GB2604702A

GB2604702A - Cavity fire barrier

Info

Publication number: GB2604702A
Application number: GB2116998.2A
Authority: GB
Inventors: Sharman Carl
Original assignee: HCS Innovations Ltd
Current assignee: HCS Innovations Ltd
Priority date: 2020-12-30
Filing date: 2021-11-25
Publication date: 2022-09-14
Also published as: GB202104228D0; GB202116998D0; GB202020744D0; AU2021290206A1; GB202102299D0

Abstract

The cover plate 10 is configured for insertion within the bracket 40 of a masonry support. The cover includes a profile plate 12 comprising a non-combustible material, with a generally C shape cross-section i.e. a planar portion with an interior and exterior face with first 20 and second 22 arms extending from the interior face at opposing ends thereof. The first arm comprises a lip 24, providing a fixing bracket, at a distal end, the second arm extends away from the planar portion and is shorter than the first. An intumescent material 14 is provided on the exterior face of the planar portion. The intumescent material may be a strip, sheet, or coating and may extend across the full width of the profiled plate, and/or cover the whole exterior and/or interior of the plate except the lip. Also claimed is a masonry support comprising the aforementioned cover wherein the cover may have an interference fit within the cavity of the bracket.

Description

Cavity Fire Barrier This invention relates to a fire barrier for use in cavities, in particular, inside cavity walls where masonry supports are used.

When designing and constructing buildings in England, for example, designers and contractors must ensure the building is constructed in accordance with appropriate Approved Documents of the Building Regulations. One of those documents is Approved Document B which addresses requirements for fire protection in all aspects of buildings. Another document to consider is Approved Document A which sets out requirements to be met with structural design. Many other countries have similar requirements.

When considering the requirement for both of the above Approved Documents, this inevitably can cause conflict and difficult details at certain junctions.

When constructing low, medium or high-rise buildings where a masonry outer skin is specified for a framed building, such as concrete, steel or timber framed buildings, the only solution currently available to meet the requirements of Approved Document A is to support the brickwork using structural masonry support at certain floors. The number of locations is dictated by the height of the building and structural engineer's design. Masonry supports are generally located at floor slabs and roof slabs so that they can be tied back to the main structure of the building.

Examples of such masonry supports can be seen in United Kingdom patent application numbers 2 444 320 and 2 305 194 and Australian patent application number 2011200797. As can be seen from each of these documents, a conventional masonry support comprises a plurality of brackets, which are fixed to an internal structure, and a support member, which is generally provided by an elongate member having a generally L-shaped cross-section. In use, one side of the elongate support member is attached to the brackets and the other side of the elongate support member is located between two adjacent brick courses or the outer wall.

Masonry supports are usually manufactured using stainless-steel in varying grades depending on exposure of the building. For example, coastal buildings will generally be exposed to harsher conditions than buildings at in-land locations. Masonry support brackets currently available have a large cavity within them. This enables the brackets to be lighter for ease of manual handling. It also provides for ease of installation and ease of adjustment of both line and level. Unfortunately, if a fire were to enter the cavity wall of the building, the cavity of the masonry support brackets provides a potential passage for fire to spread freely around the building.

Approved Document B requires measures to be put in place at each floor slab to prevent fire from spreading through clear cavities. The current approach to this type of building, is to use full width cavity fire barriers, an example of such a barrier can be found in United Kingdom patent application numbers 2 574 452. However, this results in the cavity being closed at these localised positions. Closing the cavity creates a potential path for moisture from external elements to pass through the cavity to the inner skin resulting in dampness to rooms within the building. A common practice to mitigate this is to install non-combustible cavity trays with weepholes above the cavity fire barrier. These cavity trays would generally be located at all floor slabs and for the full extent of the perimeter of the building.

Current Building Regulations do allow for clear cavities for the full height of buildings. This allows for an alternative approach using cavity fire barriers with expanding intumescent materials. These react with heat or fire and compartmentalise the cavity to prevent the potential for fire spread. This method of construction makes the noncombustible cavity trays redundant. It is common practice to adopt this form of construction with clad facade buildings.

A problem with such conventional fire barriers when a masonry support 30 is required is that they either block the whole cavity, causing the moisture problems described above, or the fire barrier is interrupted by the bracket required to support the masonry support.

