GB2540436A - Ventilated cladding system and method of forming the same - Google Patents

Abstract

The ventilated cladding system 10, for an external wall of a timber framed building, comprises a spacer 14 for attaching between a timber substrate 12 of the external wall and a render carrying layer 16, which defines a ventilated cavity 36. A render composite 18 is applied to the render carrying layer, providing a decorative finish and limiting the ingress of water. The composite has a reinforcing base layer 54 for adhering to the render carrying layer, a mesh or skrim 58 associated with the reinforcing base layer, and a decorative render that adheres to the base layer. A breathable membrane 20 or fire barrier 52 may be provided between the substrate and spacer. The system may also comprise a bracket 164 for attaching to the base of the timber substrate, the bracket comprising a perforated portion 170 for allowing ventilation, and a render support portion 176.

Description

Ventilated Cladding System and Method of Forming the Same

The present invention relates to a ventilated cladding system particularly, but not necessarily exclusively, for an external wall of a timber framed building, and a method of forming the same.

In modem methods of construction, relatively inexpensive material, such as breeze blocks, steel or timber, is often used to construct a framework of a building. An external facing wall of such a framework may be vulnerable to the weather and ingress of moisture and a cladding system is regularly used to cover the external wall of the building for decorative and/or functional purposes.

Constructing a building using timber has several advantages over other building materials such as masonry or steel, such as shorter erection time and reduced labour requirements.

For a timber frame construction, a rainscreen cladding system is often used, whereby the cladding material is spaced away from the timber structure so that a cavity is provided therebetween. Although the cladding system is not entirely watertight, the cladding material is designed to deflect most of the water. When water does penetrate the cladding or condensate is formed in the cavity, it is either drained away down the inner surface of the cladding or it evaporates from the cavity. This system thus helps to keep the timber frame dry.

Typically, such a cladding system on a timber framed structure is either self-supporting, having its own foundation which is tied to the timber frame, or is fully supported by the timber structure.

The cladding system typically comprises batons fixed to the timber frame for providing a cavity. Fixing means, such as brackets or rails, may also be provided for fixing sheets of cladding material to the batons to create an outer skin that provides an aesthetic appearance and a barrier to the weather.

As the cladding material is required to be lightweight so that the cladding sheets may be safely supported by the timber frame, the choice of suitable cladding material and thus the choice of appearance of the outer skin of the building is limited. The cladding material is typically timber boarding, laminates, slates or tiles.

Occasionally, a building requires a specific outer appearance to, for example, blend in with its built and historical environment. However, the required appearance, such as brick or stone work, may not be replicable by the cladding material due to limitation on its weight. A more expensive and labour intensive method of construction, other than a timber frame, may therefore need to be used instead of erecting a timber frame. However, the current shortage of skilled brick layers means that the speed and cost of construction are negatively impacted. Such method of construction is also weather dependent as the majority of the work is required to be undertaken outdoors onsite.

Furthermore, when designing a timber frame building, an architect has to take into consideration the loading on the timber frame by the cladding system, thus limiting the freedom of design.

It is an object of the invention to provide a ventilated cladding system, for example for a timber frame construction, which substantially mitigates or reduces these problems.

According to a first aspect of the present invention there is provided a ventilated cladding system for an external wall of a timber framed building, the system comprising a spacer having an inner surface for attaching to a timber substrate of the external wall of the timber framed building and an opposing outer surface, a render carrying layer attachable to the outer surface of the spacer for allowing render to be applied thereon, the spacer defining a ventilated cavity between the timber substrate and the render carrying layer, and a render composite for applying to the render carrying layer, the render composite providing a decorative external finish and substantially preventing or limiting ingress of water, and having a reinforcing base layer for adhering to an outer surface of the render carrying layer, a mesh or scrim associated with the base layer for further reinforcement of the render composite, and an outermost decorative render layer for adhering to the base layer.

The ventilated cladding system is advantageous as it meets building guidelines and recommendations for timber framed constructions as set out by the relevant construction standards bodies, such as the Timber Research and Development

Association (TRADA), the National House Building Council (NHBC) and the British Board of Agrement (BBA). The cavity is created and maintained by the spacer, allowing any water or moisture seeping through the render composite to be drained on an inner surface of the render composite without reaching the timer substrate. The timber substrate is thus kept dry and moisture free.

