a second aspect of the present invention.

Figure 6b shows an exploded perspective view of the connecting means of Figure 6a.

Figure 6c shows a front view of the connecting means of Figure 6a.

Figure 6d shows an end view of the connecting means of Figure 6a.

WO 2004/104312 PCT/GB2004/002195 13 Figure 7a shows a front view of one possible tile according to a second aspect of the present invention.

Figure 7b shows a top view of one possible tile according to a second aspect of the present invention.

Figure 7c shows an end view of one possible tile according to a second aspect of the present invention.

Detailed Description of the Drawings Figures 1 to 3 show three prior art construction methods.

Figure 1 shows a hollow concrete block 10 of the type standard to the construction industry. It has vertical holes 11 in the block but there are no passageways in a horizontal or sideways direction. In use, steel reinforcing bars 12 and 13 are placed vertically in the holes 11 and laterally across the top of the blocks. The lateral bars 13 are held in the mortar between blocks 10. A tradesman has to fill each hole 11 with concrete when constructing a pool. This is obviously a time consuming exercise and moreover does not give the support of a solid concrete block.

Figure 2a shows a solid concrete block 20. Figures 2b and 2c show a swimming pool construction using a solid concrete block 20. Figure 2b shows a side view and Figure 2c, a top view. An inner wall 21 and an outer wall 22 are formed leaving a cavity 24 between them into which the steel 23 is fixed and the concrete is poured.

The figures shown the cemented joints 27, the waterproof render layers 25 and the finish coat 26. Once all the work is completed, water 28 is added to the pool.

Figure 3 shows a tradesman using a compressed air concrete machine to form a pool construction using the Gunnite/Shotcrete method.

Figures 4a-d show a building block according to a first aspect of the present invention.

Referring to Figures 4a and 4b there is shown a building block 41.

Building block 41 comprises a rectangular front panel 42 supporting a pool wall finish on a front face in the form of tile shapes 43a, 43b, 43c, 43d.

WO 2004/104312 PCT/GB2004/002195 14 Block 41 also comprises a rectangular rear panel 44 identical in size and mirror image of front panel 42.

Spacer means are provided by a pair of space members 45,46 with opposing cshaped cut-outs to space the front panel from the rear panel to create a cavity 47 therebetween. Other shapes of spacer could be used to equal effect.

Interlocking means are provided to join two adjacent abutting blocks together. The interlocking means comprises projecting rims 42a, 42b on two sides adjacent of each block front panel, and corresponding projecting rims 44a, 44b on two sides adjacent of each block rear panel. The interlocking means also comprises recessed shoulders 42c, 42d on the other two sides of each block front panel and corresponding recessed shoulders44c, 44d on the other two sides of each block rear panel. When two blocks abut, projecting rims on one block engage with recessed shoulders on abutting blocks.

As shown in Figure 4c a wall can be built by laying rows of blocks above one another and pouring concrete into the cavity between the front and rear face of each block. Steel reinforcing bars 8 can be placed in the cavity formed between the front and rear panels. In this respect, horizontal bars can be laid resting on the c-shaped cut-out as each row of blocks is laid and the vertical bars tied onto the horizontal bars.

As shown in Figure 4a the pool wall finish on the front panel front face has four tile shapes formed thereon. These shapes abut against tile shapes on an adjacent abutting block to create a continuous tile effect on a wall formed by a plurality of blocks.

Also as shown, the spacer means are such as to allow the cavity of a block to be open to the cavity of another abutting block, whereby concrete poured into a wall formed by a plurality of blocks flows to form a continuous concrete wall between the block front and rear panels.

Coping stones 49 may also be provided to face the top of the wall, with each coping stone adapted to engage with the rims or shoulders on a block 41.

WO 2004/104312 PCT/GB2004/002195 Figure 4d shows a perspective view of the building block 41. The spacer means to space the front and rear panels are adapted to have a hole or shape cast in them allow the free flow of concrete from one block to the next. This in itself is a tremendous structural advantage over the conventional hollow block. In addition, due to the size of the holes, the number of horizontal steel reinforcing bars can be doubled, thus producing an even stronger structure.

The arrows show the flow of the concrete in and through the cavity. It can be seen that the concrete may flow through the top face of the block and the bottom face of the block so called vertical direction. In addition, the concrete may flow through the two side faces of the block the so called horizontal direction.

The block may be formed as a unitary construction, e.g. moulded as a unitary moulding. It may be moulded during manufacture out of concrete or another cement based material. Alternatively it may be moulded out of a plastics material.

Indeed any material which is suitable for forming into the required shape which can be used in construction may be determined by the material specialists and is intended to be encompassed by the present invention.

The pool wall finish may take on many forms. It may have a tiled effect or some other pattern. Alternatively, actual glazed tiles may be applied to the block surface during manufacture. Because the invention does not require expensive and time consuming rendering coats, many option for the finishing coat may be considered, which are still considerably cheaper than the existing methods.

