BUILDING MATERIALS AND METHODS

Abstract: An improved material for building, in the form of a laminate. The material includes at least one layer of insulating material, at least one layer of damp-proofing material, and re-inforcing means whereby to allow for the location of a cementitious outer layer, of ferro-cement, fibrecrete or the like. The laminate may also include at least one layer of a surface finish material. A method of construction utilizing such a material or laminate is also disclosed.

Description: BUILDING MATERIALS AND METHODS The present invention relates, in general, to improvements in building materials. The invention furthermore relates to structures built from such improved building materials, and to a method of construction utilising such materials. Throughout the ensuing description emphasis will be given to a building material in the form of a laminate, a laminate which, makes possible the use of so-called ferro-cement (amongst other materials). It should be understood, however, that such a material is particularised by way of example only and that, within the spirit and scope of the invention, it would be possible to include any other material of an equivalent nature. By way of example, other substantially cementitious materials may equally well be employed in conjunction with the laminate in accordance with the invention. It should furthermore be understood that, whilst the materials, and laminate, of the type described herein are particularly suited for use in the field of construction, other uses may well be feasible. Up until recent times the building industry in general has utilised for purposes of construction so-called static materials, such as for example brick, timber and/or reinforced (conventional) concrete. Such materials have been found, in a practical sense, not to afford a truly acceptable degree of flexibility in and for both construction and design. By way of example, when such so-called static materials are employed it has been found to be somewhat difficult to achieve surfaces other than straight, as for example curved, at an acceptable cost. Furthermore, such static materials have generally relied rather heavily on secondary support elements and the like whereby to satisfy prescribed design parameters, as for example thermal resistantce, strength capability, fire-rating, water¬ proofing etc. In addition conventional building techniques, utilising static materials of the type referred to above, have been found to rely for their completion on the utilisation of a number of different trades. In a practical sense the need for the utlisation of different tradesmen, all dependant on a specialised skill in order to achieve their stated purpose in an acceptable manner, ultimately will lead to an increase in overall cost of the finished structure, and also give rise to difficulties in ensuring adequate quality control and efficient and effective use of available man-power. Indeed, when using conventional building techniques serious logistical problems can normally be expected to be encountered in "mustering" at any prescribed time the tradesman or tradesmen required to effect any particular task. These problems almost invariably give rise to a lack of continuity in labour and construction and, more often than not, result in construction not being completed by the specified date. Such logistical problems and exercises can also substantially increase the overall cost involved in construction of any given structure. The present invention seeks to provide an improved form of building material, in the form of a laminate, which may be sized and shaped to suit specified building requirements and parameters. More particularly, the invention seeks to provide a building material which will readily allow for the utilisation or formation of surfaces, other than straight in architectural designs for buildings and the like, thereby allowing architects to design structures having greater aesthetic appeal and which, in an environ- mental sense, are perhaps more compatible with the surroundings or environment. The invention furthermore seeks to provide a method of construction best suited for the utilisation of such building material. When applied to the field or science of construction the building material or materials in accordance with the present invention provides for greater flexibility of design, more effective use of man-power, better quality control and, in the result, a finished product manufactured at a reduced overall cost. In accordance with one aspect of the present invention there is provided a material for use in building, said material being in the form of a laminate and including: at least one layer of an insulating material; at least one layer of a damp-proofing material; and at least one layer of a re-inforcing material, preferably expanded metal. In accordance with another aspect of the present invention there is provided a method for the construction of the external shell of a building or the like, said method including the steps of: (i) forming a slab of concrete or the like material on-site whereby to afford a flat surface for construction of said building or the like; (ii) erecting a framework, of a predetermined size and configuration, on said slab, said framework forming the basic outline for said shell, said framework having associated therewith and attached thereto at least one layer of a high tensile mesh fabric material; (iii) attaching laminated panels of said material as set out in the preceding paragraph to said erected framework; and (iv) applying a layer of cementitious material to said framework, said mesh of fabric material, in co junction with said cementitious