GB2497831A - A replacement cill and method of installation - Google Patents

Abstract

A method of installing a cill replacement unit to form part of an external wall insulation system on an existing building comprising the steps of fixing the plurality of insulation sheets 404 to an external wall of the building and adhering the cill replacement unit 400 to at least one of the plurality of insulation sheets before any render application process has been carried out on the insulation sheets of the external wall insulation system. Also claimed is a replacement cill or replacement sill comprised of insulation material with a cill nose and cill wings and a multi-face adhesion surface along a rear portion of the cill, suitable for adhering to a plurality of insulation sheets, the multi-face adhesion surface is located along a rear portion of the cill and comprises a plurality of faces that have parallel or planar longitudinal axes. The adhesive could be expanding foam. The cill could be an ultra high density expanded polystyrene sheet.

Description

"A Ciii"

introduction

This invention relates to a ciii, and in particular to a retro-fitting ciii replacement unit for integration as part of an insulation system employed on existing buildings.

Insulation methods have greatly improved over the past number of years. Older, existing buildings do not have the same level of insulation as modern new builds resulting in large heat energy loss through the roofs, wails, windows and ventilation systems of these older buildings. in order to provide increased insulation to the older buildings, and in particular to meet with an EU Directive (2002/91IEC) on energy performance in buildings to reduce energy usage and carbon dioxide emissions, many different retro-fitting insulation systems have been developed. These retro-fitting insulation systems can greatly improve the heat retention in the older building and reduce heating costs considerably.

A number of different retro-fit systems designed to increase the insulation of these older, existing buildings are known. One of which is an external wail insulation system, otherwise known as an external insulating facade system or external thermal insulation composite system. The external wall insulation system comprises of a plurality of insulation sheets, otherwise known as expanded polystyrene sheets, phenohc boards or other such approved materials, which are affixed to the outer façade of the existing building. The plurality of insulation sheets are affixed to the outer façade using fixing means, such as mushroom fixings and a weather-proofing render is then applied to the insulation sheets to maintain the weatherproof worthiness of the outer façade and provide the outer façade with a pleasing aesthetic which is very important, particularly for domestic buildings.

In this manner, the outside of an older, existing building may be retrofitted with an insulation system in a relatively straightforward manner, which does not require any extensive work to install the insulating material within the existing walls, or does not impact on the interior of the building at all. As almost all of the upgrading work is carried out on the exterior of the building, the disruption to the building's users is minimised. For these reasons, this retro-fitting external wall insulation system has proved to be extremely popular and is widely used.

As these external wall insulation systems are relatively new, certification bodies carry out stringent examinations of the manufacturing plants, the insulation systems and the materials, and the ways in which the system and materials comply with the relevant national regulations. In Ireland and the UK these bodies are typically the National Standards Authority of Ireland (NSAI) and the British Board of AgrOment (BBA).

Through this process a level of control and accreditation is created to control the suppliers and installers and guide consumers. The agrément certificates assure the consumer that the accredited external wall insulation system is of a certain quality and reaches or exceeds predetermined thresholds for effectiveness and suitability.

However, there is a problem with current external wall insulation systems. Current external wall insulation systems do not accommodate insulation panels around the cill of the windows on the outer façade of the existing buildings. As a result, retro-fitting cill replacement units have been developed by third parties which do not form part of the external wall insulation system. These retro-fitting cill replacement units are not fully integrated with the retro-fitting external wall insulation system and in many cases are not mentioned in the agrement certificate.

Typically, whilst affixing the plurality of insulation sheets to the outer façade of the existing building, the portion of the original masonry cill which protrudes outwardly from the outer façade, referred to as the nose of the cill, is cut away to allow the plurality of insulation sheets to be affixed to as much of the outer façade of the existing building as possible. Once the insulation sheet has been connected, the third party replacement cill unit is affixed to the building to create the effect of the cill and protect this location on the insulation system from water ingress.

However, these cill replacement units do not always connect with the external wall insulation system; equally the seal between the window frame and the cill may weather or pull away. In both cases, rainwater can enter the insulation system at the cill location. This is unwanted as such water ingress can lead to large amounts of water damage resulting in costly repair work and replacement of insulation panels.

Furthermore, a significant thermal bridge at the cill location is frequently created by the retrofitting of the ciii and external wall insulation which is contrary to best practice as intended by the certification body and manufacturers of the system. A thermal bridge is the non-uniform heat loss over and above the uniform heat loss of the surrounding elements. It is highly undesirable as it lessens the beneficial effects of the retro-fitting external wall insulation system.

Currently, there are a number of different cili replacement units on the market. Three of the market leaders are described hereinbelow. All have their own drawbacks and disadvantages.

The first type of retro-fitting cill replacement unit is a "Metal over Cili" arrangement whereby a metal cili, dimensioned to fit over the existing cili, is placed on top of the existing masonry cill and covers the external wall insulating system. Figure 1 shows a Metal over Cill replacement unit and an external wall insulation panel retro-fitted to an existing building.

There are a number of problems with "Metal over Cill" units. "Metal over Cill" units make no significant contribution in decreasing the thermal bridge factor in the area of the window cill. in fact, when installed as shown in Figure 1, the "Metal over Cill" unit actually increases the thermal bridging rather than decreasing it as the "Metal over Cill" is installed directly atop the existing masonry ciii. As can be seen from Figure 1, the "Metal over Ciii" unit indicated generally by reference numeral 100 has an up-stand 102 at its rear end which when installed correctly will protrude upwardly to the rear of the lowermost section of the corresponding window frame 104. However, it is not possible to always achieve this correct installation as in an overwhelming number of retro-fit instances the window frame 104 is fitted sitting directly onto the cill and it is not possible to fit the Metal over Cili unit 100 with the up-stand 102 located correctly behind a portion of the window frame 104. In other cases, a PVC slip is found on the underside of the window frame which also prevents the correct installation of the up-stand. in these cases it is common for the up-stand 102 to be removed from the "Metal over CUll" 100 by the installation contractor which is clearly not ideal as installing the "Metal over Cill" unit 100 without the up-stand 102 is not facilitated as an option in the agrément and as a result is in breach of that agrement. It is believed that use of the "Metal over Cill" unit 100 could invalidate the warranty of an installed external wall insulation system if the "Metal over Cill" unit 100 is installed on top of the external wall insulation system.