The present invention seeks to address the problem in buildings that require use of masonry supports of how to maintain a clear cavity for ventilation while providing adequate provision for meeting passive fire protection measures. The present invention does not compromise the structural integrity of the building or its passive fire protection. The present invention also facilitates the omission of non-combustible cavity trays and would result in an easier building process, cost savings and improved speed of build. The present invention is also a more sustainable form of construction using substantially less material than the conventional methods currently adopted.

According to a first aspect, the present invention provides an intumescent cover plate for a masonry support bracket, comprising a profiled plate and an intumescent material, the profiled plate comprising a non-combustible material and being configured for insertion within the bracket of a masonry support in use, wherein the profiled plate comprises an elongate plate that is configured to have a generally C-shaped cross-section, comprising a substantially planar portion comprising an exterior face and an interior face, with first and second arms extending from the interior face of the planar portion and from opposing ends thereof, the first arm extending outwards and away from the planar portion and comprising at a distal end thereof a lip providing a fixing bracket, the second arm extending away from the planar portion and being shorter than the first arm, wherein the intumescent material is applied at least to the exterior face of the planar portion.

According to a second aspect, the present invention provides a masonry support, comprising a bracket, a masonry support member and an intumescent cover plate, the bracket having a substantially U-shaped cross-section comprising a substantially planar web extending between substantially planar first and second flanges, which first and second flanges are substantially perpendicular to the web, the web, first flange and second flange together defining a cavity, the intumescent covcr platc comprising a profilcd platc and an intumcsccnt matcrial, the profiled plate comprising a non-combustible material, wherein the profiled plate comprises an elongate plate that is configured to have a generally C-shaped cross-section, comprising a substantially planar portion comprising an exterior face and an interior face, with first and second arms extending from the interior face of the planar portion and from opposing ends thereof, the first arm extending outwards and away from the planar portion and comprising at a distal end thereof a lip providing a fixing bracket, the second arm extending away from the planar portion and being shorter than the first arm, wherein the intumescent material is applied at least to the exterior face of the planar portion, wherein the profiled plate of the intumescent cover plate is locatable at least partially within the cavity of the bracket, and the intumescent cover plate being configured such that the intumescent material of the intumescent cover plate extends across the full width of the cavity of the bracket.

In the second aspect of the invention, the intumescent cover plate may be separate from the bracket and masonry support member. Alternatively, the intumescent cover plate may be connected to the bracket.

The profiled plate may additionally comprise a return extending from the distal end of the second arm. If present, the return suitably extends towards the first arm. For example, the return may be substantially perpendicular to the second arm and substantially parallel to the planar portion. The length of the return may vary depending upon the particular application of the cover plate. For example, the length of the return may be substantially the same as the length of the planar portion. Alternatively, the return may be shorter than the planar portion.

Suitably, the profiled plate comprises a unitary elongate plate that 10 is shaped by any suitable method to form the planar portion, the first arm, fixing bracket, and the second arm. If present, the unitary elongate plate is also shaped to form the return. Suitable methods of forming the profiled plate include, but is not limited to, cold rolling.

The first arm of the profiled plate suitably extends at an obtuse angle from a first end of the planar portion. The first arm may be substantially planar. Alternatively, the first arm may be curved. As a further alternative, the first arm may comprise a first portion that extends at an obtuse angle from the first end of the planar portion and a second portion extending from the distal end of the first portion, which second portion is substantially perpendicular to the planar portion. In this embodiment, the second portion of the fist arm may be substantially perpendicular to the second arm of the profiled plate.

The lip providing the fixing bracket suitably extends perpendicularly from the distal end of the first arm. Suitably, the lip extends away from the second arm of the profiled plate. In a preferred embodiment, the lip is substantially parallel to the planar portion of the profiled plate.

The second arm of the profiled plate is suitably substantially planar. The second arm of the profiled plate may extend substantially 35 perpendicular to the planar portion. The second arm and the first arm are suitably substantially parallel.

The first arm of the profiled plate may provide a supporting arm. The second arm of the profiled plate may provide an end plate. The planar portion of the profiled plate may provide a support plate.

Suitably, the fixing bracket is configured to allow the intumescent cover plate to be fixed to either a surface of the building cavity or a masonry support, in use.

The intumescent material may be provided by an intumescent strip, which intumescent strip may be applied to one or more surfaces of the profiled plate. The intumescent strip may be located on the exterior face of the planar portion. The intumescent strip may be located on the exterior and the interior face of the planar portion. In addition to the exterior face of the planar portion, the intumescent strip may be located on an interior and/or exterior face of the second arm and/or an interior and/or exterior face of the first arm and/or the 10 interior and/or exterior face of the return.

