GB2136351A - Ceilings, Support Systems Therefor and Composite Strips for Use Therein - Google Patents

Abstract

A composite strip for cladding ceilings or walls comprises a backing strip of chipboard, having at least one facing strip of a decorative timber such as oak, teak, pine or the like bonded to it. The decorative and backing strips are bonded together at complementary, non-planar, mating surfaces, which are preferably of generally crenellated (i.e. continuously tongued-and-grooved) in cross-section, or otherwise shaped to permit them to be pressed face-to-face into mating contact. In a ceiling system formed of such strips, first and second interengaging and relatively movable extruded channel sections 26, 30 having resilient, e.g. foam rubber mounting blocks 28, 32 form a frame to take up irregularities in the walls and so facilitate cutting the strips to required lengths. Support strips 52 bridging adjacent composite strips are suspended via hooks 56 from steel bars 20 which are in turn fixed to ceiling joists. <IMAGE>

Description

SPECIFICATION Ceilings and Support Systems Therefor and Composite Strips for Use Therein This invention relates to ceilings and to ceiling support systems, and is more particularly but not exclusively concerned with decorative ceilings made up of strips of timber or sheet metal.

One well known type of decorative ceiling comprises tongued- and grooved strips of timber, for example parana pine, which are typically about 3 or 4 inches wide. These strips extend perpendicularly to the usual wooden ceiling joists, and are installed by nailing them to the joists.

However, this type of ceiling suffers from a number of drawbacks.

Firstly, the room in which the ceiling is to be installed, although usually nominally rectangular, is seldom precisely rectangular, and the walls are seldom truly straight and flat. As a result, at least the two strips which fit against the two side walls (i.e. the two walls to which the strips are parallel) usually have to be carefully shaped to fit flush with the side walls, while the remainder of the strips usually have to be individually cut to precise (but slightly different) lengths. All this normally has to be done on site, i.e. in or near the room in which the ceiling is being installed. In cases where this room is in a house or other building which is already occupied, this leads to considerable disruption and inconvenience to the occupier for a considerable time, typically at least a whole day.

Secondly, to ensure invisible fixing of the strips, each strip is invidually nailed to each joist through the tongue of the strip, which is again rather time-consuming.

Thirdly, the strips frequently warp slightly across their width, which causes the tongues to withdraw slightly from the grooves and so become visible. This tends to spoil th overall appearance of the ceiling.

It is therefore an object of the present invention in its various aspects to provide ceilings and ceiling support systems in which some or all of the abovementioned drawbacks are alleviated.

According to one aspect of the present invention, there is provided a ceiling support system for supporting the ceiling of a room, the system comprising first and second elongate members, of which the first member is relatively flexible and adapted to be fixed to a wall of the room just below the ceiling to be supported, with its long dimension extending substantially horizontally, and the second member extends parallel to and is supported by the first and is provided with one or more generally horizontally extending ceiling-supporting portions, the two members having a resilient material held between them and the second member being movable, in use, with respect to the first in a direction substantially perpendicular to said wall, movement of the second member towards said wall being arranged to compress the resilient material.

Such a system is secured to the walls of the room around the entire periphery of the ceiling to be supported, irregularites in the wall being accommodated by the flexibility of the first member. The ceiling is formed in strips (as will hereinafter be described), which are all cut to substantially the same length. This length is chosen to be slightly larger than the maximum distance between the second members of the parts of the system secured to the end walls of the room, and the excess length of the strips is accommodated by the movement of the second member towards the first member against the opposition provided by the resilient material.

It will be appreciated whuononce the dimensions of the room have been carefully measured, most if not all of the cutting of both the system and the strips to length can be done off-site, thus significantly reducing the aforementioned disruption and inconvenience.

According to another aspect of the invention, there is provided an elongat composite strip of generally rectangular cross-section for use in decorative ceilings and the like, the composite strip being formed of a strip of decorative timber bonded to a strip of chipboard, the two strips being bonded together at substantially complementary non-planar mating surfaces thereof, preferably of generally crenellated form when viewed in cross-section through the width of the strip, i.e. continuously tongued-andgrooved across the width of the strip.