material, forming a ferro-cement/fibrecrete layer of said shell. In accordance with yet another aspect of the present invention there is provided a building, when constructed using the material and method of the preceding paragraphs. In order that the invention may be more clearly understood and put into practical effect reference will now be made to preferred embodiments of a building material and method of construction using such material in accordance with the invention. It should be understood, however, that the ensuing des¬ cription is given by way of non-limitative example only and is with, reference to the accompanying drawing, which illustrates a typical wall section for a struc¬ ture incorporating the laminate in accordance with the present invention. In an especially preferred or typical embodiment a building material in accordance with the present invention may comprise a laminate constructed from a number of layers of different materials, arranged in a preconceived order dependent upon the proposed usage therefor, and perhaps more particularly dependent upon whether the building material is intended for use in a structure sited (either wholly or in part) above or below ground level. In an especially preferred embodiment the materials involved in such a laminate may include so-called ferro-cement or fibrecrete including a reinforcing steel framework or mesh, a suitable insulating material, a damp-proofing, water-proofing or anti-condensation material, a layer of expanded metal, and a plaster, cementitious material or other suitable finishing material to suit aspects of acoustics and aesthetics. Such a laminate may be assembled by manual and/or mechanical means, with the use of clips, ties, adhesive, heat/pressure and/or any other suitable means of and for inter-connection or attachment. The laminate may be fabricated off site, as for example in a shop, factory or the like, on site, or a combination thereof. In the ensuing paragraphs there will be described in detail a preferred laminate structure in accordance with the invention. Ferro-cement or the like material may best be described as a type of thin-wall concrete construction which has been found to behave quite differently to conventional reinforced concrete. Fabrication of such ferro-cement generally involves the building up of several layers of relatively small diameter mesh, which is then completely impregnated with mortar in such a way as to minimize, if not remove altogether, air gaps or voids. The mesh may be constructed of any suitable material, as for example a metallic material, glass or asbestos fibres (or indeed any other suitable organic material), or even a combination thereof. Ferro-cement or any equivalent material, such as fibrecrete, has been found to be an extremely workable material and to provide for a markedly improved flexibility in design. If desired the ferro- cement or the like material may be provided with one or more ribs, either internal or external, or alterna¬ tively it may be in the form of a continuous sheet or layer. Insofar as the reinforcing steel framework or mesh making up part of the laminate in accordance with the present invention is concerned, this may take any known form. However, a general requirement for such a reinforcing framework or mesh is flexibility, especially wherein curved or non-straight surfaces, shapes or the like are called for in an overall structure. In an especially preferred configuration high tensile steel mesh may be employed with additional layers of so-called "chicken-wire" being affixed to the reinforcement mesh in any known manner, as for example by way of steel wire ties or the like. For purposes of interstitial condensation control the preferred form of laminate in accordance with the present invention should also include at least one layer of a suitable condensation control material. An especially preferred embodiment utilizes polyethylene sheeting (one or more sheets) for this purpose. For purposes of insulation the preferred form of laminate in accordance with the present invention should also include at least one layer of a suitable insulating material. In an especially preferred embodiment, as illustrated for example in Fig. 1, a product commerically known as styrofoam may be employed for purposes of insulation. It should be understood, however, that other materials having insulating properties, as for example fibreglass, may equally well be employed. It has been found, however, that a layer of styrofoam of a thickness of perhaps from 25-30 mm. will exhibit better insulation characteristics than a 75 mm. layer of fibreglass. It should be understood, however, that the thickness of the layer (or layers) of insulating material may be varied dependent on intended usage for the laminate. By way of example, if the building on which the laminate is to be employed was to be located in an extremely hot or cold climate, then the thickness of the insulating material would (or could) be increased accordingly. In order to afford a suitable, or rather markedly improved, damp-proofing or water-proofing effect the laminate in accordance with the invention should also include at least one layer of a suitable material which acts as a barrier to condensation. Examples of suitable and/or preferred damp-proofing and/or water-proofing materials include concrete additives, so-called pargeting (coating with a dense cement plaster or a similar material) , a coating of asphalt, a coating of pitch, a layer (or layers) of polyethylene sheeting, or perhaps even a membrane of neoprene or other suitable material. In an especially preferred embodiment, a bituminous membrane may be employed. The laminate in accordance with