AU2011203313A1 - Fire resistant installation - Google Patents

Abstract

A wall or roof installation 10 including a plurality of spaced apart wall, roof or floor structural members 11, and a multilayer structure 15 which extends 5 across and/or between the structural members 11. The multilayer structure 15 includes a fire resistant layer 20, which is fixed either across or between the structural members 11 and a first render layer 21, which has a thickness inbetween 2.5mm and 100mm, and which extends between the structural members 11 and across the fire resistant layer 20. The multilayer structure 15 0 resists the entry of fire into a building. fv rl) f-j ........... . (\AA r-"N e-

Description

P/00/01 1 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: FIRE RESISTANT INSTALLATION Applicant: Haig-Davis Pty Ltd The following statement is a full description of this invention, including the best method of performing it known to me: 1 6067 SYC 2 A FIRE RESISTANT INSTALLATION FIELD OF THE INVENTION This invention relates to a panel or to an installation which includes a panel which 5 resists the entry of fire into a building. The invention also relates to a method for installing a panel or an installation into a building. In particular this invention relates to an installation for the walls and roofs and floors of houses or apartments, or small or large scale commercial buildings. 0 BACKGROUND Constructing buildings using fire resistant materials is desirable, particularly in areas where there is a high risk of fire, such as bushfire-prone areas. In some areas, buildings may need to be constructed in compliance with particular 15 standards to increase the extent that the building is resistant to fire. For example, in Victoria, Australia in response to the Black Saturday bushfires in 2009, the Victorian government introduced a new residential building standard in the Victorian Building Regulations 2006. The standard specifies that new dwellings in high bushfire risk areas must be constructed using materials of particular specifications. 20 When building a dwelling for increased fire resistance during a bushfire event, not only is the construction of the dwelling required to resist ignition during the period in which the dwelling might be engulfed or at least exposed to the flame of the bushfire, but it should also be built to resist ignition once the fire front or bushfire has passed. 25 There is evidence to indicate that timber framing, of the kind which is used in walls, roofs and floors of a dwelling, can retain residual heat once the fire event has passed, and in some circumstances that heat can increase as time passes. Thus, even after some considerable time has elapsed, the timber components can ignite and thus the dwelling can again be at risk of significant fire damage or complete destruction. 30 In addition to the potential for damage to the dwelling itself, because re-ignition often occurs well after the fire front has passed, the occupants of the dwelling could well have returned to the dwelling and be unaware of the danger of re-ignition. Thus, quite unexpectedly, the occupants can be caught again in a fire situation and this is most 3 dangerous if the occupants have retired to bed and a fire takes hold before they are awoken. Construction of buildings using insulating materials is also desirable, particularly to 5 reduce the extemal heating and/or cooling costs of a building. Minimum insulation levels may be specified in some areas. However there has been dissatisfaction with some aspects of the requirements which are considered by some to increase the cost of housing and by others to restrict the 0 aesthetic design of housing. In addition, it is very difficult to retrofit existing fire resistant materials to existing housing structures without requiring significant reconstruction and affecting the aesthetics of the original structure. It would be desirable to increase the fire resistance of both new buildings and existing 15 buildings by providing an installation for a building that is able to resist the entry of fire into a building. It would be further desirable to provide an installation that is relatively inexpensive and/or relatively easy to fit, not only to new buildings but also to existing buildings. It would also be desirable to provide an installation which has insulating properties. 20 SUMMARY OF THE INVENTION The Applicant has developed a panel, and an installation which includes a panel which has a multilayer structure, which can be installed at least partly between the structural members of a wall or roof or floor of a building to resist the entry of fire into 25 a building. In some forms of the invention there is provided a wall or roof or floor installation including a plurality of spaced apart wall or roof or floor structural members and a multilayer structure which extends across and/or between the structural members, the 30 multilayer structure including a fire resistant layer which is fixed relative to the structural members across and/or between the structural members, and a first render layer having a thickness of between 2.5mm and 100mm which extends between the structural members and across the fire resistant layer, wherein the multilayer structure resists the entry of fire into a building.