Furthermore, in the cases where the "Metal over Cill" 100 is fitted without the up-stand 102, the result is that the rearmost edge of the "Metal over Cill" 100 becomes susceptible to allowing water ingress between the cill replacement unit and the remaining section of the original masonry cill beneath. This water ingress can spread into the external wall insulating system causing damage to the insulating system and requires expensive repair work to be carried out.

The "Metal over Cill" 100 creates poor aesthetics which adversely affect the overall appearance of an externally insulated building and it is deemed unsuitable by many insulation contractors for use in buildings of significant asset value or buildings with architectural features. When installed as shown in Figure 1, fitting a "Metal over Cill" 100 with a retro-fit external wall insulation system can deface the building and as a result devalue the building.

A final problem with the "Metal over Cill" replacement cill units 100 is that there are difficulties in achieving the correct angles in the manufacturing of the "Metal over Cill" replacement units 100 for retro-fit on an existing bay windows.

The second type of retro-fitting cill replacement unit is a "Concrete over Cill" arrangement whereby a replacement cill unit, pre-formed out of concrete and dimensioned to fit over the existing masonry cill, is installed on top of a previously installed external wall insulating system! in effectively the same manner as the "Metal over Cill" hereinbefore described. The "Concrete over Cill" replacement unit is shown in Figure 2. The "Concrete over Cill" unit indicated generally by reference numeral 200 comprises a cill face 202, cill wings 204 and a cill nose 206.

Although the "Concrete over Cill" replacement unit 200 is used by many installation contractors, it does not form part of the Irish agrément certification for external wall insulation systems and therefore has been assessed as being unsuitable for the purpose of preventing water ingress into the external wall insulation system. It is believed that use of the "Concrete over Ciii' unit 200 could invalidate the warranty of an installed external wall insulation system if the "Concrete over Cill" 200 is installed on top of the external wall insulation system. The lack of an agrément is most likely due to the lack of any up-stand forming part of the "Concrete over Cill" replacement unit 200.

Another problem with the "Concrete over Cill" unit 200 is that it does not make any contribution to a decrease in the thermal bridging at the window cill. Due to the properties of the concrete, very little insulating benefit is derived from the "Concrete over Cill" unit 200 and consequently, the overall insulating effect of the external wall insulation system is not benefitted by the use of the "Concrete over Cill" unit 200.

A further problem is that there are reservations about the appearance of the "Concrete over Cill" unit 200 as a cill replacement unit. Many installation contractors have expressed a preference to use different external wall insulation systems so as to avoid having to use the "Concrete over Cill" replacement unit 200. The "Concrete over Cill" unit 200 cannot properly accommodate the varying angles of existing masonry cills and the cill face 202 of the "Concrete over Cill" 200 often has a tipped forward appearance when installed over the existing masonry cills.

On retro-fit external wall insulation systems, the Concrete over Cill" unit 200 is intended to act as a weather-proofing capping over external wall insulation system to prevent water ingress into the insulation system. However, as the "Concrete over Cill" replacement unit 200 has not been approved through Irish agrement certification, it is felt within the industry that the "Concrete over Cill' unit 200 has failed to successfully demonstrate that weather-proofing purpose and use of the "Concrete over Cill" unit 200 can prejudice the longevity of the installed external wall insulation system. The "Concrete over Cill" unit 200 relies totally on a silicone sealant which is used around the contact points with the external wall insulation system to protect the insulation system from the effects of weathering and/or water ingress into the insulation system.

The third type of retro-fitting ciii replacement unit is a "Cill Face Mould" which is made of expanded polystyrene sheets and is shown in Figure 3.

The Gill Face Mould" indicated generally by reference numeral 300 is not integrated into the external wall insulation system but is instead only adhered to an incomplete render face of the external wall insulation system 302 using a basecoat of the insulation system as the adhesive. The "Cill Face Mould" 300 is adhered to the external wall insulation system after re-enforcing mesh is applied during the installation of the external wall insulation system.

If the "Gill Face Mould" unit 300 was to partially break off or crack as a result of downward pressure, or if water was to seep into the external wall insulation system due to a poorly finished surface and/or poor adhesion to the external wall insulation system, then expansion, contraction and/or warping would occur and the integrity of external wall insulation system would be breached.

There are a number of further problems with using the "Gill Face Mould" unit 300 as outlined hereinunder. The level of contact made between the external wall insulation system and the "Gill Face Mould" unit 300 will vary depending on the depth ot the basecoat used in the external wall insulation system, which is rarely uniform and can vary greatly depending on the applicator used and care taken by the contractor. Moreover, the adhesion of the "Gill Face Mould" unit 300 is largely dependent on the application of the basecoat directly to the mould to create the bond between the face of the mould and the face of the external wall insulation system. This can also depend largely on the amount of mesh re-enforced basecoat which overlaps over the top face of the mould to hold the "Gill Face Mould" 300 in location. The "Gill Face Mould" unit 300 is not designed to be supported or fixed in situ by any masonry fixings.

A further, and well-known, problem is that the "Gill Face Mould" 300 is easily broken away from the external wall insulation system when upward pressure is applied to the mould. This is very undesirable. Yet a further problem is that the "Gill Face Mould" 300 has structural weaknesses allowing many hair line cracks to develop during movement when the "Gill Face Mould" 300 is dry or partially dry after a screeding process at production stage. Hair line cracks are also known to be caused during the handling of the "Gill Face Mould" 300 which is clearly quite brittle.

The adhesion process of the "Gill Face Mould" 300 to the unfinished external wall insulation system is dependent on stable support of the mould itself during the drying and adhesion process. Any expansion, contraction, water penetration, movement caused by wind, frost or other element will adversely affect the adhesion strength of the bond between the "Cill Face Mould" 300 and the external wall insulation system. This may interfere with the adhesion during the drying period to such an extent it results in failure, partial failure or seriously weakens the bond of the "Gill Face Mould" 300 to the external wall insulation system.

