Solar thermal collector

Abstract

There is provided a cladding member (13) formed of a supporting body portion (67) having mounts (54) and a head portion (12), and an absorber surface portion (70) having a peripheral boundary wall (71) defining a recess into which a solar cell array (removed in this view for clarity) is bonded. The supporting (67) and absorber surface (70) body portions are pressure moulded from polyvinyl ester/glassfibre (30%)/fire retardant (40%)/pigment sheet moulding compound. Complementary bonding portions (72) form a glue line in assembly and have complementary water passages (73) defined therebetween. The bonding portions (72) contrive a generally sinusoidal glue space (74) that is longer that the transverse sectional dimension of the boding portions (72), cooperating with the adhesive system to resist water pressure in the passages (73).

Claims

1. A solar thermal collector of the type including a collector body having an absorber surface adapted to be exposed to sunlight and be heated thereby and a having a liquid flow passage there though adjacent said absorber surface, characterized in that said collector body is formed of body portions of material selected from polymer and polymer composite and adhesively bonded together at two or more sets of complementary bonding surface portions with spaces between said sets, a substantially continuous said liquid flow passage being defined in adjacent surfaces of said body portions in said spaces, said liquid flow passages being of a flattened cross section, whereby the transverse cross section of the flow passage has a dimension parallel to the absorber surface greater than the dimension perpendicular to the absorber surface passage in a ratio of not less than 3:1 parallel dimension:perpendicular dimension, said bonding surface portions having complementary surface profiles selected to provide a bond section across said bonding portion which is longer than the width of said bonding surface portion.

2. A solar thermal collector according to claim 1, wherein the collector body is formed of two complementary said body portions.

3. A solar thermal collector according to claim 1, wherein the body portions comprise a supporting body portion adapted to be mounted on a structure and an absorber surface body portion.

4. A solar thermal collector according to claim 1, wherein the liquid flow passage comprises a continuous sigmoidal flow passage extending from an inlet assembly to an outlet assembly, said inlet and outlet assemblies being adapted to connect the liquid flow passage to a coolant circuit.

5. A solar thermal collector according to claim 1, wherein the passage cross section is formed in part in each of the body portions.

6. A solar thermal collector according to claim 1, wherein the polymer body portions are pressure formed from sheet moulding compound selected from vinyl ester, polyester, epoxy, and phenolic composite.

7. A solar thermal collector according to claim 6, wherein the moulding compound is a vinyl ester composite including fibreglass.

8. A solar thermal collector according to claim 7, wherein the moulding compound further includes one or more of fillers, flame retardants, pigments and shrinkage control additives.

9. A solar thermal collector according to claim 1, wherein the surface profile of the bonding portion comprises a plurality of parallel ridges and grooves adapted to form a labyrinth in which a bonding material acts to join the parts.

10. A solar thermal collector according to claim 9, wherein the surface profile includes contact points between the body portions selected to maintain optimum bond thickness for the bonding material.

11. A solar thermal collector according to claim 9, wherein the parallel ridges and grooves are oriented substantially parallel to the flow direction in the passages.

12. A solar thermal collector according to claim 9, wherein the substantially parallel ridges and grooves form a polysinusoidal section.

13. A solar thermal collector according to claim 1, wherein the bonding material is an adhesive system selected from solvent free epoxy, polyurethane, acrylic and silicone systems.

14. A solar thermal collector according to claim 13, wherein the adhesive system comprises two-pack methacrylate adhesive.

15. A solar thermal collector according to claim 1, wherein the inlet and outlet assemblies comprise inlet and outlet fittings located in respective complementary inlet and outlet mounting portions formed at a part line between said body portions, said inlet and outlet fittings being bonded in their respective mounting portions as the body portions are bonded together.

16. A solar thermal collector according to claim 15, wherein the inlet and outlet assemblies are configured with quick fit and release pipe connections.

17. A solar thermal collector according to claim 1, wherein the absorber surface has bonded thereto one or more solar PV elements.

18. A solar thermal collector according to claim 1 and including: respective head and foot portions integrally formed at opposed edges of the collector body, the foot portion cooperating in substantially weatherproof overlap with the head portion of one or more other collector bodies installed on a structure, said head and foot portions being interconnected by respective one of opposed, complementary side edges of said collector body and forming therewith a cladding body, said complementary side edges providing substantially weatherproof interengagement between said cladding body and an adjacent said cladding body secured to said battens, one said side edge of said body overlapping a said side edge of said adjacent body and selected to finish said adjacent bodies to a substantially flush surface in use on said structure; mounting means on an underside of said cladding body and adapted to secure said cladding body to battens on said structure; and inlet and outlet fluid connectors bonded between said body portions and fluid-connecting said passage into an external heat exchange fluid circuit.

