GB2473670A

GB2473670A - Insulation panel coated with filled acrylic resin

Info

Publication number: GB2473670A
Application number: GB0916609A
Authority: GB
Inventors: Howard Morris
Original assignee: TRADE FABRICATION SYSTEMS Ltd
Current assignee: TRADE FABRICATION SYSTEMS Ltd
Priority date: 2009-09-22
Filing date: 2009-09-22
Publication date: 2011-03-23
Also published as: GB0916609D0

Abstract

A protective coating comprising acrylic binder and particulate filler is sprayed onto the panel while it is conveyed 10, 15, 18 through a spray booth 11. The reciprocating automated spraying device 20 moves in a direction transverse (perpendicular) to that of the panel. The sprayed insulating panel is subsequently passed through a drying oven 12 and cooling chamber 13. Preferably the drying oven is heated using an infrared emitter operating at a specific power density. The sprayer is preferably supported by a carriage (22, figure 3) movable along a track 23; the nozzles (29, figure 6) being supplied from a reservoir (25, figures 3and6) via a peristaltic pump (26, figures 3and6) and tubing (27, figures 3and6), and pressurised gas source (34, figure 6). Preferably the process is repeated with the movement of the spray guns (21, figures 3and6) being synchronised with that of the conveyor 10, 15, 18. The coated insulating (foam or inorganic fibre) panel is fixed to a building. It is preferably used with an adhesively backed, continuous polypropylene reinforcing mesh and finishing coat. The panels provide thermal insulation.

Description

A METHOD FOR MANUFACTURJNG AND INSTALLING A PRE-COATED

BUILDING INSULATION PANEL

The present invention relates to a method for manufacturing and installing a coated building insulation panel. It also relates to a building insulation panel coated by using such a method.

Insulation panels such as those comprising rock fibre, glass fibre, expanded polystyrene (EPS) foam, extruded polystyrene (XPS) foam, polyurethane (PU) foam or Phenolic foam are used widely within the building industry to cover the exterior surfaces of buildings. Raw panels mounted on a building function less efficiently, and may become detached from the building, if they are exposed to weather and so need to be coated with a weather proofing material once they have been installed on the building. In particular, the finished coating must cover any breaks in the exterior surface formed by the mounted panels, including those at joins between adjacent panels. Thus, coating is performed after the panels have been mounted onto the building. The process of coating the panels includes applying a single-coat primer coating layer, applying a reinforcing mesh while the primer coating layer is wet so as to at least partially embed the mesh in the primer coating layer, and applying one or more finish coating layers over the mesh.

It is advantageous, e.g. in terms of efficiency of materials and reliability of performance, that the various layers in the coating are of a substantially uniform consistency and thickness across each panel and across a plurality of panels covering a building. In some cases, uneven application of one or more of the coating layers results in an unsightly finish to the building andlor structural problems in the finished product. For example, a poorly applied primer coating layer may result in a gradual detachment of the supporting mesh from that layer and eventually a total failure of the system. A problem in the industry is therefore how to apply this kind of coating to the insulation panels in a more uniform thickness and consistency.

It is an object of the present invention to obviate or mitigate at least one of the problems outlined above.

According to a first aspect of the present invention there is provided a method for manufacturing a coated insulation panel by applying a protective coating comprising acrylic binders and particulate fillers, the method comprising conveying the insulation panel through a spraying booth in a first direction, reciprocating automated spraying apparatus in said spraying booth in a second direction transverse to the first direction so as to apply the coating to a surface of the panel, conveying the coated panel through a drying oven, and then conveying the dried panel through a cooling chamber.

Coating an insulation panel in accordance with the first aspect of the present invention is advantageous in that the panel is at least partially weather protected before it is conveyed to and installed on a building. This makes the installation process easier and more efficient since poor weather during installation is less likely to damage the insulation panels. Excessive moisture ingress into the panels results in a drop in thermal resistance properties, which are particularly critical where mineral fibre insulants are utilised. A further advantage is that coating a panel by conveying the panel past automated spraying apparatus is more likely to produce a uniformly coated panel than coating the panel in situ after installation on a building structure.