the invention furthermore includes a layer of what might be termed expanded metal (or an equivalent material) , formed by the subjection of a thin metal sheet to an expansion process. This expanded metal (or equivalent) acts as a reinforcing agent for the application of plaster, cementitious material or other surface-finishing material. Preferably the expanded metal sheet will have a thickness of from 4.5 to 7.0 mm. The utilisation of a building material in accordance with the present invention will also give rise to the need for a specific mode of construction of any desired structure. In a preferred embodiment such a mode of construction will involve a number of different steps or stages, as indicated hereunder. It should be understood, however, that the relative locations of the various layers of material within the laminate do not constitute an essential part or feature of the invention. Indeed, those relative locations may be varied to satisfy different building requirements. By way of example only, and dependent on whether the structure being erected is to be located wholly, or in part, above or below ground level, then the location of the damp-proofing material or condensation barrier (relative to the other materials) may be altered. The present invention also involves a method of erecting a shell for a building structure utilising materials of the aforementioned type. In this regard it should be understood that, for best utilisation of the properties of the building material or laminate in accordance with the present invention, a preferred method or mode of construction has been devised, as explained hereunder in detail. The first step in the method of construction in accordance with the present invention involves the preparation of the site for construction. In the preferred embodiment, as illustrated for example in Figure 1, the building or the like is constructed on a concrete slab. Any known method or techinque for levelling of a site and pouring of such a slab may be employed. In a second stage of the method of construc¬ tion in accordance with the present invention a frame may be erected on the slab, and affixed thereto, as for example by the use of bolts or the like (not shown) appropriately and strategically located within the concrete slab during pouring thereof. It should be understood that the frame or the like, constructed of any suitable material such as, for example, steel tubing or piping, of a pre-ordained configuration, constitutes means allowing for definition of the basic shape for the structure being erected, and also as a carrier for electrical services and the like. The configuration for such a frame may be calculated in any suitable manner. In an especially preferred embodiment, however, such a configuration is arrived at - through the use of appropriate computer means, whereby to provide a configuration best suited for the prescribed load requirements etc. and which meets the desired design shape for the overall structure. Thereafter flat metal plate, rod or angle may be attached to the support frame in any suitable manner, as for example by spot welding, pinning or the like. Such flat plate, rod or angle serves to more fully and correctly define the overall basic form for the structure. In an especially preferred embodiment the flat plate, rod or angle will be affixed at right angles to the frame itself, more specifically on the top of and at the outside edge of the individual elements of that frame. In a subsequent step a framework of high tensile fabric, more preferably of steel mesh, is located over the flat plate or rod on the support frame and is affixed thereto by any suitable means, as for example through the utilisation of steel wire ties. In an especially preferred embodiment at least one layer of such high tensile fabric mesh will be employed. It should be understood, however, that dependent upon design parameters more than one layer of such fabric may be employed. Thereafter at least one, and preferably several, layers of fine wire, as for example so-called chicken wire, are tensioned over the structure and affixed thereto, again in accordance with any known technique. The wires and mesh fabric may be cut and trimmed at any location where such structures as windows, vents and the like are required. In the next stage of construction a laminar material, consisting of at least one layer of poly¬ ethylene (preferably in the form of a sheet) , styrofoam and expanded metal will be located on the support structure. The laminate of the aforementioned type will preferably be constructed off-site and delivered on-site for installation. Preferably the laminate will be provided in the form of panels of pre-ordained sizes according to the overall design for the structure. The panels thus provided may then be affixed to the frame structure in any known manner, as for example by pinning, tieing etc. In accordance with the invention the laminate, in the form of panels, is placed on the underside of the mesh and tied into the reinforcement. Such a structure provides the support frame or formwork required to hold the ferro-cement fibrecrete or other cementitious material, and also is responsible for satisfying the other performance characteristics. Once the panels are appropriately located the mesh is completely impregnated with mortar, preferably of a 2:1 sand/cement ratio. The cement is densely compacted with the reinforcement using any known means. The resulting ferro-cement structure is highly crack resistant and has been found to be capable of with- standing great pressures. The ferro-cement structure formed may be cured in any known manner, whereby to prevent excessive drying out. In an especially