GB2179686A - Building systems - Google Patents

Abstract

A building system for the construction of walls, floors, roofs, paths and roads is provided comprising the employment of prefabricated blocks having compound shapes which are such that at least a majority thereof each exhibit projections and/or recesses arranged to co-operate interlockingly with the projections and/or recesses of other blocks of the system, whereby said interlocking blocks can be assembled without the essential use of mortar or other intervening binding material is characterised by a planar structure made from blocks which interengage with supporting beams by way of basically Z-shaped keying surfaces of the blocks and beams. <IMAGE>

Description

SPECIFICATION Building system This invention seeks to provide a building system in which bricks or blocks are employed that are of com- pound shape, that is to say, are not basically rectangular parallelepipeds. The term "brick(s) or block(s)" will be shortened to "block(s)" alonethrou- ghoutthegreaterpartofthe remainderofthisdoc- umentforthe sake of brevity.

According to the present invention, there is provided a building system for planar structures, such as walls, floors, roofs, paths and roads, the system com- prising the employment of prefabricated blocks having compound shapes which are such that they cooperate interlockingly with other blocks ofthe system, whereby said interlocking blocks can be assembled without the essential use of mortar or other intervening binding material, and comprising thefollowingfeature:-a planarstructuremadeof such blocks and of beams extending in the plane of the structure, these blocks and these beams having keying surfaces internally of said structure of basically Z-shape and interengaging each other, and each beam being longitudinally co-extensive with a pluralityofsuch blocks.

The blocks may be basicallyT-shaped, basicallyZshaped and/or may be dove-tailed and may cooperate with other compound-shaped blocks to produce buildings or other structures in which the various blocks strengtheningly support one another with interlocking co-operation, it being possiblefor the buildings or other structures to be completed, in some cases, without mortar or other binding material between the blocks or, in othercases,to employ a relatively small amount ofmortarorother binding material between the blocks as compared with buildings and other structures produced from conventional blocks.

The system advantageously employs blocks which are pre-fabricated to a high degree of precision and the required fitting together and/or interlocking of the blocks will not be achieved, during the erection of a building or otherstructure, unless the individual blocks are correctly disposed relative to one another and register accurately. If a mistake is made in positioning a block relative to others that have already been laid, the error will almost immediately be very obvious and can quickly be corrected. No cutting or breaking of any block is necessary since the system includes the use of complementary blocks such as end blocks, corner blocks, junction blocks and soon.

In the case of a building or otherstructure having upright walls, a minimum of checking is necessary upon the erection of those walls once the dimensions ofthe base of the building has been calculated and said base has been accurately marked out. An importantfeature of the system is the fact that the same block can be employed in the construction offloors and roofs as are used to erect walls thus producing a fully integrated building system in which, once an initial choice ofthe various possible block shapes has been made, the number of different shapes of prefabricated block that are actually employed in a single building or other structure can be quite small.

Fora better understanding of the invention, and to show how the same may be carried into effect, the various basic forms of building blockwhich an ex ample ofthis system employs will now be separately described, except inasmuch as different shapes of block co-operate with one another, reference being made to the accompanying drawings which, sim ilarly, are grouped to relate as far as possible to the different shapes of building block. Reference is made firstly to Figures 1 to 20 ofthe drawings which Fig uresshowtheuseofbuilding blocks that are basicallyT-shaped. Figures 1 and 2 ofthedrawingsshow two walls of a building or other structure formed from such T-shaped blocks.It will be seen that, in each horizontal course of blocks, neighbouring blocks are alternately upright and inverted and that, in the structure of Figure 1, each block is inverted relative to blocks which are verticallythereabove and/ ortherebeneath whereas, in the structure shown in Figure 2, each block in each course has the same disposition as does each blockwhich isvertically thereabove and/ortherebeneath. It will particularly be noted that, in both cases, the T-shaped blocks cooperate to form a 90'junction between two upright walls without the need to employ blocks of any other shape.It will immediately be apparent that the horizontai limb or crossbar of each block is three units wide and that the vertical limbor uprightthereof is two units tall measured from the lowermost ex tremitythereofto the top ofthe horizontal limb or crossbar.

