GB2412669A

GB2412669A - Support system for outer skin of roof

Info

Publication number: GB2412669A
Application number: GB0407617A
Authority: GB
Inventors: Mark Jones; Philip Cook; Glyn Lewis
Original assignee: EURO CLAD Ltd
Current assignee: EURO CLAD Ltd
Priority date: 2004-04-02
Filing date: 2004-04-02
Publication date: 2005-10-05
Anticipated expiration: 2024-04-02
Also published as: GB0407617D0; GB2412669B; EP1582647A1

Abstract

A roofing system (1) for retaining an outer skin of a roof in spaced relationship to an underlying roof structure (4), the system comprising: at least one elongate member (3); and a plurality of brackets (2), each comprising a supporting structure of a generally U shape, including first and second legs (21, 22) interconnected at their upper ends by a top portion (29) and carrying fixing portions (23, 24) for fixing to an underlying roof structure, each bracket further including a connecting arrangement for connecting the bracket to the elongate member.

Description

24 1 2669 Roofing system The present invention relates to a roofing

system, to brackets and roof support members for use therein and to methods of construction using such systems.

Metal cladded roofing systems have become increasingly popular over the past decade. Such systems typically comprise an outer roof structure comprising a plurality of sheets supported by a plurality of support members, these members being spaced apart from an underlying roof substructure by a plurality of brackets. The space between the sheets and underlying structure may be filled with a thermally insulating material. The brackets are typically formed from relatively thin (l.5mm) steel sheet and are provided with a flange at one end to attach the bracket to the underlying sub-structure and shaped at the other end so as to positively engage with, or be attached to, a support member. The support member may comprise a bar of approximately constant cross-section which may be formed by two side portions depending from a central portion and a spigot at one end. The three-sided shape of the bar forms a hollow interior into which the bracket is inserted. The bar is shaped as to positively engage with, or be attachable to, the bracket. The spigot which only has one side portion depending from the central portion is insertable into the end of a like rail.

In accordance with a first aspect of the present invention, there is provided a roofing system for retaining an outer skin of a roof in spaced relationship to an underlying roof structure, the system comprising: at least one elongate member; and a plurality of brackets, each comprising a supporting structure of a generally U shape, including first and second legs interconnected at their upper ends by a top portion and carrying fixing portions for fixing to an underlying roof structure, each bracket further including a connecting arrangement for connecting the bracket to the elongate member.

This provides a robust and easily erected roofing system.

It is preferred that the connecting arrangement is provided at the top of the bracket. This facilitates simple system erection. It is further preferred that each fixing portion is provided at the lower end of the respective leg. This facilitates simple fixing of the bracket to an underlying roof structure.

The bracket may be directly fixable to the elongate member. Alternatively or additionally, the bracket may be fixable to an intermediate member or spacer that is itself fixable to the elongate member.

The supporting structure may comprise a substantially flat or substantially curved portion between the two legs. The relative dimensions of the "U" may be chosen to suit the proposed use of the bracket. Such brackets are simple and inexpensive to manufacture and provide excellent strength characteristics when compared to the brackets used in the roofing systems of the prior art.

The system may further be provided with a spacer fixable between a bracket and an elongate member. The bracket is preferably provided with a spacer retention means for fixing the spacer to the bracket.

The spacer preferably comprises a thermally insulating material, such as EPDM or polypropylene. The thickness of the spacer (i.e. dimension parallel to the height of the bracket) may be between about 1 and 30mm, preferably between about 10 and 30mm and more preferably between about 20 and 30mm. The insulating material reduces heat loss by conduction through the metallic roofing structure.

The legs may be curved but are preferably straight in section. The top portion of the bracket may be curved but Is is preferably substantially flat. The provision of a top portion that is substantially flat facilitates fitting of the bracket to one or both of the elongate member and the spacer. It is preferred that the first and second legs are of substantially equal length.

It is preferred that the thickness of the top portion and first and second bracket legs is between about 0.5mm and 5.Omm, more preferably about 1.0 to 3.Omm, even more preferably about 1. 5mm to 2.5mm and most preferably about 1.5mm. The supporting structure is preferably formed from sheet metal.

