GB1584749A

GB1584749A - Production of room elements

Info

Publication number: GB1584749A
Application number: GB44664/77A
Authority: GB
Original assignee: Elcon AG
Current assignee: Elcon AG
Priority date: 1976-11-11
Filing date: 1977-10-27
Publication date: 1981-02-18
Also published as: ZA776328B; ES472487A1; MX145133A; DE2651558A1; AU514971B2; CA1115505A; CS209885B2; FR2370563A1; BR7707549A; FR2370563B1; ES463933A1; GR62000B; BE860647A; AU3014977A

Description

(54) IMPROVEMENTS IN OR RELATING TO THE PRODUCTION OF ROOM ELEMENTS (71) We, ELCON AG, a Swiss Body Corporate of 43 Baarerstrasse, CH-6301 Zug, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : This invention relates to the production of room elements.

Prefabricated transportable room elements have been proposed in the form of a self-supporting construction or a non-selfsupporting construction, and in the latter case they are. also provided with a supporting structure. Such room elements can be used for erecting both multi-storey houses and also bungalows.

Such room elements may be cast from a water hardenable material such as for example concrete. For this purpose, a reinforcement is placed in shuttering into which the casting material is then poured.

Such shuttering is, however, expensive to purchase and complicated in use. The fact that the expensive shuttering is out of use while the concrete is setting is an intolerable cost factor.

It has also been proposed to construct walls and/or ceilings of conventional buildings by the free application of water hardenable material to plaster bases strengthened by a reinforcement. In this case, first the reinforcement is brought into a form corresponding to the shape of the basic structure to be erected, i.e. first of all a profile skeleton ix set up consisting for example of metal profiles welded to one another. The skeleton comprises the walls and possibly also structures within the room, room dividers and ceiling. Lattice girders may also be used for the construction. Then, a plaster base is fixed to the profiles. As such, it is possible to use ribbed expanded metal, wire gauze, cardboard and similar structures, for example even mats.The actual walls or ceilings, as the case may be, are then produced by plastering the water hardenable material onto the reinforcement and plaster base.

This can be done mechanically or by hand.

In order to achieve a smooth surface, the freshly applied material is smoothed out fiat and filled until smooth. The plastering material may for example by gypsum, or concrete (Gunite).

A disadvantage of the method which has just been described is the relatively high reinforcing material costs. However, the reinforcement must be relatively stable in order to strengthen the plaster base adequately for the plastering process.

According to the present invention, there is provided a method of producing the walls of a room element comprising the steps of providing a vertical substrate for each wall, reinforcing the substrate with removable, substantially vertical reinforcing rods, applying to the substrate a hardenable composition in a fluid form so that the composition lies on each side of the substrate and the reinforcing rods lie within the thickness of the composition and removing the reinforcing rods from the wall after the composition has at least partly set by withdrawing the rods substantially vertically.

Further according to the invention there is provide a method of producing a room element comprising the steps of forming walls of the element by plastering both sides of plaster bases which are arranged in the configuration that the walls are to assume in the room element and which are strengthened by a reinforcement which is superfluous to the structure of the completed walls and which reinforcement lies within the thickness of the walls after plastering, and removing, after plastering, the superfluous reinforcement from the walls, the superfluous to the structure of the completed removable rods.

In this manner, during the plastering process, the plaster base is kept adequately rigid so that it will not give way and bulge when the plaster is applied. This is particularly important since the various operations connected with plastering, such as application, smoothing and finishing give rise to substantial lateral forces and the plaster base itself is inherently unstable. Excessive yielding or vibration would produce a structural fault such as for example irregular wall thickness and location, and also ;Seentricity of the plaster base within the thickness of the wall. The former faults would be noted as inaccurate and uneven wall surfaces, the latter as concealed static weakness.

Afer plastering, however, the relatively stable vertical reinforcement is no longer needed, since there is no further lateral loading on the walls until the structure has hardened and developed its own stability.

The plaster base is preferably fixed to an underfloor frame of the structure and imparts sufficient vertical rigidity to the still wet wall. Any possible distortion is prevented by using a material which has as far as possible neutral expansion properties.

After hardening, the walls themselves are stable. By removing the then superfluous reinforcement, manufacturing costs can be notably reduced, since the cost of the reinforcement represents a significant portion of the overall costs. Those parts of the reinforcement which are removed after plastering can be used again for producing further room elements.