4 Advantageously, the installation may be installed as new buildings are constructed, or may be retrofitted to existing houses. In addition, the panel can be manufactured in relatively cheap forms so that the expense of the installation is low and potentially of a 5 similar or lower cost to existing constructions. The present invention also provides a panel for installation between the structural members of a wall or roof or floor to resist the entry of fire into a building, the panel including: 0 (i) a fire resistant layer of between 2.5mm to 100mm thickness and a render layer of between 2.5mm to 100mm thickness, wherein the render layer is fixed to the fire resistant layer and extends across the fire resistant layer, or (ii) a fire resistant layer of between 2.5mm to 100mm thickness and an intermediate layer fixed to the fire resistant layer, wherein the intermediate 15 layer extends across the fire resistant layer, or (iii) a fire resistant layer of between 2.5mm to 100mm thickness, an intermediate layer and a render layer of between 2.5mm to 100mm thickness, wherein the intermediate layer is sandwiched between the fire resistant layer and the render layer and the intermediate layer and the 20 render layer each extend across the fire resistant layer. The present invention also provides a method for installing a multilayer structure between a plurality of spaced apart wall or roof or floor structural members to resist the entry of fire into a building, including the steps of: 25 (i) fixing a fire resistant layer of between 2.5mm to 100mm thickness across and/or between the structural members so that the fire resistant layer is fixed relative to the structural members; (ii) applying a first layer of render of between 2.5mm to 100mm thickness to the fire resistant layer, such that the first layer of render extends between 30 the structural members and into at least partial contact with facing surfaces of the structural members. An alternative method according to the invention includes the steps of: 5 (i) removing the inner or outer layer of a wall to expose an existing wall layer which is located across and/or between the structural members; and (ii) applying a first layer of render of between 2.5mm to 100mm thickness across the existing wall layer between the structural members and into at 5 least partial contact with facing surfaces of the structural members. A still further method according to the invention includes the steps of: (i) fixing a fire resistant layer of between 2.5mm to 100mm thickness across and/or between the structural members so that the fire resistant layer is 0 fixed relative to the structural members; (ii) fixing an intermediate layer relative to the structural members so that it extends between respective structural members; (iii) applying a layer of render of between 2.5mm to 100mm thickness across the intermediate layer between the structural members and into at least 5 partial contact with facing surfaces of the structural members. For a better understanding of the invention and to show how it may be performed, preferred embodiments thereof will now be described by way of non-limiting example only, with reference to the accompanying Figures. !0 BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a partial sectional view of a wall installation according to an embodiment of the invention. 25 Figure 2 is a partial sectional view of a roof installation according to an embodiment of the invention. Figure 3 is a vertical cross sectional view of a roof installation of Figure 2. 30 DETAILED DESCRIPTION Figure 1 shows an installation 10 according to one embodiment of the invention. The installation 10 includes standard structural members that are used in the construction of a wall of a house and comprise a plurality of spaced apart horizontal studs 11, top members 12 and bottom members 13 between which the horizontal studs 11 extend 6 and noggins 14 which extend between the horizontal studs 11 midway between the top members 12 and bottom members 13. A multilayer structure 15 which extends across and/or between the spaced apart horizontal studs 11 is also provided. 5 The structural members illustrated in Figure 1 can be constructed from any suitable material, but typically the material will be timber or steel. The multilayer structure 15 is illustrated in Figure 1 as comprising an outer fire resistant layer 20, a first render layer 21, an intermediate layer 22, and a second 0 render layer 23. The outer fire resistant layer 20 can be a fire resistant board that is applied to extend across the outer face of the horizontal studs 11. Alternatively, it can extend between the horizontal studs 11, or it can extend across the inner face of the horizontal studs, or a mixture of these arrangements can be adopted. The fire resistant layer 20 is preferably a board sold under the name "Multiboard" such as the 15 type Multiboard MB x-line. The fire resistant layer may alternatively be plasterboard or fibro cement sheet, such as those sold by James Hardie, or may be made from other suitable fire resistant materials, for example, metals such as a steel sheet, or a fire resistant timber. 20 The fire resistant layer can alternatively be a layer which is not fire resistant but which provides a barrier to the ingress of heat or sound into a building, or in other words, provides heat or sound insulation. Thus, the invention which has been described earlier herein in broad terms, or in the more specific terms in relation to the drawings covers fire resistant layers as have been described, but where those layers have 25 been described as fire resistant, it is to be appreciated that they could alternatively be heat or sound resistant. The fire resistant layer is not necessarily required to provide complete resistance to the entry of fire into the building. Rather, the fire resistant layer is intended to provide 30 a major barrier to the entry of fire into the building. Extension of the outer fire resistant layer 20 across the outer face of the horizontal studs 11 provides resistance to entry of fire adjacent the side surfaces of the horizontal studs 11. The fire resistant layer 20 can be between 2.5mm to 100mm thick. Preferably, the fire resistant layer is about 9mm. Other thicknesses can be about 4mm or 6mm.

