GB2463331A - Wet area floor former system - Google Patents

Abstract

The invention relates to floor formers used in 'wet areas', such as showers. A kit of parts (610, 710, 910) for a modular wet area floor former system comprises a plank (910) for enclosing a drain. At least one of the first and second edges of the plank is of a first height (H1). The kit of parts includes at least two floor former modules 610, 710). Each floor former module tapers from an outer (when assembled) end ( 630, 730) of a second height (H2) to an inner (when assembled) end (620, 720) of the first height (H1). Not all of the floor former modules are of the same length (X1, X2). Preferably, all the floor former modules of the kit of parts have different lengths (X1, X2, X3). Each floor former module may have a region at the outer end which is untapered and which allows the module to be shortened. The plank may have a lowered centre line. Also provided is a method of installing a modular wet area floor former system in an aperture in a floor.

Description

Wet Area Floor Former System

Field of the Invention

The invention relates to floor formers used in wet areas'. Such wet areas include showers in homes, hotels, sports centres and hospitals.

Background of the Invention

Wet areas are designed to provide drainage for water. A wet area typically has water from a shower falling on to it, and there is therefore a need to convey the water to the drainage system of the building.

The floor of a wet area is shaped, using appropriate slopes, to encourage water to drain away. The water flows downhill, along the slope.

Wet area floors differ from shower trays in several ways: (i) Shower trays tend to consist of a single molding, without any further components assembled on their upper surface. The upper surface of the tray is the surface on which the user of the shower stands. The upper surface is therefore also the surface onto which water from the shower falls, and the surface along which the water flows to the drain. In contrast to shower trays, wet area floors usually have a tiled upper surface.

(ii) Shower trays are usually mounted on top of the floor boards in a room, so do not offer level access for a user. A key design aim of many wet areas is to provide level access, with no height difference between the sloping portion of the wet area and surrounding regions of floor, which may also be tiled.

(iii) Wet areas may be of several square metres in extent, so tend to be larger than shower trays. Partly because of their larger area, wet areas often have one or more open sides. These sides facilitate access by a user, and one or more sides may remain open during use of a shower. In contrast, shower trays are almost always used with an enclosure, such as a curtain or shower screen, around all sides of the shower area.

The floor of a wet area is typically constructed in several layers. A floor former' is used to set the slope of the wet area. The floor former may also be termed a deck' The floor former may either sit: (i) Directly on the joists of the building; or (ii) On a flat surface, typically of hardboard, which is attached on top of the floor boards. The flat surface serves to support the floor former across a wider area than would be the case with a floor former mounted directly on the joists.

In either case, the floor former therefore sits in an area of a room that does not have floor boards. The floor boards normally have to be cut away to make an aperture into which the floor former is then placed. However, floor boards may not always need to be cut away, for example if the floor former is installed during construction of a new building.

A drain is mounted somewhere within the perimeter of the floor former. The drain provides a connection for water to flow into the drainage system of the building, and is the point at which used' water flows away from the wet area.

The floor former has a flat lower surface and a generally sloping upper surface. The sloping upper surface sets the gradient for the wet area.

Typically, a waterproof membrane is laid on top of the floor former. The waterproof membrane is flexible and usually less than 5mm thick. The upper surface of the membrane therefore has the same gradient as the upper surface of the floor former on which it lies. In place of a waterproof membrane, mortar may sometimes be used.

Tiling is commonly added on top of the waterproof membrane. The exact choice of tiling depends on a wide variety of factors, including aesthetics. Tiles are typically square. The length of one side of the square tile may be several centimetres, or possibly more than 10cm. Such tiles usually need to be cut to size, which is a skilled task. However, these tiles are relatively easy to clean. Much smaller tiles may be used, with a side of the order of 1cm. Such tiles can be installed without cutting, as a mosaic. However, these tiles have more grouting between them than is the case with larger tiles, so are more difficult to keep clean.

Many shower trays have a four way' fall, which means that the upper surface of the shower tray slopes in four directions. The four sloping surfaces serve to convey water to a single drain. The drain is located at the lowest point of the floor former.

