EP0182567A2

EP0182567A2 - Wall cladding

Info

Publication number: EP0182567A2
Application number: EP85308183A
Authority: EP
Inventors: Keith Cooper
Original assignee: Plasmor Insulation Ltd
Current assignee: Plasmor Insulation Ltd
Priority date: 1984-11-10
Filing date: 1985-11-11
Publication date: 1986-05-28
Also published as: GB8428459D0; EP0182567A3

Abstract

A method of forming a cladding panel comprising laying down a flexible mould of polyurethane having a plurality of regularly arranged pockets, inserting into said pockets a plurality of slips or tiles, applying to said mould and said slips or tiles a layer of a fixative so as to bond said slips or tiles together, allowing said fixative to set, and removing the formed panel from said mould. A layer of insulant material may be applied to the fixative prior to the setting thereof.
In cladding a wall with a plurality of panels formed in accordance with the invention, the panels are secured to the wall by passing fixing means through the panels, and thereafter placing filler slips extending between adjacent panels so as to conceal said fixing means

Description

This invention relates to wall cladding and more particularly to a method of forming external wall cladding having in some instances thermal insulating properties.
Wall cladding, and particularly external wall cladding, has developed over the past years in order to provide a means of waterproofing, decorative and thermal upgrading of solid walls, particularly but not exclusively to solid walls of domestic dwellings. Originally developed outside the United Kingdom, such cladding took the form of rigid insulation boards which were coated with a render after the boards had been fitted to an existing wall or other surface.
Developments since the original insulating material have involved the use of various coatings, both thick and thin, with reinforcement armatures, so as to provide the insulation with a textured coating, somewhat resembling a Tyrolean or pebble dash render, although other forms of textured finishes have been utilised.
All of the above described forms of cladding require a manual application on site, and a high degree of skill is required in order to achieve an attractive and acceptable appearance. In addition, there is the problem of cracking which is associated with render finishes, such problem giving rise to potential difficulties due to water ingress through the cracks.
Continuing research has led to the development of the so called "ventilated facades", which involve the fitting of a series of treated timber batterns to the wall with insulation packed between. A pre-formed facade planking is then nailed, screwed or otherwise secured to the batterns to provide the finish surface and ventilation for the insulation material. Because these finishes are factory produced from rigid plastics material or metal sheeting, the final appearance is usually of a roller applied textured synthetic render, or a printed brickwork, the latter looking very artifical.
When forming an external wall cladding system, there are a number of factors to be taken into consideration and for which allowance has to be made. The major of these factors and allowances are waterproofing of the exterior surface, differential expansion of the various components, water vapour pressures through the composite structure, interstitial condensation, behaviour in fire, thermal insulation values, vandalism and impact resistance, ease of application, and the final appearance of the product.
The present invention therefore seeks to provide a cladding panel which will meet the above considerations, and which at the same time obviates the disadvantages of known forms of cladding panels.
According to the present invention, there is provided a method of producing a cladding panel comprising the steps of placing into a flexible mould coated with a release agent a plurality of slips or tiles and applying a fixative to said mould and slips or tiles so as to bond said slips or tiles together, allowing the fixative to set, and removing the finished panel from the mould.
The method may also include the steps of lightly vibrating the mould and slips or tiles after the application of the fixative, and the further step of applying an insulant to the fixative prior to the setting thereof.
The flexible mould will preferably be formed of polyurethane, and the slips or tiles will preferably be coated with an anti-moisture migration substance.
The fixative for bonding the slips or tiles together will preferably be a polymer modified glass reinforced cement mortar, and the insulant will preferably be an extruded polystyrene foam sheet, the surface of which is pre-treated to provide a key for the fixative.
In order that the invention may be more readily understood, embodiments thereof will now be described, by way of example, reference being made to the accompanying drawings, wherein:-

Figure 1 is an exploded isometric view of a panel formed in accordance with the method of the invention;
Figure 2 is a front elevation of the panel of Figure 1;
Figures 3 and 4 are sectional elevations on lines III - III and IV - IV respectively in Figure 2;
Figures 5 and 6 are sectional elevations on lines V - V and VI and VI respectively in Figure 2;
Figure 7 is an isometric view illustrating the assembly or installation of a plurality of the panels of Figure l;
Figure 8 is an exploded isometric view of a panel formed in accordance with an alternative method of the invention; and
Figure 9 is a sectional elevation of the panel of Figure 8.