Preferably the mating surfaces are shaped to define, in use, respective downwardly facing mounting surfaces, e.g. each forming one wall of a respective groove, running the length of each side of the strip.

According to yet another aspect of the invention, there is provided a ceiling support system comprising, in use, a plurality of bars extending transversely of, and fixed to, the usual wooden ceiling joists, and a plurality of elongate supporting strips extending transversely of the bars and suspended therefrom by means of wire supporting hooks, the side edges of the strips being shaped to support the edges of strips of ceiling material extending parallel thereto.

The invention will now be described, by way of nonlimitative example only, with reference to the accompanying drawings, of which: Figure 1 is a somewhat diagrammatic crosssectional view of one embodiment of a ceiling and ceiling support system in accordance with the present invention; Figure 2 is a diagrammatic plan view of the ceiling support system of Figure 1; Figures 3 and 3A are sectional and plan views of part of the ceiling of Figure 1; Figures 4 and 5 show parts of alternative ceiling and supports therefor, also in accordance with the present invention; and Figures 6 and 7 show alternative embodiments of part of the ceiling of Figure 1, again in accordance with the present invention.

The ceiling and its support system illustrated in Figure 1 are indicated generally at 10 and 12 respectively, and are shown installed in a room 14 having a side wall 16. The usual wooden ceiling joists run parallel to the side wall 16, one of them being indicated at 1 8.

Assuming that the dimensions of the room 14 have been carefully measured in advance, the first step in installing the ceiling 10 is to secure a number of 3/8" circular steel bars 20 to the joists 1 8. The bars 20 extend perpendicularly to the joists 18, and they have been pre-cut to a length which extends across substantially the whole width of the room. Typically the bars 20 are spaced about 24" apart, and they are secured to the joists 1 8 in any convenient manner, for example by pairs of screws 22 between whose heads they are trapped. The relative positions of the bars 20 and the joists 18 can be seen in Figure 2, which shows the end walls 24 of the room 14, as well as both side walls 1 6.

The next step in installing the ceiling 10 is to secure the main support system 1 2 to the walls 1 6, 24 just below the bars 20.

The main support system 1 2 comprises a first, relatively flexible, elongate extrusion 26 of rectangular channel section, which is preferably white or cream in colour and made from a plastics material such as PVC. The extrusion 26 has a number of foam rubber mounting blocks 28 bonded at spaced intervals in its channel, the depth of these blocks being slightly greater than the depth of the channel. The respective outward facing surfaces of the blocks 28 therefore stand just proud of the open mouth of the channel, and these surfaces are coated with adhesive, so that the extrusion 26 can be stuck to the walls 1 6 and 24 by means of the blocks, with the open mouth of the channel almost against the wall.The flexibility of the extrusion 26 accommodates minor irregularities (i.e. non-flatness) in the wall when the extrusion is pressed against the wall, while to fit in the corners of the room 14, the extrusion is simply cut to form mitres.

The main support system 12 further comprises a second elongate extrusion 30 of rectangular channel section, which is again preferably white or cream in colour and is again made from a plastics material such as PVC. The extrusion 30 also has a number of foam rubber blocks 32 bonded at spaced intervals in its channel, the depth of these blocks being significantly less than the depth of the channel.

It will be appreciated that when the first extrusion 26 is secured to a wall, the side walls of its channel extend generally horizontally. The channel of the second extrusion 30 is dimensioned so that it is a tight sliding fit over the first extrusion 26, so that the second extrusion 30 is effectively supported on the upper side wall of the channel of the first extrusion 26. The blocks 32 are trapped between the extrusion 26 and 30, and pushing the extrusion 30 towards the wall, i.e. further over the extrusion 28, compresses them (and the blocks 28).