Obviously, other passage, spacer and panel designs can be used which do not depart from the concept of the invention and are intended to be included within the scope of the present invention. Whilst the blocks shown in Figure 4 are all rectangular, it is entirely possible for the block to be other shapes, for example curved or polygonal. This allows circular or non-linear pools to be formed. Such non-rectangular blocks work by exactly the same principle as the rectangular block with the concrete flowing in a vertical and horizontal direction through the top, bottom and the left and right sides of the block.

O Figure 5 a-d show a second aspect of the present invention. The building block 50 shown in Figure 5a is formed from separate components: a front 0 z face 51, a rear face 52 and connecting means or spacer unit 53. Figure shows the block in an assembled form. It is clear that this arrangement has all of the advantages of the unitary construction block in that the concrete can flow around the building block cavity 54 and it can be used without the need for separate rendering coats. Furthermore, reinforcing bars (commonly t' steel) can be placed in the cavity 54 with the same ease as in the unitary J- construction blocks.

(Nio The assemblable system, or flat pack system, has a number of distinct advantages.

By casting, cutting or molding the face and rear sections separately and then utilizing connecting pieces, the block can be flat-packed for ease of storage and transportation. This principal also provides added options regarding materials and use: Stainless steel and laminate sheet materials that cannot be moulded into a hollow block can now be utilized; Economy versions with an expensive face finish but a cheaper plain rear section such as "shipboard" can be used; Double-faced versions with swimming pool tiles one side and brick or stone pattern on the other, could also be produced for above ground pools, garden walls, ponds, and a multitude of other uses; With suitable material choice and adaptations a removable, re-usable system could easily be devised.

Figure 6 a-d shows a possible connecting or spacer means in more detail.

The spacer could be screwed, glued or clipped into place. One possible attachment means would be to have opposed locking means so that the spacer is effectively locked into both the front and rear faces simultaneously, for example by rotational movement.

Many other spacing means with various attachment mechanisms are envisaged and are intended to be encompassed by the present invention.

N \Mclboumc\Cascs\Paten\59000-59999\P59305ALASpecis\P59305AU Speciflation 2007-816doc.23/1 /2007 Figure 7 a-c shows an example of a front panel for use with an assemblable

O

z building block.

In summary, the present invention has overcome many problems associated with traditional swimming pool construction with the invention of a new building block. These blocks form a pre-fabricated concrete shattering system, which is factory finished and stays in situ. The blocks simply interlink together in all directions. They do not require mortar in the joints and do not need to have a face surface added. Once in place the factory finished face Cside forms the internal surface to the pool. The innovative design features and vast range of material options and colours render the whole process more controlled and more efficient.

The short and predictable installation times result in controlled budgeting costs and less chance of a delayed hand-over period. Many of the skilled labour processes normally involved are eliminated as are all the problems associated with the application and maintenance of the surface finishes.

With its pre-determined installation programme, huge savings in construction time could be made. The end product would be considerably stronger, maintenance free, longer lasting and of a higher quality than other pools currently produced.

The quality of the product with its innovative design and materials is of a higher quality and standard than anything previously produced in the swimming pool industry.

N\Mciboumne\Cwcs\Patcn\St9OO-59999\P59305 AL\Spcis\P9305 AU Specification 2007.8-I 6doc 231I 1/2007 WO 2004/104312 PCT/GB2004/002195 18 Furthermore the invention is equally applicable to the building trade in general. It is expected, at the very least, that the blocks according to the present invention will prove to be suitable for use in the steel framed buildings industry, for cons-truction works in earthquake zones an as a quick and easy method of rebuilding after disasters.

It will be appreciated that the present invention includes several different concepts that can be used in isolation of each other or together in various combinations. One of the concepts is that of allowing a filling material to flow in both a horizontal and vertical direction through a block. This is achieved by allowing the cavity of one block to be open into the cavity of an abutting block in both a horizontal and vertical direction. The front and rear faces of the blocks therefore form what is, in effect, shuttering designed to be filled by some fill material such as cement. This does not require the blocks to be stacked on top of each other and they can be offset when being built.

Another concept is the use of a building block that has a finished face. This means the block face can be used as the final face for a swimming pool without the need for further rendering and many other steps. A third concept is the use of an interlocking means to join or overlap adjacent blocks together. This allows blocks, once filled, to be joined together without the need for mortar. Another concept is the kit for constructing a building block. This allows a user to mix and match between different faces depending on the circumstances. All of these concepts have individual merits not dependant on each other but can be combined in various combinations, or altogether, to form a superior building block.

Further modifications of the invention will be apparent to those skilled in the art without departing from the scope of the present invention.