Some wet area floors are constructed with only a two way' fall, or even with a single sloping surface. A two way fall tends to have: (i) One slope running from a wall of the wet area to a drain; and (ii) The second slope running in the opposite direction to the first slope, down to the other side of the drain, with the highest end of the second slope forming the entry point to the wet area.

The drain may be elongated, and is sometimes referred to as a linear drain'.

Figure 1 shows a perspective view of a known design for a floor former 100, for a wet area floor. Floor former 100 is a single object, and provides a two-way fall. Floor former comprises: (i) A central flat portion 110.

(ii) Two sloping surfaces 120 and 130. Sloping surfaces and 130 slope towards central flat portion 110, providing the ftwo way' fall.

(iii) Two ends, 140 and 150. Surfaces 120 and 130 slope from the two ends 140 and 150 of floor former 100 towards central flat portion 110.

Central flat portion 110 has a rectangular opening, not shown in figure 1, for a linear drain.

Towards the lower left of figure 1, three orthogonal axes are indicated. The three directions x, y, and z are used consistently throughout the figures of this application.

The three directions are: (i) The x' direction. Throughout the drawings, a distance measured in the x' direction is referred to as a length'. In the example of figure 1, the length of the floor former is the distance between the ends 140 and 150 of floor former 100.

(ii) The y' direction. Throughout the drawings, a distance measured in the "y' direction is referred to as a width'. In the example of figure 1, the width of the floor former is the distance along either the end 140 or the end 150 of floor former 100.

(iii) The z' direction. Throughout the drawings, a distance measured in the z' direction is referred to as a height'. In the example of figure 1, the maximum height of the floor former is the vertical distance from the bottom to the top of either end 140 or end 150.

Figure 2 shows a plan view of floor former 200, which is the same floor former as shown in figure 1. In figure 2, surfaces 220 and 230 correspond to surfaces 120 and 130 of figure 1. Central flat portion 210 corresponds to central flat portion 110 of figure 1.

The rectangular opening in central flat portion 210 is shown as reference 260. Rectangular opening 260 houses a linear drain, which is not shown in figures 1 and 2, because it does not form part of the floor former.

Various designs of linear drain may be selected for insertion into rectangular opening 260, when floor former 100, 200 is built into the floor of a wet area.

When floor former 200 is installed as part of a wet area, a waterproof layer and tiles are placed on the sloping surfaces 240 and 250. The tiling on these surfaces therefore has a similar gradient to that of sloping surfaces 240 and 250. This gradient serves to allow water to flow to the linear drain located in central flat portion 210.

When considering the installation of floor former 200 into buildings, there are several important issues.

Firstly, many of the applications of floor formers are to existing buildings, to which wet areas are to be retrofitted many years after initial construction of the building. When retro-fitting floor former 200 to an existing building, there needs to be space for the drain and trap. The drain and trap may project 20-30cm below the floor former. It is highly undesirable to cut into the joists of a building, so the drain and trap need to be located away from the joists. This enables the drain and trap to extend downwards, either between two joists or between a wall and a joist. Linear opening 210 therefore also needs to be located away from the joists, and should not lie directly over a joist.

Other design considerations are the desirability of locating the drain and trap: (i) immediately below the shower head; and (ii) as close as possible to any existing'drain pipe in the building, e.g. a draih pipe running down a nearby wall. This minimizes the length of connecting pipe required to connect to the existing drain pipe. It also maximizes the gradient of the connecting pipe, which aids the flow of water away from the drain and trap.

When retrofitting a wet area to an existing building, a major technical problem lies in the fact that the location of the joists in the building is normally not known until installation of the wet area commences. This can have several consequences.

If floor former 200 is to be installed, then, when the floor boards have been cut away, it may prove to be the case that the location of linear opening 210 would coincide with a joist. One solution often applied in practice is then to cut away part of one or both ends 240, 250 of floor former 200.

Cutting floor former 200 may not be possible, depending on the material from which it is constructed. Cutting floor former 200 is also less likely to provide a true', i.e. rectilinear outer edge than was the case with the floor former as manufactured.