It will be appreciated that the thickness of the coating applied to the panel is dependent upon the volume of protective coating material sprayed by the spraying apparatus, the speed of the panels through the spraying booth and the type of primer coating material used. The thickness of a single coat of primer coating may be from 0.5mm up to 2.5mm, more preferably 1mm to 2mm. The final thickness of the protective coating is preferably of a uniform thickness of at least 2mm, more preferably from about 2mm up to about 5mm, and most preferably about 5mm. The panel may be conveyed through the spraying booth more than once so as to apply protective coating to the panel at the desired thickness. This is a substantial departure from existing primer coating techniques, in which a single thick coat of protective primer coating is applied to the panel after the panel has been installed on a building structure. It will be apparent that the uniformity of thickness and consistency of the primer coating is substantially improved when the primer coating is applied in multiple coats.

The panel may be dried in the drying oven by at least one infra-red emitter.

The infra-red emitter may be operated at a power density in the range 30 to 5OkW/m2.

The infra-red emitter may emit heat with a power density of substantially 40kW/rn2.

The panel may pass through the drying oven within 25 to 30 seconds. When the panel is to be coated more than once, it may be desirable to dry the panel in the drying oven between each successive coating of the panel, thus helping to ensure that the total coating which is applied to the panel is of a substantially predictable thickness. The repeated dryings in the drying oven may be performed so as to leave the coating on the panels tacky. The final drying step of all of the repeated drying steps may then be performed so as to cure the panels P. The panel may be cooled in the cooling chamber by air being directed towards it as it is conveyed through the chamber. The panel may pass through the cooling chamber within 25 to 30 seconds. When the panel is to be coated more than once and dried between successive coats in the drying oven, it may be desirable to cool the panel in the cooling chamber after each heating in the drying oven. This helps to ensure that the panel is of a substantially uniform temperature.

The spraying apparatus may be supported on an overhead carriage movable along a track. The track may extend in a direction that is substantially perpendicular to the direction of movement of the panel through the spraying booth. The coating may be supplied to the spraying apparatus by means of a peristaltic pump.

Edges of the panel may first be coated with the coating, preferably in a thin layer, before it is conveyed throughthe spraying booth. Edges of the panel created by cutting the panel to fit around building features may be painted with the coating on site during installation.

The spraying apparatus may be provided by connecting an inlet of a spraying gun to a source of the protective coating via a pump and connecting the gun to a source of source of pressurized gas so that the coating is delivered in a spray out of a nozzle of the gun.

According to a second aspect of the present invention there is provided a method of insulating a building structure comprising mounting at least one coated insulation panel on the building structure, the panel having been coated using a method according the first aspect of the present invention.

The mounting step may comprise inserting a fixing through the coated panel and into the building structure, said fixing comprising an anchor portion for anchoring to the building structure and a flattened portion on the opposite side of the panel from the anchor portion for holding the coated panel against the building.

The method may further comprise applying a reinforcing mesh over the pre-coated panel after it is mounted on the building structure. More than one panel may be mounted on the building structure, and the mesh may be applied in a continuous layer over all of said panels. The mesh may comprise polypropylene, glass fibre or nylon. The mesh may have an adhesive backing for adhering to the at least one coated panel, The method may further comprise applying a finishing coat of protective material over the pre-coated panel.

A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a diagrammatic front view of a production line for the application of a coating to a coated insulation panel in accordance with an aspect of the present invention; Figure 2 is a diagranm'iatic plan view of the production line of figure 1; Figure 3 is a diagrammatic end view of a spray booth of the production line of figure 1; Figure 4 is an end view of an infra-red oven and conveyor of the production line of figure 1; Figure 5 is an end view of cooling apparatus of the production line of figure 1; Figure 6 is a schematic representation of the spraying gun and pump of the spray booth of figure 2; Figure 7 is a front view of a building wall insulated using panels coated in accordance with an aspect of the present invention; Figure 8 is a picture of water-resistant beading which may be used in conjunction with panels coated in accordance with the present invention to prevent ingress of moisture andlor debris between gaps or joints in the panels; and Figure 9 is a side section of a fully completed building wall insulated using insulating panels coated in accordance with an aspect of the invention.

In general terms the first aspect of the present invention relates to coating an insulation board with a primer coating to provide a primer-coated insulation board which is then installed on a building structure, by a process according to the second aspect of the present invention, so as to insulate the building structure.

Referring now to figures 1 to 5, a production line for coating an insulation panel with a protective, weather-resistant primer coating comprises, in sequence, an in-feed conveyor 10, a spraying booth 11, a drying oven 12, a cooling chamber 13, a gantry 14, an out-feed conveyor 15 and an off-load station 16.