In fact,the basic T-shaped block of Figure 1 and 2 is preferably given tapered projections and depressions as shown in Figure 3 and Figure 4 or is provided with projecting nibs and matching recesses as shown in Figure 5. These projections and depressions or nibs and recesses provide a significantly improved and strengthened key between the blocks enabling them to be fitted satisfactorily together without the use of mortar or other binding material when a wholly or principally dry construction is required.Itwill beapparentfrom Figures3to5ofthe drawings that the blocks which are being described are of hollow formation and it is noted that the projections and depressions or nibs and recesses cooperate with each othertoform a satisfactory seal at the joints between the blocks which is a considerable advantage if the hollow blocks are to be filled with an initiallyfoamed or liquid insulation material orwith foamed or other concrete.

Figures 6, 7, 8, 9and 10 of the drawings illustrate the formation and use of blocks which may conveniently be known as Z-key, T-blocks. The various views which are given in each of Figures 6 to 10 ofthe drawings adequately showthe compound shape of each basicallyT-shaped block and the compound shape of the co-operating Z-key, T-biock. Figure 9 shows, on the left, the co-operation between two such blocks A and B at the 900junction between for example, two uprightwalls whereas the right-hand side of Figure 9 shows the similar co-operation between two T-blocks of simpler non-keyed shape (compare with Figures 1 and 2).Figure loins a plan view illustrating the use of dove-tailed basically T shaped blocks in co-operation with basically Zshaped blocks and a "corner" block designed to cooperate with two neighbouring Z-blocks at the 90 junction between, for example, two upright walls.

The basically T-shaped blocks of Figures 6 to 10 of the drawings are, in any construction employing them, keyed to their neighbours on all sides and this produces an equilibrium between the forces acting on each block, it being noted that Z-keyed blocks are usable in slab form as floors and also in slab form as roofs which latter can be em ployed either with, or without, additional supports.

There are four basic versions of the embodiment of the system which principally uses T-shaped building blocks, these four versions having been found to be the most satisfactory as regards ease of construction, handling, simplicity, ease of production ofthe blocks, versatility in use of the blocks and the need to produce a minimum number of accessory blocks for use at, for example, wall ends, wall junctions and the like. Thefirstofthesefourversions is illustrated in Figures 1 and 2, the second in Figures 11 to 17, the third in Figure 32 and the fourth in Figures 18 and 19.

It will be apparent that all ofthe embodiments shown in Figures lotto 19 inclusive employ the basicallyTshaped blocks lying on their sides (i.e. with their uprights horizontally disposed) and that the blocks shown in the fourviews of Figure 17 are basically Tshaped having surfaces that are to co-operate with those of other blocks either cylindrically concave or matchingly cylindrically convex.

In the version of Figure 18, each basicallyT-shaped block is of elongate formation, the blocks of Figure 18 being un-keyed whereas those of Figure 19 are shaped to keytogether, it being noted that elongate blocks of basically L-shaped cross-section are required in the embodiments of both Figures 18 and 19 where wall ends are produced and T-shaped (in plan view) junctions between walls are made.

In each of the fourversions ofthe system which principally employ T-shaped blocks,the blocks may be solid,wholly or partly hollowand may have plain and or patterned or othertextured surfaces. It will be apparent that many different combinations of pre ciseshape, size, materials, surface texturing and so on are possible that are too numerous to discuss individually. The particulartype which is chosen will depend upon individual preference, climatic conditions, geographic situation and local traditions of building.It is noted that, whilst prefabricated concrete will generally be employed and most blocks will be hollow in construction, other materials can equally well be used, if preferred, such as prestressed concrete to form blocks usableforwalls, floors, roofs and soon but a construction employing concrete is not essential and the blocks can be made from, for example, glass-reinforced plastics materials, natural wood and/or plywood.