The second extrusion 30 has an integrally formed hollow ceiling-supporting flange 34 which, when the extrusion 30 is fitted over the extrusion 26 as described above, extends substantially horizontally from and longitudinally of the base of the channel of the extrusion 30. The flange 34 has a flat upper surface 36, which forms the lower wall of a groove defined between the flange 34 and an upper horizontally and longitudinally extending hollow flange 37, also formed integrally with the extrusion 30. The lower surface 38 of the flange 34 and the lower side wall 40 of the channel of the extrusion 30 are shaped to form a decorative cornice.

As with the extrusion 26, the extrusion 30 is simply cut to form mitres in the corners of the room 14.

Once the main support system 12 has been secured to the walls 1 6 and 24 of the room 14 around its entire periphery, the ceiling 10 can be installed.

The ceiling 10 comprises a number of elongate composite strips of wood 40 of generally rectangular cross-section. Each composite strip 40 is formed of a strip 42 of decorative timber, such as pine, parana pine, mahogany, rosewood, oak, afrormosia, teak or sapele, bonded to a strip 44 of chipboard. Typically, the strips 42, 44 are 3 or 4 inches wide, the strip 42 being about 1/4" thick and the strip 44 about 1/2" thick. The strips 42, 44 are bonded together under pressure with conventional woodwork adhesive, at complementary crenellated mating surfaces 46 machined thereon, the depth of the crenellations being about 1/8". However, two portions of one of the two surfaces 46, extending one along each side of the respective strip 42 or 44 and typically 1/4" wide, are machined to define two 1/4" deep and typically 1/8" wide grooves 48 extending along each side of the composite strip 40.

To install the composite strips 40, which have already been cut to a length just greater than the previously determine maximum distance between the outer edges of the flanges 34 on the extrusions 30 secured to the end walls 24, an elongate extruded mounting strip 50 of rectangular cross-section, typically 1/8" x 1/2", and again typically made of a plastics material such as PVC, is inserted in the groove 48 extending along the left hand side of the leftmost composite strip 40 as viewed in Figure 1. The mounting strip 50 thus projects about 1/4" from the side of the composite strip 40, and the projecting portion thereof is placed upon the flat upper surface 36 of the flange 34 on the extrusion 30 associated with the left hand side wall 16; i.e.

in the groove defined between the flanges 34, 37, to be supported thereby. The opposite ends of the composite strip 40 are supported upon the respective flat upper surfaces 36 of the flanges 34 on the two extrusions 30 associated with the end walls 24, these two extrusions being pressed towards the end walls, thus compressing the blocks 28, and more particularly the blocks 32, to permit the introduction of the composite strip 40 therebetween.

An elongate extruded plastics support strip 52, whose main body portion is again of substantially rectangular cross-section, but this time about 3/4"x 1/8", then has its left hand edge inserted in the groove 48 extending along the right hand side of the leftmost composite strip 40. The support strip 52 is yet again typically made of a plastics material such as PVC, and is preferably coloured to match the extrusions 26, 30 of the main support system 1 2. Projecting upwardly from the centre of the upper surface of the support strip 52 i.e. just beside the right hand side of the leftmost composite strip 40, is an integrally formed hollow rib 54, which extends longitudinally of the support strip and into which the lower limbs of pairs of oppositely facing, approximately S-shaped, wire supporting hooks 56 are inserted at approximately 24" intervals.The upper limbs of each pair of the hooks 56 are hooked over and supported by a respective one of the bars 20, as shown in Figure 3. The leftmost composite strip 40 is thus fully supported along both of its sides by the strips 50 and 52 respectively, with the strip 50 resting on the flange 34 of the main support system 12 and the strip 52 hanging by the hooks 56 from a bar 20.

The next composite strip 40 is installed by fitting the groove 48 in its left hand side over the right hand edge of the first support strip 52, and then supporting its right hand side by means of another support strip 52, suspended from the bars 20 by pairs of hools 56 as already described.

