IE20170126A1

IE20170126A1 - Improvements relating to roofing structures

Info

Publication number: IE20170126A1
Application number: IE20170126A
Authority: IE
Inventors: Irving Russell
Original assignee: Arc Building Solutions Ltd
Priority date: 2016-06-14
Filing date: 2017-06-09
Publication date: 2018-05-30
Also published as: GB2553619B; GB2553619A; GB201709247D0; IE87093B1; GB201610341D0

Abstract

A barrier for use in building construction, the barrier comprising a first member for location against a wall, and a second member for location between a spandrel panel and a surface of a building structure.<Figure 2>

Description

Improvements Relating to Roofing Structures Field of the Invention The present invention relates to improvements for roofing structures. In particular, but not exclusively, the invention relates to providing improvements to a vertical blockworkspandrel panel junction.

Background to the Invention A spandrel panel is a structural, timber-framed panel assembly formed to the profile of a building roof, which can provide a pre-fabricated and high-performance substitute for a masonry wall.

The panel is typically triangular in form to enable it to join horizontal upper edges of internal or external walls of the building to a slanted roof, to form part of a roof structure. Internally, a spandrel panel may define part of a party wall, whereas externally a spandrel panel typically defines a gable wall.

To provide the required thermal performance, a spandrel panel typically incorporates a layer of insulating material. Since the thermal performance of the panel in part relies on its ability to act as a barrier to heat convection by air movement, it is desirable to avoid the formation of gaps around the perimeter of the panel where it meets either the roof above it or the wall below it, to minimise unwanted air movement that could carry thermal energy from one side of the panel to the other.

A junction between a spandrel panel and a wall beneath it entails an interface between timber and masonry. Often, no additional material is used at this interface, which gives rise to two problems.

Firstly, a poor interface results in inadequate fire protection due to air gaps arising between the generally planar machined underside of the spandrel panel and the relatively uneven upper surface of a masonry wall.

Secondly, providing an effective edge seal directly between timber and masonry, to prevent air flow between the panel and the wall, is challenging. In this respect, the relevant standards that must be met are specified in Building Regulations Part L 2013. If the interface is not properly sealed, air can flow from one side of the panel to the other and thereby bypass any insulation provided by the panel. Moreover, air can pass between an internal cavity of the wall to which the panel is attached and a roof void beyond the panel.

The problem of air paths bypassing building insulation is known to contribute to poor building performance. Research has shown that air, induced by differential pressure, moves through wall cavities, from one cavity to the next, using connecting roof voids. The resulting uncontrolled movement of air from wall cavities through the roof structure significantly reduces the thermal resistance of the external envelope of the building, and in turn the ability to control internal temperatures. This increases energy costs and also affects the degree of thermal stability and comfort that can be achieved in the building.

Effective edge or junction seals restrict the movement of air between wall cavities and connecting voids, thus improving the performance of the building and in turn lowering energy costs.

In some cases, a horizontal layer of low density glass fibre or plastic foam is placed on the top of a party wall cavity to act as a barrier and thereby provide a fire rating. The barrier may be fixed in place before the spandrel panel is installed by applying a layer of mastic or silicon adhesive to the wall and then pressing the barrier into contact with the adhesive. Alternatively, the barrier may be held in place by a site operative until the timber spandrel panel is located on top of the barrier and the wall. The operator then releases the barrier, which is held in place by the weight of the panel with no additional fixings.

The inconsistent application of these methods leads to confusion on building sites as well as costing issues for contractors. In addition, if the insulation barrier is not securely fitted or does not provide an effective seal between the wall and spandrel surfaces then the gaps allow unwanted air movement.

Similar problems arise at the junction between a spandrel panel and the roof. In particular, traditional fire proofing measures are installed between a spandrel panel and the roof interior once the roof has been constructed, and typically from one side of the panel only, which is difficult to achieve with accuracy in practice.

The present invention has been devised to mitigate or overcome at least some of the above-mentioned problems.

Summary of the Invention The invention resides in a barrier for use in building construction. The barrier may be configured to provide a fire rating and an effective edge seal at a spandrel panel junction. The barrier of the present invention advantageously integrates the provision of an effective edge seal and fire-rating.

The barrier comprises a first member for location against a wall, and a second member for location between a spandrel panel and a surface of a building structure. The first member may be orthogonal to the second member.