The use ofthe building system which has so far been described enables strong buildings or other structuresto be made either in dryform orsemi-dry form using very much less mortar or other binding material than is employed intheformation of traditional brick/block buildings and the like. The described system has considerable advantages as compared with traditional building systems and these advantages include stability both during and after erection of a building or other structure, ease of erection, simplicity in aligning the blocks without long experience of such work being necessary and with the use of an absolute minimum of auxiliary tools, measuring instruments and other gadgets.The blocks can be such as to interlock giving increased strength to the wall, floor, roof orthe like which is being produced whilst simultaneously eliminating errors such as discrepancies in level and the formation of crooked, zigzag, curved or other incorrectly disposed courses of blocks. The system is versatile since it can employ different forms of keying and interlocking and can employ any chosen one, or any chosen combination, ofthe different blocks that have already been described and those that will be described below. As well as being very suitable for the construction of dwelling houses and other buildings, the system can be used for many other purposes such as, for example, the paving of roads, pathways, pavements and the like and for the cladding of new or existing buildings.

Although the blocks will usually be formed from conventional concrete, they can, as has already been mentioned above, be formed from other materials which include, in addition to the examples already mentioned, light-weight concrete, clay, gypsum and synthetic plastics materials whether or not reinforced with glass fibre or the like. Where appropriate, buildings or other structures can be produced without mortar or other binding material between the blocks but grouted cavities can be included, where required, for strength and/or insulation. If required,abuildingorotherstructurecan beformedin such a way as to be capable of being readily dismantlable by including therein removable keying blocks and/or removable locking bolts.Although re ferred to generallythroughout this document as being "blocks" the fourth version that has so far been described with reference to Figures 18 and 19 ofthe drawings can be considered also as constituting panels. The blocks or panels may be given surface textures designed to simulate the use of a traditional method of construction when viewing the exposed surfaces of a building or other structure formed from such blocks or panels.

Figure 20 of the drawings somewhat diagrammatically illustrates the use of the basicallyTshaped blocks, arranged as shown in Figure 1, in forming an irregularly shaped structure having a plurality of right-angled corners and a number of access openings to its interior. It will be seen that, atthe margins ofthe access openings, additional L-shaped blocks or cuboid blocks are required to produce up rightstraightedges.

It has been found that, using principally the basicallyT-shaped blockstoform a building or other structure, those blocks, when accurately produced, fit together in the manner shown in Figures 3 and 4or Figure5 of the drawings in such a way as automatically two prevent inaccuracies in horizontal or vertical disposition, provided only that the foundation or footing is itself correctly disposed. The interengagementofthe blocks automatically prevents vertical and horizontal inaccuracies from occurring and the fact that said blocks fittightly together produces a strength which is comparable with that achieved by using traditional bricks or blocks that are connected to one another by mortar or other binding material.

Considerable time is, of course, saved by wholly or principally omitting mortarorotherbinding materials since the builders do not have to waitforthe mortarorthe like to set before the blocks can be relied upon for supporting purposes. Although the blocks are pre-fabricated, a building orotherstruc ture which is to be formed principally therefrom is actually constructed in a very similar mannertothe use of traditional bricks and blocks exceptthat, generally speaking, mortar is used very sparingly, if at all.

The final building or other structure will not have the appearance of a monolithic concrete mass but rather the appearance of a somewhat differently patterned, but otherwise traditional, block or brick construction thus avoiding an alien external appearance which tends to discourage builders and the customers for their products. Builders that work substantially only in the traditional way will find no difficulty nor stran geness in using this system since the system com prises placing a large number of relatively small blocks in pre-determined positions relative to one another as is, of course, done when using traditional bricks and building blocks. The present system does not envisage the use of relatively large prefabricated panels as forms the basis of a number of modern methods of building construction.