Suitable reinforcing rods are readily available proprietory materials and are therefore inexpensive. By virtue of their cross-sectional form, they can easily be withdrawn again from the wall in their lonigtudinal direction. An advantage of using rods of round cross-section is that by virtue of their round symmetrical crosssectional form, they require no specific orientation when they are being inserted and extracted.

To permit the reinforcing rods to be used again quickly so that only a small quantity of them is therefore required to be kept in circulation, it is advantageous if the rods are withdrawn from the plaster before this has set. In this way, the actual period of use of the rods is minimal and they can be used again relatively shortly after the plaster has been applied.

Withdrawal of the rods can also be facilitated by providing them with a separating layer prior to application of the plaster. Such a layer may be formed for example by a plastics sheath, a cardboard tube, a paper wrapping, a plastics tube, a metal tube, or a coating of grease, a release paint, a powder or a liquid.

The rods or the separating layer may be loosely connected to the plaster base prior to application of the plaster. This can be done simply and positively by wire loops, rings or the like or by means of spot welding or by threading the rods together with the separating layer through apertures in the lattice work of the plaster base.

The rods may be held by templates. If the rods are fixed to one template they may be withdrawn from the wall by relative movement betwen the template and the wall.

Further according to the present invention, there is provided apparatus for producing a room element having walls formed by plastering both sides of a plaster base, said apparatus comprising a bottom template, a top template alignable with the bottom template at a distance above the bottom template, said templates having guide bores in positions corresponding to the positions of the walls to be erected, and rods locatable in the bores and arranged to extend from the top template to the bottom template, said rods serving to reinforce the plaster base, and said rods being removable after application of the plaster.

The templates and their guide bores serve to establish the positions of the relevant rods and determine the location of the walls which are to be erected. The guide bores are therefore located in the templates in accordance with the shape of the plan view of the room element which is to be erected.

They are positioned within the wall zone of the walls which are to be produced.

In so far as each pair of templates is used only for producing a specific type of room element, it is sufficient for the templates to have guide bores only as required for this type of room element. On the other hand, if the templates are to be generally used for different types of room element, then they may be provided accordingly with further guide bores or with a substantially regular pattern of guide bores.

With such templates, it is then possible to produce room elements of any desired form.

Such a pattern of guide bores may be provided in the bottom template but the top template may only have bores corresponding to a specific plan of room element.

In this way, when producing different room elements, it is necessary only to change the top template. As a result it is possible for even unskilled workers to insert the rods accurately. The time required for changing templates is minimsied. Since the rods are guided both in the top and also in the bottom templates, adequate stability is achieved and also a sufficiently accurate wall shape is ensured. Both templates can be used for mounting the rods thereon, so facilitating removal of the rods from the room element.

Advantageously the width of each template corresponds to the overall width of the room element to be erected.

With regard to the disposition of the templates, it is advantageous for both templates to be mounted interchangeably in a housing frame. - In consequence, the two templates can on the one hand easily be associated with each other while on the other, it is readily possible to exchange the templates for others of a different type.

With regard to the use of templates of different length, it is preferred for the housing frame to have four posts which are always located in the corner zone of the room element which is to be produced, at least two of these posts being movable. The posts can thus be moved to other positions adapted to the dimensions of the various templates.

To provide a simple structure for the housing frame, it is of advantage for the posts to be connected to one another via framework supports. In this way, the housing frame forms one unit and can be moved to any desired place of use as required, but nevertheless stable and dimensionally accurate. It is also preferred for the framework supports to be provided below the bottom template. They serve then as a means of stabilising and supporting the underneath of the template.

For further reinforcement of the housing frame, it is preferred that the housing frame has at least one intermediate post for the template on at least two oppositely disposed sides. In order to make the housing frame nevertheless readily accessible, it is advantageous for the intermediate posts to be disposed in such a way that they can be moved to one side. They can then be moved aside for fitment of a different template or for removal of the room element.

To facilitate work on the room element, it is preferred for the intermediate posts to have an L-shape, the horizontal arm of the L being adapted to be connected to the top template while the vertical arm extends at a distance from the room element which is to be erected. In this way, the top template is supported while it is nevertheless ensured that the walls are freely accessible to be worked upon.

