GB2484934A

GB2484934A - An electrical box for a frame construction wall

Info

Publication number: GB2484934A
Application number: GB1018054.5A
Authority: GB
Inventors: Robert Liam Holroyd; Anthony Robert Morrison
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-10-26
Filing date: 2010-10-26
Publication date: 2012-05-02
Anticipated expiration: 2030-10-26
Also published as: GB2484934B; GB201018054D0

Abstract

An electrical box for a cavity wall with vertical wooden joists 3a, 3b is shaped to act as its own horizontal joist. The joist shaped electrical box connection has two flanges 5a, 5b to be fixed against the two vertical joists, and then sandwiched in place by plasterboard. This helps the user to quickly, easily, accurately and reliably position the electrical box both horizontally, and also at the correct height from the floor. The design can also ensure that the electrical box is flush with the plasterboard. Optional features to make the task yet easier include studs (10, Fig 3) to mark the location that the plasterboard should be cut, pins on the flanges to engage the vertical joists, and an integrated spirit level (11, Fig 3) to ensure the joist shaped electrical box is level. Because the electrical box spans between two vertical joists with a standard separation, it can have multiple socket compartments which ensures that their fascias will be perfectly spaced.

Description

An Electrical Box for a Frame Construction Wall The present invention relates to an electrical box for being assembled into a wall of vertical joists.

Electrical boxes are provided within wood frame walls to safely house electrical connections, such as plug sockets and light switches, and are also used for telecommunications and media cable sockets.

An electrical box is fixed within the cavity of a wood frame wall, and a wall board such as plasterboard is placed over it, with a hole that aligns with an open face of the electrical box. A cover plate (known as a fascia) that is larger than the hole is placed over the hole in the wall board, and screws extending from the fascia are aligned with respective threaded holes in the electrical box so that by fastening the screws, the fascia clamps to the electrical box, also sandwiching the periphery of the hole in the wall board to the electrical box.

Generally electricians are expected to arrange rectangular fascias so as to align with the floor, and where multiple fascias are required they should be horizontally aligned.

Known electrical boxes are typically metal boxes fixed in front of a horizontal joist that spans two vertical joists. These are oriented horizontally by virtue of accurate positioning of the horizontal joist which is achieved by the electrician who must typically saw, position and fasten the horizontal joist manually.

Once the electrical box is in place, typically the electrician must then measure its position vertically and horizontally (e.g. with respect to an adjacent vertical joist and with respect to the floor) to draw an outline of the box on a layer of wall board (typically plasterboard) before cutting out that area of the wall board and assembling the wall board in place in front of the electrical box. After typically skimming the wall board with plaster, the final step is to screw a cover plate to the electrical box so as to sandwich a portion of wall board around the cut out region.

This well known approach to installing electrical boxes while assembling a wall has several problems.

A first problem with this known approach is that it takes a user a long time to position the electrical box with suitable accuracy, and to align it such that a rectangular fascia thereof is aligned with the floor and/or is aligned with any neighbouring fascias.

A second problem is that it is common for the electrical box to be arranged either too far forward (out of the wall) which causes the wall board bow outward, or too far back (within the wall frame cavity) such that the act of assembling the cover plate and tightening its screws causes the wall to bow inward.

A third problem is that it takes time to measure the position of the electrical box, to identify the area of the wall board to cut out, and to cut it away from the wall board accurately and additionally it is easy for the user to make a mistake which causes a costly waste of a section of wall board or requires time consuming workmanship to correct for the mistake.

It is an object of the present invention to at least mitigate at least one of the above problems.

According to one aspect of the present invention there is provided an electrical box for a frame construction wall comprising: An elongate joist for spanning horizontally between two vertical joists of a frame construction wall, At least one electrical connections compartment provided in or on the elongate joist, A pair of planar fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, characterised in that; the planar fixing elements extend outboard of and parallel to the respective ends of the elongate joist, and are adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each planar fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and respective planar fixing elements, thereby sandwiching the planar fixing elements between the wall board and their respective vertical joists.

Such an arrangement can assist a user in quickly orienting and fixing an electrical box horizontally between two vertical joists at a desired height.

Advantageously the electrical box is joist-shaped.

According to one embodiment of the present invention the at least one electrical connections compartment has an open face arranged substantially flush with both of the planar fixing elements, such that in use when the wall board is positioned to sandwich the planar fixing elements against respective vertical joists, the wall board is then flush with the open face of the at least one electrical connections compartment.