19. A solar thermal collector according to claim 18, wherein the head and foot portions and side edge portions are formed of polymer composite.

20. A solar thermal collector according to claim 19, wherein the head and foot portions and the side edge portions are integral with one of the collector body portions.

21. A solar thermal collector according to claim 18, wherein the substantially weatherproof overlap of the respective head and tail portions is supplemented by labyrinth elements provided on one or both of the portions.

22. A solar thermal collector according to claim 19, wherein the complementary side edges comprise interengaging ridges and grooves to form a labyrinth seal.

23. A solar thermal collector according to claim 18, wherein the complementary side edges include in assembly a resilient sealing strip.

24. A solar thermal collector according to claim 18, wherein one or both of the head and foot portions includes a hollow space in which one or both of the inlet and outlet connectors are led.

25. A solar thermal collector according to claim 24, wherein hollow space is in a said head portion which is open to the underside or inside of the structure, whereby the inlet and outlet connectors may be accessed after the cladding is installed.

26. A solar thermal collector according to claim 18, wherein the mounting means comprises substantially L-shaped members associated with the foot portion and adapted in use to pass under the batten, trapping the head portion of the next adjacent cladding body resting on the batten.

27. A solar thermal collector according to claim 26, wherein the batten comprises an elongate roll formed metal or polymer composite section having a pair of upper bearing surfaces and a pair of lower bearing surfaces, each pair of bearing surfaces being formed by a peripheral flange and the floor of a channel.

28. A solar thermal collector according to claim 27, wherein the one or both of the upper bearing surfaces is provided with dimples or perforations to resist foot slip.

29. A solar thermal collector according to claim 27, wherein the upper surface of one or more of the lower bearing portions is provided with a screw location groove or dimple to permit the battens to be screwed to the rafters or studs.

30. A solar thermal collector according to claim 27, wherein the batten is stiffened by dimpling side edges of floor of the rolled section.

31. A solar thermal collector according to claim 26, wherein the L-shaped members comprise batten engagement portion or portions integrally formed with or secured to the underside of the cladding body in the region of the foot portion, and adapted in use engage the batten with the bar of the L-shape under the peripheral flange, whereby the foot portion traps the head portion of the next adjacent cladding body against the upper surfaces of the batten.

32. A solar thermal collector according to claim 18, wherein the absorber surface has bonded thereto one or more solar PV elements.

33. A solar thermal collector according to claim 32, wherein the absorber surface is recessed into its body portion to seat a solar array comprising at least a protective glass outer layer, an array of solar cells and conductive collectors, an insulative film backing and connection means providing termination for said collectors.

34. A solar thermal collector according to claim 24, wherein the upper surface of the cladding body adjacent the head portion is relieved to receive one or both of an encapsulated lead out and diode pack and allow the lead out to pass into the space inside the head space.

35. A solar thermal collector according to claim 4, wherein the coolant circuit includes adjacent solar thermal collectors.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The invention will now be described in more detail according to a preferred but non-limiting embodiment and with reference to the accompanying illustrations wherein:

(2) FIG. 1 shows the underside of a typical cladding system in accordance with the present invention;

(3) FIG. 2 is a section of a batten for use in the system of FIG. 1;

(4) FIG. 3 is an isometric view of the batten of FIG. 2;

(5) FIG. 4 is a section of an alternate batten for use in the system of FIG. 1;

(6) FIG. 5 is an isometric view of the batten of FIG. 4;

(7) FIG. 6 is a detail view from beneath of the system of FIG. 1;

(8) FIG. 7 is an isometric view of a solar thermal/PV cladding member for use in the system of FIG. 1;

(9) FIG. 8 is a top plan view of the cladding member of FIG. 7;

(10) FIG. 9 is a bottom plan view of the cladding member of FIG. 7, without batten engaging members;

(11) FIG. 10 is a bottom plan view of the cladding member of FIG. 7, with batten engaging members fitted;

(12) FIG. 11 is a bottom isometric view of the cladding member of FIG. 7, PV elements removed;

