WO2002033187A1

WO2002033187A1 - Partition wall

Info

Publication number: WO2002033187A1
Application number: PCT/EP2001/012860
Authority: WO
Inventors: John Harris; Karl Stojko
Original assignee: Lafarge, Platres
Priority date: 2000-10-20
Filing date: 2001-10-19
Publication date: 2002-04-25
Also published as: AUPR090400A0

Abstract

A plasterboard or wallboard panel (10) for use in forming a partition wall defines a plane and include a change of direction in the plane of the panel adjacent at least one edge of the panel to define a flap portion (14) such that panel (10) may be stood along an edge extending transversely to the change of direction with the flap portion (14) acting as a support/stabiliser for the panel. By using a plurality of such panels (10) joined in an series it is possible to provide a partition wall formed from plasterboard which is self supporting such that the partition does not need an internal structure such as a metal or wooden stud framework to provide stability and structural integrity to the partition. By obviating the need for a timber or steel framing to support the plasterboard, the time and cost involved for providing a partition wall can be reduced. A further advantage of the absence of studs is that the panels forming the wall may be made demountable and/or reusable as they are not glued or fixed to studs and are self supporting.

Description

PARTITION WALL

FIELD OF THE INVENTION

This invention relates to a partition wall. In particular, the invention relates to a partition wall made from plasterboard panels, wallboard or the like and to a method of making such a partition. Aspects of the invention also relate to plasterboard panels configured to make such partition wall.

BACKGROUND OF THE INVENTION Plasterboard, wallboard and the like are the materials of choice for forming internal walls and partitions in many commercial buildings and also in residential buildings, for walls which do not have to be load bearing. There are a number of methods for assembling partition walls depending on whether they are used in wet or dry locations and depending on the level of sound insulation and thermal insulation required for the partition wall. In all cases, a framework is assembled where the partition wall is to be provided to support the plasterboard. The framework comprises a series of vertical studs which are usually made either of wood or of metal and which normally includes cross bracing noggins or the like. If a metal (usually steel) framework is provided, the framework will usually include upper and lower track means in the form of a header track and a base track.

SUMMARY OF THE INVENTION

In a first broad aspect, the present invention provides a plasterboard or wallboard panel for use in forming a partition wall which defines a plane and includes change of direction in the plane of the panel adjacent at at least one edge of the panel to define a flap portion such that the panel may be stood along an edge extending transversely to the change of direction with the flap portion acting as a support/stabiliser for the panel.

By using the present invention, it is possible to provide a partition wall formed from plasterboard which is self supporting such that the partition does not need an internal structure such as a metal or wooden stud framework to provide stability and structural integrity to the partition.

By obviating the need for a timber or steel framing to support the plasterboard, the time and cost involved for providing a partition wall can be reduced. A further advantage of the absence of studs is that the panels forming the wall may be made demountable and/or reusable as they are not glued or fixed to studs and are self-supporting. Typically, at least two opposite edges of the panel of plasterboard will include a change of direction.

In a preferred embodiment, the change of direction will be 90° such that each panel of plasterboard defines two flap portions at 90° to the plane of the central portion of the panel.

A tapered edge may be defined between the central portion of the panel and one flap portion.

A tapered edge is defined between the central portion and the two opposed flap portions respectively. In an alternative embodiment, two 90° changes in direction are provided adjacent each edge and the edges of the plasterboard are thus formed into a U-shape. Typically, the partition wall will include and upper and lower track means sandwiching the walling to improve the strength, rigidity and integrity of the partition. Both the lower and upper track means may incorporate a variety of architectural finishes, if desired.

Typically, the upper and lower track means will be generally U-shaped having a base and two opposed amis with the arms of the "U" oriented a few degrees inward of negative angle to ensure a snug fit with the plasterboard walls of the partition. The partition wall could be covered in a further layer of plasterboard or similar material to improve the strength of the partition.