The height of the bracket, including a fitted spacer (if present), may be between about 60mm and 300mm, preferably about 60mm to 250mm and more preferably chosen from one of about 135, 185 and 200mm.

The angle between the substantially flat portion of the top bracket portion (if present) and at least one of the first and second legs may be between about 85 degrees and degrees and is more preferably about 90 degrees.

The overall greatest distance between the legs is typically between about 30mm and 200mm, preferably about 40mm to 80mm and more preferably about 40mm to 60mm.

The depth of the bracket is preferably approximately constant. The depth of the bracket may be between about 20 to 200mm, preferably about 40 to 150mm, more preferably between about 50 and 80mm and most preferably about 60mm.

It is preferred that the fixing portions comprise flange portions, which may extend outwardly from the legs.

It is preferred that the bracket is formed from galvanised steel, more preferably galvanised steel made to one or both of FEPO02G and Z275 BS EN 10142 standards.

It is preferred that at least one of the legs is provided with at least one corrugation in a direction substantially parallel to the longitudinal axis of the respective leg.

The connecting arrangement may preferably comprise at least one engagement member, preferably arranged so that it may frictionally and slidably engage with the elongate member. This allows the position of the bracket to be slidably connected to the elongate member or to be fixed in place by screws, nails or the like.

It is further preferred that the engagement members extend away from the legs. At least one engagement member l may be provided with at least one lug (and preferably two lugs) for engagement with the elongate member. A preferred engagement member comprises two mutually spaced lugs, each lug comprising a lug body portion and a lug end portion, the lug end portion extending at an angle from the lug body portion. It is preferred that the lug end portion extends orthogonally to the lug body portion.

Such lugs are effective at holding the bracket in relation to the elongate member.

It is preferred that the connecting arrangement comprises mutually spaced first and second engagement members, both of which, in use, may engage with the elongate member.

This provides a secure means of attaching the bracket to the elongate member. It is preferred that when at least one of the first and second engagement members is provided with at least one lug, and the roofing system comprises a spacer, then the spacer, in use, is in contact with the lug or lugs. It is further preferred that, in use, the spacer is further in contact with a surface of the elongate member.

A first surface of the first engagement member may face a first surface of the second engagement member. These surfaces may receive the spacer. Thus, two engagement members may act as a spacer retention means. In this case, it is preferred that the spacing between the first surface of the first engagement member and the first surface of the second engagement member is approximately constant and it further preferred that each of these two surfaces is substantially flat. This allows the bracket to engage spacers of approximately simple rectilinear shape.

It is preferred that at least one of the first surface of the first engagement member and the first surface of the second engagement member is provided with at least one protrusion that projects away from the said surface. Such protrusions effectively reduce the spacing between the said surfaces and thus provide a support for the spacer.

This allows the spacer to be held in spaced relationship with the supporting structure, thus reducing the area of contact between the supporting structure and the spacer.

This helps to reduce thermal losses through conduction between the supporting structure and the spacer.

Such protrusions may have an elongated shape, such as a hemicylinder. It is preferred that at least one protrusion is provided on each of the first surface of the first engaging member and the first surface of the second engaging member. The protrusions may project between about O.l and 5mm, preferably between about 0.5 and 3mm and more preferably about 1.0 and 2.Omm from the respective surface.

The first surface of the first engagement member and the first surface of the second engagement member may be arranged so as, in use, to frictionally engage with the spacer. In this case, the at least one protrusion may, in use, enhance or facilitate frictional engagement between the engagement members and the spacer.

The engagement members may be shaped such that the insertion of a spacer between the first surface of the first engagement member and the first surface of the second engagement member causes deformation of the engagement members resulting in a biasing force urging the first surface of the first engagement member and the first surface of the second engagement member into frictional engagement with the spacer. This allows relatively simple placement of the spacer, while producing a biasing force that resists inadvertent or unwanted removal from the bracket.