(13) FIGS. 12 and 13 are isometric views of two differently-keyed batten engagement members for use in conjunction with cladding members of the system of FIG. 1;

(14) FIG. 14 is a longitudinal, vertical section through the cladding member of FIG. 7; section detail of the cladding member of FIG. 7;

(15) FIG. 15 is a detail of the section of FIG. 14;

(16) FIG. 16 is a diagram of a serpentine bond-defined water channel as embodied in the cladding member of FIG. 7;

(17) FIG. 17 is a top isometric view of an alternate cladding member;

(18) FIG. 18 is a bottom isometric view of the cladding member of FIG. 17, without batten engagement members;

(19) FIG. 19 is a side view of the cladding member of FIG. 17, showing alternate mounting positions of lower batten engagement member, and an optional upper batten engagement member;

(20) FIG. 20 is a side view of the cladding member of FIG. 17, showing a conventional positioning of a single batten engagement member;

(21) FIG. 21 is an isometric detail view of barging, ridge and end capping for use in the cladding system of FIG. 1;

(22) FIG. 22 is an isometric detail view of the edge lapping of cladding members used in the system of FIG. 1;

(23) FIG. 23 is a section through the head/tail overlap of a flush-fitting alternative cladding member, indicating Detail B;

(24) FIG. 24 is a detail of the head/tail overlap Detail B of FIG. 23;

(25) FIG. 25 is an assembly of two cladding members according to FIG. 23, and showing a section line D-D thereon;

(26) FIG. 26 is the section D-D corresponding to the assembly of FIG. 25 and indicating Detail F;

(27) FIG. 27 is the Detail F;

(28) FIG. 28 is a longitudinal, vertical section through an alternative PV-only cladding member, indicating Detail E;

(29) FIG. 29 is the Detail E;

(30) FIG. 30 is a course of the cladding members of FIG. 28, in a course;

(31) FIG. 31 is a pair of solar PV cladding members for use with the members of FIG. 28 in a cladding system;

(32) FIG. 32 is a section through a roof cladding illustrating the installation method and indicating Details C, D and E;

(33) FIG. 33 is the Detail C of FIG. 32;

(34) FIG. 34 is the Detail E of FIG. 32;

(35) FIG. 35 is the Detail D of FIG. 32;

(36) FIG. 36 is a section through a roof cladding illustrating the installation method using the cladding members of FIG. 28 and indicating Detail H;

(37) FIG. 37 is the Detail H of FIG. 36;

(38) FIG. 38 is a section through a roof cladding illustrating the installation method and indicating Detail M;

(39) FIG. 39 is a fixing detail of FIG. 38;

(40) FIG. 40 is the Detail N from FIG. 30; and

(41) FIG. 41 is an overall artistic impression of a roof cladding as envisaged for the present invention.

DESCRIPTION OF THE EMBODIMENT

(42) In FIG. 1 there is a generalized impression of a cladding system embodying one example of the present invention and wherein a rolled steel batten 10 is shown as if lifted straight off a roof structure. The batten 10 has an up-slope flange 11 adapted to be entrapped between an overlying head portion 12 of a solar thermal cladding member 13 and a batten engaging portion 14 of a plain cladding member 15. A tail lap portion 16 of the plain cladding member 15 overlies the head portion 12 to weatherproof the structure.

(43) In FIGS. 2 to 5 there is illustrated two different embodiments of the batten 10, and wherein like features are numbered the same in each embodiment. The batten 10 is roll formed from anodically treated steel such as zinc-aluminium coated steel. The batten 10 has an upper flange 17 terminated by a rolled edge 20, and bounded at its inner edge by a channel 21. The channel 21 has a floor 22 having rolled therein a screw locating groove 23. The channel 21 is bounded opposite the upper flange 17 by an upper bearing portion 24, which is then turned down into web 25, and terminated by a lower flange 26 having a rolled terminal edge 27. A second screw groove 30 is provided, and a stiffening ridge 31 is rolled in between the screw groove 30 and the web 25. The upper surface of the bearing portion 24 is provide with a non-slip dimpling 32.

(44) In the embodiment of FIGS. 4 and 5, there is provided additional form stiffness to the batten by the use of periodic creasing 33 of the upper flange 17 to channel 21 turn and the channel 21 turn to the floor 22.