7 The fire resistant layer can be made of suitable materials as described herein to prevent the entry of fire into the building and/or can be made of a sufficient thickness to prevent fire entry. In some geographical areas, building standards apply that 5 dictate characteristics in relation to fire resistance. For example in Victoria, Australia, a building to which the invention may be applied may be situated in an area that is classified as a Bushfire Attack Level (BAL) "19" or "29" zone, according to building standards put in place in April 2010. To comply with the characteristics in relation to fire resistance for BAL-19 and BAL-29 zones, the fire resistant layer in an installation 0 according to the invention is preferably at least 6mm thick. If the building is situated in an area that is classified as a "BAL-40" zone, the fire resistant layer is preferably at least 9mm thick. The fire resistant layer 20 may be fixed to the structural members in any way that is 15 suitable, such as with screws, nails, masonry anchors, bolts and nuts, glues, renders or clamps. The first render layer 21 of the multilayer structure 15 is fixed to the outer fire resistant layer 20 in any suitable manner such as by its own adhesive qualities or by or with ?0 assistance of suitable fasteners such as self tapping screw fasteners. The render layer 21 can be between 2.5mm to 100mm thick although testing of the multilayer structure 15 has revealed a preference of between about 5mm to 50mm thick, particularly about 30 mm thick. Preferably, the render layer 21 can be applied to the fire resistant layer 20 after that layer has been applied to the horizontal studs 11. 25 Alternatively, it is possible that the render layer can be applied before application of the fire resistant layer 20 to the horizontal studs 11. The render layer 21 can be fixed to the fire resistant layer 20 so that the layer 21 extends between respective structural members and into at least partial contact with 30 facing surfaces of the structural members. Thus, the render layer 21 can be applied so that it is in contact with facing surfaces of the horizontal studs 11, or facing surfaces of the top and bottom members 12 and 13 and the noggins 14. For this arrangement, it is preferred to apply the render after application of the fire resistant layer 20 across or between the horizontal studs 11.

8 When the render layer 21 extends between respective structural members and into at least partial contact with facing surfaces of the structural members, the render layer can be made to completely cover the portion of the fire resistant layer 20 that is 5 exposed between the respective structural members. Advantageously, such a render layer can assist to resist the entry of fire into the building by providing a further barrier to entry of fire. In addition, by applying the render in contact with facing surfaces of the structural members, flame can be prevented or at least resisted from entering the building through gaps between the render and the facing surfaces. This is important, 0 because where the structural members are timber, ignition of the structural members only usually occurs if the structural members are exposed to flame rather than just intense heat. Timber is very good at resisting ignition in elevated heat conditions, but can ignite when exposed to flame, particularly in elevated heat conditions. As flame can penetrate through even very small openings such as fissures, the elimination of 15 such openings can be very important in the prevention of entry of flame into a building. Timber can also store heat as discussed earlier so that re-ignition can occur later and well after a fire front has passed. The heat in the timber can actually increase as time 20 passes so that ignition can be more likely well after the flame front has passed, so that the occupants of the building would not expect re-ignition of the timber in the floor, roof or walls to occur. The use of render to cover the surfaces of the timber can thus minimise the likelihood of re-ignition. 25 The render can be made or selected to adhere to the facing surfaces of the structural members to eliminate openings or gaps completely. Movement of the structural members may disturb that adhesion, but the render will likely remain in very close proximity to facing surfaces of the structural members even if the complete adhesion of the render to the surfaces is disturbed in sections of the structural members. 30 The render layer 21 can be a fire resistant layer. The render layer can be made from a mixture that includes ground perlite, fondu cement, crushed limestone and sand. Perlite improves the fire resistant properties of the render. Alternatively, other appropriate materials such as vermiculite may be used instead of or in addition to 9 perlite. Advantageously, fondu cement promotes the setting of the render layer and improves the fire resistant properties of the render. The preferred render composition that has been developed by the applicant can 5 include a mixture of the following components in the amounts specified. Material Amounts Perlite (ground fine) 1 part Perlite (ground medium) 1 part 0 Perlite (ground coarse) 1 part Sand or scoria % part Cement 1 part Limestone (crushed) 1/2 part Fondu cement % part 15 The materials are mixed in an appropriate amount of water which can be readily determined by the skilled person. Alternatively, the render may not include cement at all. For example, a mixture of perlite, lime and sand may be used. 20 The fire resistant layer 20 and/or render layer 21 can also have thermal insulation properties. Advantageously, such thermal resistant properties are likely to be present when the installations and panels of the invention are made from fire resistant materials. This beneficially provides the building with thermal insulation, and this can reduce external heating and/or cooling costs. Further advantageously, the 25 installations and panels of the invention can also provide sound insulation for the building. In some embodiments of the invention, the render layer 21 may also include a mesh substrate (or mesh layer) that has been pushed or inserted into the render layer 30 before the render hardens, so that the mesh layer is fixed into and/or at or adjacent one surface of the render layer. The mesh substrate can increase the stability of the render layer and assists in holding the render in a fixed position.