Alternatively, the intumescent material may be provided by an intumescent coating or sheet. The intumescent coating or sheet must at least be applied to the exterior face of the planar portion of the profiled plate, but may also be applied to any one of more of the interior face of the planar portion, an interior and/or an exterior face of the first arm, an interior and/or exterior face of the second arm and/or an interior and/or exterior face of the return, if present. In a preferred embodiment, the intumescent coating or sheet is applied to substantially the whole of the profiled plate. The lip providing the fixing bracket may remain free of intumescent material. In an embodiment of the invention comprising a return extending from the distal end of the second arm, the intumescent material is applied to the exterior face of the first arm, the planar portion, the second arm and the return.

Suitably, in all embodiments of the invention, the intumescent material extends across the full width of the planar portion of the profiled plate. Suitably, the intumescent material covers substantially the whole of the exterior face and/or substantially the whole of the interior face of the planar portion. Suitably, the intumescent material covers substantially the whole of the exterior face and/or substantially the whole of the interior face of the first arm. Suitably, the intumescent material covers substantially the whole of the exterior face and/or substantially the whole of the interior face of the second arm. If present, the intumescent material suitably covers substantially the whole of the exterior face and/or substantially the whole of the ifiLerior face of Lhe return.

The intumescent material may be applied to the profiled plate by any means suitable for the intumescent material and the material of the profiled plate. Suitable methods of applying the intumescent material to the profiled plate include, but are not limited to, adhesion, mechanical fixing, or spraying.

The material of the profiled plate is chosen to suit the fire performance requirements of the building the intumescent cover plate will be built into. Suitably, the profiled plate comprises a noncombustible metal, such as steel, galvanised steel or stainless steel.

The grade of material for a stainless-steel plate varies to suit the climate conditions of where the building is to be constructed. Alternatively, the profiled plate comprises a non-combustible mineral material.

The specification and performance of the intumescent material can also be configured to suit the fire performance and clear cavity requirement of the building. The intumescent material maybe provided by a high expansion intumescent material. In some embodiments, the intumescent material is provided by a high expansion intumescent material encased in aluminium foil. The fire rating specification of the intumescent material is chosen to suit the fire performance requirements of the building the intumescent cover plate will be built into.

The elongate plate providing the profiled plate suitably has a substantially constant width along the full length thereof. The width of the elongate plate may be between 10-100mm, preferably between 25-75mm, more preferably between 30-60 mm.

The elongate plate providing the profiled plate suitably has a substantially constant thickness along the full length thereof. The thickness of the elongate plate providing the profiled plate may be between 0.5-5 mm, preferably between 1-3 mm.

The distance from the fixing bracket provided by the lip to the exterior face of the planar portion of the profiled plate will be chosen to suit the bracket and cavity the intumescent cover plate will be used within. Suitably, the distance from the lip to the exterior face of the planar portion may be from 30-500mm, preferably from 50-225mm, more preferably from 50-150mm.

The distance between the first arm and the second arm of the profiled plate will be chosen to meet the requirements of use, and could vary significantly, but may be between 50-300mm, preferably 40 between 50-200mm, more preferable from 50-100mm.

Suitably, the profiled plate is configured to be partially inserted within the cavity of a bracket of a masonry support in use. The profiled plate is suitably configured to be fully inserted within the cavity of a bracket of a masonry support in use.

The size of a bracket for a masonry support varies depends on the manufacturer and application. Therefore, the dimensions of the profiled plate may be varied to fit within the cavity of the bracket.

The profiled plate may be configured such that the intumescent cover plate is an interference fit within the interior of the cavity of a bracket of a masonry support in use. In other words, the width of the elongate plate providing the profiled plate is suitably chosen to correspond with the width of the cavity of the bracket. The width of the cavity of the bracket being defined as the distance between the first and second flanges of the bracket. The first and second flanges of the brackets being substantially parallel, in order that the distance between them is substantially the same along the full length of the flanges.

In use, the intumescent cover plate is located within the cavity of a bracket for a masonry support. The C-shaped cross-section of the profiled plate enables the intumescent cover plate to be extend over and around a fixing means used to attach the bracket to an inner structure of the cavity. The intumescent cover plate is then also fixed to the inner structure of the cavity, by the lip providing the fixing bracket using any suitable fixing means. Suitably fixing means include a nail, screw or bolt. Alternatively, the intumescent cover plate could be fixed to the inner wall of the cavity by adhering the intumescent cover plate to the inner wall at the lip.