In one embodiment, the elongate member has a first and a second end, the elongate member at the first end forming a substantially hollow interior and having a certain cross-sectional shape perpendicular to the longitudinal axis of the elongate member, the second end of the elongate member having a longitudinally extending spigot suitable for insertion into the substantially hollow interior of a like elongate member, wherein the spigot has, along at least part of its length, preferably along the majority of its length and more preferably along substantially all of its length, a cross-sectional shape perpendicular to the longitudinal axis of the spigot that is substantially the same as the cross-sectional shape of the elongate member at its first end. Such an arrangement provides a secure and effective join between adjacent elongate members.

A plurality of elongate members may have such a structure.

Advantageously, the elongate member has first and second ends, and has first and second side members depending from respective sides of a central member, a substantially hollow interior being formed at the first end by the central member and first and second side members, the second end of the elongate member comprising a spigot having first and second spigot side portions depending from respective sides of a central spigot portion wherein the dimensions of the spigot is such that the spigot may be inserted into the hollow interior at the first end of a like elongate member.

A plurality of elongate members may have such a structure.

The first and second spigot side portions may extend for the majority of the length of the spigot, more preferably for substantially the entire length of the spigot. These spigots thus provide an effective join.

It is preferred that the first and second spigot side portions depend to substantially mutually the same distance from the central spigot portion. This may provide an essentially symmetrical spigot that provides a simple and effective join.

The spigot may be provided with a depression that extends substantially parallel to the longitudinal axis of the spigot.

The elongate member may have a length, excluding the spigot, of between about 0.5 and 5.Om, preferably between about 0.8 and 3.5m and more preferably selected from one of about l.O, 2.0 and 3.Om.

The spacing of the first and second side members of the elongate member corresponds to the breadth of the central member and may be between about 20 and lOOmm, preferably between about 30 and 70mm and more preferably between about 35 and 45mm. The first and second side members may depend from the central member for a distance of about 3 to 15mm, preferably about 5 to 12mm, more preferably about 9 to lOmm.

It is preferred that at least one elongate member is provided with first and second bottom members projecting inwardly towards the hollow interior from the longitudinally extending edges of the first and second side members remote from the central member. The bottom members may engage with the bracket. The elongate member may also be provided with one or more longitudinally extending lips, each one projecting from the bottom members, preferably from the edge of the bottom member remote from the respective side member with which the bottom member is associated. The lips prevent unwanted motion of a bracket once the bracket is inserted into the end of the elongate member. In use, lugs of a bracket, including the brackets described above, engage with one or more of the bottom and side members, and also may engage the underside of the central member.

In accordance with a second aspect of the invention, there is provided a bracket suitable for use in the roofing system of the first aspect of the present invention. The bracket may incorporate those features that are described with respect to the bracket in relation to the description of the roofing system of the first aspect of the present invention.

In accordance with a third aspect of the invention, there is provided an elongate member suitable for use in the roofing system of the first aspect of the present invention. The elongate member may incorporate those features that are described with respect to the elongate member in relation to the description of the roofing system of the first aspect of the present invention. For example, the elongate member may have a first and a second end, the elongate member forming a substantially hollow interior and having a certain cross-sectional shape perpendicular to the longitudinal axis of the elongate member, the second end of the elongate member having a longitudinally extending spigot suitable for insertion into the substantially hollow interior of a like elongate member, wherein the spigot has, along at least part of its length, a cross-sectional shape perpendicular to the longitudinal axis of the spigot that is substantially the same as the cross-sectional shape of the elongate member at its second end.

In accordance with a fourth aspect of the invention, there is provided a method of constructing a roof, the method comprising (a) providing (i) at least one elongate member; and (ii) a plurality of brackets, each comprising a supporting structure of a generally U shape, including first and second legs interconnected at their upper ends by a top portion and carrying fixing portions for fixing to an underlying roof structure, each bracket further including a connecting arrangement for connecting the bracket to the elongate member.

(b) fixing at least one of the brackets to the underlying roof structures and (c) fixing at least one of the brackets to the elongate member.

Step (b) may be performed prior to or after step (c).

The bracket and elongate member may incorporate those features that are described with respect to the respective component in relation to the system of the first aspect of the invention.

References to "fixing" in the present patent application does not necessarily mean that fixing components such as screws, bolts and nails are used, although this is optional. Fixing, for example, can be by frictional engagement between respective components. "Fixed" in the present application indicates that two components are joined so that they cannot be moved relative to one another accidentally during normal use. The components can, of course, be moved and removed deliberately if desired.