The ventilated cladding system is weather resistant and has low maintenance requirements. It is tested to Guideline for European Technical Approval ETAG034 and can withstand wind loads as defined by the Centre for Window and Cladding Technology standards. The system is also UV and crack resistant, with an effective working life of between 25 and 60 years. The cladding system is also fire resistant.

The render composite serves as an effective barrier to prevent or limit ingress of water. It can be made from a range of materials with a wide variety of finishes whilst remaining lightweight, giving the architect greater design freedom when designing the building. The ventilated cladding system can be used even if the building requires a traditional looking facade, such as brick or stone work, without having to engage bricklayers to lay the actual brick or stone work. Thus the system reduces construction time and costs.

Furthermore, the ventilated cladding system can be prefabricated off site, reducing on site assembly and building time. It is also less labour intensive and less time consuming to install than traditional method of cladding. The system also reduces weather dependency of the build.

Preferable and/or optional features relating to the first aspect of the invention are set forth in claims 2 to 24.

According to a second aspect of the present invention there is provided a method of forming a ventilated cladding system on an external wall of a timber framed building in accordance with the first aspect of the present invention, comprising the steps of a] securing a spacer to a timber substrate of the external wall of the timber framed building, b] securing a render carrying layer to the spacer so as to create a ventilated cavity between the timber substrate and the render carrying layer, c] applying a render composite to an outer surface of the render carrying layer to form a decorative external finish to the building.

Preferable and/or optional features relating to the second aspect of the invention are set forth in claims 26 to 37.

According to a third aspect of the present invention there is provided a ventilated cladding system for an external wall of a timber framed building, the system comprising a spacer having an inner surface for attaching to a timber substrate of the external wall of the timber framed building and an opposing outer surface, a render carrying layer attachable to the outer surface of the spacer for allowing render to be applied thereon, the spacer defining a ventilated cavity between the timber substrate and the render carrying layer, and a render composite for applying to the render carrying layer for providing a decorative external finish and to at least substantially prevent ingress of water.

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

Figure 1 shows a perspective cutaway view of a first embodiment of a ventilated cladding system on a timber substrate of an external wall of a timber framed building, in accordance with the first and third aspects of the invention;

Figure 2 shows a cross sectional side view of the ventilated cladding system of Figure 1, adjacent a roof of the building;

Figure 3 shows a cross sectional side view of the ventilated cladding system of Figure 1, adjacent to a base of the building;

Figure 4 shows a cross sectional plan view of the ventilated cladding system of Figure l;

Figure 5a shows a perspective view of a base bracket of a second embodiment of a ventilated cladding system, in accordance with the first and third aspects of the invention; and

Figure 5b shows a cross sectional side view of the base bracket of Figure 5a.

Referring to Figures 1 to 4, a ventilated cladding system 10 is attached to a timber substrate 12 of an external wall of a timber framed building, the system 10 comprises a spacer 14, a render carrying layer 16 attachable to the spacer 14 and a render composite 18 applicable to the render carrying layer 16.

In the embodiment illustrated, the system 10 further comprises a breathable membrane layer 20 or breather membrane, mechanically fixed to the timber substrate 12 by, for example nails or staples 22. The breathable membrane layer 20 allows release of moisture from the timber substrate 12 but prevents entry of moisture or particulate matter into the timber substrate 12. The breathable membrane layer 20 also serves to insulate the timber substrate 12 to prevent or limit heat loss in the building and also as a barrier from any wind driven rain that may penetrate the render composite.

The breathable membrane layer 20, which may be or include a vapour control layer, is typically and preferably a flexible, durable, lightweight sheet material made from, for example, high density polyethylene or polypropylene. The breather membrane 20 may be fixed to the timber substrate 12 in the factory, or can be applied on site as soon as the timber frame of the building is erected.

The spacer 14 in the depicted embodiment comprises two spaced apart and parallel spacer members, preferably in the form of U-shaped galvanised steel rails 24, each preferably having a side flange 26 along each longitudinal side. Each rail 24 has an inner surface 27 facing, and for attaching to, the timber substrate 12 and an opposing outer surface 28 facing the render carrying layer 16.