(45) In FIG. 6 there is illustrated a cladding system of multiple reinforced polymer solar thermal cladding members 13 and multiple plain cladding members 15, with the structure and battens removed. In this illustration, it can be seen that a water inlet 34 is manifolded at 35 to feed solar thermal cladding member inlet assemblies 36. The respective cladding member outlet assemblies 37 are connected by quick connection loops 40 to the inlet assemblies 36 of adjacent solar thermal cladding members 13, and thence to their outlet assemblies 37, to be manifolded at 41 and thence to water outlet 42. By this means a combination of parallel and series connection of panels may be used.

(46) In this embodiment, solar thermal/PV cladding members may be fitted with diode/terminal equipment located at diode mounting portion 43.

(47) FIGS. 7 and 8 are a top perspective view and top plan view respectively of a typical solar thermal/PV cladding member 13, having solar cells 44 bonded to the upper surface of the solar thermal cladding member 13 and connected through the aforementioned diode mounting portion 43 (not shown in this view) to a wiring harness connector 45. The respective loops 40 are installed to the inlet assembly 36 (not shown) by quick fit and release coupling 46. The head portion 12 is relieved to accommodate the couplings 46, and is configured to catch any casual ingress of water under the tail portion of an overlying cladding member (13 or 15).

(48) A side overlap portion 47 is complementary to a side underlap portion 50 to provide for weather resistant, side by side installation of adjacent cladding members (13 or 15). The detail of these portions are describe in detail hereinafter. Upper stiffening webs 51 have a dual function of form stiffening the head portion 12 and providing multiple bearing edges to support the tail portion of the next adjacent cladding member (13 or 15).

(49) FIGS. 9 and 10 are bottom plan views of the member illustrated in FIGS. 7 and 8 wherein the wiring harness connectors 45 are shown in circuit with a diode pack 52 occupying the diode mounting portion 43. The outline of a sigmoidal water passage (described in detail hereinafter) is represented by a flattened sigmoidal ridge 53 traced out on the underside of the member 13 between the inlet assembly 36 and the outlet assembly 37.

(50) Integral batten engagement portion mounts 54 are formed on the underside of the member 13. In the illustrated embodiment, there are two mounts 54. In some installations only the mount 54 adjacent the tail lap portion 16 need be used, or the member 13 may be moulded with a single mount 54. In, for example, high wind loading and/or some wall cladding installations, both mounts 54 may be fitted with batten engagement portions. In FIG. 10, the mounts are shown with batten engagement portions 14 installed, in this case by adhesive fixing.

(51) Lower stiffening webs 55 have a lower edge portion 56 adapted to bear on the bearing portion 24 of the batten 10.

(52) The side overlap portion 47 and the side underlap portion 50 are each provided with complementary ridges 57 to aid in weatherproofing.

(53) The batten engagement portions 14 are detailed in FIGS. 12 and 13. In this embodiment the batten engagement portions 14 are moulded as discrete members in fibre reinforced polymer, and are adhesively bonded to the batten engagement portion mounts 54 in use. The batten engagement portions 14 comprise an L-section portion 60 formed integrally with a U-section locating portion 61 adapted to engage the mounts 54. The U-section locating portion 61 may be provided with lateral locating slots 62 adapted to engage corresponding locating lugs 63 (see FIG. 11) associated with the batten engagement portion mounts 54. In the illustrated embodiment, there are two batten engagement portions 14 per batten engagement portion mount 54 with a gap there between, which provides for alternate installations where, for example, a roof truss member may pass.

(54) The use of two batten engagement portion mounts 54 necessarily requires the use of batten engagement portions 14 of differing depth, since the batten engagement portion 14 at the tail lap portion 16 must be deeper than the batten engagement portion 14 at an intermediate location to accommodate entrapment of the head portion 12. Accordingly, to avoid errors in installation of the respective batten engagement portions 14, there may be provided discrete key slots 64 corresponding to discrete key lugs 65 formed at the respective batten engagement portion mount 54. These prevent the batten engagement portions 14 being mounted on the wrong batten engagement portion mount 54 as well as preventing the batten engagement portions 14 being mounted backwards on the batten engagement portion mount 54. The L-section is braced by a plurality in integral bracing webs 66. It can be seen that the batten engagement portion of FIG. 12 is an optional intermediate portion with one discrete key slot 64 whereas FIG. 13 illustrates the necessary batten engagement portion 14 with two discrete key slots 64.