The insulation panel (indicated by the reference P where shown in the figures) may be of a semi-rigid type and may be manufactured from any suitable insulating material such as rock fibre, glass fibre, EPS foam, XPS foam, PU foam or Phenolic foam. It has two opposed major surfaces and four side edges.

The coating (indicated by reference C in figure 9) is an acrylic-based coating comprising pure acrylic binders, crushed and precisely graded mineral fillers such as calcium carbonate and/or dolomite or silica sand, additives, such as a plasticizer, that afford the paint elastomeric properties and durability, and solvent. The coating has a solids content in the range 67 to 75% by volume depending on the application. The coating may have a range of different texture grades and colours. Coalescent solvents are removed to provide for a coating that has a low volatile organic component rating.

An example of such a coating is a modified form of the TERRACOAT (trade mark) product sold by the Terraco Group of Sweden.

Before the insulation panel is supplied to the production line it is cleaned with brushes and dust-extraction equipment to remove all dust particles, salts, oils, grease etc so as to ensure the paint will bond to the surface of the panel. In some cases, insulation panels may have a cotton mesh finish to which the paint may be applied The edges of the panel may then be coated with the paint by means of manual application with brushes or with spray guns.

The panels are then stacked in a storage area 17 adjacent to the in-feed conveyor 10 and are manually loaded singly on to the in-feed conveyor in the direction of arrow A. The in-feed conveyor 10 delivers the panels to a conveyor belt 18 in the spraying booth 11.

The spray booth 11 comprises an enclosure 1 la through which the panels pass on the conveyor belt 18 under an automated spraying device 20 by which it is spray painted with the coating. The automated spraying device 20 comprises a pair of spray guns 21 (figures 3 and 6) supported over the conveyor belt 18 in a carriage 22. The carriage 22 is driven along an overhead track 23 by a transport mechanism 24 such that it reciprocates back and forth in a direction (see arrows B in figures 2 and 3) transverse to the direction of movement of the conveyor 18. The spraying device 22 is depicted in figure 3 in two locations at the ends of its length of travel in each direction. The speed of reciprocation of the carriage 22 is synchronised carefully with the speed of the conveyor 18 so as to ensure a uniform application of the coating to the panel surface. There is, in fact, a gap 1 8a between two parts of the conveyor over which the spraying device is disposed so as to restrict the amount of coating hitting the surface of the conveyer, the gap 1 8a being narrower than the length of the panel in the direction of travel.

The spray guns 21 are supplied with the coating paint from a reservoir or bulk container 25 via a peristaltic pump 26 and tubing 27 to a common manifold (not shown) from where the paint proceeds to a nozzle 29 of each gun 21. The nozzles are disposed at a height of approximately 30 cm above the surface of the panel.

A spray gun 21 is shown in more detail in figure 6 in the context of the bulk container 25 via the pump 26 and tubing 27. The gun 21 has an inlet end 30, an outlet tube 31 adjacent to the nozzle 29 and an intermediate ball valve 32 that is manually operable to open and close the valve by means of a handle 33. Air is supplied to the nozzle 29 in order that the coating leaves the nozzle in a spray. It is supplied under pressure from a source 34 of compressed air via a conduit 35 to a side port 36 immediately preceding the nozzle 29. The conduit 35 is closable by means of a manually operable ball valve 37.

From the spraying booth 11 the coated panel passes on the conveyor 18 to a drying oven 12 where the panel P is continuously transported under an array of medium wave infra-red emitters 30. The conveyor 18 is disposed relative to the oven 12 such that the panels pass under the emitters 30 at a distance of around 100mm. The emitters 30 are designed to provide an output in the range 0 to 63 kW/m2. In tests it was established that a preferred range was 30-50 kW/m2 and more preferably 40kW/rn2. The rate of progress of the conveyor 18 is such that the panels are cured by the emitters for a period of around 25 to 30 seconds.

The cured panels P are then transported by the conveyor 18 through a cooling chamber 13 so as to cool both the coating and the panels P and to accelerate the hardening of the coating. This reduces the risk of damage to the coating by way of flattening or indentation and also reduces the tendency of the coating to adhere to the surface of an adjacent panel when stored after removal from the production line. As each panel is continuously conveyed through the chamber air at ambient temperature is blown through ducts 31 such that it egresses on to the upper surface of the panel P. The temperature of the surface coating is thus cooled from around 90°C to approximately 40°C. The panels are resident in the cooling chamber for around 25 to seconds. At the exit of the cooling chamber the panels are conveyed to a gantry 14 before passing to the out-feed conveyor 15 that transports the coated panels to the off-load station 16 where the panels P are removed from the production line and stacked on to pallets for storage and/or transportation.