Each steel rail 24 is mechanically attached to the timber substrate 12 via its side flanges 26 by, for example, screw fixings 30.

The depicted embodiment advantageously comprises an elongate strip of damp proof membrane 32 provided along, and attached to, a longitudinal extent of the outer surface 28 of each steel rail 24. The damp proof membrane 32 prevents or limits tracking of damp from the render composite 18 to the timber substrate 12. The damp proof membrane 32 is preferably attached to the steel rail 24 via adhesive.

The render carrying layer 16 is typically and preferably a magnesium oxide board and has outer and inner surfaces 33a, 33b. The carrying layer 16 is mechanically attached to the outer surface 28 of each U-shaped steel rail 24, for example by screw fixings 34. It will also be appreciated that other suitable fastening means, such as brackets, may be used. The render carrying layer 16 is preferably rigid and hydroscopic such that it provides structural support and adheres well to the render composite 18. The render carrying layer 16 is preferably 12mm or around 12mm in thickness. A cavity 36 is thus formed between the timber substrate 12 and the render carrying layer 16, along the longitudinal extent of the spacer 14. The spacer 14 is dimensioned such that the cavity 36 has a depth of a minimum of around 25 mm, meeting guidelines as set out by TRADA. It will be appreciated that the depth of the cavity 36 may be greater than 25mm, for example around 27 mm, 52 mm, 77 mm, 102 mm or 152 mm.

Best seen in Figure 2, the render carrying layer 16 and render composite 18 extend only part way along the longitudinal extent of the spacer 14 such that the render carrying layer 16 and render composite 18 are spaced from an upper end 38 of the spacer 14, adjacent for example a roof of the building. A first vent 40 is provided thereto, attached to the spacer 14 and parallel to the timber substrate 12, for substantially covering a first opening 42 to the cavity 36, allowing moisture to be evaporated out from the cavity 36. The first vent 40 is preferably around 25mm in height.

Best seen in Figure 3, a second opening 44 to the cavity 36 is provided at a lower end 46 of the spacer 14 and adjacent a base of the building, and a second vent 47 is provided thereon for substantially covering the second opening 44.

The cavity 36 is thus ventilated from top to bottom, allowing airflow and moisture to be evaporated out from the cavity 36. The cavity 36 creates a barrier for preventing or limiting any water seeping through the render composite 18 and the render carrying layer 16 from reaching the timber substrate 12. Any water that enters the ventilated cavity is either drained along an inner surface of the render carrying layer 16 and exits through the second opening 44, or is evaporated and exits through the first opening 42.

Entry of water is substantially prevented or limited through the first opening 42 into the cavity 36 by an overhang 48 of the roof of the building, as shown in Figure 2, or through the second opening 42 by a metal flashing 50 at the base of the building. The damp proof membrane 32 and the breathable membrane layer 20 prevent or limit ingress of water into the cavity 36 from reaching the timber substrate 12.

As a further safety feature, and as best seen in Figure 3, a fire barrier or seal 52 is advantageously provided, attached to the timber substrate 12 via mechanical attachment means such as screw fixings 53. The fire barrier 52 is provided in the ventilated cavity 36 proximate the lower end 46 of the spacer 14. The fire barrier 52 maintains the cavity 36 under normal conditions, allowing air to circulate freely. The fire barrier 52 comprises an intumescent, which swells and increases in volume when exposed to heat. In the event of a fire, the fire barrier 52 expands to seal the cavity and prevents the spread of fire. The intumescent also produces a light char which is a poor conductor of heat, and contains hydrates which releases water vapour and thus provides a cooling effect.

The render composite 18 comprises a reinforcing base coat or layer 54 adhered to the outer surface 33a of the render carrying layer 16 and an outermost decorative render layer 56 adhered to the base layer 54. The render composite 18 provides a decorative external finish to the building and substantially prevents or limits ingress of water into the timber substrate 12.

The base layer 54 typically comprises mortar, particularly mineral reinforcement mortar, suitable for adhering to the render carrying layer 16. The mortar, is mixed using a suitable mixer, such as a paddle mixer or spray machine, left to stand for a period of time, for example 5 minutes, and then remixed before application. The base layer 54 is applied to the render carrying layer 16 as a paste using conventional trowel techniques or by a suitable machine.