(55) FIG. 14 is a detail section through the embodiment described above. The cladding member 13 is shown to be formed of a supporting body portion 67 which includes the batten engagement portion mounts 54, the head portion 12, and the flattened sigmoidal ridge 53, and an absorber surface body portion 70 having a peripheral boundary wall 71 defining a shallow recess into which is thermally bonded the solar cell 44 array (removed in this view for clarity).

(56) The supporting body portion 67 and absorber surface body portion 70 are each moulded in polymer composite. In this example, a thermosetting SMC comprising polyvinyl ester matrix with about 30% E-glass fibre reinforcing of 25 mm strand length, about 40% aluminium trihydrate fire retardant filler material and carbon black pigment, is pressure moulded with heating to cure.

(57) The respective mouldings have complementary bonding portions 72 forming a glue line in assembly. Between the bonding portions 72 the mouldings have complementary water passage portions formed which, in assembly for a water passage 73.

(58) As seen in more detail in FIG. 15, the bonding portions 72 define in assembly a glue space 74, the dimension of which is maintained at optimum for a methacrylate adhesive composition by a spacer nib 75, water passage glue space nip 76 and bonding portion boundary 77.

(59) The bonding portions 72 contrive a glue space 74 that is longer that the transverse sectional dimension of the boding portions 72 by being formed of a plurality of complementary ridges 80 and grooves 81. In FIG. 16 there is a scheme of the bonding portion 72 illustrating the water passage 73 portion, the ridges 80 and grooves 81, and the insertion points 82 for the water inlet 36 and outlet 37 assemblies.

(60) The bonding process involves surface preparation of the bonding portions 72 by way of sanding to remove surface contaminants and roughen the surface to allow better keying of the adhesive into the material. Precision is maintained by using a CNC machine and adhesive dispensing machine to control the positioning of and exact quantity of two-pack methacrylate adhesive applied to the parts. The components are brought together and a force applied to hold the parts together under pressure during the cure time of the adhesive.

(61) In FIG. 17 there is illustrated a plain cladding member 15 comprising a unitary moulding of vinyl ester thermoset composite material as described above. In keeping with the intent of integration with the active members 13, there is provided a head portion 12, and side overlap portion 47 and side underlap portion 50, both with complementary ridges 57. The composite is protected by a paint system to provide colour and UV protection. In the present example the plain top surface 83 is coated in a UV-resistant 2-pack polyurethane finish.

(62) FIG. 18 is a bottom isometric view of the underside of the member of FIG. 17. This illustration shows that the top surface is braced below by an egg-crate array of webs 84.

(63) The head portion 12 and the tail lap portion 16 are braced by closer spacing of the webs 84 in those regions. The webs 84 are configured in the head space to form lower edge portions 56 for bearing on the batten bearing surface 24 and/or upper flange surface 17, analogous to the stiffening webs 55 of FIG. 11. Similarly, the webs 84 are specialized to form the integral batten engagement portion mounts 54 with their attendant discrete key lugs 65. In addition, there is provided an alternate lower batten engagement portion mount 85, provided to allow for setting back of the batten 10 on the structure adjacent to the gutter or facia thereof, as will become apparent hereinafter.

(64) FIGS. 19 and 20 are side views of the plain cladding member 15, wherein FIG. 19 is the double-batten engagement portion embodiment and FIG. 20 is the single batten engagement portion embodiment. Particularly, FIG. 19 illustrates the alternate location of the lower batten engagement portion 14 described above.

(65) In FIG. 21, there is a generalized pictorial view of an installation of plain 15 and solar thermal/PV 13 cladding members, showing their use with barge capping 86, ridge capping 87 and end caps 90. Self-coloured and sealing screw fixings 91 are used.

(66) FIG. 22 is a close detail of the lapped portions of a solar thermal PV member 13 and plain cladding member 15

(67) FIGS. 23 to 27 goes to the detail of the side overlap 47 and underlap 50 portions of the members 13, 15 as they are laid in a course on a structure. In this embodiment, the complementary ridges 57 comprise, on the overlap portion, an outer bearing ridge 92 adapted to bear on a land portion 93 of the adjacent underlap 50. portions. In this embodiment, there is a sealant bond 94 introduced between the members 13 or 15 at this outer bearing ridge 92. Spaced inwardly of the outer bearing ridge is a drip line ridge 95 defining a drip line 96. The drip line 96 resides in a space 97 that is essentially closed at its inner boundary by a dam ridge 100 which bears on the underlap 50. The space 97 captures any casual ingress and conveys it downslope to drain.