If heat, smoke or flames enter the cavity, the intumescent material will react with the heat in the cavity, expanding and closing the cavity within the bracket. If the intumescent material is only on the exterior face of the planar portion of the profiled plate, the intumescent material will extend across the cavity from the planar portion to the interior face of the exterior wall. In this case, the second arm of the profiled plate is suitably sufficiently long to effectively close the portion of the bracket cavity the extending between the interior face of the planar portion of the profiled plate and the inner wall of the cavity. In this way, the second arm will also provide a fire barrier.

If intumescent material is applied to additional faces of the profiled plate, the intumescent material will expand in other directions too upon expose to heat, smoke or fire and close the cavity in multiple directions.

The present invention closes the cavity within a bracket used with a masonry support. Suitably, each bracket contains an intumescent cover plate according to the present invention. Furthermore, to ensure the whole cavity is closed in the event of ingress of heat, fire or smoke into the cavity, a conventional cavity fire barrier material should be located either side of the masonry support bracket(s). The combination of the intumescent cover plate and cavity fire barrier material between the brackets enables a fire barrier to be provided across the full width of the cavity only when needed. This passive fire protection method meets the current requirements of Approved Document B of the Building Regulations.

The invention will now be described, solely by way of example, and with reference to the accompanying drawings in which: Figure 1 is a side view of an intumescent cover plate according to a first embodiment of the invention, Figure 2 is a front view of the intumescent cover plate of figure 1, Figure 3 is a perspective view of the intumescent cover plate of figure 1, Figure 4 is a section through a typical masonry support bracket, Figure 5 is a section through the masonry support bracket of figure 4 showing the intumescent cover plate of figure 1 located within the masonry support bracket, Figure 6 shows the arrangement of figure 5 when the ventilation cavity 30 is closed off by the intumescent material, Figure 7 is a cross section through a cavity wall at the location of a masonry support bracket with an intumescent cover plate of figure 1 inserted within the bracket, showing the cavity open, Figure 8 shows the arrangement of figure 7, with the cavity closed by 35 the intumescent material, Figure 9 is a side view of an intumescent cover plate according to a second embodiment of the invention, Figure 10 is a front view of the intumescent cover plate of figure 9, Figure 11 is a perspective view of the intumescent cover plate of figure 9, Figure 12 is a section through the masonry support bracket of figure 4 showing the intumescent cover plate of figure 9 located within the masonry support bracket, Figure 13 shows the arrangement of figure 12 when the ventilation 5 cavity is closed off by the intumescent material, Figure 14 is a cross section through a cavity wall at the location of a masonry support bracket with an intumescent cover plate of figure 9 inserted within the bracket, showing the cavity open, Figure 15 shows the arrangement of figure 14, with the cavity closed 10 by the intumescent material, Figure 16 shows a partial cut-away view of a cavity viewed from the exterior of the building, Figure 17 is a side view of an intumescent cover plate according to a third embodiment of the invention, Figure 18 is a front view of the intumescent cover plate of figure 17, and Figure 19 is a perspective view of the intumescent cover plate of figure 17.

In the figures like reference numerals will be used no refer to corresponding features in different figures and embodiments.

Figures 1-3 and 5-8 show an intumescent cover plate 10 according to a first embodiment. The cover plate 10 comprises a profiled plate 12 25 and an intumescent material, provided by an intumescent strip 14.

The profiled plate 12 comprises an elongate plate, which has substantially the same width and thickness along the full length thereof. As can be seen particularly in figure 1, the elongate plate 16 has a substantially C-shaped cross-sectional shape. The elongate plate 16 comprises a planar portion 18, a first arm 20, a second arm 22 and a lip 24, providing a fixing bracket. The profile plate 12 is formed from the elongate plate 16, which has been bent to provide the desired shape.

As can be seen from figure 1 in particular, the first arm 20 extends outwards and away from the planar plate 18. The first arm 20 comprises a first portion 26 and a second portion 28. The first portion 26 of the first arm extends from a first end of the planar portion 18, and is arranged at an obtuse angle relative to the planar portion 18. The second portion 28 of the first arm 20 is substantially perpendicular to the planar portion 18 and substantially parallel to the second arm 22. The lip 24 extends from the distal end of the first arm 20 and is substantially parallel to the planar portion 18. The second arm 22 is substantially perpendicular to the planar portion 18.