Referring to the drawings, and firstly to Figure 1, the panel comprises a plurality of brick or other slips or tiles 2 set in a fixative layer 4 to which is affixed an insulant layer 6.
To form the composite panel illustrated in Figure 1, a flexible mould - having the reverse form of the fixative layer of Figure 1 - formed of polyurethane is laid down and coated with a release agent, whereafter brick slips or tiles are placed into the "pockets" of the mould, the brick slips having been pre-coated with an anti-moisture migration substance such as hydroxy propyl methyl cellulose.
The bricks slips or tiles are a reasonably tight fit in the pockets of the mould so as to prevent ingress into the pockets of the fixative material, and one of the planar surfaces of each slip or tile will lie in a higher horizontal plane than the upper surface of the pockets of the mould or alternatively such planar surfaces may be flush with or below said upper surface.
After placing of the slips or tiles, a fixative is then applied to the slips or tiles and the mould, the fixative being worked around and over the slips or tiles so that the fixative conforms to the shape of the slips or tiles and the mould. The fixative will preferably be a polymer modified glass reinforced cement mortar, although other materials such as polymer modified glass reinforced gypsum or a casting resin may be utilised.
In order to remove any air bubbles in the fixative, and to ensure that the fixative is in intimate contact with the slips or tiles and the mould, the whole is vibrated for a predetermined period of time.
The fixative is then allowed to set, whereafter the finished cladding panel may be removed from the mould by peeling back the mould to separate the panel and mould.
If the cladding panel is required to have insulating material thereon, a layer of insulant material in the form of an extruded polystyrene foam sheet - such as that indicated by reference numeral 6 - is applied to the fixative before the latter has set. The foam sheet, on at least that surface which is to be in contact with the fixative, may be pre-treated, as by planing, rilling or other means, so as to provide a key for the fixative. Thus the foam sheet becomes adhered to the slips or tiles through the intermediary of the fixative, and is removed therewith when the panel is stripped from the mould.
Referring now to Figures 2 to 6, it will be seen that the panel is resemblant to a wall in that the slips or tiles 2 are spaced both vertically and horizontally by the mortar joints 4A of the fixative layer 4 such that a regular pattern of the slips or tiles is established. It will be apparent from these figures that certain ones of the "pockets" of the mould did not have a slip or tile placed therein prior to the application of the fixative, such that "voids" in the fixative layer are produced. Such voids are referenced 4B in Figures 2 to 6, and as will be seen such "voids" are one-half the size of the remaining pockets, such that a full slip or tile may occupy two side-by-side communicating "voids" when a number of panels are located in fixing position as will be explained hereinafter.
It will also be seen that the insulant layer 6 is provided with grooves 6A and tongues 6B such that the insulant layers 6 may interlock when the panels are located in fixing position.
Referring now to Figure 7 which illustrates the principles in assembling and fixing a plurality of the panels previously described, three panels 10, 12, 14 each comprising slips or tiles 10A, 12A, 14A respectively, fixative layers 10B, 12B, 14B respectively, and insulant layers 10C, 12C, 14C respectively, are shown ready for movement into interengaging positions. In such positions, the voids 16 and 18 respectively of the panels 10 and 12 will be in end-to-end relationship, with the tongues 20, 22 of the insulant layers 10C and 12C in interengagement with respective grooves in the adjacent panels. Thus, the tongue 22 will engage in groove 24 in insulant layer 10C and in groove 26 in insulant layer 14C, whilst tongue 20 will engage the groove in the underside of insulant layer 14C. The discrete panels thus become fully interlocked.
It will be appreciated that the cladding is gradually built up on a wall to be clad, the cladding panels being secured to said wall by passing screws, nails or other fastening means (not shown) through the voids - such as 16 and 18 - and into said wall. When the panels have been so fixed, the composite voids formed by the end-to-end relationship of the voids 16 and 18 are filled by filler slips, such as that indicated by reference numeral 30, so as to conceal the fastening means. The filler slips will be secured in position by an adhesive or other contact fixative. The finished work thus has the appearance of a continuous cladding on the wall.
In some instances, for example for use as internal cladding, the insulant layer may be omitted from the panel, the resultant panel being secured as described. Referring now to Figures 8 and 9 which show a panel formed by an alternative method according to the invention, the panel is formed in a reverse manner to that previously described. Thus a layer 50 of insulant material such as expanded polystyrene foam having its front surface 50A rilled or grooved horizontally as indicated by reference numerals 52, and having its side edges tongued and grooved as shown at 54 and 56 respectively and its top and bottom edges tongued and grooved as shown by reference numerals 58 and 60 respectively, is laid horizontally and a layer or coating 62 of a fixative is applied thereto. The layer or coating 62 is a waterproof adhesive material such as latex modified cement mortar which permeates into the rills or grooves 52 in the layer 50 so as to become securely keyed thereto.
Prior to the setting of the mortar layer or coating 62, reinforcement 64 in the form of steel expanded metal mesh is applied to the layer or coating so as to become embedded therein, and such that the layer or coating exudes through the mesh and is exposed to the exterior thereof.
A plurality of brick or other slips or tiles - some are indicated by reference numeral 66 - are then applied to the layer or coating 62 such that they become embedded in the layer or coating but such that their outer surfaces 66A are above and not covered by said layer or coating. In this way the layer or coating 62 becomes the mould and the fixative.
Certain of the tiles - in much the same way as previously described - are omitted, to enable the finished panel to be secured in position on a wall (not shown) to be clad. After the layer or coating has set, the resultant panels may be fixed to the wall as previously described.
Instead of using the mesh reinforcement, inert fibres may be used as the reinforcement means.
In each of the described embodiments, the insulant layer has been stated as being expanded polystyrene foam, but it will be appreciated that the insulant layer may be of other form, the criterion being that it is required to be a closed cell structure not susceptible to interstitial condensation and water collection. Thus foamed silica glass and isocyanurate materails are also suitable as the insulant layer.
Because the cladding panel will be secured to the wall to be clad through the reinforcement and/or through the mortar layer, the outer surface layer of slips or tiles is effectively secured directly to the surface of the wall. Thus in the event of collapse or disappearance of the insulant for whatever reason, the outer surface layer would stay in tact and in situ.
All of the insulants referred to above provide very high insulation values; the material will insulate a 9- inch solid wall to a lower U-value than currently required by present building standards. Nevertheless, alterations in standards or customer preferences can be accommodated by varying the thickness of the insulant.
By the use of strong insulants and the inherent strength of the outer surface layer - the slips or tiles and the mortar - high impact resistance wil be achieved. Any localised damage can be easily and quickly repaired by removal and replacement of a single slip or tile or the requisite number of slips or tiles.
Individual panel replacement would also be possible by removing the filler slips and the underlying fastening means.
The final appearance of the cladding panel may be of brickwork, stonework, or any other modular traditional building material.
The invention thus provides an improved form of wall cladding, both internal with or without insulant and external with insulant, in that it is a dry fixed, factory produced panel with a traditional appearance and having its surface secured directly to the surface to be clad. Skilled labour is not required in the fixing of the panels. The relatively small size of the panel permits expansion between adjacent panels to be taken up, and contains any differential expansion between the various small limits.