(68) Inward of the dam ridge 100 and integrally formed on the underlap is a labyrinth ridge 101 to form therewith a first labyrinth portion. A second dam ridge 102 and second labyrinth ridge 103 inward of the first labyrinth portion forms a second labyrinth portion. The inner terminus of the side join is formed by an inner ridge 104 closing over the terminal edge 105 of the underlap 50.

(69) FIGS. 28 and 29 are side section and detail views respectively of the cladding member 15, illustrating the detail of attachment of the batten engagement portions 14. In the section of FIG. 28, the U-section 61 of the batten engagement portion 14 is shown in its engagement with the batten engagement portion mount 54, in both the tail lap and intermediate positions. In the detail of FIG. 29, the section is taken through the batten engagement portion at the location of the discrete key lug 65. The glue line allowance 106 is also shown in this detail.

(70) FIGS. 30 to 40 are a sequence illustrating the installation of cladding members 15 in a model having a ridge batten 107 and a fascia 110, interconnected by a roof truss portion 111. FIG. 30 shows an array of cladding apparatus 15 (one missing for clarity) and ridge capping 87 (one missing for clarity) according to the present invention and indicating the sections A-A (FIG. 32), B-B (FIG. 36) and K-K (FIG. 38).

(71) FIG. 31 is an assembly of two solar PV-only apparatus sized to integrate with standard roofing elements and having a polymer composite cladding body 124 having a head portion 12, side overlap portion 47, side underlap portion 50 and complementary ridges 57 as per conventional roofing elements. The solar PV connections are to the underside of the element. The solar cells 44 are bonded to a recess in the surface as described in the context of FIG. 14 above.

(72) FIG. 32 is a cross section view of the middle plane of the roof's outside truss portion 111. For the purposes of the model, four battens 10 are installed on the trusses by double batten screws 112 at each truss 111. The detail of the topmost batten 10 are provided in FIG. 33. The detail of the fascia adjacent batten 10 is given in FIG. 43. The detail of all battens there between is given in FIG. 44.

(73) FIG. 33 shows the arrangement of the batten 10 adjacent the ridge batten 107. The batten 10 is located intermediate of the head and tail portions of an ordinary plain cladding member 15, in this case trimmed to meet the ridge batten 107. As there is no packing thickness of head portion, and to control the pitch of the member 15, it is necessary to install a spacer 113 between the cladding member underside and the batten 10.

(74) Retaining screw 114 is driven through the spacer 113 and batten 10 and into the truss 111 before fitting off the last cladding member 15. The ridge capping 87 in this embodiment is laid over a flexible flashing 115 glued to the top cladding members 15 on each side of the ridge. Batten screw recesses 116 are formed in the ridge capping 87 to enable a batten screw fixing 117 to secure the ridge capping 87 to the ridge batten 107.

(75) FIG. 34 shows the arrangement of the batten 10 adjacent the fascia 110. As the tail lap portion 16 of this first row of cladding members 15 is not supported on the batten 10 via the head portion 12 of a next adjacent row, it is necessary to install a spacer 120, in this case secured by batten screw 121 through the batten 10 and into the truss portion 111. Thereafter the cladding member is retained against lifting by the batten engagement portion 14 hooking under the upslope-directed upper flange 17 of the batten 10.

(76) FIG. 35 represents the detail of all other batten fixings, that is, neither at the ridge or fascia. The structure, function and purpose of the components are describes herein before.

(77) FIGS. 36 and 37 shows an alternate arrangement of the batten 10 adjacent the ridge batten 107. As the batten location is substantially beneath the ridge capping 87, it is possible to drive a batten screw 122 though the cladding member 15, spacer 113 batten 10 and into the truss 111, in lieu of the screw 114 of FIG. 33.

(78) FIGS. 38 to 40 are a cross section view of the plane K-K where a screw 123 passes through the side underlap portion 50, spacer 120 and the batten 10 and into the truss 111 to secure the cladding member 15. This is possible without leaking because the screw head is overlaid by the side overlap portion 47 of the next adjacent cladding member 15.

(79) FIG. 41 is an overall impression of a complete roof in accordance with the present invention.

(80) It will be recognised by persons skilled in the art that numerous variations and modifications may be made to the invention as broadly described herein without departing from the spirit and scope of the invention as described herein and defined in the claims appended hereto.