Consequently it is common practice to prop the "Gill Face Mould" 300 with temporary timber laths 304 extending from nearby scaffolding to the underneath of the "Gill Face Mould" 300. However, this method of support is wholly unsuitable and undesirable due to the constant movement of scaffolding during the installation of the "Gill Face Mould" 300. A second method of supporting the "Gill Face Mould" 300 during the adhesion process is to use long nails pushed through the "Gill Face Mould" 300 and into the incomplete external wall insulation system on the outer façade wall to hold the "Cill Face Mould" 300 in place. In this case the integrity of the external wall insulation system is breached by the many nail holes through what is required to be a sealed weather-proof system. Water leakage through the adhesion joint between the mould and the EWI System would result in the failure of the integrity of the entire external wall insulation system.

As before, akin to the other existing cill replacement units, it is believed that use of the "Gill Face Mould" unit 300 could invalidate the warranty of an installed external wall insulation system if the "Gill Face Mould" 300 is installed on top of the external wall insulation system It is also a problem to adhere the "Gill Face Mould" to the incomplete external wall insulation system during high humidity or low temperature periods because the length of time required to allow complete drying of the adhesive between the "Gill Face Mould" and the incomplete external wall insulation system is greatly extended and it is practically speaking extremely difficult to ensure no movement of the "Gill Face Mould" during this protracted period.

Gill replacement units are known from European Patent Publication Number EP0899409 (POLYQUARTZ FORMTECHNIK GMBH). The cill replacement of EP0899409 is used as a cover cill to be installed over a broken cill. The replacement cill of EP0899409 is intended for DIY use and comprises a covering element and a substantially planar tray surface, whereby the appearance of the broken cill is replicated by the replacement cill which is altered by cutting its dimensions to fit tightly over the cill to be covered. The cill of EP 0 899 409 is not disclosed to comprise any particular thermal insulation properties.

German Patent Publication Number DE 201 19864 (MARMORIT GMBH) discloses an insulation arrangement for adjacent a window cill, however the cill unit suffers from many of the drawback mentioned hereinbefore.

U.K. Patent Publication Number GB 2 475 366 (KERRIGAN) discloses an overcill which is of the type of Concrete over Gill mentioned hereinbefore, and suffering from the same drawbacks and disadvantages. In particular, the thermal insulation properties of the overcill disclosed in GB 2 475 366 are not sufficient to overcome many of the known problems.

It is a goal of the present invention to provide a replacement cill unit and method of retro-fitting a replacement cill unit that overcome at least one of the above-mentioned drawbacks and disadvantages of the currently used retro-fitting cill replacement units.

Summary of the Invention

The present invention is directed to a retro-fitting cill replacement unit for integration as part of an external wall insulation system before a weather-proofing render is applied to the external wall insulation system. Certain variants of the cill replacement unit can also be used successfully in new build construction.

The present invention is directed to a method of installing a cill replacement unit to form part of an external wall insulation system on an existing building, the external wall insulation system comprising a plurality of insulation sheets, and, the method comprising the steps of fixing the plurality of insulation sheets to an external wall of the building; and, adhering the cill replacement unit to at least one of the plurality of insulation sheets before any render application process has been carried out on the insulation sheets of the external wall insulation system.

The advantage of providing a method of installing, or retro-fitting a cill replacement unit in accordance with the present invention is that the cill replacement unit is self-supporting and can be adjusted once the cill replacement unit has dried in adhering to the external wall insulation sheet, which is typically within twenty minutes of adhering the cill replacement unit to the external wall insulation sheet.

The thermal bridging effect is also greatly reduced.

In a further embodiment, the method comprising the step of applying a render to the cill replacement unit and the plurality of insulation sheets after the cill replacement unit has been adhered to at least one of the plurality of insulation sheets.

In a further embodiment, the method comprises the step of cutting a multi-face adhesion surface on at least one of the plurality of insulation sheets.

In a further embodiment, the method comprises adhering the multi-face adhesion surface of the cill replacement unit to the multi-face adhesion surface of the insulation sheet using an expanding foam.

In a further embodiment, the method comprises the step of shaping a generic cill replacement unit to form a shaped cill replacement unit with a pre-defined cill face gradient and/or pre-defined cill wing dimensions and/or pre-defined cill nose dimensions.

A further advantage is that the cill replacement unit is far superior to the "Concrete over Cill" unit or the "Metal over Cill" unit as both prior art units' appearance is acknowledged to be relatively poor, whilst the cill replacement unit may modified to a desired shape prior to full integration into the insulation system. Such adaptability makes the cill replacement unit more acceptable by the building users.

In a further embodiment, the method comprises the step of adhering the multi-face surface of the cill replacement unit to the multi-face surface of at least one insulation panel using an expanding foam.

In a further embodiment, the method comprises the step of applying a single pie-cut reinforcing mesh over the adhered cill replacement unit before apply a weather-proofing render.

In a further embodiment, the method comprises the step of fixing at least one of the plurality of insulation sheets to the external wall of the building using a plurality of mushroom fixings arranged in a substantially horizontal line approximately 100mm beneath the lowermost point of the cill replacement unit which is adhered to that insulation sheet.

In a further embodiment, the method comprises the step of fixing at least one of the plurality of insulation sheets to the external wall of the building using at least one mushroom fixing on either side of the cill replacement unit 100mm from the outermost point of the cill wings on the cill replacement unit which is adhered to that insulation sheet.

In a further embodiment, the method comprises the steps of applying a first basecoat and imbedding first re-enforcing mesh on all faces of the cill replacement unit; overlapping, fold-bandaging and buttertlying the first imbedded re-enforcing mesh to agrement certificate approved standards; applying a second basecoat to the first basecoat when dry and imbedding a further second re-enforcing mesh; overlapping, fold-bandaging and buttertlying the first imbedded re-enforcing mesh to agrément certificate approved standards; allowing the second basecoat to dry; applying a coat of self-levelling rapid curing polyurethane waterproofing membrane; applying an overcoat with a urethane sealant to prime all exposed faces of the cill replacement unit; allowing to dry; or applying at least two coats of acrylic paint, or other compatible weatherproofing finish, over primed weather-proofing render of the ciii replacement unit. It will be readily understood that in some scenarios, it will not be necessary to use two basecoats and apply two layers of re-enforcing mesh; a single basecoat and single re-enforcing mesh may be alternatively used. In yet a further embodiment, two basecoats and a single mesh layer, with 330 gram mesh, may be alternatively used. In all cases it is a goal to achieve a Category 1 strength bond.