The first member and the second member may define an obtuse angle, for example to complement the shape of the top of a wall. Preferably, in such embodiments the shape formed by the obtuse angle fits at least a portion of the top of a wall.

The first member and the second member may be defined by a cross-section of the barrier, for example.

The barrier may comprise a core that is encapsulated in a protective layer. The core may comprise fire-rated material, for example mineral wool such as rock fibre mineral wool. Any other suitable fire-rated material may be used, however, and the material may be selected to suit the characteristics and geometry of the spandrel panel and the building structure. The core may be shaped to define the first and second members. The protective layer may comprise plastics. The protective layer beneficially protects the core of the barrier from unwanted ingress, for example by water, and enables easier site handling.

Advantageously, the barrier may be elongate so that it extends along an edge of the spandrel panel, in use.

The barrier may be arranged to embrace the wall so that, in use, a longitudinal axis of the barrier lies parallel to a plane of the wall.

The barrier may be unitary. That is, the barrier may be a one-piece barrier in which the first and second members are formed integrally. Alternatively, the barrier may be formed from multiple pieces. For example, the first and second members may be separate components that are joined together.

In some embodiments, the first member is compressible to form a substantially air-tight seal between the wall and an opposed, parallel wall. In this case, the wall and the opposed wall may define leaves of a cavity wall. Similarly, the second member may be compressible to form a substantially air-tight seal between the spandrel panel and the building structure surface.

The second member may be arranged to cover the surface of the building structure.

The second member may be arranged to provide an interface between the surface of the building structure and the spandrel panel.

In some embodiments, the barrier defines a flexible fire barrier.

Optionally, the barrier has an L-shaped cross section, in which case one arm of the Lshape may define the first member and the other arm of the L-shape may define the second member. Therefore, the members may be defined by the cross-section of the barrier.

Alternatively, the barrier may comprise a third member for location against an opposite face of the wall to the first member, so that the wall is received between the first and third members. For example, the first and third members may be disposed at opposed ends of the second member and the third member may extend orthogonally from the second member in parallel with the first member. For example, the barrier may have a U-shaped cross section that defines the first, second and third members.

Conveniently, any one or more of the first member, the second member and the third member may be resilient, which may facilitate installation and self-retention ofthe barrier in situ.

The spandrel panel may comprise the wall against which the first member is located. This may be the case where the building structure is a roof, so that the second member is located between an upper surface of the spandrel panel and an interior surface of the roof.

Alternatively, the building structure may comprise the wall against which the first member is located, so that the first member is for location against one surface of the wall and the second member is for location between the spandrel panel and another surface of the wall. This arrangement may be applicable where the barrier is to be used as an interface between the spandrel panel and a cavity party wall, for example.

The inventive also extends to a spandrel panel comprising the barrier of the above aspect.

Another aspect of the invention provides a roof structure comprising a roof, a spandrel panel, and a barrier of the above aspect installed at a junction between the spandrel panel and the roof. The roof structure may comprise a plurality of barriers arranged together end-to-end along the length of the junction between the spandrel panel and the roof.

A further aspect of the invention provides a building comprising: a cavity party wall having a first leaf and a second leaf; a spandrel panel supported by the first leaf of the party wall; and a barrier of the above aspect installed at a junction between the spandrel panel and the first leaf of the party wall so that the first member of the barrier is disposed between the first and second leaves of the party wall and the second member of the barrier is disposed between the spandrel panel and the first leaf. The building may also comprise the roof structure of the above aspect.

The building may comprise a plurality of barriers arranged together end-to-end along the length of the junction between the spandrel panel and the first leaf of the party wall.

In another aspect, the invention extends to a barrier system comprising a barrier having an L-shaped cross-section and a barrier having a third member.

According to a further aspect, the invention resides in a method of installing a barrier as described herein. Preferably, the method comprises locating the barrier at the top of party wall blockwork.

Preferably, the barrier may be fitted before the spandrel panel is mechanically lifted into position. The method may comprise using a spandrel panel to secure the barrier in situ. The first member may be fitted and/or compressed within a party wall cavity. At least a portion of the second member may be arranged for compression underneath the spandrel panel.

The barrier may prevent the penetration of fire and air at the spandrel panel junction. Embodiments of the present invention may advantageously provide a fire rating in one or both of two planes, in particular, the vertical and horizontal planes.