preferred embodiment such curing will be facilitated by the use of wet hessian and suitable misting sprays. In the embodiment illustrated the ferro-cement can be, in effect, keyed into the concrete slab, as for example by having the lowermost edge thereof adapted to be located in a step or the like provided in the slab. Thereafter electrical conduits and the like, previously located within the support frame, may be pulled through pre-conceived blockout points in the ferro-cement layer. If desired an appropriate surface finishing material, as for example plaster, lathe or the like, may then be located internally of the struc- ture. Indeed the internal walls for the structure may be of any known or conventional material, as for example concrete block, brick, timber, stud wall and plaster or the like dependent upon the nature of the internal finish required for the structure, in turn of course dependent on the intended usage for the structure. The use of a laminate in accordance with the present invention has been found to give rise to a number of important advantages, when compared with the use of conventional so-called static materials, in terms of improvements in construction techniques (and hence degree of difficulty and overall cost) , and also in certain practical considerations (especially when compared with conventional brick veneer, solid brick or weatherboard type structures) . These advantages include: (i) increased flexibility of available shapes, curves etc. (ii) reduction in overall weight; (iii) elimination of need for cavity-type walls in certain structures; (iv) elimination of need for damp coursing; (v) possibility of integrated overall roof-wall configurations; (vi) reduction in actual wall thickness; (vii) ready adaptability for use in both above- ground and subterranean structures; (viii) improvement in ease of assembly and maintenance; (ix) improvement in insulation effect; (x) reduction in degree of condensation likely within an erected structure; (xi) higher fire resistance; (xii) higher cyclonic wind resistance; (xiii) increased resistance to storm damage; (xiv) increased resistance to impact; (xv) high resistance to water penetration; (xvi) less maintenance requirements over the life of the structure; and (xvii) higher energy value. Finally it is to be understood that the aforegoing description refers merely to preferred embodiments of the present invention, and that variations and modifications are possible without departing from the spirit and scope of the invention, the ambit of which is to be determined from the following claims.

Claims: The claims defining the invention are as follows:- 1. A material for use in building, said material being in the form of a laminate and including: at least one layer of an insulating material; at least one layer of a damp-proofing material; and at least one layer of a re-inforcing material, preferably expanded metal. 2. The material as claimed in claim 1, further including: at least one structural membrane; at least one condensation control layer, preferably in the form of a membrane; and at least one layer of a cementitious material. 3. The material as claimed in claim 1 or claim 2, wherein said insulating material is polystyrene foam, fibreglass or any equivalent material. 4. The material as claimed in any one of claims 1 to 3, wherein said damp-proofing material is in the form of at least one layer of asphalt, pitch, a dense cement plaster or polyethylene sheet, or in the form of a membrane of neoprene or a bituminous material. 5. The material as claimed in any one of the preceding claims, where said cementitious material is ferro-cement, fibrecrete or the like. 6. The material as claimed in any one of the preceding claims, wherein said laminate is formed in panels of any desired shape and/or size. 7. A method for the construction of the external shell of a building or the like, said method including the steps of: ( i) forming a slab of concrete or the like material on-site whereby to afford a flat surface for construction of said building or the like; (ii) erecting a framework, of a predetermined size and configuration, on said slab, said framework forming the basic outline for said shell, said framework having associated therewith and attached thereto at least one layer of a high-tensile mesh fabric material; (iii) attaching laminated panels of said material as claimed in claim 1, to said erected framework; and (iv) applying a layer of cementitious material to said framework, said mesh of fabric material, in conjunction with said cementitious material, forming a ferro-cement/fibrecrete layer of said shell. 8. The method as claimed in claim 7 wherein said mesh fabric material has associated therewith and attached thereto one or more layers of fine mesh material, said fabric material and said fine mesh material serving as reinforcement means for said cementitious material. 9. The method as claimed in claim 7 or claim 8, wherein said framework is constructed of piping or tubing bent into shape whereby to form said basic outline for said shell, said tubing having affixed thereto, at right angles thereto, flat metal plate, rod or angle. 10. The method as claimed in any one of claims 7 to 9, wherein said mesh fabric is constructed of metallic material, glass, asbestos fibres, or any mixture thereof. 11. The method as claimed in any one of claims 7 to 10 wherein said slab, said framework and said cementitious layer include one or more block-outs for connection of and to services.

Inventors: OATEN TERRENCE ROBERT, OATEN, TERRENCE, ROBERT
Applicants: OATEN TERRENCE ROBERT, OATEN, TERRENCE, ROBERT
Application year: 1985
Main classification: E04C2
IPC codes: E04C2