10 The mesh substrate may be made from any suitable material, such as a thin wire mesh typically known as chicken wire mesh, a steel wire mesh, fibreglass or plastic. A thin wire mesh is preferred, as there is less chance a thinner wire mesh will buckle and distort in a fire situation when compared to a thicker wire mesh. 5 It is to be noted that the multilayer structure 15 could have a significant weight, however the structural members of a wall or roof or floor can readily support the weight of the structure. Advantageously, when the multilayer structure is constructed from the preferred materials, it is relatively lightweight. 0 The intermediate layer 22 of the multilayer structure 15 is fixed to the first render layer 21 by any suitable manner, such as by adhesion between the render layer 21 and the spacer layer 22. Other methods of fixing the intermediate layer 22 to the render layer 21 can be employed, such as including nails, screws etc. Like the render layer 21, 15 the intermediate layer 22 extends between adjacent horizontal studs 11. The intermediate layer 22 can be made from a foam material. Polystyrene is a preferred foam material because it is lightweight and relatively inexpensive. Other foams are also suitable for use as the intermediate layer, such as polyurethane, 20 polyisocyanurate, polyolefin or other speciality foams. Materials other than foams may also be used for the intermediate layer, such as timber, metals, plastics, other polymer or composite structures. Lightweight materials are preferred. The intermediate layer can be a cheap and lightweight material which can assist both 25 the fire resistance and thermal insulation properties of the installation of the invention. The intermediate layer 22 is preferably of a thickness of between about 15mm to 50mm thick, such as between about 20mm to 40mm thick. The intermediate layer can be shaped to fit against the structural members. For 30 example, the intermediate layer can have bevelled or splayed edges to create a wedge between the intermediate layer and the facing structural members into which render can be inserted so that good contact between the render and the structural members can be made.

11 The intermediate layer 22 can include a portion which aids the fixing of the intermediate layer to either of the first and second render layers 21 and 23. The portion may be made of a material such as render or cement which adheres to the surface of the intermediate layer 22 and which promotes adhesion to the first and/or 5 second render layers 21 and 23. The portion may be a thin layer, which is about 1 mm to 5mm thick. Further, a mesh substrate (or mesh layer, not illustrated) can be placed on or fixed to the intermediate layer 22 and an additional and thin render layer in the order of about 0 2 to 5mm thick may be applied over the mesh layer, so that the mesh layer is fixed to the intermediate layer by the render. The mesh layer assists the fixing of the first and/or second render layers 21 and 23 to the intermediate layer 22. The mesh structure may be made from any suitable material as described herein. l5 The intermediate layer can be shaped so that it forms an air space within the multilayer installation. As shown in Figure 1, one side of the intermediate layer 22 includes two spacers 24 which are spaced apart so as to form an air space A between the intermediate layer 22 and the render layer 21. In this embodiment, the air space A extends vertically within the multilayer structure 15. ?0 Advantageously, such air spaces can also increase both the sound and heat insulating properties of walls or roofs or floors having installations with multilayer structures according to the invention. 25 In some embodiments of an installation according to the invention, there may be an opening in a section of a structural member which is adjacent to the air space. In embodiments of the invention where such an air space runs vertically for the height of the multilayer structure, the noggin or noggins which are above and/or below the air space can have an opening through them. Such openings in the noggins or in other 30 structural members of the installation allow air to enter or discharge to or from the air space. For example, entry of air into the air space can be facilitated to create a flue in order to vent hot air from within the air space and from within the multilayer structure 15. This advantageously can reduce the build-up of hot air within the multilayer structure 15 and can thus reduce the temperature within a building during an extreme 12 fire event, so that personnel within the building are less likely to be exposed to extreme temperatures within the building caused by the fire outside the building. It will be evident from the installation 10 illustrated in Figure 1, that a plurality of 5 multilayer structures 15 having air spaces can be installed across and/or between a plurality of spaced apart structural members. Where air spaces A are provided in the multilayer structures 15, openings can be provided in the structural members to communicate with the air spaces to allow air to travel through a first structural member and into the air space A of a multilayer structure 15 and then through a 0 second structural member and into the air space of another multilayer structure 15. In such an arrangement, the air spaces A in the multilayer structures 15 can communicate in order to vent hot air in the air spaces A of the multilayer structures 15 of the installation 10. 15 In some embodiments of the invention, the spacers 24 are about 110mm long, about 40mm wide and 10mm thick. With these dimensions, the spacers 24 create an air space of about 10mm depth which runs longitudinally along a length of the intermediate layer 15. 20 While Figure 1 illustrates a pair of spacers 24 in each of the intermediate layers 22, in other embodiments of the invention, the intermediate layer can have a single vertically oriented spacer to create a vertically extending air space or vent in the multilayer installation 10 on each side of the single spacer. Alternatively, the intermediate layer may be formed or shaped to create a space or vent that extends other than vertically, 25 such as horizontally, and the construction of the intermediate layer can be of any suitable kind. For example, the spacers can be fixed to the body 25 of the intermediate layer 22 by adhesive or by mechanical fasteners, or the spacers can be formed integrally with the body 25. The spacers can be formed as shown in Figure 1, or they can be otherwise formed, such as by a plurality of projections that extend 30 vertically but which are not continuous lengths. Alternatively, one surface of the intermediate layer 22 could be corrugated to form a plurality of air channels. It will be appreciated that many variations could be made.