Embodiments of the barrier may achieve up to four hours’ fire integrity in masonry party wall cavities up to 150mm, and up to one hour between a spandrel panel and the top of party wall blockwork.

Embodiments of the barrier of the present invention may advantageously provide a thermal barrier in one or both of two planes, in particular, the vertical and horizontal planes.

In some embodiments, the barrier of the present invention advantageously provides a self-levelling seal under the spandrel panel.

Embodiments of the barrier of the present invention are advantageously easy and quick to install in all weather conditions.

Embodiments of the barrier of the present invention allow consistent fitting methods to be applied to the installation of spandrel panel junction barriers.

Embodiments of the present invention allow two on-site processes to be eliminated compared to the prior art. Namely, the prior art methods of a contractor holding a glass fibre or foam barrier in place before the addition of the spandrel or the application of mastic adhesive.

Embodiments of the barrier have recognised third party approval.

Embodiments of the barrier of the present invention can be manufactured to suit any building design.

It will be appreciated that preferred and/or optional features of any aspect of the invention may be incorporated alone or in appropriate combination in any other aspect of the invention also.

Brief Description of the Drawings In order that the invention may be more readily understood, preferred non-limiting embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which like features are assigned like reference numerals, and in which: Figure 1 is a schematic perspective view of a wall barrier according to an embodiment of the present invention; Figure 2 is a schematic perspective view of the wall barrier of Figure 1 in situ in a cavity party wall; Figure 3 corresponds to Figure 2 but shows a spandrel panel installed on top of the wall barrier; Figure 4 is a schematic side-wall of a junction between a masonry wall and a spandrel panel; Figures 5 to 7 illustrate an installation process for the wall barrier of Figure 1; Figure 8 is a schematic perspective view of a barrier system according to an embodiment of the invention; and Figure 9 is a schematic perspective view of a roof barrier of the barrier system of Figure 8.

Detailed Description of Embodiments of the Invention In general terms, embodiments of the invention provide barriers that can be installed at interfaces between a spandrel panel and a wall or a roof of a building, to improve thermal performance and to provide a fire rating.

The barriers include wall barriers, which are installed between a spandrel panel and a cavity wall, and roof barriers, which are installed between a panel and a slanted roof. Together, the barriers form a barrier system that seals the interfaces of the panel to prevent unwanted air movement in a roof structure.

Figure 1 shows in schematic perspective view a wall barrier 10 according to an embodiment of the invention for installing between a spandrel panel and a party wall to provide an interface between the two.

The wall barrier 10 is defined by an elongate member comprising a core encapsulated in a protective layer. The core comprises compressible, fire-rated material such as rock fibre mineral wool, whereas the protective layer comprises water resistant material such as plastics materials, for example polythene.

Mineral wool is selected for its thermal insulation and fire retardant properties, which therefore enables the wall barrier 10 to achieve a fire rating when installed at the interface between a spandrel panel and a party wall. Moreover, mineral wool is resilient and thus ideal for absorbing irregularities in building structures to provide effective sealing at the interface.

Meanwhile, the protective layer acts to prevent ingress of water and other contaminants, and also to ease handling of the wall barrier 10. This enables the wall barrier 10 to be installed in all weather conditions, for example, and also allows the wall barrier 10 to arrive at a building site ready for installation, thereby removing a construction step associated with the prior art in that there is no need for an operative to hold the barrier during installation or to apply adhesive to the party wall.

This construction provides a barrier that is sufficiently rigid to be stored and handled with ease, whilst also having some flexibility and resilience to facilitate installation into tight spaces, and self-retention thereafter.

The wall barrier 10 is L-shaped in cross-section, to define orthogonal arms or members: a downwardly extending first arm or member 12 surmounted by a horizontally extending second arm or member 14, as viewed in Figure 1. In other embodiments, the wall barrier may be T-shaped in cross-section, so that the upper surfaces of both leaves of a cavity party wall can be covered. This may be useful for situations where two spandrel panels are used, to provide interfaces between each panel and its respective party wall leaf.