The invention will now be described by way of example only with reference to the following figures of which: Figure 1 is a perspective view of a portion of a system in accordance with the present invention, the roofing system being shown attached to an underlying roof structure; Figure 2 is a perspective view of the bracket used in the system of Figure 1; Figure 3 is a perspective view of the bar used in the system of Figure 1; and Figure 4 is a cross-sectional view of the bracket and bar of Figures 2 and 3 respectively in an assembled state.

Figure 1 shows a portion of a system 1 in accordance with the present invention, the system being shown attached to an underlying roof structure 4. Only one bracket is shown for the purpose of clarity. The system 1 comprises a bracket 2 fixed to a bar 3, with a spacer (not shown) abutting the bar 3 and bracket 2. The bracket 2 has been formed into a general "U" shape and comprises first and second legs 21, 22 depending from a top portion 29. Each of the first and second legs 21, 22 is provided with a respective flange 23, 24 that facilitates the fixing of the bracket to the underlying roof structure 4 by bolts or other convenient fixing means (not shown). The top portion 29 is provided with lugged flanges (not visible in Figure 1) that fix the bracket 2 to the bar 3 and also JO support the spacer. The bar 3 has a generally elongate structure, with uniform cross-sectional shape and dimensions perpendicular to the longitudinal axis of the bar 3 from the one end 31 of the bar 3 up to a spigot 32 provided at the other end of the bar 3. The main body of the bar 3 (that is, the section of the bar 3 excluding the spigot 32) comprises a central portion 34 at the upper surface of the bar 3 from which depends sides 33, 35. The spigot 32 extends longitudinally parallel to the main body of the bar 3, and comprises spigot side portions 36, 37 depending from a spigot central portion 38. The spigot central portion 38 and spigot side portions 36, 37 extend along the whole length of the spigot 32.

The bracket 2 is now described in more detail with reference to figure 2. The main body of the bracket 2 is made from an approximately 440 x 60mm rectangular piece of sheet steel of 1.5mm thickness that has been formed into a general square "U" shape by bending. Bracket 2 comprises legs 21, 22 that depend from either side of a top portion 29 at an angle of about 90 degrees. Each leg 21, 22 is provided with a respective flange 23, 24 that facilitates fixing of the bracket 2 to the underlying roof structure, each flange 23, 24 projecting substantially orthogonal to the respective leg 21, 22.

Each of the legs 21, 22 is provided with a corrugation (not shown) extending substantially longitudinally along the respective leg from the top portion 29 to the respective flange 23, 24. The corrugation provides extra strength to the respective leg 21, 22. The bracket 2 is further provided with an engagement mechanism that comprises two mutually spaced lugged flanges 201, 202.

The lugged flanges 201, 202 each comprise portions of sheet metal of 1.5 mm thickness that have been formed by cutting and bending portions of the rectangular piece of sheet steel to form two generally flat lugs (exemplified as 210, 211 of lugged flange 201) either side of a central lug flange. The ends 212, 213 of the lugs 210, 211 have been bent to project substantially orthogonal to the plane of the rest of the lugs 210, 211 and central lug flange. These ends 212, 213 engage with the bar 3 as described below. Rather than being produced by cutting and bending of the rectangular piece of sheet steel, the lugged flanges 201, 202 may be provided as separate pieces of sheet steel that may be fixed onto the intermediate member 29 of the bracket 2 by any known conventional means, for example, by welding. The mutually spaced lugged flanges 201, 202 are arranged so that two substantially flat surfaces 205, 206 face one another and are substantially mutually parallel, being spaced about 30mm apart. Both of these surfaces are provided with projections, exemplified as 203, 204 on surface 205.

These projections are approximately hemicylindrical, standing about lmm proud of the respective surface 205, 206. The spacing of the surfaces 205, 206 and shape and height of the projections 203, 204 are chosen so that, referring to figure 1, the spacer (not shown), when placed on the bracket 2, rests on the projections 203, 204 and the ends 212, 213 of the lugs 210, 211. The dimensions and shape of the spacer is chosen to provide the desired combined height of the bracket and spacer (when in position).