This helps the user avoid misaligning the electrical box too far within, or extending out in a way that causes a wall board placed over it to bow outward, or bow inward once a cover plate has been screwed onto the electrical box to sandwich the wall board.

The electrical connections compartment may further be provided with marking means adapted such that in use a user can mark the position of the at least one electrical connections compartment on a section of wall board by placing and/or pressing the section of wall board flush thereto.

This helps the user reliably and quickly establish the location and shape of wall board to cut out.

In one embodiment the marking means may be a pen, such as a broad permanent marking felt pen. This can allow a user to mark the open face of an electrical connections compartment so that a section of wall board is marked by contact therewith, such that the user can see the shape that needs to be cut away.

Preferably however, the marking means comprises at least one protrusion substantially orthogonal to the planar fixing elements adapted to indent an indentable wall board.

This can offer the same benefit as a pen but does not require as many steps to be performed by the user, and so promotes faster assembly of a wall.

Preferably the at least one protrusion is provided in a distributed fashion around an open face or group of neighbouring open faces of the at least one electrical connections compartment. This might be a continuous ridge, but could be two preferably three or suitably four local protrusions which could be arranged at corners of an open face of an electrical connections compartment. Alternatively there could be a line of local protrusions demarcating an open face of an electrical connections compartment.

Advantageously the at least one electrical connections compartment and the pair of planar fixing elements are provided as a single integrally moulded plastic part. This reduces the cost of the electrical box, but surprisingly it does not problematically reduce the strength of the planar fixing elements, because the inventors have realised that once the cover plate has been fixed in place the planar fixing elements are not placed under great strain.

Optionally the at least one electrical connections compartment includes at least three electrical connections compartments arranged in a row along the elongate joist1 the row of compartments being separated by respective walls.

Preferably the joist is provided as a box section beam, the box section beam having at least one cut out and corresponding cavity jointly forming a electrical connections compartment, and the box section beam extends substantially all the way between the two planar fixing elements so as to form a substantially rigid joist.

This structure can be used to provide strength to the joist so that it holds position firmly during assembly of a section of wall.

Advantageously the electrical box comprises a spirit level. Here, spirit level is not limited to any specific liquid. The spirit level may be overmoulded within the material of the electrical box, but could more advantageously be provided in a snap fit holder, such as between resilient plastic jaws. Optionally the spirit level may be provided separately for the user to assemble onto the electrical box.

Optionally there may be a cover plate corresponding to an electrical connections compartment, the plate and compartment having a screw and a respective plastic aperture sized such that on assembly the screw at least partially self taps into the plastic aperture, and such that in use the screw is prevented from being unfastened by vibration. Optionally the plastic aperture is provided with a metal captive nut and arranged such that on assembly the screw is assembled first through the nut and then through the plastic aperture. This offers a reliable connection, while mitigating the problem that screw and nut fastenings can come loose over a period of years.

Optionally also there may be provided a set of electrical boxes comprising two or more of the electrical boxes described above connected together with connection means, the connection means being adapted such that a user may break them apart by hand prior to use in assembling a section of a wall. Optionally the connection means is a strip of plastic which may be integrally moulded with the two or more electrical boxes.

Preferably the pair of planar fixing members are each provided with at least one pin-like protrusion perpendicular thereto, adapted to engage into a wooden vertical joist to support the electrical box in position during assembly of a wall board and/or one or more fascias. This makes assembly easier as it avoids the need for screws or nails to be inserted to fix the box in place. Optionally the pin like protrusion could be an integrally moulded metal component substantially in the form of a thumb tack.

Optionally the or each electrical connections compartment are provided on a back surface thereof with writing or indicia indicating the location of any neighbouring electrical connections compartments of the electrical box. This has the advantage that any subsequent user who removes a fascia will be able to find out what neighbouring electrical connections compartments there are to either side of the one he or she has opened. Such indicia could include an arrow with text.

The text could include phrases such as Single Socket Cavity" or "Double Socket Cavity".

According to a second aspect of the invention there is provided a method of assembling an electrical box within a frame construction wall having the steps of: 1) positioning an elongate joist to span horizontally between two vertical joists of the frame construction wall, 2) providing at least one electrical connections compartment in or on the elongate joist, 3) arranging a pair of planar fixing elements at respective opposed ends of the elongate joist, and fixing them to a face of rectangular cross section vertical joists of the frame construction wall, 4) marking and cutting out a cut-out region on a section of wall board, corresponding to an open face of at least one electrical connection compartment of the electrical box, 5) assembling the wall board against at least the pair of planar fixing elements so as to sandwich them between the wall board and their respective vertical joists, and 6) assembling at least one cover plate to one or more respective electrical connections compartments.