As well as being employed in the construction of actual buildings, paths, roads and the like and the ciadding of new or existing buildings, this system can be employed in producing either permanent or temporary shuttering, basically T-shaped blocks which are formed from glass fibre reinforced plastics materials or wood being particularly suitable for shuttering purposes. If exceptional strength is requi red in the blocks, they may be formed from glass fibre reinforced concrete but the particular choice of material will naturally depend upon the nature of the building or other structure that is to be formed and the purpose for which it is required.The holiowinter- iors otthe blocks can, for extra strength, be filled with concrete or cement grout and it is possible to insert reinforcing bars into those interiors, before pouring the concrete or grouting, and it has already been mentioned th at the hollow blocks can be filled with insulation material, such as urea-formaldehyde foam, by either pouring or injection.

The system is particularly convenientforforming temporary buildings or other structures since the blocks and other necessary items can be supplied in a partially assembled condition with post units bolted to beam units merely requiring the interlocking blocks to be correctly positioned. Under such circu stances it is, of course, necessary that provision should be made for disassembling the temporary building or otherstructure in one of the ways briefly discussed above.

It wili be realised that the blocks or panels that have been described can be provided in any required sizes although, in the case of blocks, it is desirable thatthe size and weight should not exceed thatwhich can readily be handled bya singleworkman.The panels that have briefly been described with reference to Figures 18 and 19 ofthe drawings can, on the other hand, be of such a size that mechanical assistance is required to move them, it being possible to provide panels otherthan those shown in Figures 18 and 19 to form a range of modular unitsthatare basically of T-shaped cross-section together with accessary units as may be required atwall ends,walljunctions,the margins of access openings and the like.The second and third version of the T-blocks may, if required, be substantially brick-sized and may be made from baked clay and other materials from which conventional bricks are formed. In a building or other structure using such bricks, it is desirable to grout the junctions between them at regular intervals, as may be necessary having regard to the particular building or other structure that is being produced, or, inthe case of hollow bricks of this form, to fill them with mortarto produce columns or pillars and to strengthen the construction at the junctions between walls.

When erecting a building or other structure using the first version of the T-blocks that has been described with reference to Figures 1 and 2 of the drawings, it will be remembered that these blocks do not possess any interlocking or keying features and it is therefore desirable, although notabsolutelyes- sential in all cases,to use mortar, grouting orother binding material in each pair or tier of blocks, using further mortar, grouting or other binding material between superposed pairs or tiers of blocks. The blocksthatare required at the corners and ends of walls are basicallysimilartotheT-shaped blocks themselves only the form of keying or interlocking has, of course, to match that employed in theTshaped blocks.Figures 7,8,9 and 10 of the drawings show various constructions that can be employed at junctions between walls, the references A and B being employed to desigate co-operating blocks that exhibit Z-keying. It will already be apparentthatthe blocks of the second version are assembled in a-similarwayto those of the first version exceptthat each T-shaped block has its upright limb substantially hor izontally, rather than substantially vertically, disposed.

In employing the third version to form a building or otherstructure, much the same technique is used as with the first version but the relative disposition of the blocks is different, T-shaped blocks being employed whose thicknesses can be varied, and in particular reduced, to allow different external patterns to be produced together with different cross-sectional relative dispositions ofthe blocks. This third version ofthe system can, if desired, be combined with the second version, using the two versions alternately in successive tiers of the blocks. The fourth version that is shown in Figures 18 and l9ofthedrawingsem- ploys elongate panels, rather than blocks, but it is noted that these basically T-shaped cross-section panels are ofsignificantly smaller widths than panels employed in known pre-fabricated building systems which has the result that the individual panels are not too heavy in weight and can, if desired, be keyed to one another eliminating, where appropriate,the use of mortar or grouting between the panels. If required, the strength of a wall or partition formed from such panels can be increased by employing a top beam that may, if required, be bolted or otherwise secured to the tops of the upright panels.

A second basic embodiment of this building system employs blocksthatare notT-shaped butthat co-operate with one another by way of keys that are substantiallyZ-shaped. Such blocks are particularly, but not exclusively, useful informing prefabricated panels, partitions and the like, a minimum or mortar or other binding material being required atthejunctions between the blocks.