The present invention is further directed towards a ciii replacement unit comprised of an insulating material, whereby the ciii replacement unit comprises a ciii nose and ciii wings along an outwardly projecting front portion of the ciii replacement unit and a multi-face adhesion surface along a rear portion of the ciii replacement unit, such that the multi-face adhesion surface of the ciii replacement unit co-operates in a complementary manner with a multi-face adhesion surface on at least one of a plurality of insulation sheets forming an external wall insulation system to which the ciii replacement unit is adhered. An overall retro-fitting, integrated insulation system is created with the ciii replacement unit adhered to the external wail insulation system.

The advantage of providing a cWi replacement unit in accordance with the present invention is that the ciii replacement unit is integrated with the external wail insulation system to provide a complete insulation system which can be accredited by an agrément certificate, and the multi-face adhesion surfaces on the cifl replacement unit and on at least one of a plurality of insulation sheets results in a large contact area being created which provides a strong integrated bond with high insulation properties between the cWi replacement unit and the insulation sheets, and, relatively high strength to the cifl replacement unit of the present invention in comparison with existing known dM1 replacement units from the prior art. indeed results of stress tests have shown that the bond established between the two expanded polystyrene sheet components in the overall retro-fitting integrated insulation system, namely the bond between the multi-face adhesion surface of the cMii replacement unit and the multi-face adhesion surface on at least one of the insulation sheets of the external wail insulation system, is extremely strong. in all cases, the expanded polystyrene system material used in either the cifl replacement unit or on the external wail insulation system gave way and broke without any failure of the joint area on the bonded multi-face adhesion surfaces.

Moreover, these stress test were carried out on untreated and unrendered expanded polystyrene sheets and the resistance to breaking with system mesh and render coats applied would be significantly higher.

A cill replacement unit comprised of an insulating material, whereby the cill replacement unit comprises a cill nose and cill wings along an outwardly projecting front portion of the cill replacement unit and a multi-face adhesion surface along a rear portion of the cill replacement unit, such that the multi-face adhesion surface of the cill replacement unit co-operates in a complementary manner with a multi-face adhesion surface on at least one of a plurality of insulation sheets forming an external wall insulation system to which the cill replacement unit is adhered, characterised in that the multi-face adhesion surface along the rear portion of the cill replacement unit comprises a plurality of faces whose longitudinal axes are arranged in the same plane or in parallel and are also arranged to face in substantially the same direction.

In this manner the multi-face adhesion surface will comprise a stepped surface with at least two faces of the multi-face adhesion surface facing in the same direction as one another but the planes of the surfaces being in parallel with one another.

A further advantage of the cill replacement unit in accordance with the present invention is that the cill replacement unit is aesthetically pleasing, and substantially avoids any thermal bridging effects.

In a further embodiment, the cill replacement unit comprises an integrated steel corner bead adjacent edges of the outwardly projecting front portion of the cill replacement unit.

In a further embodiment, the cill replacement unit is adhered to the at least one insulation sheet using an adhesive expanding foam.

In a further embodiment, the expanding foam has a thermal conductivity of not greater than 0.035 Watts per Meter Kelvin (WI(mK)). For example, the expanding foam could have a base material of Polyurethane and/or a density of substantially grams per litre. A sound insulation of less than 57 dB would be preferable and the expanding foam may for example have an adherence time of approximately two hours and/or the expanding foam could have a shear strength of 5.5 N/cm2. A temperature resistance in the range of -40°c to +110°c would be advantageous and preferable.

In a further embodiment, the cill replacement unit is comprised of an expanded polystyrene sheet.

The advantages of the cill replacement unit of the present invention are that cill replacement unit can be easily and quickly accommodated into an existing agrement certification as the cill replacement unit is manufactured from proven, tested and accepted materials throughout its manufacture and application.

Furthermore, the simplicity of installation and the harmonious way in which the cill replacement unit is incorporated and integrated into any of the current external wall insulation system minimises any delay in bringing the cill replacement unit to an accredited status.

The cill replacement unit is compatible with all known and approved insulation sheet types used in external wall insulation systems as the cill replacement unit is itself manufactured of expanded polystyrene sheet insulation. The cill replacement unit will be manufactured at approximately 100mm in height, 180mm in width and 2600mm in length, prior to being cut by a hot wire or other similar tool to the specific dimensions as required to marry up to the window frame of the building to which an external wall insulation system is being retro-fitted. It can be manufactured to other sizes.

In a further embodiment, the cill replacement unit is installed over and atop the original masonry cill thus replicating the appearance of a cill whilst substantially reducing the possibility of a thermal bridge being created.

Detailed Description of Embodiments

The invention will be more clearly understood from the following description of some embodiments thereof! given by way of example only with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic cross-sectional side view of a "Metal over Cill" replacement unit in accordance with the prior art, which is shown in situ with an external wall insulation panel which has been retro-fifted to an old building; Figure 2 is a photographic view of a "Concrete over Cill" replacement unit in

accordance with the prior art;

Figure 3 is a photographic view of a till Face Mould" in accordance with the

prior art;

Figure 4 is a perspective exploded view of a replacement cill unit in accordance with the present invention; Figure 5 is a perspective exploded view of a replacement cill unit in accordance with a further embodiment of the present invention; Figure 6 is a perspective view of the replacement cill unit of Figure 4 shown in situ, integrated with an external wall insulation system which has been retro-fitted to an old building; Figure 7 is a photographic front view of a replacement cill unit in accordance with the present invention, which is shown in situ with an external wall insulation panel and a plurality of associated fixings; Figure 8 is a further photographic side view of the replacement cill unit of Figure 7; Figure 9 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 10 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 9; Figure 11 is a is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 12 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 13 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 12; Figure 14 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 15 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 14; Figure 16 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an extemal wall insulation panel which has been retro-fitted to an old building; Figure 17 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 16; Figure 18 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 19 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 18; Figure 20 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 21 is a diagrammatic cross-sectional side view of the replacement cill unit ofFigure2O; Figure 22 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 23 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 22; Figure 24 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 25 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 24; Figure 26 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 27 is a diagrammatic cross-sectional side view of the replacement cill unit ofFigure26; Figure 28 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; Figure 29 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 28; Figure 30 is a diagrammatic cross-sectional side view of a replacement cill unit in accordance with a further embodiment of the present invention, which is shown in situ with an external wall insulation panel which has been retro-fitted to an old building; and, Figure 31 is a diagrammatic cross-sectional side view of the replacement cill unit of Figure 30.