However, there are two further significant problems with cutting floor former 200. Firstly, the ends 240, 250 of floor former 200 may be constructed to be of the same height as the floor boards that lie immediately against the outer edge of floor former 200. It may in practice prove necessary to cut up to 20 cm from one end of floor former 200, in order that the linear drain in central flat portion 210 be located between two joists, rather than over a joist. In this case, the new' outer edge of floor former 200 created by this cutting will be substantially lower in height than the surrounding floor boards, because of the slope of surface 220 or 230. When the floor former is installed, there will then be a difference in height between the top of the tiles installed on top of floor former 200, and the top of the tiles installed on the surrounding floor boards. Such a step is highly undesirable, since it fails to achieve the design aim of level access. It is then also more difficult to ensure that water does not leak down between the tiles at the join between the edge of floor former and the surrounding floor boards.

The second significant problem concerns the fact that floor former 200, after having been cut down, will be too short for the aperture cut into the floor boards. The portion of the wet area from which water will drain will therefore be smaller than originally planned, which is a major draw back.

One solution to the above problems with floor former 200 is to manufacture a range of floor formers 200, each of different length. Once the floor boards have been cut away, a floor former can be selected that is at least one size longer than the aperture cut into the floor. One or both ends of the floor former are then cut down, in order to try to locate the linear drain in central flat portion 210 away from the floor joists. However, in some circumstances, all the material will still need to be cut away from one end of floor former 200. So this solution is still likely to result in a height difference between the cut new' edge of the floor former and the surrounding floor boards. However, this solution may allow the entire aperture to be filled, or allow more of the aperture to be filled than would have been the case with a floor former whose uncut length exactly matched the aperture's length.

Other known design details of floor farmers of the type shown in figure 1 are: (1) Ends 240, 250 may have a flat portion, where the bottom and top surfaces of the former are parallel. The former does not then have any slope at all over this portion. This flat portion helps to minimize or eliminate the step that is introduced into the wet area, if part of one or both ends of the floor former has to be cut away during installation. However, when the floor former is installed with some or all of the flat portions intact, these portions do not have a gradient to help water drainage. There is therefore a greater tendency for water to accumulate on these portions in use, and then for staining to occur. Effectively, the area with adequate drainage is still reduced in comparison to a floor former of the same length without flat end portions.

(ii) The two regions of central flat portion 210 at either end of the rectangular opening 260 are both lower in height and narrower in width than any other part of the floor former. These regions are labeled as 270 and 280 respectively in figure 2. Regions 270 and 280 are structurally weaker than the remainder of the floor former. One known solution to this problem is to install reinforcing rods inside the floor former, running through regions 270 and 280. This makes the floor former more robust during transport, and less likely to fracture during installation or in use of the wet area. The disadvantage of these rods is the additional complexity of the manufacturing process, and the additional weight for shipping and handling floor former 200.

Australian granted patent specification AU-B-785461 shows one proposed system for shower areas that are to have a defined drainage point', corresponding to the drain hole typically used in shower trays. AU 461 provides support members for the construction of a shower floor. Each support member has a point at the inner end, which is the end adjacent to the defined drainage point. The components of AU 461 can be put together to create a four way fall for a drain hole. Such an arrangement therefore addresses the problems of prior art shower trays such as that shown in figure 1, discussed above.

The support members may be either rectangular or triangular in shape at their inner ends, when seen in plan view.

Another prior art system is marketed by the company Newline Bathroornware Ltd' of New Zealand as a modular solution to providing the slope of a wet area. See: http://www.newline.co.nz/profinish wedge.pdf The modules are a range of three floor formers, each with a 1:60 surface slope. Each module is 1 metre long and 1 metre wide. The modules are designed both for small indoor spaces, such as bathrooms, and for larger outdoor spaces such as balconies.

There are three types of module: (i) A wedge' starting with a 5mm height at the inner end, rising to 21mm at the outer end; (ii) A wedge' starting with a 21mm height at the inner end, rising to 37mm at the outer end; and (iii) A wedge' starting with a 37mm height at the inner end, rising to 53mm at the outer end.

Figure 3 shows an elevation view of these prior art modules. Reference 310 shows the type (i) module.

Reference 320 shows the type (ii) module. Reference 330 shows the type (iii) module. The parameter Xp shows the length of each module, and the three modules are of identical length. This is 1 metre in the system marketed by Newline.