13 The second render layer 23 is fixed to the side of the intermediate layer 22 opposite the first render layer 21 so that the intermediate layer is sandwiched between the two render layers. The second render layer 23 can be applied in the same thickness ranges and to the same extent between the structural members of the installation 10 5 as described in relation to the first render layer 21. Thus, the second render layer 23 can extend between respective structural members and into at least partial contact with facing surfaces of the structural members like the first render layer 21. The wall installation 10 can include an inner wall layer (not shown in Figure 1), which 0 is fixed to or adjacent the horizontal studs 11 on the opposite side of the horizontal studs 11 to the outer fire resistant layer 20. Typically, the inner wall layer can be plasterboard, such as gyprock plasterboard. Typically, the inner wall layer is fastened to the studs or noggins with screws or nails, however, any suitable fixing arrangement may be used. 15 Where an inner wall layer is provided, an air space can be formed between the intermediate layer 22 and the inner wall layer. Such an air space may be in addition to, or instead of, any air space that is formed between the intermediate layer 22 and the render layer 21. 20 The applicant has tested the resistance of embodiments of an installation according to the invention in a test furnace. The test was carried out to the Australian Standard AS 3959-2009 for Construction of Buildings in Bushfire-Prone Areas, which requires non failure of the tested product for a period of 120 minutes at 1,2000C. The furnace 25 reached temperatures of approximately 12000C with the testing being terminated after about four hours. Advantageously, it was found that the installation withstood the heat of the furnace for the duration of the test and there was no failure in the integrity of the installation after four hours. It was also found that the side of the installation which was not exposed to the heat of the furnace remained relatively cool, such that 30 the non-heated side could be touched by a bare hand two hours into the test. Beneficially, this indicates that the installation has good thermal insulating properties. In addition to providing resistance to the entry of fire into a building, the installation according to the invention can provide heat and/or sound insulation for a building.

14 Furthermore, the installation according to the invention is expected to cost approximately the same amount as existing building material, such as brick facades, to install, so that the advantages of the invention can be provided without significant increase in the cost of building in the normal manner. Of particular advantage, the 5 installation of the multilayer structure requires a skill level that may be readily learnt. Figures 2 and 3 show an installation according to another embodiment of the invention. The installation includes a multilayer structure 30 which extends across and/or between the spaced apart structural members of a roof 31. 0 The structural members of the roof portion of Figures 2 and 3 are the rafters 32 and the battens 33. The structural members may be constructed from any suitable material, and typically the material will be timber or steel. 15 Figure 2 shows a fire resistant layer 34 fixed relative to the rafters 32 and resting on or supported by cleats 35. In the embodiment of the invention shown in Figure 2, the fire resistant layer 34 extends between the rafters 32, which is different to the fire resistant layer 20 of Figure 1 in which the layer extended across the outer surface of the horizontal studs 11. 20 However, the fire resistant layer 34 could be fixed across or over the rafters 32 and in all embodiments, fixing can be by way of suitable fixing members, such as nails, screws, clamps, masonry anchors, bolts and nuts, glues and renders. 25 Figures 2 and 3 show a render layer 36 fixed to the fire resistant layer 34. The render layer 36 extends between respective rafters 32 and into at least partial contact with facing surfaces of the rafters 32. The render layer 36 can have any of the possible compositions or properties as 30 described earlier in relation to the render layers 21 and 23. An intermediate layer (not shown) can be fixed to the render layer 36, so that the intermediate layer extends between respective structural members. The intermediate layer can have the same construction as the intermediate layer 22 of the Figure 1 15 embodiment and can thus provide a flue or vent for dispersing hot air. Further, a second render layer (not shown) can be fixed to the outside facing surface of the intermediate layer such that the second render layer also extends between respective roof structural members. If the intermediate layer is provided and if the second render 5 layer is also provided, it will be appreciated that the construction of the installation shown in Figures 2 and 3 will be the same as that illustrated in Figure 1. In an alternative embodiment, an intermediate layer can be fixed relative to the fire resistant layer 34 between the rafters 32 of a roof. A render layer can be fixed to the 0 intermediate layer so that the intermediate layer is sandwiched between the fire resistant layer 34 and the render layer. The intermediate layer can have any suitable construction as discussed earlier in relation to the intermediate layer 22. An installation according to embodiments of the invention can also include a 5 multilayer structure, as described herein, which extends across and/or between the spaced apart structural members of a floor. A skilled person will appreciate that a multilayer structure as described herein can be fixed relative to the structural members of a floor using any of the appropriate ways described herein in relation to the roof or wall structural members. An installation according to the invention which !0 extends across and/or between the spaced apart structural members of a floor will be particularly advantageous in resisting the entry of fire into buildings which have a raised foundation, as flame can be prevented or at least resisted from entering the building through gaps between the floor and the ground. Further advantageously, the building can be provided with improved thermal insulation when a multilayer structure 25 according to the invention is installed to the floor of a building. Further advantageously, such an installation in the floor of a building can provide improved sound insulation for the building. An installation according to the invention can be installed in the walls and/or roofs 30 and/or floors of buildings as they are being built, or by retrofitting the installation to existing buildings. The installation is particularly suitable for walls and roofs with spaced apart structural members, such as horizontal studs and rafters.