It should be noted that in these embodiments, the downwardly extending member 12 is approximately at right angles with, perpendicular to, and at 90 degrees to the horizontally extending member 14. The skilled person will appreciate, however, that a precise 90 degree angle is not required and the orthogonality is such that the cross sectional profile of the wall barrier 10 substantially matches that of the upper course of blocks, which generally are rectangular in cross section and so define orthogonal upper faces. It should also be noted that in circumstances where the upper course of bocks define a domed or triangular upper surface, or capping, then the wall barrier 10 may be fabricated in other embodiments such that the horizontal member 14 and the downwardly extending member 12 are not orthogonal; for example they may define an obtuse angle between them so as to complement the lateral profile of the top of the wall. Still further, the underside of the horizontally extending member 14 may be fabricated to confirm to, to complement, or substantially to match at least a portion of the capping profile of the wall (that is, the top or upper wall surface); for instance the underside of the horizontally extending member 14 may have a lateral recess such as a slight arch.

In the illustrated embodiment, the first member 12 comprises an elongate cuboid of square cross-section. As shall become clear in the description that follows, the width of the first member 12 is specified for a press-fit into a cavity between opposed skins or leaves of a party wall. The depth of the first member 12 is specified to provide a minimum penetration into the party wall cavity. The minimum penetration may be dictated by fire rating requirements, for example, by the depth required to create a secure interface between the first member 12 and the leaves of the party wall, or by a combination of these factors. For example, the minimum penetration depth may be between 20cm and 50cm.

The second member 14 comprises an elongate cuboid of equal length to the first member 12, but which is oblong in cross-section so that the width of the second member 14 exceeds that of the first member 12.

The first and upper members 12, 14 are aligned along one of the long sides, and so the second member 14 overhangs the first member 12 transversely to the opposite side, thereby creating the L-shape cross-section. In a similar fashion, the L-shape could be formed from an upper member 14 that extends from a full-height first member 12.

The width of the second member 14 is specified such that the second member 14 covers an upper surface of a party wall leaf when the first member 12 is pressed into a cavity between that leaf and an opposed leaf, in use.

Although the first and second members 12, 14 may be fabricated separately and then joined to form the wall barrier 10, in this embodiment the first and second members 12, 14 are formed integrally with one another so that the wall barrier 10 is unitary. Conveniently, such a shape could be formed by trimming a cuboid block of core material into the required shape prior to encapsulating the resulting core to form the protective layer. Alternatively, a suitable extrusion process could be used in which wall barriers having a substantially uniform cross-section could be made in any desired length. Extruder dies could be provided with different cross-sectional shapes in order to manufacture wall barriers having different cross-sectional geometries tailored to different wall cavity sizes and wail leaf sizes.

Figure 2 shows the wall barrier 10 in situ installed into a cavity 16 between a first leaf 18 and a second leaf 20 of a conventional brickwork masonry party wall 22. The wall barrier 10 is located on the top of the party wall 22 so that a longitudinal axis of the wall barrier 10 lies parallel to a plane of the wall 22.

The party wall 22 extends between opposed shared external walls 24 of a pair of attached dwellings 26, 28 within a building 30. Each of the first and second leaves 18, 20 is associated with a respective one of the pair of dwellings 26, 28.

The wall barrier 10 is sized to extend along the entire length of the cavity 16, although in other embodiments, two or more shorter barriers 10 may be used to cover the full length of the cavity 16.

The wall barrier 10 is installed by press-fit insertion of the first member 12 into the cavity 16, so that the first member 12 is held in compression between the leaves 18, 20 of the party wall 22 when installed. This enables the wall barrier 10 to remain in place without additional fixings, if desired. The close fit also ensures that air cannot flow between the first member and the leaves 18, 20, thereby creating an air-tight seal that closes the cavity 16. In this way, the wall barrier 10 restricts unwanted air movement and so enhances the thermal performance of the building 30.

As the wall barrier 10 is of fire-rated material, the first member 12 also acts as a fire barrier between the leaves 18, 20 of the party wall 22.

When the wall barrier 10 is installed, the second member 14 covers a horizontal upper surface of one of the leaves of the party wall 22; in this case, the leaf 20 associated with the dwelling 28 shown to the right in Figure 2 is covered. The upper surface of the opposing leaf 18 is left exposed in this embodiment, although as noted above in other embodiments a wall barrier of T-shaped cross-section cover both leaves, in particular where a respective spandrel panel is to be installed at the top of each leaf.

In this configuration, a planar upper surface of the second member 14 provides a landing surface for a spandrel panel to be installed on top of the covered leaf 20 of the party wall 22, thereby avoiding a direct interface between the predominantly timber panel and the masonry of the party wall 22.