In a related aspect, the invention also provides a method of treatment of panel of plasterboard comprising filler material sandwiched between two opposed flexible panels, including the steps of: a) cutting a channel close to an edge of the panel of plasterboard, the channel extending through one flexible sheet and into the filler as far as or close to, but not through the second opposite flexible sheet to define a flap attached to the main plasterboard panel by the second flexible sheet; b) rotating the flap and fixing a face of the flap to the main panel with the flap extending at an angle to the main panel.

The method further includes the steps of; a) cutting a channel close to an opposite edge of the panel of plasterboard to the first edge, the channel extending through one flexible sheet and into the filler as far as close to, but not through the second flexible sheet to define a flap attached o the main plasterboard panel by the second flexible sheet; b) rotating the flap and fixing a face of the flap to the main panel with the flap extending at an angle to the main panel. The invention further concerns a method of producing a panel of plasterboard, the panel comprising filler material sandwiched between two opposed flexible sheets, the method comprising the step of ; a) providing a forming belt with a first tapering belt disposed parallel, but not adjacent, to one edge of the forming bell; b) travelling the panel on the forming belt, one flexible sheet being in contact with the first tapering belt, the first tapering belt defining a first slot in the plane of the panel.

The method further includes the step of: a) cutting a channel at the level of and parallel to the first slot, through the first flexible sheet not in contact with the tapering belt, and into the filler as far as or close to, but not through the second flexible sheet in contact with the tapering belt, to define a flap attached to the main plasterboard panel by the flexible sheet; b) rotating the flap and fixing a face of the flap to the main panel with the flap extending at an angle to the central portion of the panel.

The forming belt may be provided with a second tapering belt parallel, but not adjacent, to the other edge of the forming belt, the second tapering belt defining a second slot in the plane of the panel.

The method further includes the step of: a) cutting a channel at the level of and parallel to the second slot, through the first flexible sheet not in contact with the second tapering belt, and into the filler as far as or close to, but not through the second flexible sheet in contact with the second tapering belt, to define a flap attached to the main plasterboard panel by the second flexible sheet; b) rotating the flap and fixing a face of the flap to the main panel with the flap extending at an angle to the central portion of the panel.

Typically, an opposite flap will be formed in the same manner. Typically, the flaps extend at about 90° to the main panel. The flaps may be glued or othei wise fixed in their 90° orientation. The present invention also encompasses a flat panel of plasterboard or the like which has had channels cut into it for forming a panel embodying the first aspect of the present invention.

The invention further provides a method for assembling a series of panels comprising the steps of; a) abutting the flap portion of a panel to flap portion of an adjacent panel; b) fixing the adjacent flap portions together. The adjacent flap portions may be fixed by means of adhesive or screws. A method for assembling a partition wall, comprising the steps of the method for assembling a series of panels.

The invention further provides a method for assembling a partition wall, comprising the step of facing the respective rear faces of a first and second series of panels.

The method further comprises the steps of forming the first series and subsequently forming the second scries or, alternatively, comprises further the step of forming simultaneously the first and second series.

The method further comprises the steps of abutting and fixing distal end faces of the flap portions of the one series to the second series. The distal end faces of a scries are fixed with adhesive and preferably with stitcher screws to the rear face of the other series. The series are sandwiched with an upper and lower track means.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described by way of example only and with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a panel of plasterboard which has been processed to form stabilising flaps:

Figure 2 is a view of the same panel oriented vertically; Figure 3 illustrates an exploded view of a first partition wall utilising plasterboard panels embodying the present invention;

Figure 4 illustrates the completed partition wall structure;

Figure 5 illustrates a header track for a partition wall embodying the present invention; Figure 6 shows the header track in position on top of a partition wall;

Figure 7 is a detail illustrating the forming of a flange of a plasterboard panel into a U-shape rather than the L-shape shown in Figure 1 ;

Figure 7b is a detail showing two panels joined together;

Figure 7c shows a variant of the flange shown in Figure 7a end 7b; Figures 8a to 8d illustrate base tracks for use with the present invention.