16 A method for installing a multilayer structure of the invention between or to a plurality of spaced apart wall or roof or floor structural members to resist the entry of fire into a building is provided according to the invention. The method includes the step of fixing a fire resistant layer across or between the structural members so that the fire 5 resistant layer is fixed relative to the structural members. The size and spacing of structural members such as studs and rafters can vary from building to building, so the fire resistant layer may be constructed to fit within or across specified sizes of studs or rafters. o The method also includes the step of applying a layer of render to the fire resistant layer between the structural members. Preferably, the render layer is applied so that it is in at least partial contact with facing surfaces of the structural members. When the fire resistant layer is fixed relative to wall structural members, preferably it 15 is fixed across an outside facing surface of wall structural members. A render layer may then be applied to an inside facing surface of the fire resistant layer. When the fire resistant layer is fixed relative to roof structural members, preferably it is between the roof structural members. The fire resistant layer can be fixed between ?0 roof structural members using an arrangement such as shown in Figure 2. A render layer may then be applied to an outside facing surface of the fire resistant layer, ie a surface which faces away from the fire resistant layer. When a fire resistant layer is fixed relative to floor structural members, preferably it is 25 fixed between floor structural members. The fire resistant layer can be fixed between floor structural members using an arrangement similar to the arrangement shown in Figures 2 and 3 for a roof. A render layer may then be applied to an inside facing surface of the fire resistant layer. 30 An intermediate layer may be fixed to a render layer so that the intermediate layer extends between respective structural members. The intermediate layer may be any of the various embodiments of the intermediate layer described herein.

17 A layer of render may be applied across any intermediate layer that has been fixed relative to the structural members. Preferably, the layer of render extends between the structural members and into at least partial contact with facing surfaces of the structural members. 5 When the intermediate layer is fixed relative to wall structural members and the multilayer structure includes an air space extending vertically for the height of the intermediate layer, a method according to an embodiment of the invention can include the further step of providing at least one opening through at least one horizontal wall 0 structural member (for example in a noggin) at a position which allows the air space to extend vertically for the height of the multilayer structure and open out of the top and/or the bottom of the multilayer structure. As described above, such an opening or openings in the noggins allows air to travel along such air spaces for exhaust from within the multilayer structure. The air space in the multilayer structure and the 15 adjacent holes in the noggins may together work like a flue vent for hot air in the air space. Any of the layers of render may be applied in multiple stages. Preferably, a stage of any render layer is between 2.5mm to 20mm thick. For example, a first stage of a 20 render layer may be applied that is approximately 10mm thick. A second stage of a layer of render may be applied over the first stage of the render layer once the first stage of the render layer has been allowed to harden. Preferably, the second stage of the layer of render is also between 5mm to 20mm thick and more preferably approximately 15mm thick, so the total thickness of the render is about 30mm. 25 Preferably, the first stage of a render layer may be allowed to firm, and a mesh substrate can be pushed into the render before the render layer hardens. The mesh substrate may be any of the various embodiments described herein. The mesh layer is provided to increase the stability of the render layer by assisting in holding the render in place and/or by assisting the attachment of a further render layer. 30 A second stage of a render layer may be applied over the mesh layer. Preferably, the second stage of the render layer is also approximately 10mm thick, so the total thickness of the render layer is about 20mm. As indicated above, the second render layer may be applied in multiple stages.