Whilst the base layer 54 is still wet, a mesh and scrim reinforcement 58 may be preferably bedded into the base layer 54, preferably into the outer third of a depth of the base layer 54 or adjacent an outer surface of the base layer 54. This serves as further reinforcement of the render composite 18.

The base layer 54 is then dried or cured, preferably for around 24 to 48 hours, at 15°C and at most 70% air humidity. In the illustrated embodiment, a slurry layer 60 is applied onto the base layer 54, preferably by conventional trowelling techniques, ensuring any voids on the base layer 54 are filled.

The slurry layer 60 preferably has a thickness of around 2mm and is allowed to dry prior to application of the outermost decorative render layer 56. The slurry layer 60 provides a suitable surface for the outermost decorative render layer 56 to bond thereon, and preferably comprises of cement mixed with water.

The outermost decorative render layer 56 in the depicted embodiment comprises a silicone based render layer 62. The material of the silicone based render layer 62 may be stirred or may be mixed with water to aid workability, and is then applied by conventional trowelling techniques, preferably utilising a stainless steel trowel.

The silicone based render layer 62 is preferably applied in dry weather condition, and to achieve a thickness of between around 1mm and 4mm, preferably between 1.25mm and 3.75mm, and even more preferably between 1.5mm and 3.5mm.

Once applied, the silicone based render layer 62 is then rubbed in a circular motion to create an even rolled texture appearance. The layer 62 is then left to dry naturally, preferably for around 14 days.

Although the silicone based render layer 62 is white, a different colour may be achieved by tinting the material with a coloured pigment.

It will be appreciated that the outermost decorative render layer 56 may be a render other than the silicone based render layer 62. For example, the outermost decorative render layer may be an aggregate dash. A dashing render, preferably a polymer dashing render paste formed by mixing dry premixed polymer and fibre reinforced powder with water, is first applied preferably to a thickness of around 8 mm to 10 mm by either conventional trowel techniques or a suitable machine.

Before the dashing render is dried or cured, aggregates, such as aggregate stones, are applied to the dashing render, preferably to a thickness of around 3 mm to 8 mm.

As yet another alternative, the outermost decorative render layer 56 may have a brick or stone work appearance.

To achieve the brick work appearance, traditional clay brick slips or acrylic brick slips may be used which are adhered to the base layer by the appropriate adhesive.

For example, an acrylic adhesive is used in conjunction with acrylic brick slips. Acrylic brick slips are straightforward to apply, by directly placing and pushing the slips on to the adhesive. The adhesive between the brick slips is smoothed with a brush to create the mortar joints. Acrylic brick slips are lightweight and are particularly suited for using in high rise buildings.

If clay brick slips are to be used, a fibreglass mesh is used to aid adhesion of the brick slips to the adhesive and pointing mortar is then used to grout around the brick slips to achieve a brick work finish.

To achieve a stone or slate work appearance, stone or slate veneer tiles may be used. Such tiles have a tough composite backing substrate or layer, such as a fibreglass composite layer, where a stone or slate veneer layer is adhered thereon. To install the veneer tiles, a layer of adhesive is first applied to the base layer and the veneer tiles are adhere thereon. Grouts, preferably water-based epoxy grouts, are used to fill between adjacent tiles, and sealers are applied to seal the veneer tiles.

The veneer tiles allow the stone or slate appearance to be achieved without the weight of traditional stone or slate work. The veneer tiles are flexible and can be bent to the same degree as any plastic tiles. The veneer tiles are also durable and weather resistant. The backing layer improves the strength of the stone or slate veneer, whilst allowing the tiles to be flexed round corners.

The veneer tiles may be cut using hand sheers or knives, rather than diamond saws as required by traditional stone or slate tiles. As the veneer tiles are light in weight, larger sheets may be used which saves installation time and labour costs. A second embodiment illustrating an additional feature associated with a second embodiment of a ventilated cladding system is shown in Figures 5a and 5b. Similar or identical references refer to parts which are similar or identical to those described above, and therefore further detailed description is omitted.