This process is repeated for successive composite strips 40 across the entire wideth of the room 14.

The last composite strip 40 is supported along its right end edge by a further mounting strip similar to the strip 50 mentioned earlier, this further mounting strip resting on the flange 34 on the extrusion 30 associated with the right hand side wall 1 6. The extrusions 30 associated with the side walls 1 6 are pressed towards their respective side walls to permit installation of the last composite strip 40, which can be a special reduced-width strip if appropriate.

It will be appreciated that the ceiling and its support system just described can be installed relatively quickly and easily, since most, if not all, of the cutting to size necessary can be done in advance, off-site. The appearance of the finished ceiling 10 is aesthetically pleasing, by virtue not only of the decorative cornice formed on the main support system 1 2 and the decorative timber facing strips 42 of the composite strips 40, but also by virtue of the portions of the matching coloured support strips 52, coloured to match the main support system 12, visible between the composite strips 40. Additionally, the composite strips 40, because of their composite structure, have practically no tendency to warp.

Furthermore, minor irregularities in the straightness of the walls 1 6, 24 are masked by the main support system 12.

The embodiment of the invention shown in Figure 4 is similar in many respects to the embodiment described with reference to Figures 1 to 3: accordingly, similar parts have been given the same reference numbers, and only the points of difference will be described.

Thus in the embodiment of Figure 4, the composite strips 40 of Figures 1 to 3 are replaced by slightly concave (as viewed from beneath) sheet metal strips 60 of substantially the same width (i.e. 3" or 4") as the strips 40. The strips 60 are of steel, aluminium or zinc and are anodised, enamelled or cellulosed in any desired colour; additionally, they have vertically upturned edges 62, provided with horizontally outwardly extending flanges 64 The flanges 64 of the right hand side of the leftmost strip 60, of the left hand side of the rightmost strip 60, and of all the strips 60 therebetween, engage in and are supported by support strips 66, which are supported in exactly the same manner as the support strips 52 of the embodiment of Figures 1 to 3.Furthermore, the support strips 66 are substantially identical to the support strips 52, the principal differences being that (a) they are slightly narrower, and (b) they have grooves 68 along each side, shaped to receive the flanges 64. The left hand flange 64 of the leftmost strip 60, and the right hand flange 64 of the rightmost strip 60, are both supported on the portions of the main support system 12 associated with the side walls 1 6 by means of mounting strips 69. These mounting strips 69 are substantially identical to the mounting strips 50, except that they have grooves 70 along one side, shaped to receive the appropriate flanges 64.

Many modifications can be made to the described embodiments of the invention. For example, the upper limbs of the pairs of hooks 56 can be integrally formed, and the lower limbs dimensioned to snap-fit in an upwardly-facing channel or groove formed in or on the upper surface of the support strip 52 (as opposed to being inserted into the bore in the hollow rib 54, which bore is exposed simply by machinng away portions of the rib 54 at intervals corresponding to the spacing of the bars 20). Alternatively, this upwardly-facing channel or groove can have upwardly-converging walls, or walls with reentrant lips, so that the channel or groove is shaped to trap the heads of nails or screws fastened directly into the joists 18, in which case the bars 20 are omitted and the strips 52 extend transversely of and are directly fixed to the joists.

If desired, thin strips of foam rubber or foam plastic can be placed in ths respective grooves 48 along the left hand side of the leftmost composite strip 40 of Figure 1 and the right hand side of the rightmost composite strip 40, in order to urge the respective mounting strips 50 resiliently outwardly and to permit the leftmost and rightmost composite strips 40 to resiliently engage the extrusions 30 associated with the side walls 1 6. Additionally, the upper part of the left hand edge of the leftmost strip 40 and/or of the right hand edge of the rightmost strip 40 can be planed away as indicated at 80 in Figure 1, to facilitate the installation of whichever of these strips is installed last.

