FIELD OF THE INVENTION

This invention relates to a thermally insulating building fagade that can be applied to existing self-supporting buildings for the purpose of enhancing the thermal insulation of the walls thereof; providing protection for the building against the weather and environment; as well as for providing an aesthetically pleasing appearance.

The thermally insulating building fagade may also provide additional features contributing towards a thermally efficient building after fitment to such a building.

BACKGROUND TO THE INVENTION

A large proportion of existing buildings do not comply with acceptable energy efficiency standards having regard to global warming and the so-called carbon footprint that each man-made facility creates. The position can be improved by retrofitting buildings with thermally insulating fagades whereby the carbon footprint can be significantly reduced and compliance with any local standards can often be achieved.

Existing systems of retrofitting buildings with thermally insulating fagades and cladding typically involve the creation of a ventilated external wall system to protect the load-bearing wall from moisture penetration. The ventilated fagade construction prevents condensate from accessing the load-bearing wall with the result that the growth of mould and fungus is obviated, at least to a considerable extent. Commonly, wall brackets or a timber frame are fastened to the outer surface of the load-bearing wall. In the case of brackets, the brackets pass through a discontinuous layer of insulating material that may be either mineral based or organic and, if it is flammable such as certain fibre based insulating materials, it has to be provided with appropriate fire retardants or other fire protection. The brackets extend through the layer of insulation and support at their outer ends a frame, typically a wooden or metal frame, that in turn supports a suitable outer cladding material. The ventilated air space is provided between the insulation and cladding and serves to avoid the build- up of condensation consequent on air becoming cooled down below the dew- point. As a general rule, the exterior cladding will always be either cooler or warmer than the air in the ventilated air space between the two layers.

The type of construction described above is obviously carried out primarily on-site and is extremely labour intensive and expensive.

Proposals have been made to produce prefabricated thermally insulating building fagades but, as far as applicant is aware, with limited success. One of the problems experienced with prefabricated building fagades is that the external surface of a building itself is somewhat irregular or crooked and it is difficult to accommodate irregularities efficiently and effectively whilst maintaining the required degree of thermal insulation, external appearance and the absence of any air gaps. Existing pre-manufactured fagades are generally based on a timber-frame structure made using nails and screws for the assembly and such fasteners are incompatible with the use of wood-working machines on an assembled fagade panel at least in regions that the wood-working machine may reach in carrying out its activities.

As a consequence, so-called standard cladding used for the exterior of a wall it is recommended be glued onto the insulation and only a support structure in the form of a frame provides the required product integrity. Accordingly, with present systems, the ventilated space in the fagade structure is generally required if cladding is used. Often the insulation is an "infill" and it cannot support the fagade. It is also not completely water and airtight and warm air can enter and cool down with the consequence that dew can form.

It is to be understood that in this specification the term monolithic is intended to include a monolithic block or panel that is either a continuous volume of the same material or is created by permanently securing together multiple prefabricated units, or by forming one or more units in situ, so that the resultant block or panel, whilst being discontinuous insofar as the material of which it is composed is concerned, is to all intents and purposes substantially continuous in structure throughout its volume in that it can be worked as a single block by a wood-working type of machine without damage to the machine or parts thereof.

In one variation a monolithic block or panel may have prefabricated on-edge strip panels arranged as a frame and to which thermal insulation material is permanently bonded at least at outer edges of the panel and around openings such as windows and doors. In this variation on the on-edge strip panels that define openings for windows and doors may be held in position whilst the panel is being manufactured by extended on edge strip panels secured to peripheral on-edge panels. In another variation, a monolithic panel may be made as a number of layers of prefabricated material permanently laminated and, where appropriate, cross-laminated together and at least some of the layers may be different from the others and contribute towards the rigidity of the composite monolithic block or panel.

Also, the term woodworking type of machine is intended to cover any machine capable of removing material from a surface of a monolithic block or panel in three dimensions irrespective of the fact that adjacent zones of the material may be of different materials bonded permanently to other zones of a different materials. Typically a woodworking type of machine would have cutters or abrasion based tools for removing material from the monolithic block or panel with the selection of cutters or abrasion based tools being dependent on the physical properties of the materials. Simply by way of example, a suitable woodworking type of machine that is an appropriate model made by HUNDEGGER MACHINENBAU GmbH of Germany and sold as their panel cutting machines.