Figure 9 is a schematic drawing illustrating the provision of a negative angle for the header and base tracks,

Figure 10 illustrates an alternative construction for a partition wall; and

Figures 1 l a to l id show a series of profiles suitable for the header track.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings, Figure 1 and Figure 2 show a rectangular panel of plasterboard 10 which has been machined and formed so that two longitudinal edges of the plasterboard are generally transverse (90°) to the plane of the panel such that the panel defines a central area 12 and two opposed flaps or wings 14. The processing involves using a router or the like to cut a channel extending through the paper sheet 10a forming one face layer of the plasterboard and the gypsum filling as far as the second other layer 10b of the plasterboard but in such a manner that the second layer 10b is left intact. A second channel is cut extends through the one flexible sheet 10a and into the filler as far as or close to, but not through the second opposite flexible sheet 10b which second channel is located between 50 to 500 mm from the first channel. Typically, those cuts will be made about 90mm from the longitudinal edges of the panel. The flaps are then turned through 90° and glued or otherwise fixed to the rear of the plasterboard panel as shown in Figure 1. Alternatively, the flaps are fixed to the rear face of the panel by means of a reinforcing piece; the reinforcing piece is for example a metallic angle. In the figure, the width W of the central area is 1020 mm, the height h of the flaps is 90 mm. The height of the flap portion is defined by the distance between the edge and the channel parallel thereto.

When, as shown in Figure 2. the panel of plasterboard is placed in a vertical orientation, the flaps provide a change of direction in the plane of the panel that gives the panel "feet" that act as stabilisers. The height h of the panel is made to suit the application (i.e. is the height required for the partition wall).

The advantage of plasterboard panel of the present invention, is that panels such as shown in Figure 2 can be used to make partition walls without the need for either a timber or metal support framework to attach the panels to.

In one embodiment, the partition wall comprises at least one series of panels 10. In a preferred embodiment, as shown in Figures 3 and 4, a partition wall comprises opposing wall faces 15a, 15b, each comprising of a series of panels of plasterboard 10 such as shown in Figure 2, with the flaps 14 of one panel 10 glued or otherwise fixed to the flaps of an adjacent panel.

Figure 3 shows the two partition wall faces 15a, 15b separated. Figure 4 shows the completed arrangement in which the partition wall is formed by staggering the flaps 14 and bringing the walls 15a, 15b together. The distal end faces 14a of the flap portions 14 of one series 15a abut a rear face of panels 10 of the second series 15b, and vice versa.

The joints 17 where the panels 10 abut could be finished in a variety of different ways including a factory finish butt joint or a flush joint finish to conceal the joint, or a PVC or metal moulded or extruded strip could cover the joint.

The thickness "T" of the partition wall measured between the two partition wall faces 15a, 15b can be varied from as little as 50 mm to 500mm. This is a considerably greater range than is possible with exiting partition wall systems using studs The wall thickness can thus be adjusted to suit the application, to receiving insulation and the like.

Figure 5 shows upper track means in the form of a header track which fits over the top of the wall of Figure 4 as shown in Figure 6.

The header track comprises an inner section 22 whose upper face defines opposed holding gutters 24, and holding legs or tabs 26 which depend from the edges of the section. The header track include separate holding flaps 28 which define projections 30 which locate in gutters 24 and a depending flap 32 which is angled inwards. Figure 6 which illustrates a wall in which side of the header track only is completed. The upper surface of the plasterboard panel 12 is sandwiched between the tabs 26 of the inner section and the depending flap 32 of the holding flap 28.

Figure 7a shows a variant of the present invention in which a double routing process is used which forms the longitudinal edge of a panel of plasterboard 38 into a U-shaped rather than an L-shape as shown in Figure 1.

As shown in Figure 7a, the base edge 40 of the U-shape is 90mm and the shorter aπn 42 is 60mm long.