Referring to Figures 4 and 6, there is provided a cill replacement unit indicated generally by reference numeral 400.

The cill replacement unit 400 is a monobloc body piece which is adhered to an insulation sheet 402 of an external wall insulation system which has been fixed to the outer facade of a wall 404 of a building. The reveal of a window frame 406 is also shown in Figures 4 and 6.

The cill replacement unit 400 is adhered to the insulation sheet 402 using an adhesive which is spread over a contact surface area formed by a multi-face adhesion surface 500 on the cill replacement unit 400 and a multi-face adhesion surface 502 on the insulation sheet 402. The multi-face adhesion surface 500 on the cill replacement unit 400 and the multi-face adhesion surface 502 on the insulation sheet 402 of the external wall insulation system may comprise of any number of stepped horizontal and vertical surfaces. In a preferred embodiment, the multi-face adhesion surface 500 on the cill replacement unit 400 comprises one horizontal surface and two stepped vertical surfaces, and, the multi-face adhesion surface 502 on the insulation sheet 402 of the external wall insulation system comprises two stepped horizontal surfaces and two stepped vertical surfaces. In a further preferred embodiment, the multi-face adhesion surface 500 on the cill replacement unit 400 and the multi-face adhesion surface 502 on the insulation sheet 402 of the external wall insulation system comprise of three stepped vertical surfaces respectively. It will be readily understood that adhesion surfaces arranged at angles to the horizontal and vertical surfaces may alternatively or conjunctively used. The multi-face adhesion surface 502 on the insulation sheet 402 of the external wall insulation system will typically be in the range of 550mm to 600mm in length, and the surface area of each adhesion surface is in the range of 45,500 mm2to 69,000 mm2, with a total surface area on each of the multi-face adhesion surfaces 500, 502 of approximately 460,000 mm2. Therefore, a strong bond can be established between the multi-face adhesion surface of the cill replacement unit and the multi-face adhesion surface on at least one of the insulation sheets of the external wall insulation system.

The cill replacement unit 400 comprises an anti-drip notch 600 cut out of an underside of the cill replacement unit 400. It will be understood that the anti-drip notch 600 may be vee-shaped, arcuately-shaped, or rectangularly-shaped provided that a groove or indeed a protrusion is formed on the underside of the cill replacement unit 400.

Referring now to Figure 5, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 550. The cill replacement unit 550 comprises a main body piece 552 and a rearward cill insert piece 554. These two piece cill replacement unit 550 may be alternatively used instead of a monobloc piece cill replacement unit as shown in Figures 4 and 6. As before the cill replacement unit 550 is adhered to the insulation sheet 402 using an adhesive which is spread over a contact surface area formed by a multi-face adhesion surface 500 on the main body piece 552 of the cill replacement unit 550 and a multi-face adhesion surface 502 on the insulation sheet 402. The multi-face adhesion surface 500 on the main body piece 552 of the cill replacement unit 550 and the multi-face adhesion surface 502 on the insulation sheet 402 of the external wall insulation system comprise a number of stepped horizontal and vertical surfaces. The rearward cill insert piece 554 of the cill replacement unit 550 is installed atop an upwardly facing surface of the existing masonry cill 405.

With reference to Figures 7 and 8 inclusive, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 400. The cill replacement unit 400 is shown to be adhered to an insulation sheet 402. The insulation sheet 402 is fixed to a wall (not shown) using a plurality of fixings, for example mushroom fixings. A plurality of central mushroom fixings 700 are arranged in a line beneath a lowermost point of the cill replacement unit 400. The plurality of central mushroom fixings 700 are arranged approximately 100mm beneath the lowermost point of the cill replacement unit 400 and are approximately arranged 300mm apart from one another with the leftmost and rightmost mushroom fixings of the central mushroom fixings 700 are preferably approximately 40mm inside the outermost point of the multi-face adhesion surface on the insulation sheet of the external wall insulation system. Outer mushroom fixings 702 are fixed on either side of the cill replacement unit 400 from the outermost point of the cill wings 802 on the cill replacement unit 400 which is adhered to the insulation sheet 402. The outer mushroom fixings 702 are fixed at a distance of approximately 100mm from the outermost point of the cill wings 802 on the cill replacement unit and are placed at a distance of approximately 40mm above the lowermost point of the multi-face adhesion surface on the insulation sheet of the external wall insulation system. The cill face 800 may be advantageously cut to a desired cill face gradient to match the existing gradient of the existing masonry cill.

It will be readily understood that the insulation sheet 402 must be of sufficient strength to support the cill replacement unit 400 and any weight placed thereon. Normal insulation sheets 402 used in Extemal Wall Insulation Systems are capable of supporting of the order of 45 to 70 kPa. It is envisaged in a preferred embodiment that insulation sheets capable of supporting of the order of 200 kPa would be used to ensure a stable and robust cill replacement. Therefore, in conjunction with, or independently from, the arrangement of the central mushroom fixings 700 and the -20 -outer mushroom fixings 702 as described hereinabove; it is foreseen in the preferred embodiment to use insulation sheets 402 capable of supporting at least 200kPa, and preferably 300kPa. These insulation sheets 402 will preferably be at least 210mm in width and would be specifically for use as support units beneath a cill replacement unit 400, whereas elsewhere on an external wall insulation system, normal insulation sheets 402 capable of supporting of the order of 45 to 70 kPa could be used.

In use, the cill replacement unit 400 is installed by: a. Fixing central mushroom fixings 700 through the insulation sheet 402 fixed to the wall 404 on a horizontal line under the cill replacement unit 400.