Preferably, such templates are made from metal profiles, preferably steel, squaresection tubes. Such templates are stable and can be very advantageously employed during plastering as a wipe-off edge, in other words as a reference edge for the walls which are to be erected.

In order to achieve a reliable anchoring of the rods in the template, the continuous guide bores are preferably provided with bushes which guide the rods over a substantial length (for example about 20cm) by housing them with minimal clearance.

They have conical or rounded mouths to facilitate insertion of the rods and are provided with a seating flange. The advantage of guiding the rods over a length of, for example, about 20 cm is that the ends of the rods are thus secured against rotation, so that their resistance to being pressed out laterally or caused to sag is substantially increased. This effect is known as the fi.t- ment or continuity moment. A further advantage of using bushes is that they can easily be replaced when they show signs of wear. In order to reduce wear on the rods, the bushes may be made from a softer material than that of the profile rods, e.g.

bronze.

To avoid weak points in the walls to be erected, it is advantageous for the guide bores to be located in the central axis of the walls to be erected.

Preferably the rods are hollow, which provides an opportunity of introducing through the rods themselves and into the interior of the wall, a fluid which can be used either to facilitate withdrawal of the rods or to accelerate the setting process.

Withdrawal of the profile rods can be facilitated by having them taper conically towards their free end.

The invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: Figures 1 to 6 are perspective views of apparatus for producing room elements, shown in various working stages: Figure 7 is a cross-section through a top template of the apparatus and an already completed room element in the region of the junction between the ceiling and an outer wall; Figure 8 is a cross-section through an alternative form of top template, the section also extending through an intermediate post:: Figure 9 is a cross-section through a bottom template and a connecting girder of the apparatus and the bottom edge of an outside wall of a completed room element; Figure 10 is a cross-section of the same height as Figure 9 but taken at the axis of a transverse wall in the completed room element; Figure 11 is a plan view of a transverse and longitudinal wall in a completed room element; Figure 12 is a plan, in section, through a door opening of the room element; Figure 13 is a plan view of a transverse wall in a completed room element at a poistion where this extends as far as the edge of thle element without meeting a longitudinal wall; Figure 14 is a schematic front elevation of the completed room element; and Figure 15 is a schematic plan view of the same room element.

Figures 1 to 6 show an apparatus l for producing room elements of the type shown in Figure 6 and also in Figures 14 and 15.

The apparatus 1 has a rectangular housing frame 3 with four individually supported corner posts 4 and four intermediate posts 5. The corner posts are at the corners of the rectangular housing frame and are connected to one another through frame members 6. The inteWmediate posts 5 are mounted on transverse members 7 projecting laterally beyond the long sides of the housing frame. They are disposed in pairs substantially at the same intervals from one another and from the corner posts 4, i.e. in each case more or less in one third of the length 8 of the apparatus.

The posts of the pairs of intermediate posts which are disposed on one side of the apparatus are pivotal into a horizontal position in a vertical plane parallel with the long side of the apparatus, i.e. in the direction of the arrow P in Figure 3, to facilitate the supply of tools and materials and the removal of the completed room element.

The intermediate posts of the pairs which are disposed on the other side of the apparatus are rigidly or removably mounted on the transverse members of the frame. The posts are constituted by structural steel profiles, possibly rectangular metal tubes or double-T members. Similarly, the frame member 6 are constructed of structural steel profiles.

The left-hand pair (as viewed in Figure 1) of the main or corner posts 4 are displaceable on the frame members 6. The frame members 6 and the bottom parts of the corner posts have fixing holes 9 to receive rigidly fitted plugs for locking the corner posts in various positions for the production of room elements of different lengths. The intermediate posts need not be movable, but if desired several points of articulation may be provided for the pivotal posts and a plurality of fixing locations for the fixed intermediate posts. For room elements of different lengths, in each case one or more apparatuses may be provided, the length of which need not then be variable. The apparatus shown in the drawings, is a stationary apparatus with no rollers or other means for facilitating movement although such means can readily be fitted.

