Improvements in and relating to construction methods

Abstract

Method for constructing a wall by extruding concrete from a 3D printing apparatus, and using pre-cast components to form the foundations for the wall wherein the concrete comprises load-bearing concre

Description

The present invention is directed to improvements in and relating to construction methods, and in particular, to construction methods for use with 3D printing of concrete for construction. BACKGROUND 3D printing for construction of walls of buildings using materials such as concrete are known. For example, the following two publications relate to 3D printing using precursor materials such as concrete including a binder such as cement:

[0001] Published International patent specification No. WO2023137840 A1 discloses a method for 3D printing a construction using a printing unit. The method described in the patent publication comprises (1) obtaining a precursor printing material, wherein the precursor printing material comprises a binder, water and sand; (2) forming a flow of the precursor printing material towards the printing unit and adding a first additive and optionally, other additives with the precursor printing material to form the printing material and then extruding the printing material via the printing head of the printing unit. The patent specification also discloses a 3D construction printing system and a printing unit comprising a hopper and a printing head.

[0002] Published International patent specification No. WO2023138742 A1 also discloses a method for 3D printing a construction using a printing unit with a hopper and a printing head. The printing unit is a complex and expensive apparatus and it is crucial that it be used efficiently and carefully, as there is a risk that the printing unit may be subject to damage during the construction process. Furthermore, due to the cost of the equipment and its capacity for productivity, if the equipment is effectively deployed, it is important to ensure that the use of equipment is optimized and its operations are not obstructed. The present invention seeks to decouple the 3D printer / 3D printing unit from carrying out the function of forming the rising wall / foundations (as is the known current practice) and thereby remove the associated time to complete the floor slab which would otherwise render the equipment redundant for the relevant period of completing the floor slab. The present invention seeks to alleviate the disadvantages associated with known methods of using 3D printing apparatus also referred to herein as 3D printing units such as, for example, the printing apparatus / printing units comprising an extruding nozzle for extrusion and delivery of the concrete as are disclosed in the above International patent publications. SUMMARY OF THE INVENTION In one aspect, the present invention provides a method for constructing a wall by extruding concrete from a 3D printing apparatus, and using pre-cast components to form the foundations for the wall wherein the concrete comprises load-bearing concrete and the method comprises a step of extruding concrete from the 3D printing apparatus onto the pre-cast components that form the foundations for the walls to be constructed. The present invention has the advantage that the concrete extruded from the 3D concrete printer (3DCP) comprises load bearing Structural Concrete. According to the method of the present invention, the method comprises the initial step of preparing a digital model of the relevant 3DCP wall elements and the corresponding precast components to coordinate each as required in advance of casting and engagement in site operations. The process of the present invention involves the further steps of coordinating the 3D Concrete Printer and the precast / pre-formed components that comprise the foundations including the rising walls and the method preferably, also comprises the following steps: Coordination of digital models: Preparation of a digital model of the relevant 3DCP wall elements and the corresponding precast components to coordinate as required in advance of casting and engagement on site I during site operations; At the desired location of the construction i.e. Onsite, the method comprises the following steps: Selecting a location of the precast component as a reference point, set up printers work X, Y, Z and U coordinates to correspond and align printer extrusion path with Precast component set out at the pre-determined locations on the site of the walls to be constructed by extruding concrete from the 3D printing apparatus. Advantageously, the concrete extruded from the 3D printing apparatus is extruded onto the pre-cast components that form the foundations for the walls to be constructed. Thus, the pre-cast components form the foundations and the initial wall section (referred to as the “rising wall”) and this has the