Figure 3 builds on Figure 2 by showing a spandrel panel 32 installed onto the barrier 10 in vertical alignment with the leaf 20 of the party wall 22 that is covered by the second member 14 of the wall barrier 10, so that a vertical outer face of the panel 32 is coplanar with a corresponding vertical face of the leaf 20 to provide a continuous surface in the respective dwelling 28. Accordingly, the leaf 20 supports the spandrel panel 32 through the wall barrier 10.

The spandrel panel 32 is generally triangular in form, having geometry corresponding to a void that the panel 32 is to fill between the party wall 22 and a roof (not shown in Figure 3) of the building 30. The panel 32 typically has a thickness substantially corresponding to that of the leaf 20 of the party wall 22 that is to support the panel 32.

The spandrel panel 32 may be of any suitable construction, and for example typically comprises a triangular outer frame of timber beams 34 that is encased by opposed triangular planar boards 36. A void defined between the boards 36 and within the timber frame is packed with insulating material to optimise the thermal performance of the panel 32.

The spandrel panel 32 is fitted on top of the second member 14 of the barrier 10, so that the spandrel panel 32 compresses the second member 14 against the upper surface of the leaf 20 of the party wall 22 that supports both the wall barrier 10 and the spandrel panel 32. This compression forms a substantially air-tight seal between the masonry of the leaf 20 and the timber of the spandrel panel 32, to create a thermal seal between the panel 32 and the wall 22.

The second member 14 also provides a fire barrier between the underside of the spandrel panel 32 and the top of the leaf 20 that will act to slow the spread of fire from the party wall 22 to the spandrel panel 32, due to the fire-retardant nature of the barrier material.

By compressing the wall barrier 10 between the spandrel panel 32 and the party wall 22, the wall barrier 10 can also act as a levelling aid that absorbs any irregularities in the surfaces of the wall 22 and the panel 32 and thereby facilitates the interface between the two.

To illustrate this, Figure 4 is a side view of a junction between the party wall 22 and the spandrel panel 32, and shows the inconsistencies that can occur in new dwellings at this junction as a result of the brickwork construction of the party wall 22 in particular.

As Figure 4 shows, individual bricks within the party wall 22 are at slightly different heights with respect to the ground, which is unavoidable in conventional bricklaying. As a result, the top surface of the leaf 20 of the party wall 22 is uneven so that the height of the wall 22 is inconsistent along its length. To represent this, the height of the party wall 22 with respect to the ground 23 is shown at four horizontally-spaced locations labelled A to D, and these heights are not uniform.

This inconsistency would create gaps at the interface between the party wall 22 and the spandrel panel 32, as the panel 32 generally has a much straighter edge. Such gaps create air flow paths that diminish the thermal performance of the building 30, as already explained. However, by compressing locally to absorb these potential gaps, the wall barrier 10 overcomes this problem and thereby provides a more effective fire-rated interface than is possible in a direct coupling of the panel 32 to the wall 22.

Figures 5 to 7 illustrate a process for installing a set of wall barriers 10 into the cavity 16 of the party wall 22. In the example shown in Figures 5 to 7, short wall barriers 10 are used so that multiple barriers 10 are required to span the length of the party wall 22.

Figure 5 shows a wall barrier 10 being installed into the cavity 16 of the party wall 22 in perspective view, whereas Figure 6 provides a side-view of the same stage of the installation process.

As shown in Figures 5 and 6, the first member 12 of the wall barrier 10 is oversized in comparison to the cavity 16 between the two party wall leaves 18, 20. Since the wall barrier 10 is flexible, the first member 12 can be pressed into the cavity 16 such that it is subsequently held in a compression fit arrangement The first member 12 is compressed between the leaves 18, 20 of the party wall 22, which as already noted helps to provide an effective edge seal.

As shown in Figure 5, a plurality of wall barriers 10 may be arranged end-to-end along the length of the party wall 22. In this example, the complete length of the party wall 22 is filled in its entirety using individual lengths of wall barrier 10. The wall barriers 10 engage one another firmly to form an effective seal. In some embodiments, overlapping lips may be provided on neighbouring wall barriers to optimise the joints between them.

Moving on to Figure 7, once the one or more wall barriers 10 have been pressed into the party wall cavity 16, the spandrel panel 32 is lifted into position and the wall barrier 10 is compressed underneath it to provide a fire barrier and air seal at this junction.