The frame members 6 support a bottom template 10. This has, engaging the bottom webs of the frame members 6, aligning fittings 11 for lateral alignment of the template (Figure 9). As can also be seen from this Figure, the bottom template is made of rectangular metal tubes, the width of which is equal to the wall thickness 12 envisaged for the room element. The template represents the plan view of the room element which is to be produced. By means of the template shown in Figures 1 to 6, room elements of two different plan formats can be produced, one of which is shown in Figure 15. The bearers of the template have on their top and bottom faces aligned bores 13 into which in each case a guide bush 14 is fitted. The upper ends of the bushes 14 and bottom ends of vertical rods 15 which are to be introduced into them may have rounded edges or a conical shape to facilitate insertion.In order to achieve bottom edges 16 of a room element which may be chamfered off at any desired angle, wedges or possibly half-moon shaped spacers can be placed under the template.

The main or corner posts 4 have at the top end in each case a carrying lug and a guide pin 17, 18 respectively. The carrying lugs 17 serve for attachment of a prefabricated rectangular ceiling frame 19 (Figure 2). The rectangular ceiling frame 19 has longitudinal members 20 formed from C-profiles and which can be fitted by plugs or bolts on the lugs 17 and which are connected to one another via transverse lattice girders 21 which are welded to them. A substrate or plaster base 22 consisting of cardboard provided with apertures and interlaced with wire braid is fixed by means of wires or by spot welding to the underside of the lattice girders. In an alternative arrangement, the ceiling frame 19 which is provided with the plaster base 22 may already be given an application of plaster prior to insertion into the apparatus 1.This can be achieved by pouring the plaster 2 into a flat mould or by dipping into a plastering material followed by surface filling. Prior to insertion into the apparatus, such a plastered structure must have set at least to a large extent. Furthermore, measures must be taken to facilitate connecting the wall plaster to the plaster of the prefabricated ceiling; for example corresponding areas may be left unplastered or parts of the plaster base in these areas may project downwards beyond the substantially completed ceiling surface.

The guide pins 18 serve for accurate orientation of a top template 25. This has a form similar to that of the bottom template 10 but is made from broader profiles or members than the latter, since it is not supported over its entire length. Furthermore, the members of the top template serve to determine the wall thicknesses of the room element only from the outside.

The top template 25 has, corresponding to those of the bottom template 10 and in line therewith, bush-lined guide bores 13. As can be seen from Figures 3 and 4, the top template 24 has fewer guide bores 13 than the bottom template. This is because the top template is intended only for the production of room elements of the plan shown in Figure 15. For the production of room elements having a different plan, a different top template is needed having guide bores which are aligned with those guide bores of the bottom template which are unoccupied in Figure 4. In another arrangement, not shown, the bottom template has a lattice-like arrangement of guide bores spaced apart from one another by approximately 50 cm, of which in each case only those corresponding to those used in the top template remain occupied, while the pothers are left free.

The left-hand edge (as viewed in Figure 7) i.e. the outer edge, of the top template 25 forms a reference surface for aligning the outer wall surface 27 of the room element after application of the plaster 24.

This edge 26 thus determines the width of the room element overall and also the smoothness and evenness of the outer wall surface and thus the dimensional accuracy of the completed element.

As can also be seen in Figure 7, the top template 25 has a locking clamp 28 for gripping the ceiling frame 19 by pressing the longitudinal member 20 thereof against the underside of the template. In another arrangement, the longitudinal members may have in their vertical webs, holes for engagement of holding means independent of the top template, in which case then the locking clamps 28 can be omitted.

During production of a room element, the top template which is resting on the corner posts 4 and which is aligned by means of the guide pins 18, is additionally supported vertically and laterally by the intermediate posts 5. End faces 29 of horizontal arms of the posts 5 bear against the outside faces 26 of the template in order to brace them laterally. Located in horizontal bores 30 of the posts are retractable guide pins 31 which engage into complementary bores 32 in the template in order to provide additional vertical support (Figure 8).

The vertical arms of the individual intermediate posts 5 are located at a certain distance from the outsides of the room element which is to be produced, so that this is freely accessible to be worked upon. As shown in Figure 8, the intermediate posts 5 have below the pins 31 and parallel to those pins 33 which engage holes 34 provided for the purpose in the ceiling frame in order to support this latter independently of the template, as previously mentioned.

In this arrangement, the top template 25 also has laterally projedting supports 35 which transmit the weight of the template 25 to the intermediate posts without excessively straining the pins 31. In this case, the tops of the intermediate posts 5 then extend somewhat lower than in the arrangement shown in Figures 3 to 5. The bottom extensible pin 33 has a conical ring 36 for laterally supporting the ceiling frame 19.