significant advantage that the printing apparatus does not need to be at the site until it is required for extruding concrete directly onto the pre-cast foundation components to form a first layer of extruded load-bearing concrete and then continuing to extrude concrete onto the first layer of extruded load-bearing concrete and then onto the subsequent layers of extruded load-bearing concrete. In another aspect of the present invention, the present invention provides a double-leaf wall constructed using the method of the above aspect of the present invention. In a further aspect of the present invention, there is also provided a single leaf wall constructed using the method of the above aspect of the present invention. Thus, the present invention relates to an improved method of construction using a 3D printing unit. A 3D printing unit is used for extruding / printing concrete according to the improved method of the present invention using pre-cast foundation elements / beams to provide load-bearing support for the extruded printing material as it is continued to be extruded to form the rising wall from the foundations level upwards with the printing material being extruded on to the pre-formed foundation beams which are locatable at pre-determined locations on a site to enable concrete to be extruded from a 3D printing unit and to form a rising wall from the level of the pre-formed concrete up. Further aspects of the present invention will be described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which are shown: Embodiment 1- Method of 3D printing of concrete coupled with traditional strip foundation: Figure 1 is a cross-sectional view of a trench dug in a site on which walls are to be formed by extruding printing material from a 3D printing unit in a known process referred to herein as “3D printing material” and referred to generally in the art, as “3D printing of concrete” for building walls where the precursor material is concrete (Fig 1, &Fig 29); Figure 2 is a cross-sectional view of the trench including the poured strip foundation (Fig 2, &Fig 30); Figure 3 is a cross-sectional view of the trench with the mortar for the base of precast concrete beams that are pre-formed and brought on-site to be located at pre- locations (Fig 3, &Fig 31); Figure 4 is a cross-sectional view of the precast ground beams placed at the predetermined locations, where appropriate, for constructing a wall that will subsequently be 3D printed by extruding printing material from the 3D printing unit (Fig 4, &Fig 32); Figure 5 is a cross-sectional view of a shallow base of hardcore material infilled into the trench (Fig 5, &Fig 33); Figure 6 is a cross-sectional view of the piping for providing services placed where located for the walls and building that is being constructed (Fig 6, &Fig 34); Figure 7 is a cross-sectional view of the hardcore material being infilled in the trench (Fig 7, &Fig 35); Figure 8 is a cross-sectional view of the blinding infilled so as to be flush with the pre-cast ground beam(s) that have been placed at the pre-determined locations on the site under construction (Fig 8, &Fig 36); Figure 9 is a cross-sectional view of the construction with the Radon barrier I Damp Proof Coursing (DPC) laid down in appropriate locations (Fig 9, &Fig 37); Figures 29 to 37, respectively, are perspective views corresponding to Figures 1 to 9, respectively, as indicated above for each of the respective Figures. Method of building walls for double Leaf construction using 3D printing of Concrete: Figure 10 is a cross sectional view of the pre-formed insulated precast concrete beams placed at the appropriate, pre-determined locations for load-bearing and onto which printing material (e.g. Concrete) can be extruded so as to form walls of the building that is under construction (Fig 10, &Fig 38); Figure 11 is a cross sectional view of a radon barrier / damp proof course (DPC) which may preferably be a self-adhesive radon barrier I DPC with the sealing side facing the preformed insulated concrete beams (Fig 11, &Fig 39); Figure 12 is a cross-sectional view showing the extrusion of the precursor material, e.g. concrete being extruded up to the DPC level as shown in Figure 12, having already selected a location of the precast component as a reference point, and having set up printing units to pre-determined coordinates along the X, Y, Z and II axes so as to correspond and align the extrusion path of the printing unit with the selected locations of the precast component placed at the pre-determined positions on the site for constructing walls (Fig 12, &Fig 40); Figure 13 is a cross-sectional view showing the rigid insulation cut to shape and fitted into cavity of the double leaf walls (Fig 13, &Fig 41); Figure 14 is a cross-sectional view of the DPC bridging cavity (Fig 14, &Fig 42); Figure 15 is a cross-sectional view of the air tightness