The shape ofthe Z-key can be varied but it has been found convenient to employ four basic forms of Zkey any ofwhich will join the blocks quickly and ef fectivelytogetherwithoutessentiallyemploying any mortar or other binding material.

It is possible to build a wall or other structure employing Z-keyed blocks in a semi-dryform overlaying everytierofZ-keyed blocks with mortar or other binding material to secure the superposed tiers together in a conventional way. If a fully dryconstruction is preferred, it is desirable to incorporate end keying systems of substantially M-, substantially S-, orsubstantially Z-form into the blocks to ensure that a building or other structure can be erected quickly and accurately whilst automatically maintailing stability and both vertical and horizontal alignment.

Figure ofthe drawings shows various views of a block and illustrates the first, third and fourth versions of the Z-key, Figure 22 gives various views of a number of blocks provided with the first version ofthe Z-keyfitted together, Figure 23 is an elevational view showing a hollow block, provided with the second version ofthe Z-key from which it will be seen how said block will interengage neighbouring similar blocks.

Figure 24 isa plan view showing walls ofa building that are formed by employing hollow blocks exhibiting the first version ofthe Z-key but Figure 24 also shows the shapes of blocks that are required at a right-angled junction between two walls, two forms ofT-shaped junction between walls and a cruciform junction between fourwalls, Figure25shows further details of the basic blocks and junction blocks that are illustrated in Figure 24 and additionally shows, in black, one block that is required at the end of an upright wall when said end should present a flat surface that extends per pendicularly between the opposite side faces of the wall, and Figure 26 illustrates hollow Z-keyed blocks which are used as permanentformworkforthe construction of beams together with details of one way of fit- ting those blocks together and, atthetop ofthe Figure, the shape of auxiliary hollow blocks that may be used surroundinglyto support upright reinforcing rods orthe like that are interconnected by strengthening wires.

The Z-keyed blocks that have just been described can be employed in much the same situations as the basicallyT-shaped blocks discussed above and, to a large extent, havethe same advantages, as compared with the bricks or blocks that are employed in conventional building systems, as do those pre viously described blocks.

There now follows a description of a third basic embodiment of blocks employed in a building system which blocks are dove-tailed and will here inafter be cal led, for the sake of brevity "dove" blocks. Such blocks are again particularly, but by no means exclusively, useful in constructing prefabricated panels, partitions and the like, very little, if any, mortar or other binding material being required at the junctions between the blocks. The dove blocks again employ Z-keys for interengagement and, once again, these Z-keys may be varied in shape but con venientlyareprovided infourdifferentversionsas has already been described above with reference to Figures 21 to 26 ofthe drawings.

As already briefly described with reference to Fig ures 21 to 26 of the drawings, the dove blocks can advantageously be used in buildings or other structures of semi-dry form, each tier of Z-keyed dove blocks being overlaid with mortar or other binding material to secure itto the superposed tier in a substantially conventional manner. Again, if a substantially fully dry construction is required, it is preferable for the dove blocks to incorporate end keys of one of the sameforms, and forthe same purposes, as have already been mentioned with reference to Figures 21 to 26 ofthe drawings.

Each dove block is actually shaped to comprise two half Z-form blocks of symmetrically identical form,thetwo halves being integrally produced. This form of block has the particularadvantagethat, in use, the forces acting on the opposite ends thereof will almost always substantially counterbalance one another so that a particularly structurally stable building will result.

The dove blocks have substantiallythe samever satility of usage, and advantages as compared with the bricks or blocks that are employed in conventional building systems, that have already been discussed above in regard to the version ofthe system which principally employs basicallyT- shaped blocks.

Figure 27 of the drawings gives several different views of a hollow dove block just described, and Figure 28 is a plan view, somewhat similarto Figure 24, showing a plurality of the hollow dove blocks 4 employed in walls which also include matchingly shaped cruciform connecting blocks 1, "half" wall end blocks 2, T-junction blocks 3 and rightangled corner blocks 5.