This method can assist a user in quickly orienting and fixing an electrical box horizontally between two vertical joists at a desired height.

Preferably the cut-out region in the wall board is smaller than a border wall of the open face of the corresponding at least one electrical connection compartment, and the step of assembling the at least one cover plate includes the step of sandwiching the wall board between a cover plate and a corresponding border wall.

This has the advantage that the electrical box is less reliant on the strength of the planar fixing members after assembly and so these can be provided thinner than would otherwise be necessary, with the benefit that any local bulge in the outer surface of the wall board in the vicinity of a planar fixing member is minimised and may be un-noticeable.

According to a third aspect of the invention there is provided an electrical box for a frame construction wall comprising: An elongate joist for spanning horizontally between two vertical joists of a frame construction wall, at least one electrical connections compartment provided in or on the elongate joist, and a pair of fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, the fixing elements being adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and flush with an open face of the at least one electrical connections compartment, characterised in that; the open face of the at least one electrical connections compartment is provided with marking means adapted such that in use a user can mark the position of the at least one electrical connections compartment on a section of wall board by placing and/or pressing the section of wall board flush thereto.

This has the advantage that a user can quickly and reliably identify a shape to cut out of a section of wall board through which to assemble a fascia to an electrical box.

According to a fourth aspect of the invention, there is provided an electrical box for a frame construction wall comprising: an elongate joist for spanning horizontally between two vertical joists of a frame construction wall, at least one electrical connections compartment provided in or on the elongate joist, and a pair of fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, the fixing elements being adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and flush with an open face of the at least one electrical connections compartment, characterised in that; the electrical box further comprising a spirit level.

This has the advantage that a user can quickly and reliably position and orient an electrical box at a desired height between two vertical joists such that a rectangular fascia thereof will be aligned with the floor.

A preferred embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Fig la is an illustration of an installation of an electrical box in a frame wall according to the known art as viewed from above.

Fig lb is a front view of the installation shown in fig Ia.

Fig I c is an isometric view of the installation shown in fig I a.

Fig 2a is an illustration of an installation of an electrical box in a frame wall according to an embodiment of the present invention as viewed from above.

Fig 2b is a front view of the installation shown in fig I a.

Fig 2c is an isometric view of the installation shown in fig la.

Fig 3 is a close up view of the electrical box shown in figure 2a illustrating marking means and spirit level.

Turning now to figure Ia, there is shown a top view of an electrical box according to the known art. The electrical box 1 is screwed to a wooden joist 2 which in turn is nailed to vertical joists 3a, 3b. The vertical joists form sections of a frame wall, and the horizontal joist positions the electrical box, as required by an electrician. The height, orientation and depth of the electrical box into the wall cavity, are all set by the position of nails 3i, 3ii, while the position of the electrical box I along the horizontal joist 2 is set by screws Ii, lii. A section of wall board 4, typically plasterboard, is placed against the two vertical joists 3a, 3b and in this case its outer surface 4a is flush with the open face 5 of the electrical box 1. A fascia 8 is provided with screws 8i, Bii extending from its rear surface, which pass into and assemble onto a connection feature (not shown) within the electrical box I. When assembled the rear face of the fascia should align with the front surface 4a of the plasterboard. If the electrical box is positioned too far forward, then the fascia is likely to stand proud of the plasterboard. If the electrical box is positioned too far back then there is a danger of pushing the plasterboard inward when tightening the screws or the screws too short to engage into the connection feature.

Figure lb shows a front view of the installation illustrated in figure Ia. Here it can be seen that any error in positioning the horizontal joist 2 whilst hammering in the nails 3i, 3ii will cause the base of the electrical box to misaligned with the floor. It is necessary for an electrician to hold the horizontal joist 2 carefully whilst hammering the nails 3i, 3ii in, which can be difficult.

Figure lc shows an isometric view of the installation shown in figure I, with a layer of plasterboard 4 being assembled. To identify where to cut holes in the plasterboard it is necessary to measure the height and horizontal position of the electrical box and then mark this on the plasterboard, which is difficult, time consuming and may cause mistakes.