The thickness of the elongate plate 18 providing the profiled plate 12 in this embodiment is 2mm. The width D of the elongate plate 18 in this embodiment is 44mm. The length A of the second arm 22 is 65mm. The distance B from the lip 24 to the exterior face 30 of the planar portion 18 of the profiled plate 12 in this embodiment is 72mm. The distance C between the second portion 28 of the first arm 20 and the second arm 22 of the profiled plate 12 in this embodiment is 205mm.

It can also be seen from Figure 1, in particular, that the length A of the second arm 22 is slightly less than the distance B between the lip 24 and the exterior face 33 of the planar portion 18.

In the embodiment of figures 1-8, the intumescent material 14 is 20 provided by an intumescent strip. In this embodiment, the intumescent strip 14 is mechanically fixed to the exterior face 30 of the planar portion 18. The mechanical fixing is any suitable fixing and is generally indicated by reference numeral 32.

The hole 34 for mechanically fixing the intumescent cover plate 10 to the inner wall of a cavity, which may be a concrete slab edge, is located in the lip 24, thus providing a fixing plate.

The specification of the intumescent strip 14 is chosen to reflect 30 the passive fire requirements of the specific application Figure 2 shows the intumescent strip 14 covering substantially the full height and width of the exterior face of the planar portion 18. This provides maximum coverage and flexibility with fitting cavity fire barriers either side of the masonry support bracket when all are placed in situ.

Figure 4 shows a section through a typical masonry support bracket 40. The bracket 40 has a substantially U-shaped cross-sectional shape comprising a planar web 42 and a first flange 44 and a second flange (not shown) extending from the planar web 42. Together, the planar web 42 and first 44 and second (rot shown) flanges define a cavity 46, the extent of which is indicated by the arrow 48. A masonry support 30 is attached to the first 44 and second (not shown) flanges.

Figure 5 shows a section through a masonry support bracket 40 of 5 figure 4 with the intumescent cover plate 10 inserted within it the cavity 46 of the bracket 40. As can be seen in this figure, the lip 24 is used to fix the cover plate 10 to the inner wall of the cavity (not shown) just above the planar web 42 of the bracket. In this arrangement the dimensions of the cover plate 10 are such that the second arm 22 extends from the interior face 36 of the planar portion 18 of the profiled plate 12 to contact the planar web 42 of the bracket 40. Thus, part of the cavity 34 of the bracket 40 is closed by the second arm 22 of the cover plate 10. The remaining extend of the ventilation cavity is indicated by arrow 52, and it can be seen that it is greatly reduced compared to that in figure 4. The intumescent strip 14 is on the exterior face 30 of the planar portion 19 of the profiled plate 12 and therefore points towards the remaining ventilation cavity indicated by arrow 32.

Figure 6 shows the arrangement of figure 5, when the cavity has been exposed the heat, smoke or fire. It can be seen in this figure that the intumescent strip 14 has expanded to fill the remainder of the ventilation cavity. A complete closure of the cavity has now been created preventing the spread of fire from one compartment to another.

Figure 7 shows the intumescent cover plate 10 located within a masonry support bracket 40. The profile enables easy insertion within a masonry support bracket 40 without compromising its fixings 60 back to the concrete slab edge 62. The bracket 40 has a masonry support 50 attached to the first 44 and second (not shown) flanges of the bracket and the function of the masonry support 50 is to support the external masonry skin 70. Not influencing the mechanical fixings 60 of the bracket 40 is a fundamental requirement of the intumescent cover plate 10 since the structural support cannot be compromised. Also shown is non-combustible thermal insulation 80 secured to the face of the inner wall 90 which in turn is fixed to the structural slab 62. In this state, free air flow along the full height of the building is enabled via the ventilation cavity 52. This enables moisture from external elements to pass freely to the ground.

Figure 8 shows what happens when a fire 95 enters the ventilation void within the cavity of the building. The intumescent fire strip 14 on the exterior face 30 of the planar portion 18 of the profiled plate 12 has expanded due to the heat created by the smoke and flames 95.

This seals off the remaining ventilation void within the cavity of the bracket 40 preventing the ability for fire to spread through the bracket 40. The profile of the intumescent cover plate 10, and its location within the cavity 46 of the bracket 40, prevents flames entering the closed cavity 54 around the mechanical fixing 60.