This arrangement offers the advantage that the ceiling frame of 9 room element with the plaster not yet set is also supported after the top template has been removed.

As can be seen particularly in Figure 1, the corner posts 4 have rigidly mounted thereon vertical rails 37 which serve to determine the outside dimensions of the room element, i.e. they serve as reverence edges for finishing the outer wall faces as well as serving shuttering for the edges of the end wall faces.

Round rods 15 which connect the templates to one another are inserted vertically into the guide bushes of the aligned bores 13 in the top and bottom template. The rods 15 have at the top end a screw thread and carry screwed onto this a nut which together with a washer forms a seating flange 38. Above the seating flange 38, each rod is shaped into a ring or lug 39 to facilitate handling. In another arrangement, it is possible to screw onto the top end of each rod a nut which is rigidly connected to a ring or lug. As can be seen in Figure 9, each rod has a rounded or conical bottom end 40 which facilitates insertion of the rod through the top template and a separating shell into the bottom template.

Since the material in the central portion of a round rod contributes only a little to its rigidity, the rods 15 can be made hollow, i.e. they may be constructed as tubes. Such a tube permits the incorporation of fluid media into the wall; for example, a pressurised medium to facilitate extraction of the rods or tubes, a heated medium to accelerate setting of the plaster, a cooled medium to retard setting or a medium containing certain chemicals may be introduced through the tubes to escape through holes in the walls of the tubes and sheaths, into the plaster mass.

In the arrangement shown in Figures 7, 9 and 10, the rods are enclosed by a sheath 41 in the form of a loosely pushed-on cardboard tube. The rods are passed through the top template and thereupon through the relevant sheath and into the bottom template. The rods 15 shown here are solid but they may alternatively be hollow.

As can be seen in Figures 4, 5 and 7, the cardboard tubes 41 which constitute the separating sheaths and which are reinforced by the rods 15 are connected, like the lattice girders of the ceiling 19, to one another by a plaster base 22. In the embodiment shown, the plaster base 22 is constructed of an open-work cardboard through the holes in which a wire braid is passed, and is secured by wires to the likewise cardboard sheaths 41. If metal sheaths are used, the plaster base can be welded to it. In this case, fixing can alternatively be achieved by an adhesive. If the sheath has an oil, grease or paste coating, then care must be taken that the fixing of the plaster base does not attack the rods 15 themselves. In this case, short lengths of pipe, cylindrical rings or the like may be secured to the plaster base by means of wire, welding or gluing.

The plaster base may be continuously fitted on one side of the rods or may be alternately threaded through and between them. Where the plaster base 22 is disposed in the middle of the wall, in other words in line with the axes of the rods, it can be so shaped that it extends around a part of the rods, or the wires of the interwoven braid can be shaped alternately to one side and the other so that the rod can be inserted between them substantially in the same plane as the plaster base. The rods with their sheaths are preferably disposed in the middle of the thickness of the wall in order to avoid any weakening towards one side and in order to ensure that the wall is of symmetrical construction, so that the risk of distortion is as low as possible.

Areas of the room element, such as for example the corners between walls or between walls and ceilings, which are subject to high stresses, and also the areas around door and window openings can additionally be strengthened by a thin layer of expanded metal or what is known as lozenge lattice.

Instead of this or in addition to it, other known reinforcing aids may be used.

Figure 5 also shows working platforms and areas 43, 44 diagrammatically. This illustration serves however purely as an indication and other expedient arrangements may be used instead.

In another arrangement, side parts 45, 46 of the template 25, 10 may be independent of the other parts thereof. In this case, then, it is possible to make up outside of the apparatus and from the side parts, the rods 15, the sheaths 41, an elastic underlay 47, the plaster base 22 and the aforesaid strengthenings and other parts, a complete frame for a side wall which now only needs to be introduced into the apparatus and provided with plaster. This has the advantage that the time wastage involved by the apparatus can be shortened and that it is possible to work on a horizontal backing.

In order to hold together the side wall frame which is so built up, it is possible instead of using the guide bushes 14 to use clamping means which pass through slots in the outsides of the template parts, engage the rods 15 and hold them fast.