Alternatively or additionally, the shape and size of the spacer may be chosen such that when the spacer is mounted on the bracket, a force is exerted on the spacer, resisting removal from the bracket 2. This may occur because the dimension of the spacer at the point corresponding to the location of the projections is greater than the dimension between the projections on the opposed surfaces 205, 206. In this case, the upper portion of the lugged flanges 201, 202 may be urged apart from their normal positions, thus creating a resistive force that acts on the spacer to prevent its inadvertent removal. Those skilled in the art will realise that the magnitude of this resistive force will be determined by, inter alla, the size of the spacer in relation to the gap between the projections, the thickness of the material making up the lugged flanges 201, 202, the position of the projections 203, 204 and the material making up the lugged flanges 201, 202.

Those skilled in the art will realise that the projections 203, 204 may be of different shape and may be, for example, hemispherical, pyramidal, triangular or cuboid. Different numbers of projections may be used, and it is possible that the dimensions (one or more of length, breadth and height) of a projection may vary according to its position on the surface of the respective lugged flange 201, 202.

The bracket 2, including the lugged flanges 201, 202 is about 187.5mm high (the main body, without the lugged flanges 201, 202 being about 172. 5mm high).

S The bar 3 will now be described in detail with reference to figure 3. The bar 3 has a generally elongate structure, with uniform crosssectional shape and dimensions perpendicular to the longitudinal axis of the bar 3 from the one end 331 of the bar 3 up to a spigot 332 provided at the other end of the bar 3. The main body of the bar 3 (that is, the section of the bar 3 excluding the spigot 332) comprises a central portion 334 at the upper surface of the bar 3 from which depends sides 333, 335. Bottom portions 338, 339 extend substantially parallel to the central portion 334 from the edges of the sides 333, 335 that are not associated with the central portion 334. Longitudinally extending lips 340, 341 extend from bottom portions 338, 339 inwardly; these assist in helping to locate and fix the bracket 2 to the bar 3. The spigot 332 extends longitudinally parallel to the main body of the bar 3, and comprises spigot side portions 336, 337 depending from a spigot central portion 338. The spigot central portion 338 and spigot side portions 336, 337 extend along the whole length of the spigot 332. Prior art spigots provide only one such spigot side portion and this has been found to be unacceptable. The dimensions of the spigot 332 are such that the spigot 332 may readily be inserted into the cavity formed at the one end 331 of a like bar 3. The two spigot side portions 336, 337 improve the stability and rigidity of the mated structure. The spigot 332 is provided with a depression 39 that runs centrally along the spigot central portion 338, substantially parallel to the longitudinal axis of the spigot 332.

The bar 3 is made by cutting a piece of sheet metal of approximately 1. 5mm thickness to an appropriate size and bending it into the appropriate shape. The overall length of the bar 3 is 1035mm, with the spigot 332 being 35mm long.

The relationship between the bracket 2 of figure 2 and the bar 3 of figure 3 will now be described with reference to figures 2, 3 and 4. A spacer (not shown) is mounted on the upper part of the bracket 2 but has been omitted from figure 4 for clarity, as has lugged flange 202. The spacer has a generally cuboid shape and is made of a thermally insulating plastics material. The spacer IS is provided with two substantially parallel elongate bores into which lugged flanges 201, 202 may be inserted so that the lower surface of the spacer abuts against the lug ends (e.g. 212, 213) associated with the lugs (e.g. 210, 211). This ensures that the spacer is well supported by the bracket 2. The spacer is shaped so that a portion of the lower surface of the spacer that is, in use, located between the surfaces 205, 206 abuts against the projections (e.g. 203, 204) provided on those surfaces 205, 206. The spacer is also provided with two further substantially parallel bores that allow the spacer to fit, in use, around the lips 340, 341 of the bar 3 so that a bracket-spacer ensemble may be slid along the bar 3 into position. Furthermore, the fact that the lower portion of the spacer does not abut onto the top portion 29 of the bracket 2 reduces heat loss via conduction. The upper face of the spacer abuts against the lower surface of bar central portion 334. This provides a convenient way of positioning the spacer, and such abutment helps to resist unwanted movement of the bracket-spacer ensemble. l

Referring to the bracket 2, the lugs 210, 211 are shaped so as to fit in the space defined by respective lips 340, 341, bar bottom portions 338, 339 and bar sides 333, 335.