Figures 9-15 show an intumescent cover plate 110 according to a second embodiment of the invention. The cover plate 110 comprises a profiled plate 112 and an intumescent material, provided by an intumescent sheet 114.

The profiled plate 112 comprises an elongate plate 116, which has substantially the same width and thickness along the full length thereof. As can be seen particularly in figure 9, the elongate plate 116 has a substantially C-shaped cross-sectional shape. The elongate plate 116 comprises a planar portion 118, a first arm 120, a second arm 122 and a lip 124, which lip 124 provides a fixing bracket. The profiled plate 112 is formed from the elongate plate 116, which has been bent to provide the desired shape.

As can be seen from figure 9, in particular, the first arm 120 extends outwards and away from the planar plate 118. The first arm 120 comprises a first portion 126 and a second portion 128. The first portion 126 of the first arm extends from a first end of the planar portion 118, and is arranged at an obtuse angle relative to the planar portion 118. The second portion 128 of the first arm 120 is substantially perpendicular to the planar portion 118 and substantially parallel to the second arm 122. The lip 124 extends from the distal end of the first arm 120 and is substantially parallel to the planar portion 118. The second arm 122 is substantially perpendicular to the planar portion 118.

The thickness of the elongate plate 118 providing the profiled plate 112 in this embodiment is 2mm. The width H of the elongate plate 118 in this embodiment is 44mm. The length E of the second arm 122 is 30mm. The distance F from the lip 124 to the exterior face 130 of the planar portion 118 of the profiled plate 112 in this embodiment is 65mm. The distance G between the second portion 128 of the first arm 120 and the second arm 122 of the profiled plate 112 in this embodiment is 100mm.

It can also be seen from Figure 9, in particular, that the length E of the second arm 122 is less than the distance F between the lip 124 and the exterior face 130 of the planar portion 118.

In the embodiment of figures 9-15, the intumescent material 114 is provided by an intumescent sheet. In this embodiment, the intumescent sheet 114 covers substantially the whole of the profiled plate 112, except for the lip 124. The intumescent sheet 114 in this embodiment is mechanically fixed to the planar portion 118 as indicated at 132 and also at the second portion 128 of the first arm 120 indicated at 138. The mechanical fixing is any suitable fixing. As an alternative to the mechanical fixings 132 and 138, the intumescent sheet 114 could be adhered to the profiled plate 112.

The hole 134 for mechanically fixing the intumescent cover plate 110 to the inner surface of a cavity, which may be a concrete slab edge, is located in the lip 124, thus providing a fixing plate.

The specification of the intumescent sheet 114 is chosen to reflect the passive fire requirements of the specific application.

Figure 12 shows a section through a masonry support bracket 40 of figure 4 with the intumescent cover plate 110 inserted within it the cavity 46 of the bracket 40. As can be seen in this figure, the lip 124 is used to fix the cover plate 110 to an inner surface of the wall cavity (not shown) just above the planar web 42 of the bracket. In this arrangement the dimensions of the cover plate 110 are such that the second arm 122 extends from the interior face 136 of the planar portion 118 of the profiled plate 112 towards the planar web 42 of the bracket 40, but does not make contact with the planar web 42. A ventilation cavity indicated by arrow 152 is formed between the exterior wall of the cavity and the exterior face of the planar portion 118 of the intumescent cover plate 110.

Figure 13 shows the arrangement of figure 12, when the cavity has been exposed the heat, smoke or fire. It can be seen in this figure that the intumescent sheet 114 has expanded in all directions to fill the cavity 46 of the bracket 40, including the ventilation cavity 152. A complete closure of the cavity 46 has now been created preventing the spread of fire from one compartment to another.

Figure 14 shows the intumescent cover plate 110 located within a masonry support bracket 40. The profile enables easy insertion within a masonry support bracket 40 without compromising its fixings 60 back to the concrete slab edge 62. The bracket 40 has a masonry support 50 attached to the first 44 and second (not shown) flanges of the bracket 40 and the function of the masonry support 50 is to support the external masonry skin 70. Not influencing the mechanical fixings 60 of the bracket 40 is a fundamental requirement of the intumescent cover plate 110 since the structural support cannot be compromised. Also shown is non-combustible thermal insulation 80 secured to the face of the inner wall 90 which in turn is fixed to the structural slab 62. In this state, free air flow along the full height of the building is enabled via the ventilation cavity 152. This enables moisture from external elements to pass freely to the ground.