membrane located over the preformed insulated concrete beam(s) (Fig 15, &Fig 43); Figure 16 is a cross-sectional view showing the separation layer of insulation along the internal face of the walls formed from the extruded concrete (Fig 16, &Fig 44); Figure 17 is a cross-sectional view showing the screed in place following pouring of the screed (Fig 17, &Fig 45) ; Figure 18 is a cross-sectional view showing the concrete extrusion resuming by extruding concrete from the 3D printing unit (Fig 18, &Fig 46); Figures 38 to 46, respectively, are perspective views corresponding to the cross-sectional views of Figures 10 to 18, respectively, as indicated above for each of the respective Figures. Method of building walls for single Leaf construction using 3D printing of Concrete: Figure 19 is a cross-sectional view of an insulated precast concrete beam(s) placed in a pre-determined location (Fig 19, &Fig 47); Figure 20 is a cross-sectional view of a radon barrier, preferably, a self-adhesive radon barrier I damp proof course (DPC) located on the sealing side of the pre-formed insulated concrete planks (Fig 20, &Fig 48); Figure 21 is a cross-sectional view showing the concrete extruded to the DPC level having already carried out the step of selecting a location of the precast component as a reference point, and having set up the printing units to work X, Y, Z and U coordinates to correspond and align the printing unit extrusion path with the precast component locations (Fig 21, &Fig 49); Figure 22 is a cross-sectional view of the DPC placed on top of the extruded concrete walls (Fig 22, &Fig 50); Figure 23 is a cross-sectional view of an air tightness membrane placed over the preformed insulated concrete beams (Fig 23, &Fig 51); Figure 24 is a cross-sectional view of a separation layer of insulation placed along the internal face of the concrete walls formed by 3D extrusion of concrete using 3D printing units (Fig 24, &Fig 52); Figure 25 is a cross-sectional view of the screed poured (Fig 25, &Fig 53); Figure 26 is a cross-sectional view of the extrusion of concrete resuming and progressing with extruding concrete to form the walls of the desired construction eg. a building (Fig 26, &Fig 54); Figure 27 is a cross-sectional view of the insulation adhesive applied to the external face of concrete walls formed by 3D extrusion of concrete (Fig 27, &Fig 55); Figure 28 is a cross-sectional view of the insulation attached externally (Fig 28, &Fig 56); Figures 47 to 56, respectively, are perspective views corresponding to the cross-sectional views of Figures 20 to 28, respectively, as indicated above for each of the respective Figures. Method of construction using 3D printing of Concrete, coupled with Pile Foundation: Figure 57 is a cross-sectional view of the trench dug out to form the foundations for the construction using 3D printing unit (Fig 57, &Fig 87); Figure 58 is a cross-sectional view of a hole formed by drilling a hole for locating a pile into the hole, and filling with concrete (Fig 58, &Fig 88); Figure 59 is a cross-sectional view of the pile caps cast for locating on the pile (Fig 59, &Fig 89); Figure 60 is a cross-sectional view of the mortar located in position for the base of the precast beam(s) that are located at pre-determined locations on site (Fig 60, &Fig 90); Figure 61 is a cross-sectional view of the precast ground beams placed at the selected pre-determined locations (Fig 61, &Fig 91); Figure 62 is a cross-sectional view of the shallow base of hardcore infilled (Fig 62, &Fig 92); Figure 63 is a cross-sectional view of the piping put in place for providing services to the site; (Fig 63, &Fig 93) Figure 64 is a cross-sectional view of the construction with the remainder of hardcore infilled (Fig 64, &Fig 94) Figure 65 is a cross-sectional view of the blinding infilled so as to be flush with the pre-cast ground beams (Fig 65, &Fig 95) Figures 87 to 95, respectively, are perspective views corresponding to the cross-sectional views Figures 57 to 65, respectively, as indicated above for each of the respective Figures. Double Leaf Concrete: Figure 66 is a cross-sectional view of the radon barrier / DPC laid (Fig 66, &Fig 96); Figure 67 is a cross-sectional view of the insulated precast concrete planks placed at predetermined locations for providing load-bearing support for a wall to be formed thereon by extruding printing material eg. concrete from a 3D printing unit (Fig 67, &Fig 97); Figure 68 is a cross-sectional view of a radon barrier I DPC preferably, a self-adhesive radon barrier / DPC with the sealing side of insulated concrete planks (Fig 68, &Fig 98) Figure 69 is a cross-sectional view of the concrete extruded up to DPC level having already carried out the step of Selecting a location of the precast component as a reference point, set up printing unit to extrude along the relevant X, Y, Z and U coordinates to