Figure 7 shows the wall barriers 10 in situ after the spandrel panel 32 has been manoeuvred into position and arranged on top of the wall barriers 10, from which it is clear that the wall barriers 10 are compacted under the spandrel panel 32; that is, the second member 14 of each wall barrier 10 is compressed under the weight of the spandrel panel 32. The flexible nature of the mineral wool from which the barriers 10 are formed ensures that inconsistencies in the height of individual bricks ofthe party wall 22 are compensated for, as mentioned above.

Figure 8 corresponds to Figure 3 but also shows an interface between the spandrel panel 32 and a roof40 ofthe building 30.

Although not entirely visible in Figure 8, the roof 40 is of conventional A-frame construction, being defined by a set of opposed pairs of rafters 42 that extend away from an apex 44 of the roof 40 at oppositely-inclined pitches, the rafters 42 being covered by a roof sheet 46 and braced with a series of horizontal battens 48.

Accordingly, the spandrel panel 32 takes the form of an isosceles triangle having shorter edges at inclinations corresponding to the roof pitches, and its longest edge abutting the wall barrier 10, in use.

A roof barrier 50 is installed between the panel 32 and the roof 40 to provide a thermally sealed and fire-rated interface between the panel 32 and the roof 40, said interface extending on both pitches of the panel 32 between the apex 44 of the roof 40 and points at which the roof 40 meets the party wall 22 internally. Thus, the roof barrier 50 performs the same role as the wall barrier 10, but for the roof interface.

Accordingly, between them the wall barrier 10 and the roof barrier 50 fully envelop the edges of the spandrel panel 32 to create a barrier system that seals the entire perimeter ofthe panel 32.

To perform its role effectively, the roof barrier 50 is formed in the same manner as the wall barrier 10, namely as a block of rock fibre mineral wool or other suitable material defining a core that is encapsulated in a protective layer of plastics such as polythene. The roof barrier 50 is therefore easy to handle and can be installed in all weather conditions.

As Figure 9 shows most clearly, the roof barrier 50 is U-shaped in cross-section, having a pair of parallel downwardly-extending members defining arms 52 that are connected by an orthogonal bridge member 54. The arms 52 and the bridging member 54 may be formed separately and then assembled into a roof barrier 50. Alternatively, the arm 52 and bridging member 54 may be formed integrally, for example by trimming a cuboid block of core material into the required shape and then encapsulating the resulting core in the protective layer.

Returning to Figure 8, the roof barrier 50 is installed onto the spandrel panel 32 before the panel 32 is moved into place on top of the party wall 22. Installing the roof barrier 50 entails pressing it onto the edge of the panel 32 that is to engage the roof 40 by sliding the panel 32 into a gap defined between the arms 52 until the panel 32 engages the underside of the bridge member 54.

Accordingly, the bridge member 54 of the roof barrier 50 performs the same function as the second member 14 of the wall barrier 10 in that it lies between the spandrel panel 32 and a surface of a building structure, in this case the roof, to provide an interface between the two. Similarly, the arms 52 perform a similar role to the first member 12 of the wall barrier 10 in that they engage a vertical wall, the side of the spandrel panel 32 in this case, to hold the barrier in place.

In this embodiment, a respective roof barrier 50 is installed onto each pitch of the spandrel panel 32. In other embodiments, multiple shorter roof barriers 50 may be installed on each pitch. In another alternative, a single barrier having a profile corresponding to that of the panel 32 may be used to cover both pitches of the panel 32.

The bridge member 54 is dimensioned such that the gap that separates the arms 52 is slightly smaller than the width of the spandrel panel 32. Accordingly, the arms 52 are deflected and compressed as the roof barrier 50 is pressed onto the spandrel panel 32. Thereafter, the resilience of the arms 52 arising from the properties of the mineral wool from which they are constructed presses the arms 52 into engagement with the sides of the panel 32, thereby providing a retention force that holds the roof barrier 50 in place. Thus, like the wall barrier 10, the roof barrier 50 can be installed in a simple operation that requires no additional fixings.

Once the roof barrier 50 is installed onto the spandrel panel 32, the panel can be moved into place on top of the party wall 22 within the roof 40. The roof 40 is then constructed, which involves installing the roof sheet 46 over the roof barrier 50. As the roof barriers 50 on each pitch of the panel 32 are pressed into engagement with the roof sheet 46, for example as the battens 48 are secured, a substantially air-tight seal that provides effective thermal insulation is created. Moreover, the roof barriers 50 provide a fire rating in that they act to slow progress of fire between the panel 32 and the roof 40.