Figure 2a shows a top view of an electrical box according to one embodiment of the present invention. As can be seen, the electrical box provides a joist structure bridging the vertical joists so that a separate wooden joist is not needed. The electrical box has a box beam structure with cut outs and dividing walls which presents a strong rigid joist. The dividing walls define multiple socket compartments 6a, 6b, 6c, in this case three compartments, one of which is a double sized compartment 6c suitable for two mains electricity sockets. In this example fascias could be assembled which jointly provide four mains sockets.

Alternatively the two smaller (single) compartments 6a, 6b could be provided with telecommunications or media sockets, e.g. telephone, network cable or TV cable.

The two single compartments and the double socket compartment take up most or all of the length of the joist 2 (which does not include the two flanges 5) because in this example the electrical compartments and the joist are a single structure I, 2.

The flanges 5a 5b are positioned at opposite ends of the joist 2 and extend parallel to the joist 2 but flush with the open faces of the socket compartments 6a, 6b, 6c.

It can be seen that no significant part of the electrical box I extends through the plasterboard 4, although screws do extend between socket compartments and respective fascias through a hole in the plasterboard 4.

In the assembled arrangement shown, flanges 5a, 5b are fixed to the front surfaces of the vertical joists by screws, and then sandwiched against the vertical joists 3a, 3b by the plasterboard 4.

Figure 2b shows a front view of the installation of figure 2a. Each socket compartment 6a, 6b, 6c has two screw receiving bores 7 in a respective boss. The bore includes a mouth section being a brass captive nut (not shown) and a deeper section which has a plastic bore having a diameter less than the thread of a respective screw of a fascia (not shown). Each compartment also has cable entry tabs 9i, ii,iii with weakened connections to the rest of the socket compartment 6.

This allows cables to be fed either between the compartments 6a, 6b, 6c or from one of those compartments into the wall cavity.

Figure 2c shows an isometric view of the installation of figure 2a. A section of plasterboard 4 is shown ready to be pushed back into position to be assembled to the wall, so as to sandwich the flanges 5a, 5b between the vertical joists 3a, 3b and the plasterboard 4. A cut out hole 13 made by a user in the plasterboard 4, which is aligned with the shape of the open faces of the socket compartments 6. In contrast to known designs, the cut out 8 is the same size as the open face of the matching socket compartment 6a, 6b, 6c. In the prior art the cut out will be large enough to permit the electrical box to extend through the plasterboard, and thus must be larger than the open face of the compartment 6a, 6b, 6c.

Figure 3 shows a detailed view of an electrical box according to a preferred embodiment. Each socket compartment has a border 9 which in this example is very narrow, in particular equal to the thickness of the wall of the socket compartment. In another embodiment the border could extend inward of the periphery of the socket compartment. In this embodiment the border is rectangular, and has a stud 10 at each corner. The studs extend far enough in the direction perpendicular to the open face of the compartment, such that they will leave a visible mark in a suitable wall board such as plasterboard when the plasterboard is pressed flush with the electrical box. Additional studs may be provided in a line so as to mark a dotted line on the wati board. The studs could be elongate, so as to form a dashed mark, or there could be a linear stud extending around the border so as to form a continuous mark. As an alternative a thick felt pen could be provided with the electrical box for a user to mark the border, and transfer the ink to the plasterboard, however this is less convenient than protrusions to form indentations.

The electrical box in this embodiment also has a spirit level 11 to enable a user to quickly and easily ensure the electrical box is horizontal before fixing the flanges 5 to the vertical joists 3. The spirit level is connected to the electrical box, in this case at the back of the base wall of a socket compartment. This position avoids damage to the spirit level but ensures it can be seen when positioning socket compartments at typical heights such as at or below adult eye level. The spirit level 11 is preferably connected by a snap fit or a pair of resilient plastic jaws 12. Alternatively it could be supplied separately, or could be overmoulded in a plastic moulded electrical box.

Like features are given like numerals in the diagrams.