The assembled side wall frame is inserted into the apparatus after the ceiling frame 19 has been fitted. In this case, bores in the ends of the upper side parts receive the guide pins 18 at the upper ends of the corner posts, and the fittings 11 engage the top webs of the frame members 6 in order to align the lower side part 46.

The procedural steps when making a room element can be seen from the Figures 1 to 6. In Figure 1, the bottom template 10 is inserted into the apparatus 1. In Figure 2, the prefabricated ceiling frame 19 is fixed by bolts on the lugs 17 of the corner posts 4. The ceiling frame illustrated is composed of the longitudinal and transverse members 20 and 21 which are rigidly connected to one another, and the plaster base 22 has not yet been plastered. In another arrangement the ceiling frame may already be provided with plaster 24 which must however be already substantially set before insertion mto the apparatus.

In Figure 3, the top template 25 is fitted and aligned by the guide pins 18. The intermediate posts 5 which for the sake of clarity are not shown in Figures 1 and 2 are here set up and engage the top template.

In Figure 4, the round rods 15 are inserted into the bores 13 so that their mounting flanges 38 are resting on the top of the top template 25. After insertion of the rods 15 through the bores 13 in the top template 25, the cardboard tubes 41 which serve as sheaths are pushed on. Before the rods 15 enter the bores 13 in the bottom template, strips 47 of an elastic material, possibly a foam material, are placed on the top of the bottom template so that they later form a part thereof which is rigidly connected to the bottom edge of the wall which is to be made. The elastic strips 47 have prestamped holes through which the rods 15 can be passed. In this condition, then, door and window frames 48, 49 and other parts and equipment intended to be installed rigidly into the walls and ceiling of the room element can be positioned and bonded on or welded to the sheath 41 or plaster base 22. In the front part of Figure 4, the plaster base is in the form of open-work cardboard 22 through which a wire gauze is threaded, and is secured by tie wires 42 to the cardboard tubes 41 which surround the rods 15 which rigidify the said tubes. In heavily stressed areas, an additional reinforcement in the form of expanded metal or in the form of additional vertical or horizontally disposed metal rods tied or welded in place in situ may be provided and be left in position. The subsequently removable vertical rods 15 represent an aid for aligning the various fitments, and the sheaths 41 may be colour coded for this purpose.

In a similar manner, electrical conductors, pipes, plumbing and other installa tions may be laid and fitted.

In the arrangement in which the side parts 46, 45 are independent of the other parts of the templates 10, 25, the rods 15 are provided with their sheaths 41, inserted into the bores or slots in the template parts and secured therein by means of clamps.

Then the necessary reinforcements and other fitments are p]aced in position, whereupon the completed side wall frame can be inserted into the apparatus after the ceiling frame has been suspended. When this happens, the bores in the ends of the top side part 45 receive the guide pins 18 at the top ends of the corner posts 4 and the aligning fittings 11 of the bottom side part 46 engages the frame member 6.

Whereupon, the other parts of the top template are inserted between the side parts thereof and secured to them by screws or by form-locking engagement. The intermediate walls in the interior of the room element are then set up in the manner previously described.

At those places where a transverse wall 50 of a room element, as shown in Figures 13 and 15, extends to an outside thereof, so that in a completed building it abuts a corresponding transverse wall of an adjacent room element, there is at the relevant side of the apparatus a guide rail Sl formed from a structural profile, possibly a square section metal tube, the width of which is equal to the envisaged thickness of the transverse wall. The rail serves as a screed guide and as a boundary for the transverse wall to ensure its dimensional accuracy. Such guide rails 51 are fixed to the sides of the apparatus by means of known devices, possibly in bores in the frame members 6 and pin members which can be inserted into the top template 25.

Then, a plaSter consisting of gypsum or other water hardenable material is applied around the rods 15, conduits and other fitments and onto the plaster base 22.

In the arrangement in Figure 5, this is done by a special spray gun 52, although application may be carried out in any desired manner. Prior to setting, the plaster can then be screeded and then rubbed smooth.

The reference surfaces 25, 51, 37 of the apparatus as well as certain fitments, such as door frames 48, can serve as guides when the plastering is screeded, so that the thickness and alignment of the walls can be accurately observed. Usually, the walls are plastered and screeded from both sides, although it would be possible to apply the plaster from one side only, so that it also penetrates onto the other side of the plaster base. If an already plastered ceiling 19 has not already been placed in the apparatus 1, the cealing can be plastered when plastering the walls; the cealing can be plastered only on the underside or on both sides. The plaster is then finished off flush with previously installed equipment such as electrical switches and socket housings, conduit connecting flnages, anchorings and the aforesaid door and window frames.