Figure 7b illustrates the butting and joining of two longitudinal edges of plasterboard as shown in Figure 7a together using the U-shapped "foot", The base edges 40 are butted together and may be either glued using cornice adhesive 41 or the like or screwed together using stitcher screws 43 or by using both fixing methods.

This further improves the structural integrity o the partition wall.

Figure 7c shows a further embodiment of the plasterboard panel 10. In this embodiment, a tapered edge 70 is defined between the central portion 12 and the flap portion 14 of the panel 10. The tapered edge 70 facilitates the junction of the panel 10 to a neighbour element. The tapered edge 70 provides a space to be filled with joint-pointing and/or with joint-filling. In the case where the neighbour element is an adjacent panel 10' provided also with a tapered edge 70', a V-shaped slot 72 is defined. The term "edge" refers to the finished comer of the panel 10 situated on the front side of the panel, once the flap portion 14 of the panel is rotated toward the rear side of the panel 10.

The tapered edge 70 is formed on the second flexible sheet 10b, which is not cut. The tapered edge 70 is formed on a panel 10 provided with a slot. The slot extends parallel to the flap portion 14, The slot is formed close to a first edge of the panel 10, the distance between the slot and the first edge defining the height of the flap portion 14. The flap portion 14 is defined by the first channel cut at the level of and parallel to the first slot. The first channel extends through the first sheet 10a and into the filler as far as or close to, but not through the second sheet 10b. The flap portion 14 is attached to the central portion 12 of the panel 10 by the second flexible sheet 10.

In a preferred embodiment, the panel 10 is provided with a second tapered edge 70. Thus, a tapered edge 70 is defined between the central portion 12 and the two opposed flap portions 14, respectively. The second tapered edge 70 is formed on the second flexible sheet 10b in the same way as the first tapered edge.

The method of producing a plasterboard panel 10 with a tapered edge 70 is now detailed. The panel 10 is constructed of gypsum filling between the two flexible sheets 10a, 10b and is produced on a forming belt. The method comprises the step of providing the forming belt with a first tapering belt disposed parallel, but not adjacent, to one edge of the forming belt. The belt is thus parallel to the direction of conveyance of the panel. The belt is fixed on the forming belt at a distance defining the height h of the flap portion 14. Then the method comprising the step of travelling the panel 10 on the forming belt, the panel 10 laying on the second sheet 10b on the forming belt. The second flexible sheet 10b being in contact with the first tapering belt. Consequently, the first tapering belt defines a first slot in the plane of the panel 10. The method further comprises the step of cutting a channel at the level of and parallel to the first slot. The channel is out through the first flexible sheet 10a not in contact with the tapering belt, and into the filler as far as or close to, but not through the second flexible sheet 10b in contact with the tapering belt, to define a flap portion 14 attached to the main plasterboard panel by the flexible sheet 10b. At this state, the method defines a flat panel 10 piovided with a slot on one side, and on the other side, with a channel. The slot and channel are at the same level and parallel to each other. That permit to easily transport a number of panels 10. The method of producing a panel of plasterboard further includes a step of rotating the flap 14 and fixing a face of the flap to the central portion 12 of the panel 10 with the flap extending at an angle to the central portion 12.

In the embodiment where the panel is provided with a second tapered edge 70, the method provides a second tapering belt parallel, but not adjacent, to the other edge of the forming belt. The distance between the tapering belt and the edge defines the height h of the flap portion 14. The method further comprises the step of cutting a second channel at the level and parallel to the second slot. In this embodiment, the panel is provided with two channels and to slots, each at distance from the respective closest edge of the panel. A number of panels may be easily transported. As shown in Figure 4 and also in Figure 10, it is preferable that the joints are always staggered. This improves the integrity of the wall. Also, aligning the joints would increase the transmission of noise across the partition wall and would thus be generally undesirable. Thus, it is contemplated that a "starter" panel of half the usual standard width (in the specific embodiment 505 mm instead of 1010 mm) be provided as a standard component of the partition wall system of the present invention.