18 Methods according to embodiments of the invention may be used to install a multilayer structure according to the invention to the structural members of a wall or roof or floor while the building is being constructed. 5 Methods according to embodiments of the invention may also be used to retrofit a multilayer structure to an existing building. In such an embodiment of the method, the existing exterior cladding of the walls of a building may be removed and a new fire resistant layer according to the invention may be fixed to the structural members. o Optionally, a new outer wall cladding can be fixed to the building once the method has been performed. Alternative methods according to other embodiments of the invention may also be used to retrofit a multilayer structure to an existing building. In such alternative 15 methods, the existing interior layers of the floors or the walls of a building (for example, the plasterboard) may be removed to expose an existing wall layer which is located across and/or between the structural members. The existing wall layer can be fixed across and/or between the structural members. If the plasterboard of a wall is removed, the existing wall layer can for example be the inside facing surface of ?0 existing exterior cladding. If the exterior cladding is removed, the existing wall layer can be the interior plasterboard. A layer of render may then be applied across the existing wall layer between the structural members and into at least partial contact with facing surfaces of the 25 structural members, while suitable intermediate layers and further render layers can be provided as necessary. Another embodiment of the invention provides a multilayer panel for installation between the structural members of a wall or roof or floor to resist the entry of fire into 30 a building. The panel includes a fire resistant layer and a render layer. The multilayer panel can also include an intermediate layer. The render layer may be fixed to the fire resistant layer and extend across the fire resistant layer. The intermediate layer may be fixed to the render layer so that it extends across the render layer.

19 Alternatively, the intermediate layer may be fixed to the fire resistant layer so that it extends across the fire resistant layer. The intermediate layer can be sandwiched between the fire resistant layer and the render layer so that the intermediate layer and the render layer each extend across the fire resistant layer. 5 A further embodiment of the invention provides a method for installing a panel according to the invention between the structural members of a wall or roof or floor. The method includes the step of fixing the multilayer panel between the structural members of a wall or roof or floor. The panel may be fixed with any appropriate 0 method, such as using screws, nails, clamps, render or glues. It is to be understood that above description and figures are provided by way of illustration of the invention and in no way limits the scope of the invention. The invention is susceptible to variations, modifications and/or additions other than those 5 specifically described, and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the scope of the following claims.

Claims (36)

1. A wall or roof or floor installation including a plurality of spaced apart wall or roof or floor structural members and a multilayer structure which extends 5 across and/or between the structural members, the multilayer structure including a fire resistant layer which is fixed relative to the structural members across and/or between the structural members, and a first render layer having a thickness of between 2.5mm and 100mm which extends between the structural members and across the fire resistant layer, wherein the multilayer 0 structure resists the entry of fire into a building.

2. An installation according to claim 1, wherein the fire resistant layer has a thickness of between 2.5mm and 100mm. 5

3. An installation according to claim 2, wherein the fire resistant layer is fixed across the structural members of a wall and the first render layer is fixed to an inside facing surface of the fire resistant layer, such that the first render layer extends between respective structural members and into at least partial contact with facing surfaces of the structural members. !0

4. An installation according to claim 2, wherein the fire resistant layer is fixed across or between the structural members of a roof to extend across or between the members and the first render layer is fixed to an outside facing surface of the fire resistant layer, such that the first render layer extends 25 between respective structural members and into at least partial contact with facing surfaces of the structural members.

5. An installation according to any one of the preceding claims, wherein the multilayer structure further includes an intermediate layer fixed to the first 30 render layer, wherein the intermediate layer extends between respective structural members.

6. An installation according to any one of claims 1 to 4, wherein the multilayer structure further includes an intermediate layer between the fire resistant layer 21 and the first render layer, wherein the intermediate layer extends between respective structural members.

7. An installation according to claim 5 or 6, wherein the intermediate layer forms 5 an air space within the multilayer structure.

8. An installation according to claim 7, wherein the installation is fixed to the structural members of a wall and the air space extends vertically for the height of the intermediate layer. 0

9. An installation according to claim 7, wherein the air space extends vertically for the height of the multilayer structure and opening out of the top and/or the bottom of the multilayer structure. 15

10. An installation according to any one of claims 5 to 9, wherein the multilayer structure further includes a second render layer which is fixed to the outside facing surface of the intermediate layer such that the second render layer extends between respective structural members. ?0

11. An installation according to claim 10, wherein the second render layer extends between respective structural members and into at least partial contact with facing surfaces of the structural members.

12. An installation according to claim 10 or 11, wherein the second render layer 25 has a thickness of between 2.5mm and 100mm.

13. An installation according to any one of the preceding claims, including a mesh layer fixed across and/or within the first render layer to increase the stability of the first render layer. 30

14. An installation according to claim 10 or 11, including a mesh layer fixed across and/or within the second render layer to increase the stability of the render layer. 22

15. A panel for installation between the structural members of a wall or roof or floor to resist the entry of fire into a building, including a fire resistant layer of between 2.5mm to 100mm thickness and a render layer of between 2.5mm to 100mm thickness, wherein the render layer is fixed to the fire resistant layer 5 and extends across the fire resistant layer.

