GB2218452A - Method and device for ensuring minimum thickness render coat - Google Patents

Abstract

A device 4 for enabling application of a surface coating 7 which devices is integrally formed of plastics material and comprises a circular disc 6 having two elongate, cylindrical portions 8, 9 extending from the centre on opposite sides and in opposite directions along the same axis transverse to a diameter of the disc 6; one cylindrical portion 9 having a pointed end and forming the penetration portion and the other cylindrical portion 8 forming the required-render-thickness indicating portion extending over a distance so that, when in a position of use, its free end face lies at the required distance from the disc 6 as to indicate the required thickness or minimum required thickness (a) of render 9 when applied to the support surface 1; said disc 6 having a plurality of apertures (5) extending therethrough, and through which an adhesive or bonding agent 2 may flow 3' when the device 1 is pressed into its position of use and a method of using such. <IMAGE>

Description

METHOD AND DEVICE FOR ENSURING MINLMUM THICKNESS RENDER COAT The present invention is related to the installation of thermal insulation for the normally exterior walls of buildings wherein at least one thermal insulation panel is mechanically secured to the wall and, subsequently, has at least one layer of render or plaster applied thereto.

'The present invention concerns a method and a device for use in the method for enabling a minimum and even thickness of render or plaster to be applied to the surface of an insulating panel or other wall surface.

Within the U.K. there is a housing stock of 21.7 million individual dwellings of which it is estimated that some 9 to 10 million dwellings are constructed with solid walls.

It is considered that in order to bring the insulation standards up to an acceptable level, insulation should be applied to the exterior walls of many houses and during the course of the last ten years many systems have been introduced in order to meet the technical requirements of this rapidly developing market. The Applicants have designed and developed an external wall insulation system which is referred to as "Swis-Slab" and which generally comprises the fixing by plug and screw means to the external walls of a building one or more insulating panels preferably of a polyisocyanurate resin, polystyrene or a phenolic foam slab.Once the insulating panels are secured in juxtaposed abutting relationship on the surface of the wall, a reinforcing layer of material, such as a mesh of glass reinforced scrim or like mesh or a stainless steel mesh or other type of metal mesh is laid against the exterior surface of the insulating panels and secured in position by the application of an overlying surface of adhesive or other bonding material such as cementitious adhesive tile adhesive or other bonding agent or even by mechanical means particularly in the case of metal meshes.

In the case where a steel reinforcing mesh or other reinforcement means is provided, mechanical means, such as the device according to the present invention, might replace the bonding agent or be used in addition thereto. In any event, the reinforcing means is secured to the insulation panel and then there is provided one or more thin coat renders on top of the reinforcing material (as mentioned, such as fabric or metal layer) as the final protective decorative coat to which chippings or the like may be subsequently applied.

Normally render coat is applied with a thickness of between 5 to 15 millimeters in a freehand traditional method or by spray or other mechanical means. However, it is extremely difficult to ensure that a standard even thickness is applied to the whole surface area.

In virtually all cases provision of the design or required thickness is an essential or important ingredient of these layers as regards the quality of the system and the serviceability of this render coat in terms of crack and vandal resistance. The external render may or may not be dashed. Minimum and even thickness of render is required.

Thus to meet building requirements and specifications and the believed likely British standard requirements in this connection it is important to ensure a minimum and even thickness of external render and preferably a specific thickness of external render and it is for such purposes that the present method and device are proposed.

According to the present invention, a device for enabling a minimum thickness of a surface coating, such as a render coat, to be applied to a support surface, such as a thermal insulation panel, comprises a penetration member or portion which may be driven or pressed into said support surface, a stop member or portion having a stop surface which limits the penetration of the penetration member or portion into said support surface, and a thickness guide or indicating member or portion extending or projecting from said stop member or portion in a direction away from said penetration member by an amount generally equal to the required minimum thickness of said surface coating.

As mentioned, the device is primarily intended for use in the application of external wall insulation systems wherein thermal insulation panels are secured to the wall and then a reinforcing layer, such as a reinforcement fabric or metal layer, applied prior to the application of possibly an adhesive layer, such as a polymer cement adhesive (tile adhesive) and one or more render coats.

The device may be applied to the panels once the reinforcing fabric and adhesive bonding layer therefor has been applied and preferably prior to setting thereof so that the setting acts to retain the device in position.