A description will now be given ofways in which the various forms of block that have so far been described can be employed in forming buildings and other structures. When basicallyT-shaped or other blocks ofthe kind that have been described, having Z-keys, are used in co-operation with one another, the Z-keys will effectively lock adjoining blocks together by directing the forces which act upon the junctions between the blocks and otherwise upon the blocks themselves in such a way as to enhance or reinforce the stability of the structure that is com- posedofsaid blocks.In particular,theZ-keystransform the tensile forces to which the described blocks or slabs are subject into compressive forces which latterforceswill not normally crush building materials of the kind used to produce blocks, bricks and slabs unless said forces are excessively strong.

Figures29, 30and31 ofthedrawings illustrate three different forms offloorthat may be constructed using the building system. Figure 29 shows the employment ofthe previously described dove blocks or slabs arranged in a pre-cast concrete or steel beam or timber joist framework that is of matching crosssectional shape and that provides said beams or joists at pre-determined substantially regular intervals.

Figure 30 is similarto Figure 29 but shows the use of basically T-shaped blocks or slabs, arranged with their uprights in horizontal positions, in a framework that is similar to the framework of Figure 29. Itwill be noted that the basicallyT-shaped blocks exhibitZkeys ofsubstantiallythe kind shown in Figure 23 and that similarly keyed dove blocks or slabs are also employedto fill the gaps which would be left if T-blocks or slabs alone were used.

Figure31 ofthedrawingsillustratestheemploy- ment of Z-keyed blocks arranged between the beams or joists of a frameworkthat is similartotheframe- work of Figure 29 except that said beams joists necessarily have a cross-section which matches those of the blocks or slabs with which they areto co-operate.

It is important, when using the blocks in one ofthe ways that is illustrated in Figures 29 to 31 ofthe drawings that said blocks should be forced tightly against one another in a horizontal direction that is perpendicularto the lengths of the beams or joists of the co-operating framework. Under such circumstances, the blocks or slabs will co-operate ef fectivelywith one anotherto form a stable floor in which no underneath support, between the beams or joists, is necessary.A tie beam may often advantageously be emplloyed to maintain the blocks firmly pressed against one another as just described, such tie beam being either pre-cast or cast in situ. The use of a tie beam forthis purpose is particularly advan tageouswhen the blocks are in the form of roof slabs.

Obviously, there is a limit to the span of blocks which will remain reliably interconnected, without support, merely by the co-operation of their own interlocking portions, this limit being dependent upon the sizes of the blocks or slabs that are employed, the strength of the material from which they are made and the load that, in use, they will be cailed upon to bear.lt is again possibleto employ pre-cast or pre-stressed beams in supporting co-operation with the blocks or slabs, the blocks slabs ofafloororthe likethat is formed in this way needing no mortar, grouting or other bind ing material.

When using blocks or slabs that have Z-keys as shown in Figure3l,thoseblocksorslabshavesym- metrically identical Z-keys at their opposite sides for co-operation with the neighbouring blocks or slabs and/or with the similarly keyed beams or joists ofthe supporting framework. In the case of basicallyT- shaped blocks or slabs as shown in Figure 30, each block or slab has Z-keys at its two opposite sides which keys are identical, but not symmetrically ident- ical, to one another. These keys areto be found both at the opposite sides ofthe upright of each basically T-shaped block or slab and at the opposite ends of the horizontal limb or crossbar thereof.If necessary, further strengthening can be produced byforming Zkeys or substantially right-angled S-keys on the sur faces ofthe floor blocks or slabs that are substantially perpendicularto the surfaces carrying the keys that have already been mentioned. Examples of such surfaces are those which are shown as facing a viewer of Figure 29, 30 or 31 of the drawings at the foot of each such Figure.