Figure 15 shows what happens when a fire 95 enters the ventilation void within the cavity of the building. The intumescent sheet 114 on all surfaces of the profiled plate 112, except the lip 124, has expanded in all directions due to the heat created by the smoke and flames 95. This seals off the cavity 46 within the bracket 40, including the ventilation void within the cavity of the bracket 40 preventing the ability for fire to spread through the bracket 40.

Figure 16 shows a partially cut-away view from the exterior of a building showing multiple brackets 40 to which a masonry support 50 has been attached. Also shown, is an intumescent cover plate, which may be either 10 of figures 1-3 and 5-8 or 110 of figures 9-15 or 210 of figures 17-19, located within each bracket 40. Figure 16 shows that non-combustible thermal insulation strips 80 are located on the interior surface of the cavity between the brackets 40.

Figures 17-19 show an intumescent cover plate 210 according to a third embodiment of the invention. The cover plate 210 comprises a profiled plate 212 and an intumescent material, provided by an intumescent sheet 214.

The profiled plate 212 comprises an elongate plate 216, which has substantially the same width and thickness along the full length thereof. The elongate plate 216 comprises a planar portion 218, a first arm 220, a second arm 222, a lip 224, which lip 224 provides a fixing bracket, and a return 230. The profiled plate 212 is formed from the elongate plate 216, which has been bent to provide the desired shape.

As can be seen from figure 17, in particular, the first arm 220 extends outwards and away from the planar plate 218. The first arm 220 comprises a first portion 226 and a second portion 228. The first portion 226 of the first arm extends from a first end of the planar portion 218, and is arranged at an obtuse angle relative to the planar portion 218. The second portion 228 of the first arm 220 is substantially perpendicular to the planar portion 218 and substantially parallel to the second arm 222. The lip 224 extends from the distal end of the first arm 220 and is substantially parallel to the planar portion 218. The second arm 222 is substantially perpendicular to the planar portion 218. The return 230 extends from the distal end of the second arm 222 towards the first arm. In this embodiment, the return 230 is substantially perpendicular to the second arm 222 and substantially parallel to the planar portion 218.

The thickness of the elongate plate 218 providing the profiled plate 212 in this embodiment is 2mm. The width M of the elongate plate 218 in this embodiment is 44mm. The length I of the second arm 222 is 30mm. The distance J from the lip 224 to the exterior face 219 of the planar portion 218 of the profiled plate 212 in this embodiment is 95mm. The distance K between the second portion 226 of the first arm 220 and the second arm 222 of the profiled plate 212 in this embodiment is 100mm. The length L of the return 230, in this embodiment is 75mm.

It can also be seen from Figure 17, in particular, that the length I 20 of the second arm 222 is less than the distance J between the lip 224 and the exterior face 219 of the planar portion 218.

In this third embodiment of the invention, the intumescent material 214 is provided by an intumescent sheet. In this embodiment, the intumescent sheet 214 covers substantially the whole of the surface of the profiled plate 212 that includes the exterior face 219 of the planar portion 218, except for the lip 224. The intumescent sheet 214 in this embodiment is mechanically fixed to the profiled plate 212 as indicated at 232 and also at the second portion 228 of the first arm 220 indicated at 238. The mechanical fixing is any suitable fixing. As an alternative to the mechanical fixings 232 and 238, the intumescent sheet 214 could be adhered to the profiled plate 212.

The hole 234 for mechanically fixing the intumescent cover plate 210 35 to the inner surface of a cavity, which may be a concrete slab edge, is located in the lip 224, thus providing a fixing plate.

The specification of the intumescent sheet 214 is chosen to reflect the passive fire requirements of the specific application.

The intumescent cover plate 210 of the third embodiment of the invention 210 is used in the same way as the intumescent cover plate 10 and 110 of the first and second embodiments of the invention. In particular, the cover plate 210 is inserted within the cavity 46 of a bracket, such as bracket 40 shown in figure 4. The intumescent cover plate 210 is then fixed to an internal surface of a cavity vie hole 234 in lip 224. In the event that heat, smoke or fire enters the wall cavity, the intumescent material 214 applied to the exterior surface of the profiled plate 212 will expand away from the exterior surface of the first arm, the second arm, the planar portion and the return to fill the cavity 46 in the bracket 40.