The system of the present invention is well suited for use in commercial applications but can also be used in domestic applications, for example for partition wall that are not load bearing.

Figures 8a to 8d illustrate lower track means in the form of a series of base track designs. Figure 8a has a straight edged cross section. Figure 8b illustrates the floor of the base traGk including recesses 48 for receiving carpets, floor tiles or the like. Figure 8c illustrates a base track including a rubber strip 50 running along the underside for protecting existing floor treatments. Figure 8d illustrates a base track in a shape of traditional skirting board. The base tracks could be made in an engineering grade material sudi as steel or in PVC extrusion, or other suitable material.

The base tracks may define channels or the like to receive cables for IT applications, power or the like or allow room for Gable to pass underneath the panels 10.

The header track and also the base track are both manufactured with a few degrees inward of negative angle to ensure that the tracks are a snug fit against the plasterboard and that no gaps occur between the face of the plasterboard wall and the edges of the tracks.

In order to improve the strength of the partition wall it is possible to apply another layer of plasterboard to the face of the wall. The layer could be standard 10mm, 13mm or 16mm layer of plasterboard, a fire resistant panel or perhaps a water resistant layer of plasterboard or a fibre cement panel. Ideally, the outer layer of plasterboard would be applied to a transverse direction with the longitudinal axis of the panels forming the partition wall at 90° which improve the strength and sealing of the joints beneath and on the lower plasterboard forming the plasterboard wall. The fire resistant layer (Fireshield) could be applied using stitcher/laminating screws. Other surface treatments of the partition wall to either increase its strength, water resistance or for other purposes, could of course be used.

Is it also an option to infill the partition wall to improve its acoustic, fire performance, insulation or the like.

In some variants because of the absence of studs it is possible that the panels forming the wall may be demountable and/or reusable as they are not glued or fixed to studs and are self-supporting.

Figure 9 is a schematic drawing illustrating the provision of a negative angle for the header and base tracks. The arms of the U-shaped of the tracks may be oriented a few degrees inward; the arms preferably form inwardly from the 90° position an angle in the range of 0" to 5°, Thus, the two opposed arms of the "U" are oriented in the range of 85° to 90° from the base

Figure 10 illustrates an alternative method of construction of a partition wall wherein the back of each panel of the partition wall is fixed with adhesive 44 to the outer edge of an opposite panel forming the opposite wall. Additional stitcher screws 46 join the ami 42 of one wall face 38a to the rear face of the opposite wall face 38b. The screws will typically be spaced 150mm apart up the wall. However, it would be appreciated that the panels would have to be formed to specific tolerance levels to allow this. Panels of plasterboard arc manufactured to dimensional tolerances of about + 1 mm. However in the pioccss for turning a flat panel of plasterboard into a panel incorporating a U shaped change of direction the "error" can be taken up in the arm 42, which can vary in length without affecting the fit of the panels together. The width of the panel 38 and the length of the ami 40 can be made accurate to about 0.01mm or better. Optionally stitcher or laminating screws 60 can be used extending through the front of one panel 38 into the ami 42 of another. This has been found to greatly increase the structural strength and stability of the partition wall. The heads of the stitcher screws may be concealed by screws head caps, plaster propping or similar. Where stitcher screws may have to pass through the tracks, holes may be pre-punched in the tracks.

Figure 1 l a to 1 lb illustrate a number of possible for the header track including a standard profile in Figure 1 l a including a camber, a profile 1 16 having a shadow recess at the ceiling line (Fig, l i b), a box header (Fig. l ie) and a cornice style header (Fig. 1 Id). The header and the base tracks may be exposed or unexposed in the finished wall. If the tracks are to be unexposed a series of slots may be provided in the tracks for receiving the transverse flaps 14 of the panels.