Installing the outer mushroom fixings 702 on either side of the cill wings 802 of the cill replacement unit 400.

b. Cut a multi-face surface 502 on an upper rear portion of the insulation sheet 402 which is fixed to the wall 404 to allow the cill replacement unit 400 to sit higher than an upper face of the existing masonry cill 405. A complementary multi-face surface 500 should be cut on the cill replacement unit 400 to ensure a correct and snug fit between the multi-face surfaces 500, 502, thus eliminating any thermal bridge through the adherence point; c. Adhere the cill replacement unit 400 to the insulation sheet 402 using expanding foam on all cill replacement unit faces that contact the insulation sheet 402 fixed to the wall 404 and the face of the original masonry cill 405; d. Allow adequate time for the cill replacement unit 400 to adhere to the insulation sheet 402. Typically, twenty minutes may suffice.

e. Cut a sheet of insulation to size and adhere to the upwardly facing cill face of the remaining masonry cill to eliminate the thermal bridging through that location and area.

f. Cut the cill face 800 of the replacement cill unit 400 to the required gradient to conform to regulations and in line with the remaining now covered and insulated masonry cill face.

g. Embed corner beads to front top edge of cill face 800; -21 -h. Apply a first basecoat and embed re-enforcing mesh on all the remaining faces of the cill replacement unit 400 and to the insulation board 402 adhered to the remaining masonry cill face. Overlap, told bandage and butterfly the re-enforcing mesh to agrément approved standards using agrément approved methods; Apply a second basecoat to the dried first basecoat and embed further re-enforcing mesh, and, allow to dry; j. Apply a coat of self-levelling rapid curing polyurethane waterproofing membrane. Overcoat with a urethane sealant to prime all exposed faces of the cill replacement unit 400 and allow to dry; k. Finish with at least two coats of acrylic paint or other approved render finishes over the primed weather-proofing basecoat, or, use another known water-proofing solution as currently available.

Referring now to Figures 9 to 31 inclusive, there are shown various embodiments of a cill replacement unit in accordance with further embodiments of the present invention.

Essentially the different embodiments of the cill replacement units, shown in Figures 9 to 31 inclusive, encompass different dimensions and designs so as to accommodate different thicknesses of external wall insulation systems, different window frames and different original cills. For example, in Ireland a 100 mm thick insulation sheet is commonly used in External Wall Insulation Systems retrofitted to existing buildings. In the United Kingdom, a 70mm thick insulation sheet is commonly used. The different designs of the cill replacement units shown in Figures 9 to 31 accommodate the different thicknesses of insulation sheet. Moreover, different upstands, cill face angles and window frame reveals require slightly different cill replacement units to ensure good thermal insulation and low possibility of water ingress.

With reference to Figures 9 and 10 in particular, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 900. The cill replacement unit 900 comprises a main body 910 in abutment to and adhered to an insulation sheet 908. The insulation sheet 908 insulates an old wall 902 of an existing building having an original cill 906 and a window frame 904, made of a non-timber composite e.g. -22 -U PVC.

The ciii replacement unit 900 comprises the main body 910 and a rearward ciii piece 912 which rests atop the face of the original ciii 906 adjacent the upstand of the original ciii 906. The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the ciii replacement unit 900 and the insulation sheet 908.

Referring to Figure 11, wherein like pads previously described have been assigned the same reference numerals, there is provided a ciu replacement unit indicated generally by reference numeral 1100. The cifi replacement unit 1100 comprises a main body 1104 in abutment to and adhered to an insulation sheet 908. The insulation sheet 908 insulates an old wail 902 of an existing building having an original masonry cWi 1102 and a window frame 904.

The cifi replacement unit 1100 comprises the main body 1104 and a rearward ciii piece 1106 which rests atop the face of the original cWi 1102 adjacent the upstand of the original ciii 1102. The rearward ciu piece 1106 increases the cWl replacement unit 1100 ability to prevent thermal bridging. The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the ciu replacement unit 1100 and the insulation sheet 908.

With reference to Figures 12 and 13, wherein like parts previously described have been assigned the same reference numerals, there is provided a ciii replacement unit indicated generally by reference numeral 1200. The ciu replacement unit 1200 comprises a main body 1204 in abutment to and adhered to an insulation sheet 908.

The insulation sheet 908 insulates an old wail 902 of an existing building having an original ciu 1202 and a window frame 904.

The ciii replacement unit 1200 is comprised solely of a monobioc body piece 1204.

The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the ciu replacement unit 1200 and the insulation sheet 908.

Referring to Figures 14 and 15, wherein like parts previously described have been assigned the same reference numerals, there is provided a ciu replacement unit -23 -indicated generally by reference numeral 1400. The cill replacement unit 1400 comprises a main body 1404 in abutment to and adhered to an insulation sheet 908.

The insulation sheet 908 insulates an old wall 902 of an existing building having an original cill 1402 and a window frame 904.

The cill replacement unit 1400 comprises the main body 1404 and a rearward cill piece 1406 which rests atop the face of the original cill 1402 adjacent the upstand of the original cill 1402. The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the cill replacement unit 900 and the insulation sheet 908. In this embodiment, the window frame is made of timber and installing the cill replacement unit 1400 as shown earlier is not acceptable as the timber drip bead to the front of the lower section of the window frame must remain clear of the cill replacement unit 1400. In order to install an external insulation system with the cill replacement unit 1400 it is necessary to relocate the existing timber window forward to a position flush with existing substrate, or, flush with the inside edge of the insulation sheet 908. The procedure of installing the cill replacement unit 1400 to the insulation sheet 908 and to the existing substrate of the existing building are similar. The installation completion of the main body 1404 of the cill replacement unit 1400 will typically be conducted on site where the exposed faces of the rearward cill piece 1406 under the window frame will be base coated, re-enforcing mesh irnbedded, base coated and finish coat applied over the joint and tying-in the main body 1404 of the cill replacement unit 1400 and the upper exposed faces of the insulation sheet 908 under the window frame together.

With reference to Figures 16 and 17, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 1600. The cill replacement unit 1600 comprises a main body 1604 in abutment to and adhered to an insulation sheet 908.

The insulation sheet 908 insulates an old wall 902 of an existing building having an original cill 1602 and a window frame 904.

The cill replacement unit 1600 is comprised solely of a monobloc body piece 1604.