Claims

Claims: 1. An electrical box for a frame construction wall comprising: An elongate joist for spanning horizontally between two vertical joists of a frame construction wall, At least one electrical connections compartment provided in or on the elongate joist, A pair of planar fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, characterised in that; the planar fixing elements extend outboard of and parallel to the respective ends of the elongate joist, and are adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each planar fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and respective planar fixing elements, thereby sandwiching the planar fixing elements between the wall board and their respective vertical joists.
2. An electrical box according to claim I wherein each of the at least one electrical connections compartment has an open face arranged substantially flush with both of the planar fixing elements, such that in use when the wall board is positioned to sandwich the planar fixing elements against respective vertical joists, the wall board is then flush with the open face of the at least one electrical connections compartment.
3. An electrical box according to claim 2 wherein an open face of the at least one electrical connections compartment is provided with marking means adapted such that in use a user can mark the position of the at least one electrical connections compartment on a section of wall board by placing and/or pressing the section of wall board flush thereto.
4. An electrical box according to claim 3 wherein the marking means is a pen.
5. An electrical box according to claim 3 wherein the marking means comprises at least one protrusion substantially orthogonal to the planar fixing elements adapted to indent an indentable wall board.
6. An electrical box according to claim 4 wherein the at least one protrusion is provided in a distributed fashion around an open face or group of neighbouring open faces of the at least one electrical connections compartment.
7. An electrical box according to any preceding claim wherein the elongate joist, the at least one electrical connections compartment and the pair of planar fixing elements are provided as a single integrally moulded plastic part.
8. An electrical box according to any one of the preceding claims wherein the at least one electrical connections compartment includes at least three electrical connections compartments arranged in a row along the elongate joist, the row of compartments being separated by respective walls.
9. An electrical box according to any one of the preceding claims wherein the joist is provided as a box section beam1 the box section beam having at least one cut out and corresponding cavity jointly forming an electrical connections compartment1 and the box section beam extends substantially all the way between the two planar fixing elements so as to form a substantially rigid joist.
10. An electrical box according to any one of the preceding claims further comprising a spirit level.
11. The electrical box according to claim 101 where the spirit level is provided connected to the electrical box.
12. An electrical box according to any one of the preceding claims, provided with a cover plate corresponding to an electrical connections compartment, the plate and compartment having a screw and a respective plastic aperture sized such that on assembly the screw at least partially self taps into the plastic aperture, and such that in use the screw is prevented from being unfastened by vibration in use.
13. An electrical box according to any one of the preceding claims1 where the pair of planar fixing members are each provided with at least one pin-like protrusion perpendicular thereto, adapted to engage into a wooden vertical joist to support the electrical box in position during assembly of a wood board and/or one or more fascias.
14. An electrical box according to any one of the preceding claims1 where the or each electrical connections compartment are provided on a back surface thereof with writing or indicia indicating the location of any neighbouring electrical connections compartments of the electrical box.
15. A set of electrical boxes comprising two or more of the electrical box of any one of the preceding claims, the electrical boxes being connected together with connection means, the connection means being adapted such that a user may break them apart by hand prior to use in assembling a section of a wall.
16. A method of assembling an electrical box within a frame construction wall having the steps of: 1) positioning an elongate joist to span horizontally between two vertical joists of the frame construction wall1 2) providing at least one electrical connections compartment in or on the elongate joist, 3) arranging a pair of planar fixing elements at respective opposed ends of the elongate joist, and fixing them to a face of rectangular cross section vertical joists of the frame construction wall, 4) marking and cuthng out a cut-out region on a section of wall board, corresponding to an open face of at least one electrical connection compartment of the electrical box, 5) assembling the wall board against at least the pair of planar fixing elements so as to sandwich them between the wall board and their respective vertical joists, and 6) assembling at least one cover plate to one or more respective electrical connections compartments.
17. The method of assembling an electrical box within a frame construction, according to claim 13, where the cut-out region in the wall board is the same size as a border wall of the open face of the corresponding at least one electrical connection compartment, and where the step of assembling the at least one cover plate include the step of sandwiching the wall board between a cover plate and a corresponding border wall.
18. An electrical box for a frame construction wall comprising: An elongate joist for spanning horizontally between two vertical joists of a frame construction wall, At least one electrical connections compartment provided in or on the elongate joist, and a pair of fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, the fixing elements being adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and flush with an open face of the at least one electrical connections compartment, characterised in that; the open face of the at least one electrical connections compartment is provided with marking means adapted such that in use a user can mark the position of the at least one electrical connections compartment on a section of wall board by placing and/or pressing the section of wall board flush thereto.