The spacing between the bar central portion 334 and bottom portions 338, 339, and the shape and height of the spacer are such that lug ends 212, 213 (each of which is bent away from the generally planar surface of the respective lugged flange 201, 202) engage with the bar bottom portions 339, 338 respectively so as to resist relative movement of the bracket 2 and bar 3.

It will be understood that the underlying roof structure 4 does not form part of the present invention.

Claims

Claims 1. A roofing system for retaining an outer skin of a roof in spaced

relationship to an underlying roof structure, the system comprising: at least one elongate member; and a plurality of brackets, each comprising a supporting structure of a generally U shape, including first and second legs interconnected at their upper ends by a top portion and carrying fixing portions for fixing to an underlying roof structure, each bracket further including a connecting arrangement for connecting the bracket to the elongate member.
2. A roofing system according to claim 1 wherein the connecting arrangement is provided at the top of the bracket.
3. A roofing system according to claim 1 or claim 2 wherein each fixing portion is provided at the lower end of the respective leg.
4. A roofing system according to any preceding claim further comprising a spacer fixable between a bracket and an elongate member.
5. A roofing system according to any preceding claim wherein at least one bracket is provided with a spacer retention means for fixing a spacer to the bracket.
6. A roofing system according to claim 4 or claim 5 wherein the spacer comprises a thermally insulating material.

S
7. A roofing system according to any preceding claim wherein the fixing portions comprise flange portions.
8. A roofing system according to any preceding claim wherein the connecting arrangement comprises at least one engagement member arranged so that it may frictionally and slidably engage with the elongate member.
9. A roofing system according to claim 8 wherein the at least one engagement member extends away from the legs.
10. A roofing system according to claims 8 or claim 9 wherein at least one engagement member is provided with at least one lug for engagement with the elongate member.
11. A roofing system according to claim 10 wherein at least one engagement member comprises two mutually spaced lugs, each lug comprising a lug body portion and a lug end portion, the lug end portion extending at an angle from the lug body portion.
12. A roofing system according to claim 11 wherein each lug end portion extends substantially orthogonally to the respective lug body portion.
13. A roofing system according to any claims 10 to 12 wherein the connecting arrangement comprises mutually spaced first and second engagement members, each comprising two mutually spaced lugs, each lug comprising r a lug body portion and a lug end portion, the lug end portion extending at an angle from the lug body portion.
14. A roofing system according to any preceding claim wherein the elongate member has a first and a second end, the elongate member at the first end forming a substantially hollow interior and having a certain crosssectional shape perpendicular to the longitudinal axis of the elongate member, the second end of the elongate JO member having a longitudinally extending spigot suitable for insertion into the substantially hollow interior of a like elongate member, wherein the spigot has, along at least part of its length, a cross-sectional shape perpendicular to the longitudinal axis of the spigot that IS is substantially the same as the cross-sectional shape of the elongate member at its first end.
15. A roofing system according to any preceding claim wherein the elongate member, having first and second ends, has first and second side members depending from respective sides of a central member, a hollow interior being formed by the central member and first and second side members, the second end of the elongate member comprising a spigot having first and second spigot side portions depending from respective sides of a central spigot portion wherein the dimensions of the spigot is such that the spigot may be inserted into the hollow interior at the second end of a like elongate member.
16. A roofing system according to claim 15 wherein the elongate member is provided with first and second bottom members projecting inwardly towards the hollow interior from the longitudinally extending edges of the first and second side members remote from the central member.
17. A roofing system according to claim 16 wherein the elongate member is provided with one or more longitudinally extending lips, each one projecting from the respective bottom member.
18. A roofing system substantially as hereinbefore described with reference to the figures.
19. A bracket suitable for use in the roofing system according to claims 1-18.
20. A bracket substantially as hereinbefore described with reference to figures 1, 2 and 4.
21. An elongate member suitable for use in the roofing system according to claims 1-18.
22. An elongate member substantially as hereinbefore described with reference to figures 1, 3 and 4.