Now follow the secondary jobs which have to be carried out while the plaster is still wet, such as making good, fitting picture rails and batons and the like. Preferably, at this point in time, as far as possible, also all the other secondary jobs are carried out such as incorporation of electrical conductors in conduits, fitting of skirting boards, etc., without having to wait for the plaster to set.

After all the jobs which are possible in the wet state have been carried out, initially no further significant lateral loading of the room element will occur, so that the top template 25 with the rods 15 suspended therefrom via the mounting flange 38 can be lifted off (Figure 6). When this happens the rods 15 are withdrawn from the sheaths 41, which remain in the wall structure of the room element together with the plaster base 22. The top template 25 has supporting lugs 54 to which a crane can be applied to lift out these elements. Otherwise, the corner posts may have hydraulic or spindle operated lifting means which engage the template and lift it off. In this way, those reinforcements which are no longer required for the supporting strength of the walls of the room element can be removed to be used again later.The cavities remaining in the sheath 41 may if necessary be filled with plaster.

In another arrangement the vertical rods 15 may be fixed into the bottom template 10, in which case then the completed room element is lifted off them. If the room element is thereby securely fixed to a top template or is otherwise reinforced and if the plaster base is vertically continuous or is so fixed that it can withstand relatively high traction forces, then the room element can be lifted off even prior to complete setting of the plaster.

If the apparatus 1 is movable, the plaster can be set by running the room element into an oven or autoclave to accelerate the process. Otherwise, the element remains in the apparatus until the plaster has set.

Once the room element has acquired sufficient strength by the plaster setting, it can be removed from the apparatus and conveyed to a work site at which those jobs which can be carried out in the set state or which could not otherwise be completed earlier can be performed. After sufficient drying out, which usually coincides with solidification by setting, the room element can then be painted or decorated and is then ready to use.

The element can be used in conjunction with a supporting frame for constructing multi-storey buildings.

For erecting single storey buildings such as bungalows and the like, the room element can be made up with other room elements on a building site without using a supporting frame.

Figures 14 and 15 show a front view and plan view respectively of a room element suitable for the aforementioned purposes.

It is open at a side 55 and this side allows it to be applied against another room element in order to form a complete dwelling unit. The room element 2 illustrated contains a part 56 of a living room, a kitchen 57 with a cooker 58 and a sink 59 and also a sanitary closet with a flushing toilet 60, a shower cubicle 61 and a wash basin 62. Tte room element is rectangular and is of dimensions such that it can without difficulty be transported by road. The aforementioned supporting frame construction 63 is shown by broken lines in Figures 14 and 15.

WHAT WE CLAIM IS:- 1. A method of producing a room element comprising the steps of forming walls of the element by plastering both sides of plaster bases which are arranged in the configuration that the walls are to assume in the room element and which are strengthened by a reinforcement which is superfluous to the structure of the completed walls and which reinforcement lies within the thickness of the walls after plastering, and removing, after plastering, the superfluous reinforcement from the walls, the superfluous reinforcement being provided by removable rods.

2. A method according to claim 1, wherein the rods are withdrawn from the plaster before the plaster has set.

3. A method according to claim 1 or claim 2, comprising varying the temperature of the rods in order to influence the setting time of the plaster.

4. A method according to claim 1, wherein the rods are provided with a separating layer prior to application of the plaster.

5. A method according to any one of claims 1 to 4, wherein the rods or the separating layers are loosely connected to the plaster base prior to application of the plaster.

6. A method according to any one of claims 1 to 5, comprising the step of applying templates to hold the rods rigidly and with dimensional accuracy.

7. A method according to any one of claims 1 to 5, comprising the step of fixing the rods to a template and withdrawing the rods from the wall by a relative movement between the template and the wall.

8. A method according to any one of claims 1 to 7, comprising the step of feeding a pressurised fluid to facilitate withdrawal of the rods.