The panels may be transported as a routed flat panel for gluing or otherwise forming into a panel having stabilised flaps. Transporting flat panels may be more efficient than transporting the finished panels with flaps.

One advantage of the present invention is that it is possible to construct plasterboard walls from one side only. This is advantageous where is limited or no access to one of the wall, for example with shaft walls for lifts and the like.

Although the aforegoing description refers to partition wall, it will be appreciated that the plasterboard panels of the present invention can be used in a single layer to cover walls such as lift wells and the like. The panels can be fixed directly to the wall without studs, Features, which are used with existing stud based partition walls, can be used with the studless wall embodying the present invention. For example cover strips can be used on the edges of the plastcrboards panels where the edges abut. The partition wall may be covered with or made from pre-decorated panels having various finishes such as coloured linerboard, printed paper, laminated vinyl or pre-painted finishes.

In one variant, not illustrated, the acoustic insulation properties of the wall may be improved by installing a foam seal between the rear of the plasterboard panel 38 and the ami 42. Preferably, a foam seal is disposed between the distal end faces 14a of the flap portions 14 of the one series 15a and the rear faces of the panels 14 of the second series 15b.

Clearly, the dimensions of the plasterboard panel, width of the flaps, thickness of the plasterboard may be varied from that described above.

It will be appreciated by persons skilled in the art numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not respective.

Claims

1. A plasterboard or wallboard panel ( 1 ) for use in forming a partition wall which defines a plane and includes change of direction in the plane of the panel ( 10) adjacent at least one edge of the panel ( 10) to define a flap portion (14) such that the panel ( 10) may be stood along an edge extending transversely to the change of direction with the flap portion ( 14) acting as a support/stabiliser for the panel (10).

2. A plasterboard or wallboard panel as claimed in claim 1 wherein two opposite ends of the panel of plasterboard ( 10) include a change of direction.

3. A plasterboard or wallboard panel as claimed in claim 2 wherein the change of direction is about 90° such that each panel of plasterboard (10) defines two flap portions (14) at 90° to the plane of the central portion (12) of the panel (10).

4. A plasterboard or wallboard panel as claimed in claim 3, wherein a tapered edge (70) is defined between the central portion (12) and one flap portion (14).

5. A plasterboard or wallboard panel as claimed in claim 4, wherein a tapered edge (70) is defined between the central portion ( 12) and the two opposed flap portions (14) respectively.

6. A plasterboard or wallboard panel as claimed in claims 2 to 5 wherein two changes in direction of about 90° are provided adjacent each edge such that the ends of the panel of plasterboard (10) are generally formed into a U-shape.

7. A plasterboard or wallboard panel as claimed in claim 6, wherein the flap portions (14) are fixed to the rear face of the panel (10).

8. A plasterboard or wallboaul panel as claimed in claim 7, wherein the flap portions (14) are glued to the rear face of the panel ( 10).

9. A plasterboard or wallboard panel us claimed in claim 8, wherein the flap portions (14) are fixed to the rear face of the panel (10) by means of a reinforcing piece.

10. A plasterboard or wallboard panel as claimed in claim 9, wherein the reinforcing piece is a metallic angle.

1 1. A series of panels ( 15a, 15b) as claimed in anyone of claims 1 to 10 wherein flap portions (14) of one panel ( 10) aie abutted and joined to flap portions ( 14) of an adjacent panel (10).

12. A series of panels a claimed in claim 1 1 wherein the flap portions (14) are joined together by means of adhesive or screws, or both.

13. A partition wall comprising al least one series ( 15a) of panels ( 10) as claimed in claim 1 1 or claim 12.

14. A partition wall of claim 13, comprising a first and a second opposed spaced apart series (15a, 15b) of panels ( 10).

15. A partition wall as claimed in claim 14, wherein the flap portions (14) of one series (15a) are staggered with respect to the flap portions (14) of the second series (15b).