correspond and align the printing unit extrusion path with the precast component placed at the pre-determined locations (Fig 69, &Fig 99); Figure 70 is a cross-sectional view of the rigid insulation cut to shape, fitted into cavity (Fig 70, &Fig 100); Figure 71 is a cross-sectional view of the DPC bridging cavity (Fig 71, &Fig 101); Figure 72 is a cross-sectional view of an air tightness membrane placed over the insulated concrete beams; (Fig 72, &Fig 102); Figure 73 is a cross-sectional view of a separation layer of insulation placed along internal face of concrete (Fig 73, &Fig 103); Figure 74 is a cross-sectional view with the screed poured (Fig 74, &Fig 104); Figure 75 is a cross-sectional view of the resumed extrusion of concrete from the printing unit to form the walls of the construction (Fig 75, &Fig 105); Figures 96 to 105, respectively, are perspective views corresponding to the cross-sectional views in Figures 57 to 65, respectively, as indicated above for each of the respective Figures. Single Leaf Concrete: Figure 76 is a cross-sectional view of the radon barrier / DPC laid (Fig 76, &Fig 106) Figure 77 is a cross-sectional view showing the insulated precast concrete planks placed (Fig 77, &Fig 107) Figure 78 is a cross-sectional view showing the radon barrier / DPC preferably self-adhesive radon barrier / DPC with the sealing side of pre-formed insulated concrete planks (Fig 78, &Fig 108); Figure 79 is a cross-sectional view of the concrete extruded to DPC level; having already carried out the step of Selecting a location of the precast component as a reference point, set up printers work X, Y, Z and U coordinates to correspond and align printer extrusion path with precast component set out Figure 80 is a cross-sectional view showing the DPC placed on top of extruded concrete (Fig 80, &Fig 110) Figure 81 is a cross-sectional view of an air tightness membrane over insulated concrete planks (Fig 81, &Fig 111); Figure 82 is a cross-sectional view of a Separation layer of insulation along internal face of concrete (Fig 82, &Fig 112); Figure 83 is a cross-sectional view of the screed poured (Fig 83, &Fig 113) Figure 84 is a cross-sectional view of resumed concrete extrusion (Fig 84, &Fig 114); Figure 85 is a cross-sectional view of the insulation adhesive to external face of concrete (Fig 85, &Fig 115); Figure 86 is a cross-sectional view of the insulation attached externally (Fig 86, &Fig 116); Figures 106 to 116, respectively, are perspective views corresponding to the cross-sectional views in Figures 76 to 86, respectively, as indicated above for each of the respective Figures; and Figure 117 is a plan view of a site on which a 3D printing unit is used for extruding / printing concrete according to the improved method of the present invention using pre-cast foundation elements / beams to provide load-bearing support for the extruded printing material as it is continued to be extruded to form the rising wall from the foundations level upwards with the printing material being extruded on to the pre-formed foundation beams which are locatable at pre-determined locations on a site to enable concrete to be extruded from a 3D printing unit and to form a rising wall from the level of the pre-formed concrete up. In the drawings, the following reference numerals are used to refer to the corresponding following features: Legend for the drawings / Figures: 1. T rench 2. Traditional concrete strip foundation 3. Steel reinforcement 4. Mortar 5. Precast concrete ground beam 6. Service void precast into ground beam 7. Hardcore 8. Services I Venting 9. Blinding 10. Radon Barrier &DPC 11. Spantherm Insulated Concrete Planks 12. Load bearing 3DCP Readymix Concrete 13. Self-Adhesive Radon Barrier &DPC 14. Rigid Insulation cut to shape 15. DPC 16. Air tightness membrane 17. Separation layer 18. Screed 19. External Insulation Adhesive 20. External Insulation 21. Drilled concrete pile 22. Pile cap 25. Printing apparatus / Printing unit (as shown in schematic in Figure 117). Steps of the method of the present invention: Method for constructing a wall using a 3D printing unit / printing apparatus in conjunction with traditional strip foundation: Step 1: Digging the trench (as shown in Fig 1, &Fig 29) Step 2: Pouring strip foundation (Fig 2, &Fig 30) Step 3: Applying mortar for base of precast beam (Fig 3, &Fig 31) Step 4: Placing Precast ground beams (Fig 4, &Fig 32) Step 5: Infilling shallow base of hardcore infilled (Fig 5, &Fig 33) Step 6: Placing piping for Services (Fig 6, &Fig 34); and Step 7: Infilling the remainder of hardcore (Fig 7, &Fig 35) Step 8: Blinding infilled flush with ground beam (Fig 8, &Fig 36) Step 9: Laying / placing the Radon barrier / DPC (Fig 9, &Fig 37) Method of construction to form Double Leaf Concrete wall using 3D printing unit in accordance with the method of the present invention Step 10: Placing insulated