In some embodiments, the desired thickness of the primer coat C on the panels P is thicker than it is desirable to apply in a single pass through the production line. In this case, rather that transporting the panels P from the off-load station 16 to a storage/transport location, the panels P are simply transported back to the in-feed conveyor 10 for a second pass through the production line. It will be appreciated that the panels P may be passed through the production line and recoated with the primer coating C as many times as needed in order to achieve the desired thickness of primer coating C. In some embodiments, it is desirable to enhance the bond between the successive layers or coatings of primer coating C on a panel P by reducing the drying effect of the drying oven 12 either by passing the panels P through the oven 12 more quickly or by reducing the output of the infer-red emitters 30, or by allowing the panels P to air dry, so that the panels P are tacky during application of the subsequent coating of primer coating C. It will be apparent that this arrangement of the spray guns 21 and the controlled environment in which the spray guns 21 are used applies a more uniform coating to the boards than would be possible were the coating C applied on a building site after the panel has been mounted onto the wall of a building. The drying and curing process would also be extremely difficult to implement on site, and contributes to a more uniform and reliable coating on the insulation panels P. A process for installing the primed panels P, produced in the manner described above, on a building is now described with reference to figures 7 to 9.

Figure 7 shows a plurality of coated and cured panels P installed, in a brickwork pattern, on the side wall 38 of a building around a window 39 in the building. Coated panels P adjacent to the window 39 are cut to fit where necessary.

Panels P adjacent an edge formed by the building wall 38 and an adjoining insulation-covered wall (not shown) are mitred together with panels P covering the adjoining wall. Any exposed edges of panels P surrounding the window or at an edge of the building wall 38 are covered using a durable, water-resistant beading 40 so as to prevent damage to the panels P. Such beading and its application to building insulation panels is known in the building industry.

Figure 8 shows an example of beading 40 installed onto a pair of insulation panels P mitred together over the edge of a building wall. The beading 40 comprises an elongate edge portion 40a which, when installed, lies along the outward edge of the mitre joint between the two panels P. Planar mounting portions 40b extend alongside and are joined to either side of the edge portion 40a such that the mounting portions 40b are substantially perpendicular to one another. When installed, the mounting portions 40b lie against portions of the panels P adjacent to the exterior edge of the building structure. As shown in figure 8, the beading 40 in this embodiment is mounted onto the building structure by driving standard mounting fixings 40c through the mounting portions 40B and into the panels P at regular intervals. It will of course be appreciated that the beading 40 may be affixed to the panels P by any desirable method.

Thus, as shown in figure 9, each coated panel P is fixed to the wall 38 via masonry fixings 41, as shown in detail in figure 9. First, bonding mortar 42 is applied to the wall 38 and the insulation panel P applied onto the bonding mortar 42 so as to mount the panel P on the wall 38. Masonry fixings 41, each comprising a wall plug 43 and an anchoring pin 44, are then inserted into the wall 38 through the panel P at regularly spaced intervals such that there are roughly 4 or 5 fixings 41 for each square metre of insulation panel. It will be appreciated that the regularity of the fixings is dictated by the weight and rigidity of the panels P, and the structure of the wall on which the panels P are being mounted.

In order to insert each fixing 41, a hole is drilled through the panel P, including the primer-coating C, and into the wall 38. The plastics wall plug 43 comprises a tubular shaft 45 formed in one piece at one end with an annular disc 46 of larger diameter. The wall plug 43 is inserted into the hole, through the panel P and into the wall 38 until the annular disc 46 sits against the panel P. The anchoring pin 44 is then inserted through the centre of the annular disc 46, into the tubular shaft 45, and is hammered home so as to force a portion of the tubular shaft 45 outwardly against the sides of the hole and anchor the fixing 41 in the hole. The fixing 41 maintains the panel P against the wall 38 via pressure on the panel P from the annular disc 46.

The process for fixing the coated panels P to the wall 38 is identical to that for fixing standard uncoated panels to a wall. It is generally considered necessary to apply a primer coat to the uncoated panels over the fixings when the panels have been mounted so as to externally seal the holes in the panels. However, it has been determined by the inventors that a sufficient seal of the hole is achieved simply by the engagement of the annular disc 46 with the primer coating C on the primed panels P. Thus, the panels P are sufficiently sealed without the need to apply a further primer coating after the panel P has been affixed to the wall 38 of the building.