SUMMARY OF THE INVENTION

In accordance with a first aspect of this invention there provided a method of manufacturing a prefabricated fagade that includes the steps of supplying data to a computer controlled wood-working type of machine wherein the data represents a digital three-dimensional replica of a surface of a wall of a building onto which a fagade is to be attached with the data encapsulating any unevenness and surface irregularities in the wall as well as the positions and sizes of any windows, doors or other apertures in the wall, wherein the wood-working type of machine has a reach commensurate with the dimensions of the fagade; causing the wood-working type of machine to shape an attachment surface of a generally rigid monolithic panel that includes thermal insulation material so that the attachment surface has a shape that is a reverse image of the corresponding surface of the building.

The method may include permanently bonding to an outer surface of the panel that is opposite the attachment surface, a cladding, such bonding being carried out either before or after machining of the attachment surface has been carried out. The attachment surface may have one or more ventilation channels formed therein as a part of the processing of the monolithic panel using the woodworking type of machine.

In a first variation of the invention a monolithic panel is constructed of a plurality of laminated layers of thermal insulation material permanently bonded together with selected layers contributing towards the rigidity of the composite monolithic panel. The rigid thermal insulation material is preferably of a closed cell type that is resistant to absorbing water. In a second variation of the invention the monolithic panel is a rigid body of foamed heat insulating material having edges formed by on-edge strips of suitable material that can be used as a mould or as a mould liner wherein a reaction mix is introduced into voids between the on-edge strips for forming rigid foamed heat insulating material that becomes permanently bonded to the strips. In the instance of foamed rigid heat insulating material, the cladding may be bonded to the heat insulating material during the foaming and moulding process or, alternatively, after formation and generally after processing the attachment surface and any obverse surface of the rigid heat insulating panel.

A further feature of the second aspect of the invention provides for the obverse (outer) surface of the rigid thermal insulation material opposite the attachment surface to be machined to provide parallel grooves therein for enabling air to flow and collect or deliver thermal energy as it flows in the grooves. The grooves are preferably orientated to be generally vertical in use and may be interconnected by transverse manifold grooves at upper and lower ends. The fagade panel may in that instance form part of a geothermal storage system. The outer cladding may include a layer of ultra-high performance concrete (UHPC) in which instance the panel may contribute significantly to the structural strength of the fagade.

The bonding of the plurality of layers or a layer of cladding may be conducted using a vacuum press process.

In accordance of a second aspect of the invention there is provided a prefabricated fagade manufactured by a method as defined above.

In accordance of a third aspect of the invention there is provided a method of attaching a prefabricated thermally insulating fagade to an existing building wherein the prefabricated thermally insulating fagade is made of a monolithic panel that has an attachment surface conforming to data representing a digital three-dimensional replica of the relevant area of an outside wall of a building onto which a fagade is to be attached such that the attachment surface encapsulates any unevenness and surface irregularities in the relevant area of the wall as well as the positions and sizes of any windows, doors or other apertures in the relevant area of the wall, the method comprising adhesively bonding the attachment surface to the corresponding area of the outside wall of the building such that the ingress of moisture between the corresponding surfaces of the wall and prefabricated fagade is substantially eliminated.

Further features of the third aspect of the invention provide for the method to include securing a plurality of supporting brackets to a wall of an existing building corresponding to that over which the fagade is to be attached so as to support a lower edge of the fagade during the adhesive attachment of the fagade to the wall; and for the securing of the fagade to the wall to include the use of fasteners extending through a fagade and into the wall.

It will be understood that the fagade provided by this invention has an outer surface formed by cladding that may already be provided with a finishing layer and, therefore, after installation on a building, no further processing is required on site. Indeed, the cladding could be of a permanent type that is unworkable by a woodworking type of machine and that may be in the form of thin tiles of naturally occurring stone (which term includes a wide range of marble materials) or the like, or of ceramic or glass materials or steel sheeting. Of course, it is within the scope of this invention that further finishing may take place on site but it is envisaged that such activity will be optional and the cost thereof may be avoidable. A currently preferred material for the cladding is a suitable ultra-high performance concrete (UHPC). It is envisaged that the size of a fagade panel can be up to about 3 metres and more in width (that generally corresponds to the height of a wall) which will be determined by the width capabilities of the relevant wood-working machinery. The length of the panels can be as long as may be required by virtue of the woodworking machine being of the travelling or gantry type, or the panel being fed through the machine in the direction of the length thereof. However, from a practical point of view, the length of the panels will generally be limited by standard road transport regulations that provide for maximum lengths of the order of 12 metres that do not require a special permit and the presence of special traffic police or other escort personnel.