precast concrete planks (Fig 10, &Fig 38) Step 11: Applying self-adhesive radon barrier I DPC sealing side of insulated concrete planks (Fig 11, &Fig 39) Step 12: Selecting a location of the precast component as a reference point, set up printers work X, Y, Z and U coordinates to correspond and align printer extrusion path with precast component set out Step 13: Extruding Concrete to DPC level (Fig 12, &Fig 40) Step 14: Cutting Rigid insulation to desired shape, and fitting into cavity (Fig 13, &Fig 41) Step 15: DPC bridging cavity (Fig 14, &Fig 42) Step 16: placing Air tightness membrane over insulated concrete planks (Fig 15, &Fig 43) Step 17: Applying separation layer of insulation along internal face of concrete (Fig 16, &Fig 44) Step 18: Pouring screed (Fig 17, &Fig 45) and Step 19: Resuming concrete extrusion resumes (Fig 18, &Fig 46). Method of construction using 3D printing to form Single Leaf Concrete wall using the method of the present invention: Step 10: Placing insulated precast concrete planks at pre-determined locations for load bearing and on to which pre-cast concrete beams, the 3D printing unit will extrude the printing material to form a rising wall (Fig 19, &Fig 47); Step 11: Self-adhesive radon barrier / DPC sealing side of insulated concrete planks (Fig 20, &Fig 48) Step 12: Selecting a location of the precast component as a reference point, set up printers work X, Y, Z and II coordinates to correspond and align printer extrusion path with precast component set out Step 13: Concrete extruded to DPC level (Fig 21, &Fig 49) Step 14: DPC placed on top of extruded concrete (Fig 22, &Fig 50) Step 15: Air tightness membrane over insulated concrete planks (Fig 23, &Fig 51) Step 16: Separation layer of insulation along internal face of concrete (Fig 24, &Fig 52) Step 17: Screed poured (Fig 25, &Fig 53) Step 18: Concrete extrusion resumes (Fig 26, &Fig 54) Step 19: Insulation adhesive to external face of concrete (Fig 27, &Fig 55) Step 20: Insulation attached externally (Fig 28, &Fig 56) Method steps of construction in conjunction with Pile Foundation: Step 1: Digging the trench (Fig 57, &Fig 87) Step 2: Drill hole for pile, fill with concrete (Fig 58, &Fig 88) Step 3: Pile caps cast (Fig 59, &Fig 89) Step 4: Mortar for base of precast beam (Fig 60, &Fig 90) Step 5: Precast ground beams placed (Fig 61, &Fig 91) Step 6: Shallow base of hardcore infilled (Fig 62, &Fig 92) Step 7: Services placed (Fig 63, &Fig 93) Step 9: Blinding infilled flush with ground beam (Fig 65, &Fig 95) Method steps of construction to form Double Leaf Concrete wall: Step 10: Radon barrier / DPC laid (Fig 66, &Fig 96) Step 11: Insulated precast concrete planks placed (Fig 67, &Fig 97) Step 12: Self-adhesive radon barrier / DPC sealing side of insulated concrete planks (Fig 68, &Fig 98) Step 13: Selecting a location of the precast component as a reference point, set up printers work X, Y, Z and U coordinates to correspond and align printer extrusion path with precast component set out Step 14: Concrete extruded to DPC level (Fig 69, &Fig 99) Step 15: Rigid insulation cut to shape, fitted into cavity (Fig 70, &Fig 100) Step 16: DPC bridging cavity (Fig 71, &Fig 101) Step 17: Air tightness membrane over insulated concrete planks (Fig 72, &Fig 102) Step 18: Separation layer of insulation along internal face of concrete (Fig 73, &Fig 103) Step 19: Screed poured (Fig 74, &Fig 104) Step 20: Concrete extrusion resumes (Fig 75, &Fig 105) Method steps of construction to form Single Leaf Concrete using the method of the present invention: Step 10: placing / laying radon barrier / DPC (Fig 76, &Fig 106) Step 11: Placing insulated precast concrete planks (Fig 77, &Fig 107) Step 12: Self-adhesive radon barrier / DPC sealing side of insulated concrete planks (Fig 78, &Fig 108) Step 13: Selecting a location of the precast component as a reference point, set up printers work X, Y, Z and U coordinates to correspond and align printer extrusion path with precast component set out Step 14: Extruding Concrete to DPC level (Fig 79, &Fig 109) Step 15: Placing DPC on top of extruded concrete (Fig 80, &Fig 110) Step 16: Placing an Air tightness membrane over insulated concrete beams (Fig 81, &Fig 111) Step 17: Applying a separation layer of insulation along internal face of concrete (Fig 82, &Fig 112) Step 18: Pouring screed (Fig 83, &Fig 113) Step 20: Applying insulation adhesive to external face of concrete (Fig 85, &Fig 115) Step 21: Applying insulation externally (Fig 86, &Fig 116). Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be 5 understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not 10 restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A method for constructing a wall by extruding concrete from a 3D printing apparatus, and using pre-cast components to form the foundations for the wall wherein the concrete comprises load-bearing concrete.