The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the cill replacement unit 1600 and the insulation sheet 908. In this -24 -embodiment, the adhesion strength of the ciii replacement unit 1600 is further enhanced by the fact the ciii replacement unit 1600 extends and is adhered to an underside of the window frame 904 using expanding foam, thus assisting in counter-acting any downward pressure on the dli replacement unit 1600. There is between a 2mm and 4 mm upstand at an uppermost point of the monobioc body piece 1604 on the cili replacement unit 1600 to accommodate the application of a sealant bead.

With reference to Figures 18 and 19, wherein like parts previously described have been assigned the same reference numerals, there is provided a cili replacement unit indicated generally by reference numeral 1800. The ciu replacement unit 1800 comprises a main body 1804 in abutment to and adhered to an insulation sheet 908.

The insulation sheet 908 insulates an old wail 902 of an existing building having an original ciii 1802 and a window frame 904.

The ciu replacement unit 1800 is comprised solely of a monobioc main body piece 1804. As with all of the ciu replacement units of the present invention, the multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the ciu replacement unit 1800 and the insulation sheet 908. in the present embodiment, and with particular reference to Figure 18, the window frame is a non-timber composite frame which is located at a forward position, which is to say, forward of the original substrate of the existing building, for the purpose of reducing the thermal bridge around the window frame 904 to achieve a substantially thermal bridge free performance. The adhesion strength of the ciu replacement unit 1800 is further enhanced by the fact the cWl replacement unit 1800 extends beneath and is adhered to an underside of the window frame 904 and the upper face of the original masonry cWi 1802 using expanding foam.

Referring to Figures 20 and 21 in particular, wherein like parts previously described have been assigned the same reference numerals, there is provided a ciu replacement unit indicated generally by reference numeral 2000. The ciu replacement unit 2000 comprises a main body 2004 in abutment to and adhered to an insulation sheet 908.

The insulation sheet 908 insulates an old wail 902 of an existing building having an original cWl 2002 and a window frame 904.

-25 -The ciii replacement unit 2000 comprises the main body 2004 and a rearward ciii piece 2006 which rests atop the face of the original ciii 2002 adjacent the upstand of the original ciii 2002 and beneath an underside of the window frame 904. The multi face adhesion surfaces 500, 502 on the ciii replacement unit 2000 and the insulation sheet 908 are used to form the strong adhesion between the ciii replacement unit 2000 and the insulation sheet 908 respectively.

With reference to Figures 22 and 23, wherein like parts previously described have been assigned the same reference numerals, there is provided a cM replacement unit indicated generally by reference numeral 2200. The ciu replacement unit 2200 comprises a main body 2204 in abutment to and adhered to an insulation sheet 908.

The insulation sheet 908 insulates an old wail 902 of an existing building having an original ciD 2202 and a window frame 904.

The cM replacement unit 2200 is comprised solely of a monobioc body piece 2204.

The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the cMi replacement unit 2200 and the insulation sheet 908. As with the embodiment shown in Figure 18, the window frame is located at a forward position for the purpose of reducing the thermal bridge around the window frame 904. Again, the adhesion strength of the cWi replacement unit 2200 is increased as the cM replacement unit 2200 extends beneath and is adhered to an underside of the window frame 904.

With reference to Figures 24 and 25, wherein like parts previously described have been assigned the same reference numerals, there is provided a cUll replacement unit indicated generally by reference numeral 2400. The ciu replacement unit 2400 comprises a single monobioc main body 2404 in abutment against and adhered to an insulation sheet 908. The insulation sheet 908 insulates an old wail 902 of an existing building having an original ciu 2402 and a window frame 904. The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the cUll replacement unit 2400 and the insulation sheet 908.

As mentioned hereinbefore, the regulations in the United Kingdom only stipulate that a 70mm thick insulation sheet be used. With references to Figures 26 to 31 inclusive, the ciu replacement units as envisaged in accordance with various embodiments of the -26 -present invention are shown installed to such insulation sheets.

Referring now to Figures 26 and 27 in particular, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 2600. The cill replacement unit 2600 comprises a main body 2604 in abutment to and adhered to an insulation sheet 2608. The insulation sheet 2608 insulates an old wall 902 of an existing building having an original cill 2602 and a window frame 904.

The cill replacement unit 2600 comprises the main body 2604 and a rearward cill piece 2606 which rests atop the face of the original cill 2002 adjacent the upstand of the original cill 2002 and in front of a foremost point of the window frame 904. The multi face adhesion surfaces 500. 502 on the cill replacement unit 2600 and the insulation sheet 2608 are used to form the strong adhesion between the cill replacement unit 2600 and the insulation sheet 2608 respectively.

With particular reference to Figures 28 and 29, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 2800. The cill replacement unit 2800 comprises a main body 2804 in abutment to and adhered to an insulation sheet 2608.

The insulation sheet 2608 insulates an old wall 902 of an existing building having an original masonry cill 2802 and a window frame 904.

The cill replacement unit 2800 is comprised solely of a monobloc main body piece 2804. The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the cill replacement unit 2800 and the insulation sheet 2608.

Referring now to Figures 30 and 31 in particular, wherein like parts previously described have been assigned the same reference numerals, there is provided a cill replacement unit indicated generally by reference numeral 3000. The cill replacement unit 3000 comprises a main body 3004 in abutment to and adhered to an insulation sheet 2608. The insulation sheet 2608 insulates an old wall 902 of an existing building having an original cill 3002 and a window frame 904. The cill replacement unit 3000 comprises the main body 3004 and a rearward cill piece 3006 which rests atop the -27 -face of the original cill 3002 adjacent the upstand of the original cill 3002. The multi face adhesion surfaces 500, 502 are used to form the strong adhesion between the cill replacement unit 3000 and the insulation sheet 2608.

In a preferred embodiment, a stock bead may be installed over the first basecoat on the wall of the existing building and ovel the reveals on the existing building and on all adjacent faces of the cill. Thereafter, the user would apply a sealant to that stock beading to form a continuous and unbroken seal at substantially all points where the cill replacement unit makes contact with the External Wall Insulation System, before the finish coat of the Extemal Wall Insulation System is installed.

It has been found in modelling the cill replacement unit of the present invention that a temperature factor of at least 0.93 can be achieved. In contrast, the "Metal over Cill" solution known from the prior art could only achieve a temperature factor of 0.75. The temperature factor is a normalised measurement of the efficiency of a thermal insulation, where a figure between 0' and 1' reflects the temperature factor, with 0' representing an external temperature, and 1' representing an internal temperature.