Figure 4 shows a perspective view of module 420. Module 420 corresponds to module 320 of figure 3.

In order to create a large floor with a constant 1:60 slope, two or three of the modules shown in figure 3 can be placed together. In such an arrangement, the outer end of a module 310 abuts the inner end of a module 320. The outer end of the module 320 abuts the inner end of a module 330.

Figure 5 shows an elevation view of this arrangement, in order to explain how the modules might be used to make a floor. Module 510 corresponds to module 310 in figure 3.

Module 520 corresponds to module 320 in figure 3. Modules 510 and 520 have been placed immediately against each other. Together, they provide a 2 metre long floor former, with a constant 1:60 sloping upper surface.

Module 530 shown in figure 5 corresponds to the left portion of module 330 in figure 3. In order to create module 530, module 330 has been cut in half, and the inner portion 530 retained. The length of module 530 is shown as Xp/2', i.e. half that of modules 510 and 520.

Module 530 abuts the outer end of module 520. Modules 510, 520 and 530 together provide a 2.5 metre long floor former.

The 2.5 metre long floor former of figure 5 may be used in an outdoor area, such as a balcony. Alternatively, it may be used in a relatively large wet area floor within a building.

A linear drain is also shown in the document on Newline's website. The modules are used with the drain, which is U-shaped in cross-section. The drain can be located against the inner end of module 310. The inner end of module 310 abuts one side of the drain, which corresponds to one upright arm of the U-shaped drain, when viewed in cross-section. Modules of the type shown as 310 may be placed on either side of the drain. Modules 320 and 330 may also be arranged outside of modules 310.

Thus it is possible to create a two way fall, with a wet area of just over six meters in length. Such a system would require three modules 310, 320 and 330 arranged on one side of the drain, and three similar modules on the other side of the drain. The slope would be a constant 1:60, starting at the outer ends. The height of the inner end of each slope would be 5mm, and the height of the outer end would be 53mm.

In order to provide the correct width of floor, several modules may be laid side by side. So a 5 metre wide floor could be created, by laying five modules side-by-side.

Statement of Invention

A first aspect of the present invention comprises a kit of parts for a modular wet area floor former system in accordance with claim 1.

A second aspect of the present invention comprises a method of installing a modular wet area floor former system in accordance with claim 10.

The appended dependent claims provide further preferred features of the invention.

Brief Description of the Drawings

Figure 1 shows a perspective view of a prior art floor former.

Figure 2 shows a plan view of the floor former of figure 1.

Figure 3 shows a side elevation view of a set of floor

former modules of the prior art.

Figure 4 shows a perspective view of one of the modules of figure 3.

Figure 5 shows a side elevation view of the set of floor former modules of figure 3 in use.

Figures 6-8 show perspective views of floor former modules in accordance with the invention.

Figure 9 shows a perspective view of a plank in accordance with the invention.

Figure 10 shows a plan view of the plank of figure 9.

Figure 11 shows a side elevation view of floor former modules in accordance with an embodiment of the invention.

Figure 12 shows a side elevation view of a floor former module and a plank, arranged in an aperture in a floor.

Figure 13 shows a side elevation view of two floor former modules and a plank, arranged in an aperture in a floor.

Description of Preferred mbodiments

Figures 6-8 show perspective views of floor former modules in accordance with the invention. Each of the floor former modules has a flat lower surface, and an upper surface that tapers in height from an outer end to an inner end.

Figure 6 shows a perspective view of floor module 610.

The inner end 620 of floor former module 610 is of height Hi. The outer end 630 of floor former module 610 is of height H2. The length of floor former module 610 is Xi, measured between the inner end 620 and the outer end 630.

Figure 7 shows a perspective view of floor module 710.

The inner end 720 of floor former module 710 is of height Hi. The outer end 730 of floor former module 710 is of height H2. The length of floor former module 710 is X2, measured between the inner end 720 and the outer end 730.

Figure 8 shows a perspective view of floor module 810.

The inner end 820 of floor former module 810 is of height Hi. The outer end 830 of floor former module 810 is of height H2. The length of floor former module 810 is X3, measured between the inner end 820 and the outer end 830.

Figure 9 shows a perspective view of plank 910 for enclosing a drain. The drain is not show on figure 9.