A significant advantage of pre-priming the panels P is that when the panels P are transported to the building and as they are being affixed to the wall 38, the primer coating C is sufficient to protect the panels P from the weather in the short term.

Thus, in contrast with the traditional method of installation, a change in the weather whilst the coated panels P are being installed is less likely to result in damage to the coated panels P. It is most preferred in this embodiment that the coated panels P are delivered for installation having been coated with a 5mm thickness of primer coating C, applied in 1mm layers by repeatedly spraying the board as described above. It will be appreciated, however, that the panels P can be coated with a reduced thickness of primer coating C, and that once installed the panels P can be coated with an extra layer of primer coating if necessary. Although this is likely to result in a less uniform finish than if the panels P are pre-coated to a 5mm thickness, the uniformity should still be increased over the application of the entire primer coat on site, and the panels P still benefit from the weather-proofing protection offered by the reduced thickness primer coating during installation.

During installation of the panels P, it is possible that stresses and impacts from the construction environment will cause damage to the panels P. The likelihood of this is, of course, reduced by the primer coating C which adds toughness to the surface of the, often relatively soft, materials of which insulation panels P are commonly comprised. Should any panel be sufficiently damaged that the panel splits, the split portion should be cut back to provide straight edges against which a replacement piece of panel may be placed. Should a small area of the insulation panel lose some or all of its primer coating C as the result of a knock or scrape, or as a result of being cut to fit around a building feature such as a window, that small area or end portion of the panel can be repaired by local application of primer coating (preferably of the same composition as primer coating C) on site so as to seal that portion of the panel P. Once all of the panels P have been fixed to the exterior of the building, a polypropylene reinforcement mesh 47 is applied to the exterior surface of the building formed by the panels P before the beading 40 is applied to the exposed edges of the panels P as described above. The mesh 47 is applied to the surface in a continuous sheet, which has a width of 600mm. Each successive wrapping of the mesh 47 around the exterior surface of the building preferably overlaps the previous wrapping by at least 100mm. In contrast to the standard installation procedure for insulation panels, the polypropylene mesh 47 is not embedded into the primer coating C because the coating C was applied to the panels P by machine in a production line, as described above with reference to figures 1 to 6, and is therefore already dry. Rather, an adhesive is used to bond the mesh to the panels P. The adhesive is preferably provided together with the mesh 47 in the form of a self-adhesive backing.

Using an adhesive mesh 47 rather than a mesh which is embedded in a primer coating is advantageous in that the primer coating C is not solely relied upon to hold the mesh onto the panel P. Bearing in mind that application of primer coating on site can result in uneven application of the primer to the panel P, it will be appreciated that if sufficiently little primer is applied to an area of a panel P then the mesh will not adhere properly to the primer and thus to the panel P. Moreover, if there are delays in installation of the mesh then the primer may dry before the mesh is applied to it.

These irregularities are likely to result in unreliable support for the render in the finished building, and may lead to the need for regular and expensive repairs to the building. In contrast, where a pre-primed board is used and an adhesive backed mesh is applied on top, the primer coating C thickness is substantially more uniform and the surface of the pre-primed panel P is smoother, and the adhesive mesh 47, using adhesive rather than relying on the consistency and thickness of primer coating on the panel P, reliably sticks to the dry primer coating C on the panel P. When the mesh has been applied to the building, a finishing render 48 is applied to the mesh. The finishing render may comprise the same material as the primer coating C which was applied to the panel P on the production line. The purpose of the finishing render 48 is to make good and conceal the mesh 47, protecting it from the elements, and also to provide a decorative finish to the building.

In some cases the finish render 48 is applied in more than one coat, and in any case at least one the coat may comprise particulate material so as to add strength to the finishing render. It will be appreciated that, although the finishing render must be applied to the panels P after they have been mounted onto the wall 38, the task of applying the render is substantially easier, and the result more reliable, in view of the more uniform and reliable surface created by the automatically applied primer coating C on the pre-primed panels P, the uniformity and reliability being further improved by the self-adhesive mesh 47.

It will be appreciated that the above embodiment is exemplary in nature and that many of the specific elements may readily be modified or removed entirely. For example, in some embodiments no further addition is required to the panels P once mounted and they may form part of the exterior of a wall in a building structure. In some embodiments no mesh is required and a finishing coat may be directly applied to the panels P. In yet further embodiments, the mesh and finishing render may be replaced entirely by some form of external cladding.