Claims

1. A method of forming a cladding panel comprising the steps of placing into a flexible mould coated with a release agent a plurality of slips or tiles, applying a fixative to said mould and slips or tiles so as to bond said slips or tiles together, allowing the fixative to set, and removing the finished panel from the mould.

2. A method according to Claim 1, including the step of vibrating the mould and slips or tiles after the application of the fixative.

3. A method according to Claim 1 or Claim 2, including the step of applying an insulant to the fixative prior to the setting thereof.

4. A method according to any of Claims 1 to 3, wherein the slips or tiles are coated with an anti-moisture migration substance prior to insertion into the mould.

5. A method according to any of Claims 1 to 4, wherein said fixative is a polymer modified glass reinforced cement mortar, a polymer modified glass reinforced cement gypsum, or a casting resin.

6. A method according to any of Claims 2 to 5, wherein the insulant is a layer of extruded polystyrene foam.

7. A method of forming a cladding panel comprising the steps of applying to a layer of insulating material a layer of fixative, embedding reinforcing means in said layer of fixative such that the fixative overlies said reinforcing means, and applying to said fixative a plurality of slips or tiles such that the slips or tiles become embedded in but project from said fixative, and allowing the fixative to set.

8. A cladding panel formed in accordance with the method of any of Claims 1 to 6 or Claim 7.

9. A method of cladding a wall with a plurality of cladding panels in accordance with Claim 8, comprising securing the panels to the wall to be clad by passing fastening means through the layer of fixative and where present the layer of insulant, and thereafter applying filler slips to the panels so as to conceal said fastening means.