When a wet area floor is constructed, the drain is fitted into aperture 920 of plank 910.

Plank 910 has a first edge 930 and a second edge 940.

Each of edges 930 and 940 is of height Hi.

However, in alternative embodiments of plank 910 in accordance with the invention, only first edge 930 may be of height Hi. In that case, second edge 940 would be of a different height, which is preferably greater than height Hi.

Centre line 950 of plank 910 is shown as a dotted line on figure 9. Centre line 950 may be of a third height H3.

Third height H3 is less than first height 1-Il. This arrangement encourages water to drain from first edge 930 and second edge 940 towards centre line 950, and thus into the drain located in aperture 920.

In alternative embodiments of plank 910 where the height of second edge 940 is not equal to height Hi, then the height of second edge 940 must be at least equal to height H3. This feature discourages the formation of significant quantities of standing water along second edge 940.

In one practical embodiment of the plank of figure 9, height Hi may be 12mm and height H3 may be 10mm. These are exemplary dimensions only, and the invention is not limited to these dimensions.

Figure 10 shows a plan view of plank 1010, which corresponds to plank 910 of figure 9. Plank 1010 has an aperture 1020, which corresponds to aperture 920 in figure 9.

Figure 10 shows that aperture 1020 may be surrounded by a border region 1030. Border region 1030 may be a flat portion of the upper surface of plank 1010. Such a flat region may serve as a suitable seat for the outer edges of a linear drain, to be inserted into aperture 1020.

Various designs of linear drain may be used in plank 1030.

The width of plank 1010 is shown as width W' on figure 10. Width W is the extent of plank 10 in the y direction.

Although planks 910 and 1010 are shown as being symmetrical about their centre lines, this may not be the case. In alternative embodiments of the invention where the height of second edge 940 differs from the height of first edge 930, then the distance between second edge 940 and the centre line 950 of the plank may be set in order to achieve a suitable gradient to accommodate the likely levels of water flow at this portion of the plank.

Floor formers 610, 620 and 630, together with plank 910, comprise a kit of parts for a modular wet area floor former system. Plank 910 is suitable enclosing a drain, and first edge 930 of plank 910 is of first height Hi.

Figures 6-10 therefore illustrate one exemplary embodiment of the invention. A kit of parts in accordance with the invention comprises at least two floor former modules 610, 620, each of the at least two floor former modules: (i) having a flat lower surface; (ii) tapering in height from an outer end to an inner end; (iii) having an inner end of the first height Hi; (iv) having an outer end of a second height H2, the second height H2 being the same for each floor former module and being greater than first height Hi.

The length Xl, X2 between the inner end and the outer end of the floor former modules is not the same for all the floor former modules.

Figure ii shows a side elevation view of floor former modules 1110, 1120 and 1130, to enable an easy comparison of their relative dimensions. Floor former modules 1110, 1120 and 1130 correspond respectively to floor former modules 610, 710 and 810 of figures 6-8. In Figure 11, the outer end of each floor former module is towards the right of the page.

Figure 11 demonstrates that all the floor former modules 1110, 1120 and 1130 have the same height Hi at their inner ends. In addition, all the floor former modules 1110, 1120 and 1130 have the same height H2 at the outer ends. However, each of the floor former modules 1110, 1120 and 1130 has a different length. Floor former module 1110 is of length Xl, floor former module 1120 is of length X2, and floor former module 1130 is of length X3.

Although three floor former modules 610, 710, 810 have been shown, it would be likely that a kit of parts in accordance with the invention would comprise between 2 and 8 different lengths of module. The lengths of these modules might increase, for example, in increments of 50mm or 100mm.

In one example, the shortest of eight modules might be of 300 mm length. The longest would be 1000 mm. Each successively longer module in the kit of parts would be 100mm longer than the next longest.

Height H2 may be the same as the height of a standard floor board. In the United Kingdom, this would be 22mm.

Height Hi might be 12mm, as mentioned earlier in connection with figure 9.

In some applications, a flat supporting surface may be arranged in the aperture in the floor, directly on top of the floor boards. The flat supporting surface may, for example, comprise hardboard. The plank and/or floor former module(s) of the invention would then be assembled on top of the hardboard. The plank may be screwed to the hardboard or the joists, in order to secure it.