The second embodiment of the ventilated cladding system comprises a base bracket or beading 164 provided adjacent the base of the building and is attachable to or adjacent to a base of the timber substrate 12. The base bracket 164 has a back plate 166 for abutting against the timber substrate 12 and is provided with one or more apertures 168 for receiving fixing means, such as screw fixings or nails so that the base bracket 164 can be attached to the timber substrate 12. A base plate 170 extends away, preferably perpendicularly or substantially perpendicularly, from the back plate 166. The base plate 170 has a plurality of perforations 172 therethrough forming a perforated portion 174. The perforated portion 174 serves as a vent, similarly to the second vent 47 in the first embodiment of the ventilated cladding system 10, covering the second opening 44 and allowing the cavity 36 to be ventilated. A render support portion 176 is provided at a distal end of the base plate 166 for supporting at least one of the render carrying layer 16 and the render composite 18. Similar to the first embodiment, the render support portion 176 is preferably U-shaped or substantially U-shaped, having a base 178 and two side walls 180. The render support portion 176 defines a channel 182 therein for receiving a portion of the render carrying layer 16 and/or the render composite 18. The render support portion 176 serves as a structural support for the render carrying layer 16 and the render composite 18, and the shape of the render support portion 176 retains the render carrying layer 16 and the render composite 18 thereon.

Although flat, flush or coplanar in the first embodiment, the base 178 of the render support portion 176 is preferably inferiorly offset from the base plate 170. When the building is experiencing strong wind, condensate at or adjacent the second vent 47 may be blown back into the cavity 36, or moisture may be blown into the cavity 36. The offset render support portion 176 effectively forms a baffle for the base 178 of the render support portion 176 to ensure the cavity 36 is ventilated and condensate can escape the cavity 36. The height of the side walls 180 of the render support portion 176 is preferably less than than the height of the back plate 166 to allow fixing means to be inserted through the back plate 166 unimpeded or substantially unimpeded.

To install the cladding system, as already discussed above, the spacer 14 is secured to the timber substrate 12 of the external wall of the timber framed building, preferably after a breathable membrane layer 20 and/or a fire barrier or seal 52 are secured to the timber substrate 12. If the base bracket 164 is required, the base bracket 164 is attached to the timber substrate 12.

The render carrying layer 16 is then secured to the spacer 14, and also to the base bracket 164 if utilised, so as to create a ventilated cavity 36 between the timber substrate 12 and the render carrying layer 16. To further prevent moisture from reaching the timber substrate 12, the damp proof membrane 32 is preferably secured and provided between the spacer 14 and the render carrying layer 16. The render composite 18 is then applied to the outer surface of the render carrying layer 16 to form a decorative external finish to the building.

It is thus possible to provide a cladding system 10 that is light weight and suitable to be used with a high rise building, and/or a timber framed building. It is suitable to be used with brick slips or stone veneer tiles to create the traditional brick or stone work appearance, and has advantages of being less labour intensive and time consuming to install. The system may also be assembled off site in a factory thus reducing building time on site. The cladding system 10 meets guidelines and recommendations for timber frame constmctions.

It will be appreciated that although a breathable membrane layer and/or damp proof membrane are preferably provided as additional means to prevent moisture from entering into the timber substrate, they may be dispensed with to simplify cladding system installation. The fire seal may also be dispensed with if other suitable means to prevent or limit spread of fire are in place.

Although the breathable membrane layer is preferably made from high density polyethylene or polypropylene, other suitable materials which provide similar weather proofing characteristics may be used.

It will be appreciated that rails provided to form the spacer may be made of a material other than galvanised steel, as long as it is of a suitable material for maintaining the cavity and providing structure support to the render carrying layer and the render composite. Furthermore, the spacer may be provided by batons, for example treated timber batons. The spacer may also be provided as a single spacer member, or more than two spacer members.

Although the base bracket preferably extends a whole or substantially whole lateral extent of the render carrying layer, it may also only extend part way to allow a plurality of spaced apart base brackets to be used.

The render support portion of the base bracket may be in a shape other than U-shaped, for example L-shaped.

The base bracket is preferably formed as one piece to provide maximum rigidity. It is preferably formed with plastics. Where attachment of a layer is described to be achieved by mechanical fixing means, it will be appreciated that the attachment may be achieved by other fixing means, such as adhesive.