2. A method as claimed in claim 1 comprising an initial step of preparing a digital model of the relevant 3DCP wall elements and the corresponding precast components to coordinate each as required in advance of casting and engagement in site operations.

3. A method as claimed in claim 1 or claim 2 wherein the method comprises the further steps of coordinating the 3D Concrete Printer and the precast / pre-formed components that comprise the foundations including the rising walls and the method preferably, also comprises the following steps: Coordinating of digital models: Preparing a digital model of the relevant 3DCP wall elements and the corresponding precast components to coordinate as required, in advance of the steps that are carried out at the site of construction.

4. A method as claimed in claim 1 wherein the method comprises a step of extruding concrete from the 3D printing apparatus onto the pre-cast components that form the foundations for the walls to be constructed.

5. A method as claimed in any preceding claim wherein the method comprises the step of coordinating the 3D Concrete Printer and the precast / pre-formed components.

6. A method as claimed in any preceding claim wherein the method also comprises the following steps:locating the pre-cast components at pre-determined locations at the site of construction (i.e. onsite)Selecting a location of the precast component as a reference point, setting up printers work X, Y, Z and U coordinates to correspond andaligning the printer extrusion path with the location of the precast component at the pre-determined locations on the site of the walls to be constructed by extruding concrete from the 3D printing apparatus.

7. A method as claimed in any preceding claim wherein concrete extruded from the 3D printing apparatus is extruded onto the pre-cast components that form the foundations for the walls to be constructed whereby concrete is extruded onto the pre-cast foundation components to form a first layer of extruded load-bearing concrete and then continuing to extrude concrete onto the first layer of extruded load-bearing concrete and then onto the subsequent layers of extruded loadbearing concrete.

8. A method of construction using a 3D printing unit adapted for extruding a printing material comprising a binder for construction of walls; comprising the following steps:(a) Providing pre-formed foundation members adapted for load-bearing;(b) Arranging the pre-formed foundation members in a pre-determined configuration to support a wall to be formed by extruding a printing material on to the load-bearing pre-formed foundation members.

9. A method as claimed in any of the preceding claims wherein the method comprises the following steps:Step 1: Digging the trench (as shown in Fig 1, &Fig 29)Step 2: Pouring strip foundation (Fig 2, &Fig 30)Step 4: Placing Precast ground beams (Fig 4, &Fig 32)Step 5: Infilling shallow base of hardcore;Step 6: Placing piping for Services;Step 7: Infilling the remainder of hardcore;Step 8: Blinding infilled flush with ground beam;Step 9: Laying / placing the Radon barrier / Damp Proof Course (DPC); and subsequently, printing printing material.

10. A method as claimed in any preceding claim wherein the method comprises the step of: Applying mortar for base of precast beam after step 4 and before step 5.

11. A double-leaf wall constructed using the method as claimed in any of the preceding claims.

12. A single leaf wall constructed using the method as claimed in any of claims 1 to 10.

13. A wall constructed using the method as claimed in any of claims 1 to 10 comprising insulation.

14. A wall as claimed in claim 12 or claim 13 constructed using the method as claimed in any of claims 1 to 10 including a separation layer of insulation along internal face of the wall.

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