Under certain circumstances, it may be felt appropriate to provide additional support at or near the midpoint of the length of the extrusions 30. This can be done as shown in Figure 5, by cutting a slot 82 in the upper surface of the hollow upper flange 37 beneath the appropriate bar 20, and engaging the lower outwardly extending limbs of an inverted U-shaped wire supporting hook 84, supported on the bar 20, in this slot.

Although the mating surfaces 46 of the composite strips 40 are described as crenellated (i.e. continuously tongued-and-grooved) across their width, they can take any other convenient non-planar form, as long as they are shaped to permit them to be moved generally perpendicularly to each other into mating contact with each other (i.e. pressed together face-toface, rather than slid longitudinally into engagement with each other, as would be necessary if they were shaped for dovetail-type interengagement). This capability of being pressed together face-to-face is particularly important, since the composite strips 40 can be up to 1 6 feet long: at this length, longitudinal engagement would not be feasible.

Two further developments of the composite strips 40 are shown at 40a and 40b in Figures 6 and 7 respectively, where elements corresponding to elements of Figures 1 to 3 have been given the same references but with the suffix a or b as appropriate.

Thus the composite strip 40a of Figure 6 comprises a backing strip 44a of chipboard which is just over three times the width of the strip 44 of Figure 1, and which has three identical strips 42a of the decorative timber, similar in width to the strips 42 of Figure 1, bonded thereto. The strips 42a are uniformly spaced across the width of the strip 44c and the left-hand and right-hand ones respectively define with the strip 44a grooves 48a identical to the grooves 48 of Figure 1.

Additionally the strip 44a is provided with deeper and wider grooves 90 in the portions of its crenellated surface 46a beneath the spaces defined between adjacent strips 42a: these grooves 90 thus extend beneath the adjacent edges of the strips 42a. Respective rectangularsection plastics extrusions 92, generally similar to the mounting strips 50, are inserted into the grooves 90. The function of the extrusion 92 is to fill the spaces defined between adjacent strips 42a in an aesthetically pleasing manner, and to this end they can be coloured to tone or contrast with the decorative timber of the strips 42a, or coloured to match some other item in the room in which the composite strips 40a are being fitted.

If desired, the extrusion 92 can have foam rubber pads (not shown) bonded or otherwise secured to the sides thereof which face the backing strip 44a, in order to resiliently urge them away from the strip 44a and into contact with the portions of the surfaces 46a of the strips 42a they underlie.

The composite strips 40a are secured to a ceiling or other surface by means of extruded plastics mounting strips 94. The strips 94 each have a pair of parallel flanges 96 extending from each side thereof, to receive and embrace a respective side edge of the backing strip 44a.

The upper flanges 96, as viewed in Figure 6, are aligned with each other, and are received in grooves 98 cut in the upper (or rear) surface 100 of the backing strips 44a. The grooves 98 are dimensioned such that the upper surfaces 100 of the strips 44a and the upper surfaces 102 of the flanges 96 all lie in a common plane, and thus form one contiguous (or common) surface.

The lower flanges 96, which are also aligned with each other, are received in respective ones of the grooves 48a.

The central portion 104 of each strip 94 has a deep channel 106 formed on it, the base of this channel having uniformly longitudinally spaced fixing holes 108 extending therethrough by which the strips 94 can be screwed to the joist of the ceiling or to some other surface to be clad with the strips 40a.

Once the composite strips 40a have been secured in position, the mounting strips 94 are concealed by sliding further extrusions 92 into the grooves 48a benath (as viewed in Figure 6) the mounting strips. Again, foam rubber pads (not shown), mounted in the channel 106, can be provided to urge the extrusions 92 downwardly.

In the composite strip 40b of Figure 7, the crenellated mating surfaces 46b of the strips 42b and 44b follow a generally curved contour, concave for the backing strip 44b and convex for the decorative timber strip 42b. Additionally, the strip 42b has a concave lower (or exposed) surface. However, the decorative timber strip 42b is initially flat rather than curved, and is forced into its curved shape during its bonding to the backing strip 46b. In this way, a composite strip having a convex lower surface and the appearance of being made entirely from an expensive decorative timber can be made from a relatively thin strip of the decorative timber: a strip of similar dimensions and made entirely from the decorative timber would require much greater initial thickness of the decorative timber, and would therefore be extremely expensive.