It will be appreciated that although a single magnesium oxide board may be used to provide the render carrying layer, it will be appreciated that multiple boards may be used side by side in order to completely cover the external wall of the building. Magnesium oxide board is particularly suitable to be used as it is non-combustible and rigid, however other suitable material having similar properties may also be used.

The mesh or scrim, and/or the slurry coat, strengthen the base layer of the render composite. However, it will be appreciated that they may be dispensed with.

The words ‘comprises/comprising’ and the words ‘having/including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of this invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departure from the scope of the invention as herein described.

Claims (39)

Claims

1. Ventilated cladding system for an external wall of a timber framed building, the system comprising a spacer having an inner surface for attaching to a timber substrate of the external wall of the timber framed building and an opposing outer surface, a render carrying layer attachable to the outer surface of the spacer for allowing render to be applied thereon, the spacer defining a ventilated cavity between the timber substrate and the render carrying layer, and a render composite for applying to the render carrying layer, the render composite providing a decorative external finish and substantially preventing or limiting ingress of water, and having a reinforcing base layer for adhering to an outer surface of the render carrying layer, a mesh or scrim associated with the base layer for further reinforcement of the render composite, and an outermost decorative render layer for adhering to the base layer.

2. Ventilated cladding system as claimed in claim 1, wherein the mesh or scrim is embedded in the base layer.

3. Ventilated cladding system as claimed in claim 1 or claim 2, wherein a slurry layer is provided between base layer and the render composite.

4. Ventilated cladding system as claimed in claim 2 or claim 3, wherein the base layer comprises mortar.

5. Ventilated cladding system as claimed in any one of claims 2 to 4, wherein the outermost decorative render layer comprises a silicone based render.

6. Ventilated cladding system as claimed in any one of claims 2 to 4, wherein the outermost decorative render layer comprises an aggregate dash.

7. Ventilated cladding system as claimed in any one of claims 2 to 4, wherein the outermost decorative render layer comprises brick slip tiles.

8. Ventilated cladding system as claimed in claim 7, wherein the brick slips are made of acrylic.

9. Ventilated cladding system as claimed in any one of claims 2 to 4, wherein the outermost decorative render layer comprises stone or slate veneer tiles.

10. Ventilated cladding system as claimed in claim 9, wherein the and each stone or slate veneer tile has a composite backing layer and a stone or slate veneer layer attached to the backing layer.

11. Ventilated cladding system as claimed in any one of claims 7 to 10, the outermost decorative render layer being flexible.

12. Ventilated cladding system as claimed in any preceding claim, further comprising a breathable membrane layer provided between the timber substrate and the spacer.

13. Ventilated cladding system as claimed in any preceding claim, further comprising a fire barrier or seal provided between the timber substrate and the spacer for closing off the cavity in the event of fire.

14. Ventilated cladding system as claimed in any preceding claim, wherein the render carrying layer is rigid

15. Ventilated cladding system as claimed in any preceding claim, wherein the render carrying layer is hydroscopic.

16. Ventilated cladding system as claimed in any preceding claim, wherein the render carrying layer includes a magnesium oxide board.

17. Ventilated cladding system as claimed in any preceding claim, the spacer having at least two spaced apart and parallel spacer members.

18. Ventilated cladding system as claimed in any preceding claim, the or each spacer being made of treated timber or galvanised steel.

19. Ventilated cladding system as claimed in any preceding claim, further comprising a damp proof membrane attachable to the outer surface of the spacer and provided between the spacer and the render carrying layer for preventing tracking of damp from the render composite to the timber substrate.

20. Ventilated cladding system as claimed in any preceding claim, the ventilated cavity being at least 25mm in depth.

21. Ventilated cladding system as claimed in any preceding claim, further comprising a base bracket for attaching to or adjacent to a base of the timber substrate, the bracket having a perforated portion for allowing ventilation of the ventilated cavity, and a render support portion.

22. Ventilated cladding system as claimed in claim 21, wherein the base bracket comprises a back plate for attaching to the timber substrate and a base plate extending away from the back plate, the base plate having the perforated portion provided therein and the render support portion provided at a distal end of the base plate.