When hardboard lies under the floor former system, H2 may be less than 22mm. Consider the example of a 4mm layer of hardboard provided in the aperture in the floor. In this case, H2 may be set at 18mm. The top of the outer end of the floor former(s), when mounted on the 4mm layer of hardboard, would then correspond to the 22mm height of standard UK floorboards.

Each floor former may be rectangular or square in plan view, with the widths of inner and outer edges in the y direction being the same. The width of the plank has been marked as W' on figure 9. In addition, all the floor former modules of the kit of parts might advantageously have the same width. For example, width W might be 1000mm, and the inner and outer ends of all the modules in the kit of parts would then also have a width of 1000mm.

In order to accommodate a wet area with a design width of e.g. 1800 mm, two floor former modules of the same length may be selected. Both could then have their width reduced, i.e. be shortened in the y direction. This width reduction would be such as to make their total combined width 1800mm, after shortening. Alternatively, one of the two floor formers could be shortened to a width of 800mm, and the other left with its original width of 1000mm.

Each floor former module may be made of a material that is suitable for cutting, and the shortening may then be achieved by cutting.

The width chosen for the floor formers of the kit of parts may depend on their eventual use. Larger buildings, for example sports centers and hospitals, may offer sufficient space for wet areas that are both longer and wider than those in typical homes. A kit of parts for such a larger building might therefore have: (1) Wider floor formers than in a kit of parts for domestic use; and (ii) A range of lengths of floor former module that starts and finishes at larger sizes than in a kit of parts for domestic use.

Each floor former module may be adapted to allow a reduction in the length in the x direction by removal of material from the outer end. Each floor former module may therefore be made of a material that is suitable for cutting. In addition, the outer end of at least one floor former module of the kit of parts may have a portion with an upper surface that is parallel to the lower flat surface, whereby this portion of the floor former module does not taper in height.

In addition to the kit of parts described above, the invention also comprises a method of installing a modular wet area floor former system in an aperture in a floor.

Either one or two of floor former modules 610, 710, 810 may be selected to construct a wet area floor in an area of floor without floor boards.

The method comprises selecting the plank from the kit of parts and installing the plank in the aperture. Then a first floor former module is selected from the kit of parts. The first floor former module is then installed in the aperture in the floor, so that the inner end 620, 720 or 820 of the first floor former module 610, 710 or 810 abuts the first edge 930 of the plank.

Figure 12 shows a side elevation view of an example of the construction of a wet area floor former system, resulting from the method of the invention.

Floor former module 1220 of figure 12 corresponds to floor former module 1120 shown in figure 11, and is of length X2. In this figure: (j) The inner end of floor former module 1120 would abut first edge of plank 1230; (ii) The outer end of floor former 1220 would abut one or more floor boards, which are not shown in figure 12; and (iii) The second edge of plank 1230 would abut a wall of the wet area, which is not shown in figure 12.

The method of the invention may further comprise selecting a second floor former module 610, 710, 810 from the kit. This second floor former module is then installed in the aperture in the floor, whereby an inner end 620, 720, 820 of the second floor former module abuts the second edge 940 of the plank. In this case, the second edge of the plank 940 also needs to be of first height Hi. The outer end 630, 730, 830 of the first floor former module may then abut one or more floor boards at a first end of the aperture. The outer end 630, 730, 830 of the second floor former module may abut a wall at a second end of the aperture.

Figure 13 shows a side elevation view of an example of the construction of a wet area floor, which uses two floor former modules. First floor former module 1330 of figure 13 corresponds to floor former module 1130 shown in figure ii, and is of length X3. Second floor former module 1320 of figure 13 corresponds to floor former module 1120 shown in figure 11, and is of length X2.

In figure 13: (j) The inner end of first floor former module 1330 abuts the first edge of plank 1350; and (ii) The outer end of first floor former module 1330 abuts one or more floor boards, which are not shown in figure 13.

(iii) The inner end of second floor former module 1320 abuts the second edge of plank 1350; (iv) The outer end of second floor former module 1320 abuts a wall of the wet area, which is not shown in figure 13.