The retention effect of the bonding agent may be enhanced by providing apertures and/or recesses and/or spaced apart members, preferably of the stop member or portion, into and/or between which and/or over which the bonding agent may flow once the device is located by insertion of the penetration member through the reinforcing layer and into the insulation layer and pressed-in until the stop surfaces abut the reinforcing layer or possibly with a reduced thickness thin layer of adhesive remaining therebetween. The adhesive will flow over and/or into said above mentioned retention enhancing means and then will set thus holding the device finely in position.

The penetration member or portion is preferably a pointed shaft and preferably a pointed cylindrical shaft which in the modified embodiment is provided with barbs or like retention means.

Where the reinforcement layer is of a metal mesh, e.g.

a stainless steel mesh, an adhesive or bonding agent may possibly not be used but rather the device is preferably modified so that the penetration member or portion has additional retaining means such as, a suitably ribbed shape, barbs or a fish-tail arrangement or the like which once the penetration member has been inserted into the insulation layer, act to prevent or resist subsequent pulling-out of the device.

This arrangement overcomes the hitherto difficulty of securing metal meshes and holding such flat which had been achieved by separate mechanical fixings which served no other purpose and were costly.

The stop member or portion may simply comprise one or more arms, a protruberance, a shoulder of the device or a flange or other like member preferably extending or having said stop surface extending transversely of the penetration member to limit movement thereof into the supporting surface which will normally be the insulating panel.

The retention effect enhancing means which cooperates or cooperate with the adhesive ot bonding agent may be a recess or shoulder or aperture preferably in the stop member or portion.

In a preferred embodiment when the stop member or portion is a disc extending transversely of said penetration member, the disc has one or more apertures extending therethrough so that when pressed in to its position of use adhesive will flow througn the apertures and at least form an enlargement on the surface remote fran the supporting surface so that upon setting the device is held in position by the set adhesive. Six apertures are preferably provided through the disc.

The thickness guide or indicating member or portion preferably comprises a cylindrical member or portion extending fran said stop member or portion for a distance such that when the device is pressed into position the free end of said member or portion indicates the required or minimum thickness level of render which should be applied.

The device will preferably be highly or brightly coloured so that it can be clearly seen although the top layer applied to the wall may cover the end if desired.

Preferably the device is installed at centres of, say a metre, in order to form a grid and to enable or ensure that if all the devices are covered evenly and the final surface is level, the minimum thickness of render should be no less than the squared off up-stand or indicating portion from the disc or stop portion.

The device is preferably integrally formed and preferably of plastics material, preferably by injection moulding or the like. The amount of projection of the indicating member or portion may be different dependent upon the thickness of the finishing render.

According to a preferred embodiment of the invention, the device is integrally formed of plastics material and comprises a circular disc having two elongate, cylindrical portions extending from thecentre on opposite sides and in opposite directions along the same axis transverse to a diameter of the disc; one cylindrical portion having a pointed end and forming the penetration portion and the other cylindrical portion forming the required-renderthickness indicating portion extending over a distance so that, when in apositionof use, its free end face lies at the required distance from the disc as to indicate the required thickness or minimum required thickness of render when applied to the support surface; said disc having a plurality of apertures extending therethrough and through which an adhesive or bonding agent may flow when the device is pressed into its position of use.

Also according to the present invention, a method of determining a minimum thickness of render is applied to a support surface, comprises inserting into said surface a plurality of spaced apart devices, each of which have stop means to limit the degree of insertion and a projecting portion of a length such that its free end lies at a distance from the supporting surface equivalent to the required thickness or minimum thickness of render, and subsequently applying one or more layers of render to a depth reaching the free end of said projecting portion.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a fragmentary perspective view and partial section of an insulation panel to which a render and chippings have been applied and showing a device forming one embodiment of the invention; Fig. 2 is a vertical section through the construction of Fig. l; Fig. 3 is an elevation of the device of Figs. 1 and 2; Fig. 4 is a perspective view from above of the device of tigs. 1 to 3; Fig. 5 is a perspective view from above of a modified device forming a second embodiment; and Fig. 6 is a perspective view of a modification.