In order that the invention may be more fully understood an expanded description thereof will now follow with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a schematic illustration of the recordal of data representing a three-dimensional replica of an outer surface of a building;

Figure 2 is a schematic front elevation of a front wall of a small dwelling;

Figure 3 schematic plan view of a structural wall showing e panel in exploded relationship relative to it; Figure 4 is a schematic edge-on view showing an assembly of smaller panels located next to each other to create a monolithic laminated panel for processing according to a first variation of the invention;

Figure 5 is a schematic elevation of a part of the monolithic panel illustrated in Figure 4 showing the offset of joints between coplanar panels in successive layers thereof; Figure 6 is schematic edge-on view similar to Figure 4 but showing a general arrangement of on-edge strips defining voids between them for moulding of a rigid heat insulating foam material in situ in the required voids according to a second variation of the invention;

Figure 7 illustrates the arrangement shown in Figure 6 in elevation;

Figure 8 illustrates schematically in section cladding panels attached to a fagade according to the invention wherein the cladding panels cannot be machined;

Figure 9 is a schematic section through a part of a fagade according to the invention in exploded relationship relative to its corresponding part of a building wall;

Figure 10 is the same as Figure 9 but showing the fagade secured to the corresponding part of a building wall and also with a cladding panel secured to its operatively outer surface;

Figure 1 1 is a schematic elevation of a fagade panel secured to a wall and having at its lower edge brackets that may support the fagade while the glue sets or cures; and, Figure 12 is a flow diagram illustrating one series of production procedures of a fagade according to the invention.

DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

In one implementation of the invention, a method of manufacturing a prefabricated fagade (1 ) comprises the steps of, in the first place, recording, using appropriate optical or laser equipment (2), data representing a digital three-dimensional replica of an outside wall (6) of a building onto which a fagade is to be attached. The data is recorded in sufficient detail to ensure that it encapsulates any unevenness and surface irregularities in the wall (6) as well as the positions and sizes of any windows, doors or other apertures in the wall. The resolution will generally be aimed at achieving an accuracy of approximately 1 millimetre or any other selected distance compatible with the water resistant adhesive securing of the formed attachment surface of the fagade to the cooperating surface of the load-bearing wall of a building.

The data can be recorded on any suitable recording medium (3) such as an optical disc, a memory stick, a fixed or removable hard disk or solid state drive, or, more commonly, the hard disk or solid state drive or other memory of a laptop or notebook type of computer. This step is indicated by numeral (21 ) in Figure 12 .

The data is recorded in, or is converted to, a suitable format for supply to a computer controlled wood-working machine that has a reach commensurate with the dimensions, typically the width, of the fagade that is to cover a wall or part thereof that is to receive it as indicated above.

In preparation for producing a fagade according to the invention, monolithic panels are created in the first instance. This may take place in numerous different ways, two variations of which are described below. In an embodiment of the first variation of the invention, and with reference to Figures 4 and 5 of the drawings, multiple prefabricated panels (4) of a suitably rigid grade of stone wool such as that sold under the trade name ROCKSHELL™ which is of a closed cell type that is resistant to absorbing water are assembled to form the monolithic panel of the fagade. The multiple panels are arranged in layers that are laminated and permanently bonded together with the lamination preferably in being a cross-lamination to form a monolithic body. The individual panels of such a material may for example be of a size measuring 1 m x 2m x 50mm with the layers being loaded into a vacuum press and arranged in successive layers such that joints between adjacent panels are out of alignment with joints between panels of each adjacent layer, as will be apparent from a reference to Figure 5 in which the obscured joints of an immediately adjacent layer are shown in dotted lines. As shown in Figure 4, one or more central layers (5) may be made of a material such as a suitable grade of plywood the intention of which is to impart suitable rigidity to the composite monolithic panel.