Blocks or slabs that have Z-keys at their opposite sides and that, as can be seen in Figures 31, are themselves basically Z-shaped in cross-section, are advantageously employed in erecting buildings and other structures, the blocks or slabs co-operating, as shown in Figure 31, with the beams and/or joists of a framework. It can sometimes be an advantage to secure pre-cast or pre-stressed beamstogetherto form a slab and this has the advantage that said beams or joists will be lighter in weight than is conventional, thus avoiding the need for heavy lifting machinery and other mechanical handling equipment to move various parts of the building or othorstructure that is being erected into their appointed positions.Once again, the advantage that the blocks or slabs auto maticaily position themselves relative to one another in both vertical and horizontal directions is immediately attained. Also, since no mortar or other binding material is really necessary between the auto matically interlocking blocks or slabs, a roof can be placed on a building or other structure erected using this system without having towaitfor mortaror other binding material to set and attain a required de gree of strength.

When using the dove blocks to produce a floor or the like as shown in Figure 29, each Block has Z-keys at its opposite sides and is inverted relative to its im mediate neighbour(s). The form of construction is basically very similarto that illustrated in Figure 31 and, similarly, the dove blocks can be formed as precast and pre-stressed slabs.

It remains onlyto emphasise that the various forms of key, which most ofthe blocks, slabs and panels that have been described exhibit, are intended for interlocking purposes rather than forjoining the blocks, slabs and panels together. The keys redirect the forces to which the blocks and soon are subject, when in use, in such a way as to strengthen the junctions between them and to strengthen the blocks, slabs and panels themselves. No mortar or other binding material is really necessary in most cases although, as has been described, there are circumstances in which the use of a minimum quantity thereof is advantageous. The blocks, slabs or panels can be formed from almost any material that has the required strength, durability, resistance to the climate in which it will be used and that is not inherently hazardous (i.e. an otherwise suitable material that is highly inflammable orthat omits poisonous fumes when exposed to fire would clearly not be satisfactory).

Examples ofthe various keys th at have been described are illustrated in the accompanying drawings as follows. The M-key is shown in Figure 15, the sub stantially right-angled S-key is shown in Figure 14, the arcuate-key is shown in Figure 17,the first version oftheZ-key is shown in Figures 6 and 27, the second version ofthe Z-key is shown in Figures 7, 13 and 23, the third and fourth versions ofthe Z-key are shown in Figures 21 and 22, a wedge key which has previously been referred to as being an auxiliary block required at wall end and the margins of access openings and the like is shown in Figures 16 and 1 9whilst Figures 3 and 4 show the previously mentioned projections and depressions, which also act as keys, and Figure 5 shows the previously mentioned nibs and recesses which similarly act as keys.

Claims (6)

1. A building system for planar structures, such as wells, floors, roofs, paths and roads, the system comprising the employment of prefabricated blocks having compound shapeswhich are such that they co-operate interlockinglywith other blocks of the system, whereby said interlocking blocks can be assembled without the essential use of mortar or other intervening binding material, and comprising the following feature:- a planar structure made of such blocks and of beams extending in the plane of the structure, those blocks and these beams having keying surfaces internally of said structure of basi cally Z-shape and interengaging each other, and each beam being longitudinally co-extensive with a plurality of such blocks.

2. A system as claimed in claim 1, wherein the basicallyZ-shaped keying surfaces of the blocks give the blocks a dovetail appearance as viewed along the keying surfaces.

3. Asystem as claimed in claim 1 or 2 whereinthe basically Z-shaped keying surfaces of at least some ofthe blocks give the blocks a basically Z-shape as viewed along the keying surfaces.

4. A system as claimed in any preceding claim wherein at least some ofthe blocks are substantially rectangles as viewed perpendicularly to the plane of the structure.

5. Asystem as claimed in anyprecedingclaim wherein atleastsomeofthe blocks areT-shaped as viewed perpendicularly to the plane ofthestructure.

6. A building system, substantially as here inbefore described with reference to any one of Figures 29to 31 ofthe accompanying drawings.