The exterior wall (not shown) insulation illustrated in Figs. 1 and 2 comprises an insulation layer or panel 1 of, for example,polyisocyanurate resist which there is applied a reinforcing layer 2 of , for example, fabric or stainless steel mesh, which is initially mechanically held in position and then bonded to the panel 1 by application of an adhesive polymer cement scrim coat 3 which flows through the interstices of the mesh to bond with panel 1.Whilst the wet cement adhesive coat 3 is still wet, a plurality of devices 4 (only one shown) according to the invention are pressed into the insulation foam of panel 1 and into the wet coat 3 in order that the adhesive cement may flow into and through the small apertures 5 of the disc 6 of each device 4 as indicated by reference numeral 3 in Figs. 1 and 2 so as to be firmly held in place making it difficult to remove without causing widespread damage. The devices 4 are located and predetermined spacing for example, at centres of such as 1 metre in order to form a grid.Subsequently, at least one render coat 7 is applied to a thickness such that the end faces 8 of all the devices 4 are covered evenly and the final surface is level, the minimum thickness of the render should be no less than the squared-off up-stand of the thickness indicating portion 8 of the device 4 which is selected to meet the requirements concerned. Subsequently, a stone chipping decoration 9 is provided.

Each device 4 for enabling a minimum thickness of render coat 3 to be applied in the embodiment of Figs. 1 to 4 comprises an integrally moulded device 4 of plastics material such as polycarbonate and is prererably brightly coloured or at Least the end face 8' thereof is brightly coloured. The device 4 comprises two cylindrical portions separated by a disc 6 having apertures 5 extending therethrough. rhe upper cylindrical portion 8 acts as the thickness indicating portion whilst the lower cylindrical portion 9 with pointed end 9' functions as a penetration portion for insertion through layers 2 and 3 and into the insulation of panel layer 1.The distance a that the portion 8 extends beyond the upper face as shown but which is, in use, normally the outer vertical face of disc portion 6, is selected according to the predetermined required minimum thickness of render layer 7 and in one example is 7 mm whilst the portion 9 is 15 mn and the disc 6 is 1 mm thick with a diameter of 15 mm and a hole size of 2 mm. Of course the amount portion 8 projects beyond disc portion 6 will be selected for different uses and may be anywhere between approx. 5 mm and 15 mm. The disc may be, for example, between 1 and 2 mm thick.

In the modified arrangement of the device 10 of Fig. 5 such is similar to the previously described device except that barbs or engaging projections 11 are provided (as a fishtail arrangement) on the outside of penetration portion 9 to provide for increased gripping effect to inhibit pulling out and is especially suitable for holding metal mesh in place initially. In one example of such modified device,length a of portion 8 may be 7 mm, b 25 mm and the diameter of disc 6is 20 mn although other dimensions are possible. The adhesive cement may be omitted in this arrangement if required.

A preferred modification is shown in Fig.6 wherein six holes 5 are provided in place of the previously illustrated four of Figs. 1 to 4.

It will be appreciated that various modifications and changes may be effected without departing from the present invention and the generalities of the introduction are hereby repeated. For example portions 8 and 9 may be other than cylindrical and a differently shaped projection or projections may be provided in place of disc portion 6 to act as stop member or portion e.g. one or more projecting arms may be provided instead which may be apertured ir required. Still further alternatively, the stop member or portion and the projecting indicating member or portion may be integral and run one into the other e.g. a large cylindrical portion may replace portions 6 and 8 and extend beyond its stop surface so that its outer circular surface (equivalent to 8' but of larger diameter) acts as the minimum level indicating surface Recesses or shoulders or other projections may replace apertures 5 as means into or around or over which adhesive may flow to provide a holding action on the device when setting of the adhesive.

Claims (1)

1. A device for enabling a minimum thickness of a surface coating, such as a render coat, to be applied to a support surface, such as a thermal insulation panel, comprises a penetration member or portion which may be driven or pressed into said support surface, a stop member or portion having a stop surface which limits the penetration of the penetration member or portion into said support surface, and a thickness guide or indicating member or portion extending or projecting from said stop member or portion in a direction away from said penetration member by an amount generally equal to the required minimum thickness of said surface coating.

2. A device as claimed in claim 1, in which the penetration member or portion is a pointed shaft and preferably a pointed cylindrical shaft.

3. A device as claimed in claim 1 or 2, in which the penetration member or portion is provided with barbs or like retention means.