16. A partition wall as claimed in claim 15 wherein distal end faces (14a) of the flap portions (14) of one series (15a) abut a rear face of panels (10) of the second series (15b).

17. A partition wall as claimed in claim 16 wherein the distal end faces of the flap portions (14) are fixed with adhesive and preferably stitcher screws to the rear face of panels of the second series.

18. A partition wall as claimed in any one of claims 14 to 17 including an upper and lower track means sandwichin 'ag the series.

19. A partition wall as claimed in claim 18 wherein the upper and lower track means are generally U-shaped having a base and two opposed arms with the arms of the "U" oriented a few degrees inward of negative angle to ensure a snug fit with the plasterboard walls of the partition.

20. A partition wall as claimed in claim 19, wherein the two opposed arms of the "U" are oriented in the range of 85° to 90° from the base.

21. A partition wall as claimed in claim in claim 19 or 20 wherein the lower traGk is made in an engineering grade material such as steel or is a PVC extrusion.

22. A partition wall as claimed in any one of claims 19 to 21 wherein the lower track defines channels.

23. A partition wall as claimed in claim 22 wherein the channels receive cables for IT applications or power or allow room for cable to pass underneath the panels ( 10).

24. A partition wall as claimed in any one of claims 14 to 23 wherein a foam seal is disposed between the distal end faces of the flap portions of the one series and the rear faces of the panels of the second series.

25. A partition wall as claimed in any one of claims 13 to 24 wherein a further layer of plasterboard or similar material covers at least one face of the wall.

26. A partition wall as claimed in any one of claims 13 to 25 comprising no internal timber or metal support framework.

27. A partition wall as claimed in any one of claims 13 to 25 wherein a V-shaped slot is defined between two adjacent panels (10) in the series.

28. A method of treatment a panel of plasterboard comprising filler material sandwiched between two opposed flexible sheets (10a, 10b), comprising the steps of: a) cutting a channel close to a first edge of the panel of plasterboard, the channel extending through one flexible sheet (10a) and into the filler as far as or close to, but not through the second opposite flexible sheet (10b) to define a flap (14) attached to the main plasterboard panel by flexible sheet (10b); b) rotating the flap (14) and fixing a face of the flap to the main panel with the flap extending at an angle to the central portion (12) of the panel (10).

29. The method of claim 28 further comprising the step of: a) cutting a channel close to an opposite edge of the panel of plasterboard to the first edge, the channel extending through one flexible sheet (10a) and into the filler as far as close to, but not through the second flexible sheet (10b) to define a flap (14) attached o the main plasterboard panel by the second flexible sheet (10b); b) rotating the flap ( 14) and fixing a face of the flap to the main panel with the flap extending at an angle to the central portion (12) of the panel (10).

30. A method of producing a panel of plasterboard, the panel comprising filler material sandwiched between two opposed flexible sheets (10a, 10b), the method comprising the step of : a) providing a forming belt with a first tapering belt disposed parallel, but not adjacent, to one edge of the forming belt; b) travelling the panel ( 1 ) on the forming belt, one flexible sheet ( 1 Ob) being in contact with the first tapering belt, the first tapering belt defining a first slot in the plane of the panel (10).

31. The method of claim 30 further including the step of: a) cutting a channel al the level of and parallel to the first slot, through the first flexible sheet (10a) not in contact with the tapering belt, and into the filler as far as or close to, but not through the second flexible sheet (10b) in contact with the tapering belt, to define a flap (14) attached to the main plasterboard panel by the flexible sheet (10b); b) rotating the flap (14) and fixing a face of the flap to the main panel with the flap extending at an angle to the central portion (12) of the panel (10).

32. The method as claimed in claim 30 or 31 , wherein the forming belt is provided with a second tapering belt parallel, but not adjacent, to the other edge of the fomiing belt, the second tapering belt defining a second slot in the plane of the panel (10).