It will be appreciated by a person skilled in the art that the invention could be modified to 5 take many alternative forms to that described herein, without departing from the scope of the appended claims.

For example, the U-shaped barrier that is described above as a roof barrier could equally be used as a wall barrier, with the leaf of the party wall being received between the arms of the barrier.

Claims

1. A barrier for use in building construction, the barrier comprising a first member for location against a wall, and a second member for location between a spandrel panel and a surface of a building structure.

2. The barrier of claim 1, wherein the first member is orthogonal to the second member.

3. The barrier of any preceding claim, wherein the first member and the second member are defined by a cross-section of the barrier.

4. The barrier of any preceding claim, comprising a core that is encapsulated in a protective layer.

5. The barrier of claim 4, wherein the core comprises fire-rated material.

6. The barrier of claim 4 or claim 5, wherein the core comprises a mineral wool.

7. The barrier of any of claims 4 to 6, wherein the protective layer comprises plastics.

8. The barrier of any of claims 4 to 7, wherein the core is shaped to define the first and second members.

9. The barrier of any preceding claim, wherein the barrier is elongate.

10. The barrier of any preceding claim, wherein the barrier is arranged to embrace the wall so that, in use, a longitudinal axis of the barrier lies parallel to a plane of the wall.

11. The barrier of any preceding claim, wherein the barrier is unitary.

12. The barrier of any of claims 1 to 10, wherein the barrier is formed from multiple pieces.

13. The barrier of any preceding claim, wherein the first member is resilient.

14. The barrier of any preceding claim, wherein the first member is compressible to form a substantially air-tight seal between the wall and an opposed, parallel wall, wherein the wall and the opposed wall define leaves of a cavity wall.

15. The barrier of any preceding claim, wherein the second member is resilient.

16. The barrier of any preceding claim, wherein the second member is compressible to form a substantially air-tight seal between the spandrel panel and the building structure surface.

17. The barrier of any preceding claim, wherein the second member is arranged to cover the surface of the building structure.

18. The barrier of any preceding claim, wherein the second member is arranged to provide an interface between the surface of the building structure and the spandrel panel.

19. The barrier of any preceding claim, wherein the barrier defines a flexible fire barrier.

20. The barrier of any preceding claim, wherein the barrier has an L-shaped cross section.

21. The barrier of any of claims 1 to 19, comprising a third member for location against an opposite face of the wall to the first member, so that the wall is received between the first and third members.

22. The barrier of claim 21, wherein the first and third members are disposed at opposed ends of the second member.

23. The barrier of claim 21 or claim 22, wherein the third member extends orthogonally from the second member in parallel with the first member.

24. The barrier of claim 23, wherein the barrier has a U-shaped cross section that defines the first, second and third members.

25. The barrier of any of claims 21 to 24, wherein the third member is resilient.

26. The barrier of any of claims 21 to 25, wherein the spandrel panel comprises the wall against which the first member is located.

27. The barrier of any of claims 1 to 25, wherein the building structure comprises the wall against which the first member is located, so that the first member is for location against one surface of the wall and the second member is for location between the spandrel panel and another surface of the wall.

28. A spandrel panel comprising the barrier of any preceding claim.

29. A roof structure comprising a roof, a spandrel panel, and a barrier of any of claims 1 to 27 installed at a junction between the spandrel panel and the roof.

30. The roof structure of claim 29, comprising a plurality of barriers arranged together end-to-end along the length of the junction between the spandrel panel and the roof.

31. A building comprising: a cavity party wall having a first leaf and a second leaf; a spandrel panel supported by the first leaf of the party wall; and a barrier of any of claims 1 to 27 installed at a junction between the spandrel panel and the first leaf of the party wall so that the first member of the barrier is disposed between the first and second leaves of the party wall and the second member of the barrier is disposed between the spandrel panel and the first leaf.

32. The building of claim 31, comprising the roof structure of claim 29 or claim 30.

33. The building of claim 31 or claim 32, comprising a plurality of barriers arranged together end-to-end along the length of the junction between the spandrel panel and the first leaf of the party wall.

34. A barrier system comprising a barrier according to claim 20 and a barrier according to any of claims 21 to 25.