4. A device as claimed in any of claims 1 to 3, in which the penetration member or portion has additional retaining means such as a suitably ribbed shape, barbs or a fish-tail arrangement or the like shaped and constructed such that once the penetration member has been inserted into the insulation layer, such retaining means or additional retaining means act to prevent or resist subsequent pulling-out of the device.

5. A device as claimed in any of claims 1 to 4, in which the stop member or portion comprises one or more arms, a protruberance, a shoulder of the device or a flange or other like member.

device as claimed in claim 5, in which said stop member or portion extends or has said stop surface extending transversely of the penetration member to limit movement thereof into the supporting surface, which will normally be an insulating panel.

7. A device as claimed in any of claims 1 to 6, in which retention effect enhancing means are provided and is or are such as to cooperate with the adhesive or bonding agent and may comprise a recess and/or shoulder and/or aperture and/or spaced apart members, preferably in or comprising the stop member or portion.

8. A device as claimed in claim 7, in which when the stop member or portion is a disc extending transversely of said penetration member, the disc has one or more apertures extending therethrough as retention effect enhancing means such that when pressed in to its position of use adhesive may flow through the apertures and at least form an enlargement on the surface remote from the supporting surface so that upon setting the device is held in position by the set adhesive.

9. A device as claimed in claim R in which four or, preferably, six apertures are provided extending through the disc.

10. A device as claimed in any of claims 1 to 9, in which the thickness guide or indicating member or portion comprises a cylindrical member or portion extending from said stop member or portion for a distance such that when the device is pressed into position the free end of said member or portion indicates the required or minimum thickness level of render which should be applied.

11. A device as claimed in any of claims 1 to 10, in which the device or end of the indicating member is highly or brightly coloured so that it can be clearly seen.

12. A device as claimed in any of claims 1 to 11, in which the device is integrally formed and preferably of plastics material, preferably by injection moulding or the like.

13. The device for enabling application of a surface coating which is integrally formed of plastics material and comprises a circular disc having two elongate, cylindrical portions extending from the centre on opposite sides and in opposite directions along the same axis transverse to a diameter of the disc; one cylindrical portion having a pointed end and forming the penetration portion and the other cylindrical portion forming the required-render-thickness indicating portion extending over a distance so that, when in a position of use, its free end face lies at the required distance from the disc as to indicate the required thickness or minimum required thickness of render when applied to the support surface; said disc having a plurality of apertures extending therethrough and through which an adhesive or bonding agent may flow when the device is pressed into its position of use.

14. A method of determining a minimum thickness of render applied to a support surface, comprises inserting into said surface, at spaced apart locations, a plurality of devices, each of which have stop means to limit the degree of insertion and a projecting portion of a length such that its free end lies at a distance from the supporting surface equivalent to the required thickness or minimum thickness of render, and subsequently applying one or more layers of render to a depth reaching the free end of said projection portion.

15. A method as claimed in claim 14, in which the uppermost layer is applied to cover said free end.

16. A method as claimed in claim 14 or 15 in which the device is installed at centres of, for example, a metre, in order to form a grid and to enable or ensure that if all the devices are covered evenly and the final surface is level, the minimum thickness of render should be no less than the squared off up-stand or indicating portion from the disc or stop portion.

17. P method as claimed in any of claims 14 to 16, wherein the render is applied in the application of external wall insulation systems wherein thermal insulation panels are secured to the wall and then a reinforcing layer, such as a reinforcement fabric or metal layer, applied prior to the application of an adhesive layer, such as a polymer cement adhesive (tile adhesive) and then one or more of said render coats are applied.

1B. A method as claimed in claim 17 in which the device is applied to the panels once the reinforcing fabric and adhesive bonding layer therefor has been applied and preferably prior to setting thereof so that the setting acts to retain the device in position.

19. A method as claimed in claim IB, in which the retention effect of the bonding agent is enhanced by providing apertures and/or recesses and/or spaced apart members, preferably of the stop member or portion, into and/or between which and/or over which the bonding agent may flow once the device is located by insertion of the penetration member through the reinforcing layer and into the insulation layer and pressed-in until the stop surfaces abut the reinforcing layer or possibly with a reduced thickness thin layer of adhesive remaining therebetween; the adhesive flows over and/or into said above mentioned retentionenhancing means and is allowed to set thus holding the device firmly in position.

20. A method substantially as herein described with reference to the accompanying drawings.

21. A device for enabling application of a minimum thickness of surface coating substantially as herein described with reference to the accompanying drawings.