The panels need not be fixed to walls using masonry fixings and may be fixed by other means, such as brackets or adhesive bonding. The panels are not limited to use in walls but may form an external part of a roof structure.

The operation of the various components of the production line is controlled by a PLC or similar.

The production line is operable to process panels at a speed of greater than 120 panels per hour.

The coating is such that it can be touched up easily by manual application at any stage, if damaged.

It will be understood that the process can be applied to panels of any size.

The coating has high bond strength and provides a durable surface layer for protection against the weather including upper and lower extremes of climactic temperature. The elastomeric nature of the coating enables it to cover defects and minor cracks.

The coating can be made available in different textures (using different filler grades, additives andlor nip coating rollers between the spraying booth and the dying oven) and different colours (by adding pigments) for decorative application.

The coating is post preferably an acrylic-based coating, but may be a silicone-based coating or a polymer-modified cement coating. It will be appreciated that the thicknesses of coating may change depending on the application and on the type of coating. It will be appreciated that the finishing render may be acrylic-based, silicone-based or a polymer-modified cement.

It will be appreciated that numerous modifications to the above described design may be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A method of manufacturing a coated insulation panel by applying a protective coating comprising acrylic binders and particulate fillers, the method comprising conveying the insulation panel through a spraying booth in a first direction, reciprocating automated spraying apparatus in said spraying booth in a second direction transverse to the first direction so as to apply the coating to a surface of the panel, conveying the coated panel through a drying oven, and then conveying the dried panel through a cooling chamber.
2. A method according to claim 1 wherein the steps of conveying the insulation panel through the spraying booth and reciprocating the automated spraying apparatus are repeated at least once.
3. A method according to claim 2 wherein the step of conveying the panel through the drying oven is repeated with the other repeated steps.
4. A method according to claim 3 wherein the step of conveying the panel through a cooling chamber is repeated with the other repeated steps.
5. A method according to any of claims 2 to 4 where in the number of times the repeated steps are repeated is sufficient to coat the insulation panel to a thickness of from 2mm up to 5mm.
6. A method according to claim 5 wherein the panel is coated to a thickness of substantially 5mm.
7. A method according to any preceding claim, wherein the panel is dried in the drying oven by at least one infra-red emitter.
8. A method according to claim 7, wherein the infra-red emitter is operated at a power density in the range 30 to 50kW/rn2.
9. A method according to claim 8, wherein the infra-red emitter emits heat with a power density of substantially 40kW/rn2.
10. A method according to any preceding claim, wherein the panel passes through the drying oven within 25 to 30 seconds.
11. A method according to any preceding claim, wherein the panel is cooled in the cooling chamber by air being directed towards it as it is conveyed through the chamber.
12. A method according to any preceding claim, wherein the panel passes through the cooling chamber within 25 to 30 seconds.
13. A method according to any preceding claim, wherein the spraying apparatus is supported on an overhead carriage movable along a track.
14. A method according to claim 13, wherein the track extends in a direction that is substantially perpendicular to the direction of movement of the panel through the spraying booth.
15. A method according to any preceding claim wherein the coating is supplied to the spraying apparatus by means of a peristaltic pump.
16. A method according to any preceding claim, wherein edges of the panel are first painted with the coating before it is conveyed through the spraying booth.
17. A method according to any preceding claim, wherein the spraying apparatus is provided by connecting an inlet of a spraying gun to a source of the protective coating via a pump and connecting the gun to a source of source of pressurized gas so that the coating is delivered in a spray out of a nozzle of the gun.
18. A method of insulating a building structure comprising: mounting at least one coated insulation panel on the building structure, the panel having been coated using a method according to any of claims ito 17.
19. A method according to claim 18 wherein said mounting comprises inserting a fixing through the coated panel and into the building structure, said fixing comprising an anchor portion for anchoring to the building structure and a flattened portion on the opposite side of the panel from the anchor portion for holding the coated panel against the building.
20. A method according to claim 18 or 19 wherein the method further comprises applying a reinforcing mesh over the pre-coated panel after it is mounted on the building structure.
21. A method according to claim 20 wherein more than one panel is mounted on the building structure, and the mesh is applied in a continuous layer over all of said panels.
22. A method according to claim 21 wherein the mesh comprises polypropylene.
23. A method according to any of claims 20 to 22, wherein the mesh has an adhesive backing for adhering to the at least one coated panel.
24. A method according to any of claims 18 to 23 further comprising applying a finishing coat of protective material over the pre-coated panel.