The strips 40b can be mounted by means of mounting strips identical to the mounting strips 94 of Figure 6.

If desired, a pluralitry of strips 42a of different widths, can be bonded to a single backing strip 44a, or a combination of one or more flat strips 42a can be combined with one or more curved strips 42b on a single backing strip.

The strips 40, 40a and 40b can clearly be used to cover surfaces other than ceilings, for example walls, and can also be used to make kitchen cupboards and the like.

Claims (36)

1. An elongate composite strip or board for use in decorative ceilings and the like, the composite strip being formed of a strip of decorative timber bonded to a strip of chipboard, the two strips being bonded together at substantially complementary non-planar mating surfaces thereof, which are shaped to permit the surfaces to be moved generally perpendicular of each other into mating contact with each other.

2. A composite strip as claimed in claim 1, wherein said mating surfaces are of generally crenellated form when viewed in cross section through the width of the strip, i.e. continuously tongued-and-grooved across the width of the strip.

3. A composite strip as claimed in claim 1 or claim 2, wherein the mating surfaces are shaped to define, in use, respective downwardly facing mounting surfaces.

4. A composite strip as claimed in claim 1 or claim 2, wherein the mating surfaces are shaped to define similar grooves running the length of each side of the strip.

5. A composite strip as claimed in claim 1 or claim 2, wherein the mating surfaces are shaped to define a groove running the length of one side of the strip and a tongue complementary to said groove running the length of the other side of the strip.

6. A ceiling support system for supporting the ceiling of a room, the system comprising first and second elongate members, of which the first member is relatively flexible and adapted to be fixed to a wall of the room just below the ceiling to be supported, with its long dimension extending substantially horizontally, and the second member extends parallel to and is supported by the first and is provided with one or more generally horizontally extending ceilingsupporting portions, the two members having a resilient material held between them and the second member being movable, in use, with respect to the first in a direction substantially perpendicular to said wall, movement of the second member towards said wall being arranged to compress the resilient material.

7. A ceiling support system as claimed in claim 6, wherein the first elongate member is of channel-section and is adapted to be fixed to the wall with the open mouth of the channel towards the wall and the two sides of the channel extending substantially horizontally.

8. A ceiling support system as claimed in claim 7, wherein the first elongate member is provided with resilient mounting blocks secured in the channel at spaced intervals therealong, by means of which the first member can be stuck to the wall.

9. A ceiling support system as claimed in claim 8, wherein said resilient mounting blocks are made of foam rubber of foam plastic.

10. A ceiling support system as claimed in any one of claims 7 to 9, wherein the second elongate member is also of channel-section, with its channel shaped to fit over and slidably engage the outer surfaces of the sides of the channel of the first elongate member.

11. A ceiling support system as claimed in claim 10, wherein said resilient material comprises resilient blocks secured in the channel of the second elongate member at spaced intervals therealong, so as to be compressed between the inside surface of the base of the channel of the second elongate member and the outer surface of the base of the channel of the first elongate member.

12. A ceiling support system as claimed in any one of claims 6 to 11, wherein said generally horizontally extending ceiling-supporting portion on the second elongate member extends the whole length of the second member, and has an upwardly facing ceiling-supporting surface and a downwardly facing surface shaped to form at least part of a decorative cornice.

13. A ceiling support system as claimed in any one of claims 6 to 12, wherein the first and second elongate members are plastics extrusions, for example of PVC.

14. A ceiling support system as claimed in any one of claims 6 to 13, in combination with and supporting a ceiling comprising a plurality of composite strips or boards each comprising a strip of decorative timber bonded to a strip of chipboard, the two strips being bonded together at substantially complementary non-planar mating surfaces thereof.