9. Apparatus for producing a room element having walls formed by plastering both sides of a plaster base, said apparatus comprising a bottom template, a top template alignable with the bottom template at a distance above the bottom template, said templates having guide bores in positons corresponding to the positions of the walls to be erected, and rods locatable in the bores and arranged to extend from the top template to the bottom template, said rods serving to reinforce the plaster base, and said rods being removable from the walls after application of the plaster.

10. Apparatus according to claim 9, further comprising a housing frame, said templates being removably mounted in the housing frame.

11. Apparatus according to claim 10, wherein the housing frame comprises four posts located in positions corresponding to the corner zones of the room element.

12. Apparatus according to claim 11, wherein at least two of said posts are removable from the housing frame.

13. Apparatus according to claim 11, wherein at least two of said posts are adjustable in position in the housing frame.

14. Apparatus according to any one of claims 10 to 13, wherein the housing frame comprises frame members for supporting the bottom template from beneath.

15. Apparatus according to any one of claims 10 to 14, wherein the housing frame comprises, on at least two oppositely disposed sides, at least one intermediate post for the top template.

16. Apparatus according to any one of claims 9 to 15, wherein each template is made up of metal profiles.

17. Apparatus according to claim 16, comprising guide bushes in the metal profiles, said guide bushes defining said guide bores.

18. Apparatus according to any one of claims 9 to 17, wherein the guide bores are located on the central axis of the walls which are to be erected.

19. Apparatus according to claim 16, wherein the metal profiles have a width corresponding to the required thickness of the walls.

20. Apparatus according to any one of claims 9 to 19, wherein the rods are of circular cross-section.

21. Apparatus according to any one of claims 9 to 20, wherein the rods are hollow.

22. Apparatus according to any one of claims 9 to 21, wherein the rods are fixed to at least one of the two templates.

23. Apparatus according to any one of

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The element can be used in conjunction with a supporting frame for constructing multi-storey buildings. For erecting single storey buildings such as bungalows and the like, the room element can be made up with other room elements on a building site without using a supporting frame. Figures 14 and 15 show a front view and plan view respectively of a room element suitable for the aforementioned purposes. It is open at a side 55 and this side allows it to be applied against another room element in order to form a complete dwelling unit. The room element 2 illustrated contains a part 56 of a living room, a kitchen 57 with a cooker 58 and a sink 59 and also a sanitary closet with a flushing toilet 60, a shower cubicle 61 and a wash basin 62. Tte room element is rectangular and is of dimensions such that it can without difficulty be transported by road. The aforementioned supporting frame construction 63 is shown by broken lines in Figures 14 and 15. WHAT WE CLAIM IS:-

1. A method of producing a room element comprising the steps of forming walls of the element by plastering both sides of plaster bases which are arranged in the configuration that the walls are to assume in the room element and which are strengthened by a reinforcement which is superfluous to the structure of the completed walls and which reinforcement lies within the thickness of the walls after plastering, and removing, after plastering, the superfluous reinforcement from the walls, the superfluous reinforcement being provided by removable rods.

23. Apparatus according to any one of

claims 9 to 22, further comprising a layer surrounding the rods to facilitate their removal from the walls.

24. Apparatus according to claim 23, wherein the said layer is a coating of a liquid, a powder or a paint, or is defined by a sheath which houses the rod.

25. Apparatus according to any one of claims 9 to 24, further comprising screeding guides on the templates or the housing frame.

26. Apparatus according to any one of claims 9 to 25, wherein the width of each template corresponds to the overall width of the room element to be erected.

27. Apparatus according to claim 11 or any claim dependent thereon, further comprising lug mean on each of the posts for attachment of a ceiling frame of the room element.

28. Apparatus according to any one of claims 9 to 27, wherein the guide bores in at least one of the templates are located in a substantially regular pattern.

29. A method of producing the walls of a room element comprising the steps of providing a vertical substrate for each wall, reinforcing the substrate with removable, substantially vertical, reinforcing rods, applying to the substrate a hardenable composition in a fluid form so that the composition lies on each side of the substrate and the reinforcing rods lie within the thickness of the composition, and removing the reinforcing rods from the wall after the composition has at least partly set by withdrawing the rods substantially vertically.

30. A method of producing a room element substantially as herein described with reference to the accompanying draw ings.

31. Apparatus for producing a room element substantially as herein described with reference to the accompanying draw ings.

32. A room element produced by a method according to any one of claims 1 to 8, claim 29 or claim 30.