The method of the invention may comprise reducing a length of the first and/or second floor former modules.

This reduction ensures that, together, the plank and the floor former module(s) fill the aperture in the floor.

The reduction in length may comprise removing material from the outer end of the first floor former module and/or the outer end of the second floor former module.

This removal may comprise cutting the first and/or second floor former modules and discarding the outer end(s) Prior to installing the plank and/or the first floor former module, a flat supporting surface such as hardboard may be arranged in the aperture in the floor.

When the plank and floor former(s) of the invention have been installed in an aperture in a floor, a waterproof membrane may be laid on top of the floor former(s). The waterproof membrane is flexible. The upper surface of the membrane has the same gradient as the upper surface of the floor former on which it lies. Tiling may then be added on top of the waterproof membrane.

The arrangement of figures 1 and 2 is considered to be

the closest prior art to the invention.

One of the disadvantageous features of floor former modules 100, 200 of figures 1 and 2 relates to the fitting of these modules into some sizes of floor aperture. In some circumstances, all the material to be removed from the floor former module 100, 200 would need to be cut away from just one end of floor former 100, 200. Such cutting may result in a height difference between the cut new' edge of the floor former and the surrounding floor boards, which may amount to several millimeters.

Importantly, with the invention, a variety of floor former modules, of different lengths, are available to construct a wet area floor. One advantage of the invention is that it is easy to manufacture and transport a varied selection of modules 610, 710, 810 of differing lengths. For example, the set of modules in the kit of parts might span the whole range of lengths from 300mm to 1000mm. There may possibly be only 50 mm difference in length between successively larger floor former modules, and the differences could easily be smaller. In many applications of floor former modules such as 610, 710, 810, appropriate selection of the modules from the kit of parts will ensure that no reduction of the length of the modules will be required when constructing a wet area floor, no matter where plank 910 must be placed in the aperture in the floor.

In some cases, a reduction in the length of module may still be required, because of the necessary location of plank 910 in the aperture. However, with modules 610, 710 and 810 of the invention, it is more likely that the reduction can be achieved by reducing the length of two floor former modules by a smaller amount than would be the case with a single module 100, 200. As a result, any height difference between the cut new' outer edges of the floor former modules 610, 710, 810 and the surrounding floor boards will be less than that normally achievable with floor former 100, 200 in the same aperture. Thus the invention may help achieve the aim of level access for users of the wet area floor.

One result of the invention may therefore be that a greater proportion of wet areas can be constructed with no height difference between the outer end of the floor former module used and the floor that surrounds the wet area.

A further disadvantageous feature of the prior art

concerned the regions 270 and 280 being structurally weaker than the remainder of floor former 100, 200, see figure 2. Floor former modules 610, 710, 810 of the invention do not have a portion corresponding to regions 270 and 280 of figure 2. In addition, plank 910 is not joined directly to the inner edges of floor former modules 610, 710, 810. The invention may therefore provide a lower risk of breakage in transit than was the

case with the prior art. Due to the absence of the

reinforcing rods sometimes used in prior art module 200, the arrangement of the invention may provide lower manufacturing and transport costs. The overall length of the longest dimension of the kit of parts of the invention may also be less than that for floor former module 200.

Neither the arrangement of Australian granted patent specification AU-B-785461 nor that shown at the Newline' website discussed in the prior art section are considered to form part of the common general knowledge for the person skilled in the art. Australian granted patent AU- 3-785461 was found during an on-line search, in the knowledge of the present invention. The arrangement shown at the Newline' website was found after a further search, based on the inventor details of the Australian granted patent AU-B-78546l. The present invention is novel over the arrangement shown at the Newline' website, at least through the various floor former modules of the kit of parts of the invention having the same heights Hi and H2 for their inner and outer ends. A comparison of figures 3 and ii shows this difference clearly. A second novel feature is that, in the kit of parts of the invention, not all the floor former modules are of the same length.

As can be seen from figure 3, the arrangement shown in the Newline' website shows various formers with: (i) The same length; (ii) Different heights at their inner ends; and (iii) Different heights at their outer ends.

The arrangement shown in the Newline' website permits the modules to be fitted together contiguously, and to provide one slope of constant gradient along all the modules when so arranged.