1 5. The combination of claim 14, wherein the mating surfaces are of generally crenellated form when viewed in cross section through the width of the strip, i.e. continuously tongued-andgrooved across the width of the strip.

16. The combination of claim 14 or claim 15, wherein the mating surfaces are shaped to define, in use, respective downwardly facing mounting surfaces running the length of each side of the strip.

17. The combination of claim 14 or claim 15, wherein the mating surfaces are shaped to define similar grooves running the length of each side of the strip.

18. The combination of claim 14 or claim 15, wherein the mating surfaces are shaped to define a groove running the length of one side of the strip and a tongue complementary to said groove running the length of the other side of the strip.

19. A ceiling support system as claimed in any one of claims 6 to 13, in combination with and supporting a ceiling comprising a plurality of sheet metal strips.

20. The combination of claim 19, wherein each sheet metal strip is provided along each side thereof with a generally horizontally outwardly extending portion.

21. The combination of any one of claims 14 to 1 7, 19 and 20, further comprising, in use, a plurality of bars extending transversely of, and fixed to, the usual wooden ceiling joists, and a plurality of elongate supporting strips extending transversely of the bars and suspended therefrom by means of wire supporting hooks, the side edges of the supporting strips being shaped to support the edges of said composite or sheet metal strips.

22. The combination of claims 1 7 and 21, wherein the side edges of the supporting strips are shaped to fit in the grooves in the sides of the composite strips.

23. The combination of claims 20 and 21, wherein the side edges of the supporting strips are provided with grooves shaped to receive the horizontally outwardly extending portions of the sheet metal strips.

24. The combination of any one of claims 14 to 1 7, 19 and 20, further comprising, in use, a plurality of elongate supporting strips extending transversely of, and fixed to, the usual wooden ceiling joists, the side edges of the supporting strips being shaped to support the edges of said composite or sheet metal strips.

25. The combination of claims 17 and 24, wherein the side edges of the supporting strips are shaped to fit in the grooves in the sides of the composite strips.

26. The combination of claims 20 and 24, wherein the side edges of the supporting strips are provided with grooves shaped to receive the horizontally outwardly extending portions of the sheet metal strips.

27. A ceiling support system comprising, in use, a plurality of elongate supporting strip extending transversely of, and fixed to, the usual wooden ceiling joists, the side edges of the supporting strips being shaped to support the edges of strips of ceiling material extending parallel thereto.

28. A ceiling support system comprising, in use, a plurality of bars extending transversely of, and fixed to, the usual wooden ceiling joists, and a plurality of elongate supporting strips extending transversely of the bars and suspended therefrom by means of wire supporting hooks, the side edges of the supporting strips being shaped to support the edges of strips of ceiling material extending parallel thereto.

29. ceiling support system as claimed in claim 27 or claim 28, wherein the side edges of the supporting strips are provided with'grooves.

30. A ceiling support system as claimed in claim 27 or claim 28, wherein the side edges of the supporting strips are shaped to fit in grooves in the sides of said strips of ceiling material.

31. A composite strip as claimed in any one of claims 1 to 5, comprising at least two of said strips of decorative timber, extending parallel to each other and each narrower than and bonded to said strip of chipboard.

32. A composite strip as claimed in claim 31, wherein said strips of decorative timber are laterally spaced apart on said strip of chipboard, adjacent edges of said strips of decorative timber being shaped to receive and retain an extruded plastics strips which fills the space between said adjacent edges.

33. A composite strip as claimed in any of claims 1 to 5, 31 and 32, wherein the or one of the strips of decorative timber has a generally convex crenellated mating surface and a correspondingly concave exposed surface.

34. An elongate composite strip substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

35. An elongate composite strip substantially as hereinbefore described with reference to Figure 6 of the accompanying drawings.

36. An elongate composite strip substantially as hereinbefore described with reference to Figure 7 of the accompanying drawings.