Claims

2. A building block according to any preceding claim wherein the said spacer means comprises passageways in said means to space the front panel from the rear panel.
3. A building block according to any preceding claim wherein the building block is adapted to allow the cavity of one building block to be open to the cavity of an abutting building block in both vertical and horizontal axes.
4. A building block according to any preceding claim wherein the building block is further adapted to permit reinforcing bars to pass through the cavity. A building block according to Claim 4 wherein the reinforcing bars pass through the cavity in both a vertical and horizontal direction.
6. A building block according to any preceding claim wherein, in use, said interlocking means stops water seeping between the blocks when the swimming pool is filled with water. ?J.\Mclboum\Cascs\Patent\59000-59999\P59305AL1\Spccis\P59305AU Spcification 2007-8-16doc23/1 1/2007
7. A building block according to any preceding claim wherein said building O block is of unitary construction. s 8. A building block according to any preceding claim wherein said building block further comprises an insulation layer.
9. A building block according to Claim 8 wherein said insulation layer is on Sthe first and/or second panel. A building block according to any preceding claim wherein said building block is used to build a structure by laying rows of blocks one above another and pouring a filling material into the cavity formed between said first and said second faces of the blocks.
11. A building block according to Claim 10 when dependent on Claim wherein horizontal reinforcing bars are laid in the cavity of each row before the next row is formed.
12. A building block according to any preceding claim wherein said filling material is concrete.
13. A building block according to Claim 12 wherein when said concrete is poured into said cavity it forms a substantially continuous concrete membrane between said first and said second panels.
14. A building block according to any of Claims 10 to 13 inclusive wherein said structure is a wall.
15. A building block according to any of Claims 10 to 13 inclusive wherein said structure is a swimming pool. N \Melboume\Cases\Parcnt\59000.59999\P593O5 AU\Spccis\P59305.AU Specification 2007-8-16 doc23/1 /2007
16. A building block according to any preceding claim wherein the finished surface of the first panel comprises a pool wall finish. 0 z
17. A building block according to Claim 16 wherein said pool wall finish comprises one or more tile shapes wherein said tile shapes are so sized, shaped and configured so as to abut against tile shapes on an adjacent Sabutting block to create a continuous tile effect.
18. A building block according to any preceding claim wherein the finished 010 surface of the second panel is adapted to comprise a brick or stone effect.
19. A building block according to any preceding claim wherein said building block further incorporates drainage channels.
20. A building block according to any preceding claim wherein said building block is manufactured out of a cement based material such as pumice, marblite and resin concrete.
21. A building block according to any of Claims 1 to 20 inclusive wherein said building block is manufactured out of a non-cement based material including plastics, metal, fibreglass, stainless steel, ceramic tile, solid marble or combinations thereof.
22. A kit for constructing a building block according to any of Claims 1 to 6 and Claims 8 to 21 inclusive when not dependent upon Claim 7, comprising a first panel, a second panel and means to space the first panel from the second panel to create a cavity therebetween, whereby said first panel, said second panel and said spacer means are formed separately and can be assembled to form a building block.
23. A kit for constructing a building block according to Claim 22 wherein said first panel and said second panel are constructed out of different materials. N \Mclboum\Cases\Pacnx\59000-59999\P59305.AU\Specis\P59305 AU Specification 2007-8-166doc23/I 1/2007
24. A kit for constructing a building block according to Claims 22 or 23 O z wherein a finished surface on the first panel is different from a finished surface tc on the second panel. A kit for constructing a building block according to any of Claims 22 to 24 Sinclusive wherein the finished surface(s) is/are selected from a pool wall finish, a brick or stone effect, a cement based material including pumice, marblite or Sresin concrete, a non-cement based material such as plastic, metal, tile, stone, O 010 solid marble, fibreglass or stainless steel, and combinations thereof.
26. A kit for constructing a building block according to any of Claims 22 to inclusive wherein said spacer means has interchangeable end fittings appropriate to the first and second faces.
27. A kit for constructing a building block according to any of Claims 22 to 26 inclusive wherein said spacer means is attached to said first and second panels by clipping, screwing or gluing.
28. A kit for constructing a building block according to any of Claims 22 to 27 inclusive wherein the kit can be supplied in flat packed form.
29. A structure comprising building blocks according to any preceding claim.
30. A method of forming a structure using building blocks according to any of Claims 1 to 27 inclusive.
31. A structure according to Claim 29 wherein said structure is a wall.
32. A structure according to Claim 29 wherein said structure is a swimming pool. N \Melboume\Cascs\Pntent\59000-59999\P59305 A\Specis\P59305.AU Specification 2007-8-16doc23/I 1/2007
33. A building block substantially as herein described with reference to and N as illustrated in any combination of Figures 4 to 7. O
34. A structure comprising a building block substantially as herein described with reference to and as illustrated in Figures 4 to 7. l
35. A method of forming a structure using building blocks substantially as herein described with reference to and as illustrated in any combination of Figures 4 to 7. Mebownc\Cases\Patent\S9000-59999\PS93OSALASpcis\P93OS AU Specification 2007.8-16 doc 23/1112007