33. The method as claimed in claim 32, further including the step of: a) cutting a channel at the level of and parallel to the second slot, through the first flexible sheet (10a) not in contact with the second tapering belt, and into the filler as far as or close to, but not through the second flexible sheet (10b) in contact with the second tapering belt, to define a flap (14) attached to the main plasterboard panel by the second flexible sheet ( 10b); b) rotating the flap (14) and fixing a face of the flap to the main panel with the flap extending at an angle to the central portion ( 12) of the panel (10).

34. The method of claim 29 or 33, wherein the flaps extend at about 90° to the central portion (12) of the panel ( 1 ).

35. The method of claim 34 wherein the flaps ( 14) are glued or otherwise fixed in their orientation relative to the panel.

36. The method of claim 35, wherein the flaps (14) are fixed to the rear face of the panel (10) by means of a reinforcing piece.

37. The method of claim 36, wherein the reinforcing piece is a metallic angle.

38. A method for assembling a series ( 15a, 15b) of panels, as claimed in claims 1 1 or 12, comprising the steps of: a) abutting the flap portion ( 14) ofa panel ( 10) to flap portion ( 14) of an adjacent panel ( 10); b) fixing the adjacent flap portions ( 14) together.

39. The method of claim 38, wherein the adjacent flap portions are fixed by means of adhesive or screws.

40. A method for assembling a partition wall as claimed in claim 13, comprising the steps of claim 38 or 39.

41. A method for assembling a partition wall as claimed in claim 14 to 27, comprising the step of facing the respective rear faces of a first and second series (15a, 15b) of panels.

42. The method as claimed in claim 41 further comprises the steps of fomiing the first series (15a) and subsequently forming the second series (15b).

43. The method as claimed in claim 41 further comprises the step of fomiing simultaneously the first and second series (15a, 15b).

44. The method of claim 42 or 43 further comprises the steps of abutting and fixing distal end faces (14a) of the flap portions ( 14) of the one series (15a, 15b) to the second series.

45. The method of any one ofclaims 41 to 44, wherein the distal end faces ( 14a) of a series (15a, 15b) are fixed with adhesive and preferably with stitcher screws (42, 43, 60) to the rear face of the other series.

46. The method of any one of claims 41 to 45, wherein the series ( 15a, 15b) are sandwiched with an upper and lower track means.

47. A panel of plasterboard comprising:

- filler material sandwiched between a first and a second flexible sheets (10a, 10b);

- on the second sheet (10b), a first slot close to a first edge of the panel of plasterboard;

- a first channel at the level of and parallel to the first slot, the first channel extending through the first sheet ( 10a) and into the filler as far as or close to, but not through the second sheet ( 10b) to define a flap attached to the central portion (12) of the panel ( 10) by the second flexible sheet ( 10b).

48. A panel of plasterboard of claim 47, further comprising:

- on the second sheet ( 10b), a second slot parallel to the first slot ;

- a second channel at the level of and parallel to the second slot, the first channel extending through the first sheet ( 10a) and into the filler as far as or close to, but not through the second sheet ( 10b) to define a flap attached to the central portion (12) of the panel (10) by the second flexible sheet ( 10b), the second slot is located between 50 to 500 mm from the first slot.

49. A panel of plasterboard of claim 48, wherein the slots have a triangular shape in transversal section,

50. A panel of plasterboard of claim 48, wherein the slots have a half-circular shape in transversal section.

51. A panel of plasterboard comprising filler material sandwiched between two opposed flexible sheets, wherein a first channel located close to a first edge of the panel of plasterboard, the first channel extending through one flexible sheet and into the filler as far as or close to, but not through the second opposite flexible sheet to define a flap attached to the central portion ( 12) of the panel (10) by the second flexible sheet.

52. A panel of plasterboard as claimed in claim 51 wherein a second channel extends through the one flexible sheet and into the filler as far as or close to, but not through the second opposite flexible sheet which second channel is located between 50 to 500 mm from the first channel.