After completion of layering that can conveniently take place in a vacuum press, the vacuum press may be activated. The press may generate a maximum pressure of just below 1 bar (10 tons/m ² ). The assembly step is indicated by numeral (22) in Figure 12 whilst the vacuum pressing is step is indicated by numeral (23). The product is a monolithic panel as envisaged by this invention.

The heat insulating material may also or alternatively include cellular glass insulation such as that sold under the trade name FOAMGLAS ^® by Pittsburgh Corning Corporation of the USA or a suitable foamed concrete. Turning now to the second variation of the invention, and with initial reference to Figures 6 and 7 of the drawings, the monolithic panel may be in the form of a rigid body of foamed heat insulating material (1 1 ) such as a suitable grade of foamed polyurethane or polystyrene material, having edges to the panels and apertures through them formed by on-edge strips (12) of suitable material that can be used as a mould or as a mould liner and to which the rigid foamed heat insulating material becomes permanently bonded as it cures.

The on-edge strips can be used with a jig as a mould, or as a mould liner, and are selected to ensure permanent bonding to the rigid foamed heat insulating material as it cures. The strips may for example be of a suitable cement board, ultra-high performance concrete (UHPC), or engineered wood having a width corresponding to the desired thickness of the completed fagade, typically of the order of 200 mm in the instance of a normal domestic dwelling, but that will generally be dictated by the purpose and function of the building concerned.

The assembly of strips will generally include strips (13a, 13b) that form apertures for windows and doors or other required apertures through the fagade. Preferably, strips defining the sides of any window and door apertures may have the side strips (13a) extending up the full height of the fagade with transverse strips (13b) being located to define the top and bottom of each aperture.

As the frame members need to be machined by the woodworking type of machine in unison with the rigid foam that fills the voids between them, the strips need to be of a material that can be machined by appropriate cutters or abrasion based working tools of a woodworking type of machine.

The strips may be held relative to each other by a suitable bonding agent if not by a mould or jig itself. The foaming mixture is added to the voids that are to be filled in order to provide the composite monolithic panel that can then be machined as provided by the invention. It will be understood that the fagade provided by this invention has an outer surface that is preferably provided with a finishing layer such as cladding (14) or synthetic resin plaster that is or has a finishing layer such that at the time of installation on a building no further processing is required on site. In instances in which the panel itself is made of stone wool, the cladding could be of a similar nature only more dense such as that sold under the trade name Rockpanel™. Of course, as may be required, it is within the scope of this invention that additional finishing may take place but it is envisaged that such activity will be optional. As indicated above, the cladding could be of a type that cannot be machined easily such as cladding of tiles of natural stone or ceramic or glass material or steel sheeting.

A preferred cladding at the time of filing this patent application is one of ultrahigh performance concrete (UHPC) that can be used to contribute significantly or substantially towards the rigidity and robustness of the fagade.

In either event, the invention is implemented by causing the computer controlled wood-working machine to shape an attachment surface (15) of the monolithic panel of rigid thermal insulation material so that the attachment surface has a shape that is a reverse image of the corresponding surface of the building. This step is indicated by numeral (24) in Figure 12.

The cladding (14) may be permanently bonded to the panel in a step that is indicated by numeral (25) in Figure 12 and the bonding can conveniently be carried out in a vacuum press as indicated by numeral (26). In instances in which the cladding needs to be machined, the fagade with the cladding attached can be machined as indicated by numeral (27) in Figure 12.

In instances in which the cladding is of a naturally occurring stone or ceramic or glass material or steel sheeting that cannot be worked by the woodworking machine, the individual tiles (17) may be spaced slightly as shown in Figure 8. In such an instance, it may be appropriate to form shallow grooves (18) in the outer surface of the fagade to correspond to a space between two edges of the cladding tiles.

The formed fagade is then ready for transport and delivery to the building where it is to be installed and where the method of attaching it to an existing building can be carried out. The prefabricated thermally insulating fagade thus has its attachment surface adhesively bonded to the corresponding relevant area of the outside load-bearing wall (6) of the building such that the ingress of moisture between the corresponding surfaces of the wall (6) and prefabricated fagade is substantially eliminated.