19. An electrical box for a frame construction wall comprising: An elongate joist for spanning horizontally between two vertical joists of a frame construction wall, At least one electrical connections compartment provided in or on the elongate joist, and A pair of fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, the fixing elements being adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and flush with an open face of the at least one electrical connections compartment, characterised in that; the electrical box further comprising a spirit level.
20. An electrical box for a wall as hereinbefore described with reference to figures 2a to 3.Amendments to the claims have been filed as follows Claims: 1. An electrical box for a frame construction wall comprising: An elongate joist for spanning horizontally between two vertical joists of a frame construction wall, At least one electrical connections compartment provided in or on the elongate joist, A pair of planar fixing elements arranged at respective opposed ends of the elongate joist, for fixing to rectangular cross section vertical joists of a frame construction wall, Wherein; The planar fixing elements extend in the longitudinal direction of the joist outboard of the respective ends of the elongate joist, and are adapted such that a user can fix the elongate joist horizontally between two vertical joists by fixing each planar fixing elements to a face of a respective vertical joist, so as to permit the user to assemble a wall board onto the two vertical joists and respective planar fixing elements, thereby sandwiching the planar fixing elements between the wall board and their respective vertical joists, Characterised in that; The at least one electrical connections compartment and the pair of planar fixing elements are provided as a single integrally moulded plastic part.2. An electrical box according to claim I wherein each of the at least one electrical connections compartment has an open face arranged substantially flush with both of the planar fixing elements, such that in use when the wall board is positioned to sandwich the planar fixing elements against respective vertical joists, the wall board is then flush with the open face of the at least one electrical connections compartment.3. An electrical box according to claim 2 wherein an open face of the at least one electrical connections compartment is provided with marking means adapted such that in use a user can mark the position of the at least one electrical connections compartment on a section of wall board by placing and/or pressing the section of wall board flush thereto.4. An electrical box according to claim 3 wherein the marking means is a pen.5. An electrical box according to claim 3 wherein the marking means comprises at * least one protrusion substantially orthogonal to the planar fixing elements adapted to indent an indentable wall board.6. An electrical box according to claim 4 wherein the at least one protrusion is * provided in a distributed fashion around an open face or group of neighbouring open faces of the at least one electrical connections compartment.7. An electrical box according to any one of the preceding claims wherein the at least one electrical connections compartment includes at least three electrical connections compartments arranged in a row along the elongate joist, the row of compartments being separated by respective walls.8. An electrical box according to any one of the preceding claims wherein the joist is provided as a box section beam, the box section beam having at least one cut out and corresponding cavity jointly forming an electrical connections compartment, and the box section beam extends substantially all the way between the two planar fixing elements so as to form a substantially rigid joist.9. An electrical box according to any one of the preceding claims further comprising a spirit level.10. The electrical box according to claim 9, where the spirit level is provided connected to the electrical box.11. An electrical box according to any one of the preceding claims, provided with a cover plate corresponding to an electrical connections compartment, the plate and compartment having a screw and a respective plastic aperture sized such that on assembly the screw at least partially self taps into the plastic aperture, and such that in use the screw is prevented from being unfastened by vibration in use.12. An electrical box according to any one of the preceding claims, where the pair of planar fixing members are each provided with at least one pin-like protrusion perpendicular thereto, adapted to engage into a wooden vertical joist to support the electrical box in position during assembly of a wood board and/or one or more fascias.13. An electrical box according to any one of the preceding claims, where the or each electrical connections compartment are provided on a back surface thereof with writing or indicia indicating the location of any neighbouring electrical connections compartments of the electrical box.14. A set of electrical boxes comprising two or more of the electrical box of any one of the preceding claims, the electrical boxes being connected together with connection means, the connection means being adapted such that a user may break them apart by hand prior to use in assembling a section of a wall.15. A method of assembling an electrical box within a frame construction wall S.....* 5 having the steps of: rE 1) positioning an elongate joist to span horizontally between two vertical joists of the frame construction wall, 2) providing at least one electrical connections compartment in or on the elongate joist, 3) arranging a pair of planar fixing elements at respective opposed ends of the elongate joist, extending in the longitudinal direction of the joist outboard of the :. : respective ends of the elongate joist, and fixing them to a face of rectangular cross * section vertical joists of the frame construction wall, 4) marking and culling out a cut-out region on a section of wall board, corresponding to an open face of at least one electrical connection compartment of the electrical box, 5) assembling the wall board against at least the pair of planar fixing elements so as to sandwich them between the wall board and their respective vertical joists, and 6) assembling at least one cover plate to one or more respective electrical connections compartmentsthe method being characterised in that; the at least one electrical connections compartment and the pair of planar fixing elements are provided as a single integrally moulded plastic part.16. An electrical box for a wall as hereinbefore described with reference to figures 2a to 3. * SS* .* St * S **** * S S...S*55545 * . S. SV S S * S.S s.S.b * S