16. A panel according to claim 15, including an intermediate layer fixed to the render layer on a side of the render layer opposite the fire resistant layer, wherein the intermediate layer extends across the render layer. 0

17. A panel for installation between the structural members of a wall or roof or floor to resist the entry of fire into a building, including a fire resistant layer of between 2.5mm to 100mm thickness and an intermediate layer fixed to the fire resistant layer, wherein the intermediate layer extends across the fire resistant 15 layer.

18. A panel for installation between the structural members of a wall or roof or floor to resist the entry of fire into a building, including a fire resistant layer of between 2.5mm to 100mm thickness, an intermediate layer and a render layer ?0 of between 2.5mm to 100mm thickness, wherein the intermediate layer is sandwiched between the fire resistant layer and the render layer and the intermediate layer and the render layer each extend across the fire resistant layer. 25

19. A method for installing a multilayer structure between a plurality of spaced apart wall or roof or floor structural members to resist the entry of fire into a building, including the steps of: (i) fixing a fire resistant layer of between 2.5mm to 100mm thickness across and/or between the structural members so that the fire resistant layer is 30 fixed relative to the structural members; (ii) applying a first layer of render of between 2.5mm to 100mm thickness to the fire resistant layer, such that the first layer of render extends between the structural members and into at least partial contact with facing surfaces of the structural members. 23

20. The method of claim 19, wherein the fire resistant layer is fixed across an outside facing surface of wall structural members, and the first layer of render is applied to an inside facing surface of the fire resistant layer. 5

21. The method of claim 19, wherein the fire resistant layer is fixed between roof structural members, and the first layer of render is applied to an outside facing surface of the fire resistant layer. 0

22. A method for installing a multilayer structure between a plurality of spaced apart wall structural members to resist the entry of fire into a building, including the steps of: (i) removing the inner or outer layer of a wall to expose an existing wall layer which is located across and/or between the structural members; 15 and (ii) applying a first layer of render of between 2.5mm to 100mm thickness across the existing wall layer between the structural members and into at least partial contact with facing surfaces of the structural members. 20

23. The method of any one of claims 19 to 22 further including the step of fixing an intermediate layer to the first render layer so that the intermediate layer extends between respective structural members.

24. A method for installing a multilayer structure between a plurality of spaced 25 apart wall or roof or floor structural members to resist the entry of fire into a building, including the steps of: (i) fixing a fire resistant layer of between 2.5mm to 100mm thickness across and/or between the structural members so that the fire resistant layer is fixed relative to the structural members; 30 (ii) fixing an intermediate layer relative to the structural members so that it extends between respective structural members; (iii) applying a layer of render of between 2.5mm to 100mm thickness across the intermediate layer between the structural members and into at least partial contact with facing surfaces of the structural members. 24

25. A method according to claim 23 or 24, wherein the intermediate layer forms an air space within the multilayer structure. 5

26. A method according to claim 25, wherein the multilayer structure is installed between wall structural members and the air space extends vertically for the height of the intermediate layer.

27. A method according to claim 25 or 26, including the further step of making at 0 least one opening through at least one horizontal wall structural member in communication with the air space to allow the air space to extend vertically for the height of the multilayer structure and open out of the top and/or the bottom of the multilayer structure. 5

28. A method of any one of claims 19 to 27, wherein at least one of the render layers is applied in at least two stages, including the steps of: (i) applying a first stage of the render layer of between 2.5mm to 20mm thick; (ii) allowing the first stage of the render layer to harden; ?0 (iii) applying a second stage of the render layer of between 2.5mm to 20mm thick.

29. A method according to claim 28, wherein a mesh layer is pressed into the first stage of the render layer before hardening, so that the mesh layer is fixed 25 across and/or within the first render layer to increase the stability of the render layer.

30. A method of installing the panel of any one of claims 15 to 18 between the structural members of a wall or roof or floor, including fixing the panel so that 30 the fire resistant layer is fixed across and/or between the structural members and the render layer is between the structural members.

31. An installation, method or panel of any one of the preceding claims, wherein the fire resistant layer is a fibro cement board. 25

32. An installation of any one of claims 1 to 14, a panel of any one of claims 16 to 18 or a method of any one of claims 23 to 29 wherein the intermediate layer is a polystyrene layer. 5

33. An installation, method or panel of any one of the preceding claims, wherein the render layer is fire resistant.

34. An installation, method or panel of any of the preceding claims, wherein the 0 render layer includes crushed perlite.

35. An installation, method or panel of any one of the preceding claims, wherein the render layer includes crushed perlite and fondue cement. 5

36. An installation, method or panel of any one of the preceding claims, wherein the fire resistant layer is an insulating layer which provides heat and/or sound resistance.