The pre-manufactured fagade elements may be fixed to the existing structure, without the need to adjust the elements on site. The system does not necessarily need any further on-site finishing.

In order to enhance the utility of the fagade that is to be installed on a wall facing in the general direction of the sun (generally south in the northern hemisphere and north in the southern hemisphere) it may, as illustrated in Figures 9 to 1 1 , be provided with multiple parallel straight channels (19) of rectangular shape in cross-section into the obverse operatively outer face of the rigid insulation before the cladding is attached to it. The result is shown in Figures 9 and 1 1 . Thereafter, the cladding (14) can be secured to the obverse face of the fagade. In this embodiment of the invention the cladding is preferably an ultra-high performance concrete (UHPC) that can contribute significantly to the strength and rigidity of the fagade but many other materials may be used.

It is within the scope of this invention that a special heat conductive layer in the form of a suitable thickness aluminium sheet could be secured and sealed to the obverse (outer) face of the fagade so as to cover it as well as the channels and provide flow passages formed between the channels in the operatively outer face and the heat conductive layer. An external surface of the heat conductive layer may have a suitable surface finish for promoting heat transfer into an outer surface of the heat conductive layer and the inner surface may be treated to promote the conducting of heat away from the inner surface, typically by contact with air passing through the channels. Heat transfer can be enhanced by making the channels follow a sinuous or zigzag path.

The upper ends and the lower ends of the flow channels each communicate with a transverse manifold channel (20) that in turn communicates with a suitable inlet or outlet in one or other form and possibly communicating directly with a transverse manifold channel of an adjacent solar energy collecting fagade panel such that a heat collecting fluid that will typically be air can pass through the channels in use between the inlet and outlet. The entire exposed surface of the fagade may be coated with a waterproof layer prior to its attachment to a wall (6) to thereby prevent the ingress of moisture. The waterproof layer may be spray coated onto the outer fagade surface. The entire fagade is glued to its corresponding wall surface by spraying the relevant surface of the wall (6) or the fagade (1 ) or both with a suitable adhesive and then engaging the two with each other. A layer of glue is shown in Figure 10 and indicated by numeral (31 ). In order to assist in this matter and also to ensure that the fagade does not move when the glue is setting or curing a row of brackets (32) (see Figure 1 1 ) can be secured to the wall (6) to correspond with the position of the lower edge of the fagade so that its weight can be supported on the brackets during this procedure. In addition to this, fasteners can be passed through the fagade and into the wall (6) in selected positions, as may be dictated by circumstances. The result is that the fagade is firmly attached to the wall and no space is left for any moist air to enter and cause the deleterious effects mentioned above. The need for a ventilated fagade system is thus eliminated as the cladding is air and water tight.

A monolithic manufactured fagade as described makes it possible to utilize a fully computerized production process with minimal manual input. The fagade may be made of a size of say 3 000mm x 10 000mm to 12,000 that can be cut, shaped, routed and laminated exactly according to the 3D laser survey and up to an accuracy of about 1 mm and possibly less according to technological developments. Irregularities of up to 30 mm or more on either side of a perpendicular can be readily accommodated.

It is to be noted that the cost of the fagade is substantially reduced in consequence of the fact that the manufacturing process is considerably streamlined and the refurbishment period of a building is vastly improved in that the use of the building is not interrupted by the renovation.

The weight of the fagade as compared to the nearest competitive prefabricated fagade known to applicant may be substantially reduced to between 30 to 40kg/m ² as opposed to about 100 to 150kg/m ² . This also simplifies the fixing of the fagade to its existing structure. All manufacturing processes are done in a controlled environment.

Of course, the outer surface of the fagade can be machined to provide any aesthetic appearance or, indeed, a practical shape such as a converging tapered shape where the outer surface of the fagade panel approaches a window or door so that an enhanced appearance and practical visibility of the windows and door may result. Of course, in the instance of a window, enhanced light is made available to the window. It should also be noted that parts of the panels that are cut out of any monolithic panel in order to form openings can be sliced and re-used by including them in future panel blocks without loss of quality. Numerous variations may be made to the examples of the invention described above without departing from the scope thereof.