23. Ventilated cladding system as claimed in claim 22, wherein the render support portion is U-shaped or substantially U-shaped and defines a channel therein for receiving a portion of at least one of the render carrying layer and render composite.

24. Ventilated cladding system as claimed in claim 23, wherein a base of the render support portion is inferiorly offset from the base plate.

25. A method of forming a ventilated cladding system on an external wall of a timber framed building as claimed in any one of claims 1 to 24, comprising the steps of a] securing a spacer to a timber substrate of the external wall of the timber framed building, b] securing a render carrying layer to the spacer so as to create a ventilated cavity between the timber substrate and the render carrying layer, c] applying a render composite to an outer surface of the render carrying layer to form a decorative external finish to the building.

26. A method of forming a ventilated cladding system as claimed in claim 25, wherein step c] is divided into steps: c](i) applying a base layer to the render carrying layer; c](ii) adhering an outmost decorative render layer to the base layer.

27. A method of forming a ventilated cladding system as claimed in claim 26, wherein prior to step c](ii) further comprises step: c](iii) bedding a mesh or scrim into the base layer.

28. A method of forming a ventilated cladding system as claimed in claim 26 or claim 27, wherein prior to step c](ii) further comprises step: c](iv) applying a slurry layer to the base layer prior to adhering the outmost decorative render layer thereon.

29. A method of forming a ventilated cladding system as claimed in any one of claims 26 to 28, wherein the base layer is applied to the render carrying layer as a paste and is then set or cured.

30. A method of forming a ventilated cladding system as claimed in any one of claims 26 to 29, wherein the outermost decorative render layer comprises a silicone based render applied to the render carrying layer as a paste and is then set or cured.

31. A method of forming a ventilated cladding system as claimed in any one of claims 26 to 29, wherein the outermost decorative render layer comprises an aggregate dash whereby an adhesive layer is applied to the render carrying layer as a paste and the aggregate is applied to the adhesive layer before the outermost decorative render layer is then set or cured.

32. A method of forming a ventilated cladding system as claimed in any one of claims 26 to 29, wherein the outermost decorative render layer comprises brick slip tiles whereby an adhesive layer is applied to the render carrying layer as a paste and the brick slips are applied to the adhesive layer before the outermost decorative render layer is then set or cured.

33. A method of forming a ventilated cladding system as claimed in any one of claims 26 to 29, wherein the outermost decorative render layer comprises stone or slate veneer tiles, whereby an adhesive layer is applied to the render carrying layer as a paste and the stone or slate veneer tiles are applied to the adhesive layer.

34. A method of forming a ventilated cladding system as claimed in any one of claims 25 to 33, prior to step a] further comprising step: d] attaching a breathable membrane layer to the timber substrate prior to securing the spacer to the timber substrate.

35. A method of forming a ventilated cladding system as claimed in any one of claims 25 to 34, wherein prior to step a] further comprises step: e] attaching a fire barrier or seal to the timber substrate prior to securing the spacer to the timber substrate.

36. A method of forming a ventilated cladding system as claimed in any one of claims 25 to 35, wherein prior to step b] further comprises step: f] attaching a damp proof membrane on an outer surface of the spacer prior to securing the render carrying layer to the spacer.

37. A method of forming a ventilated cladding system as claimed in any one of claims 25 to 36, wherein prior to step b] further comprises step: g] attaching a base bracket at or substantially at a base of the timber substrate, such that when the render carrying layer is secured to the spacer at step b], the render carrying layer is supported by a render support portion of the bracket and the ventilated cavity is ventilated through a perforated portion of the bracket.

38. Ventilated cladding system for an external wall of a timber framed building, the system comprising a spacer having an inner surface for attaching to a timber substrate of the external wall of the timber framed building and an opposing outer surface, a render carrying layer attachable to the outer surface of the spacer for allowing render to be applied thereon, the spacer defining a ventilated cavity between the timber substrate and the render carrying layer, and a render composite for applying to the render carrying layer for providing a decorative external finish and to substantially prevent ingress of water.

39. Ventilated cladding system substantially as described herein with reference to Figures 1 to 4 or Figures 5a and 5b of the accompanying drawings.