Claims

Claims 1 An intumescent cover plate for a masonry support bracket, comprising a profiled plate and an intumescent material, the profiled plate comprising a non-combustible material and being configured for insertion within the bracket of a masonry support in use, wherein the profiled plate comprises an elongate plate that is configured to have a generally C-shaped cross-section, comprising a substantially planar portion comprising an exterior face and an interior face, with first and second arms extending from the interior face of the planar portion and from opposing ends thereof, the first arm extending outwards and away from the planar portion and comprising at a distal end thereof a lip providing a fixing bracket, the second arm extending away from the planar portion and being shorter than the first arm, wherein the intumescent material is applied at least to the exterior face of the planar portion.
2. An intumescent cover plate according to claim 1, further comprising a return extending from a distal end of the second arm.
3. An intumescent cover plate according to claim 2, wherein the return extends towards the first arm.
4. An intumescent cover plate according to any one of claims 1 to 3, wherein the profiled plate comprises a unitary elongate plate providing the planar portion, the first arm, the fixing bracket, the second bracket and optionally the return.
5. An intumescent cover plate according to any one of the preceding claims, wherein the first arm comprises a first portion that extends at an obtuse angle away from the first end of the planar portion and a second portion extending from the distal end of the first portion, which second portion is substantially perpendicular to the planar portion.
6. An intumescent cover plate according to claim 5, wherein the second portion of the first arm is substantially parallel to the second arm.
7. An intumescent cover plate according to any one of the preceding claims, wherein the lip extends away from the second arm.
8. An intumescent cover plate according to any one of the preceding claims, wherein the lip is substantially parallel to the planar portion.
9. An intumescent cover plate according to any one of the preceding claims, wherein the second arm is substantially planar.
10.An intumescent cover plate according to any one of the preceding claims, wherein second arm is substantially perpendicular to the planar portion.
11.An intumescent cover plate according to any of the preceding claims, wherein the intumescent material is a high expansion intumescent material.
12.An intumescent cover plate according to any one of the preceding claims, wherein the intumescent material is provided as one or more chosen from the group comprising an intumescent strip, an intumescent sheet and an intumescent coating.
13.An intumescent cover plate according to any one of the preceding claims wherein the intumescent material is applied to the exterior surface of the first arm, the planar portion, the second arm and, if present, the return.
14.An intumescent cover plate according to claim 13, wherein the intumescent material is applied to the exterior and interior surface of the first arm, the planar portion, and the second arm.
5. An intumescent cover plate according to claim 14, wherein the intumescent material is also applied to the interior surface of the return, if present.
16.An intumescent cover plate according to any one of the preceding claims, wherein the intumescent material extends across the full width of the profiled plate.
17.An intumescent cover plate according to any one of claims 1 to 11, wherein the intumescent material covers the whole exterior face of the profiled plate except the lip.
18.An intumescent cover plate, according to claim 17, wherein the intumescent material also covers the whole of the interior face of the profiled plate, except the lip.
19.An intumescent cover plate according to any one of the preceding claims, wherein the non-combustible material of the profiled plate is a non-combustible metal chosen from the group comprising steel, galvanized steel, stainless steel.
20.An intumescent cover plate according to any one of claims 118, wherein the profiled plate comprises a non-combustible mineral material.
21.A masonry support system, comprising a bracket, a masonry support member and an intumescent cover plate according to any one or claims 1 to 20, the bracket having a substantially U-shaped cross-section comprising a substantially planar web extending between substantially planar first and second flanges, which first and second flanges are substantially perpendicular to the web, the web, first flange and second flange together defining a cavity, the intumescent cover plate comprising a profiled plate and an intumescent material, the profiled plate comprising a non-combustible material, wherein the profiled plate comprises an elongate place that is configured to have a generally C-shaped cross-section, comprising a substantially planar portion comprising an exterior face and an interior face, with first and second arms extending from the interior face of the planar portion and from opposing ends thereof, the first arm extending outwards and away from the planar portion and comprising at a distal end thereof a lip providing a fixing bracket, the second arm extending away from the planar portion and being shorter than the first arm, wherein the intumescent material is applied at least to the exterior face of the planar portion, wherein the profiled plate of the intumescent cover plate is locatable at least partially within the cavity of the bracket, and the intumescent cover plate being configured such that the intumescent material of the intumescent cover plate extends across the full width of the cavity of the bracket, the masonry support member being attachable to the bracket.
22.A masonry support system according to claim 21, wherein the intumescent cover plate is an interference fit within the cavity of the bracket.