Condensation has also been reduced by the cill replacement unit of the present invention.

Throughout the preceding specification, the terms "cill" and "cill replacement unit", which are alternatively known as "sill", shall be understood to encompass any type of horizontal member or object located beneath a window, door, or other opening with the purpose or dispelling water away from a wall beneath and protecting a top face of the wall from weathering effects.

It will be further understood that the term "cill replacement unit" does not necessitate that the original masonry cill be excised and replaced, but rather that the cill replacement unit is installed over and on top of the original masonry cill thus replacing the appearance of the original masonry cill on the building.

Unless stated to the contrary, all measurements have been taken standard room temperature of 21 degrees centigrade and a standard sea-level pressure of approximately 1 bar.

-28 -The terms comprise" and "include', and any variations thereof required for grammatical reasons! are to be considered as interchangeable and accorded the widest possible interpretation.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims (1)

1. <claim-text>-29 -CLAIMS1. A method of installing a cill replacement unit to form part of an external wall insulation system on an existing building, the extemal wall insulation system comprising a plurality of insulation sheets, and, the method comprising the steps of: fixing the plurality of insulation sheets to an external wall of the building; and, adhering the cill replacement unit to at least one of the plurality of insulation sheets before any render application process has been carried out on the insulation sheets of the external wall insulation system.</claim-text> <claim-text>2. A method as claimed in claim 1, the method comprising the step of applying a render to the cill replacement unit and the plurality of insulation sheets after the cill replacement unit has been adhered to at least one of the plurality of insulation sheets.</claim-text> <claim-text>3. A method as claimed in claims 1 or 2, the method comprising the step of culling a multi-face adhesion surface on at least one of the plurality of insulation sheets.</claim-text> <claim-text>4. A method as claimed in any preceding claims, the method comprising the step of shaping a generic cill replacement unit to form a shaped cill replacement unit with a pre-defined cill face gradient and/or pre-defined cill wing dimensions and/or pre-defined cill nose dimensions.</claim-text> <claim-text>5. A method as claimed in any preceding claims, the method comprising the step of adhering the multi-face surface of the cill replacement unit to the multi-face surface of the at least one insulation panel using an expanded foam.</claim-text> <claim-text>6. A method as claimed in any preceding claims, the method comprising the step of applying a single pre-cut reinforcing mesh over the adhered cill replacement unit before apply a weather-proofing render.</claim-text> <claim-text>7. A method as claimed in any preceding claims, the method comprising the step of fixing at least one of the plurality of insulation sheets to the external wall of the -30 -building using a plurality of mushroom fixings arranged in a substantially horizontal line approximately 100mm beneath the lowermost point of the cill replacement unit which is adhered to that insulation sheet.</claim-text> <claim-text>8. A method as claimed in any preceding claims, the method comprising the step of fixing at least one of the plurality of insulation sheets to the external wall of the building using at least one mushroom fixing on either side of the cill replacement unit 100mm from the outermost point of the cill wings on the cill replacement unit which is adhered to that insulation sheet.</claim-text> <claim-text>9. A method as claimed in any preceding claims, the method comprising the steps of: applying a first basecoat and imbedding first re-enforcing mesh on all faces of the cill replacement unit; overlapping, fold-bandaging and buttertlying the first imbedded re-enforcing mesh to agrément certificate approved standards; applying a second basecoat to the first basecoat when dry and imbedding a further second re-enforcing mesh; overlapping, fold-bandaging and buttertlying the first imbedded re-enforcing mesh to agrément certificate approved standards; allowing the second basecoat to dry; applying a coat of self-levelling rapid curing polyurethane waterproofing membrane; applying an overcoat with a urethane sealant to prime all exposed faces of the cill replacement unit; allowing to dry; and, applying at least two coats of acrylic paint, or other render finish, over primed weather-proofing render of the cill replacement unit.</claim-text> <claim-text>10. A cill replacement unit comprised of an insulating material, whereby the cill replacement unit comprises a cill nose and cill wings along an outwardly projecting front portion of the cill replacement unit and a multi-face adhesion surface along a rear portion of the cill replacement unit, such that the multi-face adhesion surface of the cill replacement unit co-operates in a complementary -31 -manner with a multi-face adhesion surface on at least one of a plurality of insulation sheets forming an extemal wall insulation system to which the cill replacement unit is adhered, characterised in that the multi-face adhesion surface along the rear portion of the cill replacement unit comprises a plurality of faces whose longitudinal axes are arranged in the same plane or in parallel and are also arranged to face in substantially the same direction.</claim-text> <claim-text>11. A cill replacement unit as claimed in claim 10, wherein the cill replacement unit comprises an integrated steel corner bead adjacent edges of the outwardly projecting front portion of the cill replacement unit.</claim-text> <claim-text>12. A cill replacement unit as claimed in claims 10 or 11, wherein the cill replacement unit is adhered to the at least one insulation sheet using an expanding foam.</claim-text> <claim-text>13. A cill replacement unit as claimed in claim 12, wherein the expanding foam has a thermal conductivity of not greater than 0.035 Watts per Meter Kelvin (WI(mK)).</claim-text> <claim-text>14. A cill replacement unit as claimed in any of claims 10 to 13, wherein the cill replacement unit is comprised of an expanded polystyrene sheet.</claim-text> <claim-text>15. A cill replacement unit as claimed in any of claims 10 to 13, wherein the cill replacement unit is comprised of an ultra high density expanded polystyrene sheet.</claim-text> <claim-text>16. A support unit for a cill replacement unit as claimed in any of claims 10 to 15, wherein the support unit is compdsed of an insulation sheet having a capability to support at least 200 kPascals along its vertical longitudinal axis, when the support unit is installed as an insulation sheet on an external wall of an existing building and as part of a external wall insulation system.</claim-text> <claim-text>17. A method of installing a cill replacement unit as hereinbefore described with reference to the accompanying drawings.</claim-text> <claim-text>18. A cill replacement unit as hereinbefore described with reference to the -32 -accompanying drawings.</claim-text> <claim-text>19. A support unit for a ciii replacement unit as hereinbefore described with reference to the accompanying drawings.</claim-text>