AU2005242185B2

AU2005242185B2 - Shower base system

Info

Publication number: AU2005242185B2
Application number: AU2005242185A
Authority: AU
Inventors: Murray Gilbert Goodhue
Original assignee: Mdj Holdings Pty Ltd
Current assignee: Mdj Holdings Pty Ltd
Priority date: 2004-12-09
Filing date: 2005-12-09
Publication date: 2011-08-18
Anticipated expiration: 2025-12-09
Also published as: AU2005242185A1

Abstract

A shower base including a unitary moulding that has a plurality of sides. The shower base includes a floor on which a person stands while taking a shower, when the shower base is installed. It also includes a thin-walled upstand at at least one of said sides of 5 the base, which upstand is: (i) of a thickness sufficiently small for the upstand to be accommodated between wall studs and a wallboard attached directly to the studs at the respective side of the base without either rebating the studs or packing out the wallboard at the studs, and (ii) of a height great enough to prevent water rising by capillary action behind the wallboard and over the upstand. The shower base also 10 includes a channel in said moulding, immediately adjacent said upstand, to receive and seat a lowermost edge of said wallboard.

Description

Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Shower base system The following statement is a full description of this invention, including the best method of performing it known to us: 2 Shower base system Field of the invention This invention relates generally to shower bases and is concerned in particular with shower bases of unitary or integral form. Shower bases embraced by the invention 5 may serve as the floor surface of the shower cubicle or as a substrate on which the floor surface is provided by other means such as floor tiles. Background of the invention For a number of years, shower bases have been moulded as integral units in a variety of materials, typically fibreglass-reinforced, and most commonly by vacuum 10 forming a skin onto a polymer body. Despite their integral structure, water leakage associated with shower bases has remained a significant problem for the building industry, and a leading source of claims under building insurance policies. Leaks in shower bases arise from two principal sources, i.e. gradual long term cracking through the base, and seal breaches at the peripheral interface with adjacent 15 walls. The cracks tend to arise from temperature change stresses and load stresses, and are a source of water leaks even when the base is formed as a fibreglass reinforced tray for floor tiling. This is because tile grout is generally water pervious and water that seeps through the grout then passes through the cracks in the base. The leakage at the peripheral interface arises as a result of the traditional method 20 of installing the shower bases. Australian building design standards require that the cement sheet or other wallboard above the base extends down in front of a peripheral lip on the base: the overlap zone is then filled with a suitable sealant. This structure requires either packing of the studs to ease out the wallboard, or, more usually, checking out of rebates in all of the wall studs. Formation of the rebates is generally 25 done very roughly, in part because access to the location of the rebating is often uncomfortable or difficult, and the sealing is typically effected with silicone product which is pressed under the lower edge of the wallboard. Because of variability among 3 the rebates and in the silicone sealant, cracks and gaps readily occur, along which water can easily penetrate by capillary action. Quite apart from longer term leakage issues, conventional installation practice with shower bases is time consuming and labour-intensive, because of the need to 5 rebate each stud and fit the base into the rebates. An example of a known integral shower base is to be found in Australian patent application number 200222980, which includes a channel in an outer and upper rim portion that receives an upright wall member such as a wall panel, door, glass sheet or the like. As with shower base products generally, rebating of the wall studs would be 10 necessary to correctly position the base for receiving wallboard panels in the channel. Shower base systems in which there is an upstanding peripheral lip sandwiched between a frame and wallboard or between a wall and tiles are disclosed in US patent 5,371,980 and International Patent Publication WO01/50932. The shower base of WOO1/50932 is vacuum formed, which requires the upstanding lips to be separate 15 articles embedded in the base. References herein to any specific prior reference is not to be taken as an admission that the disclosures in the reference are or were common general knowledge. It is an object of the present invention to provide a shower base system, of a 20 structure that reduces the incidence of water leaks relative to known shower base systems, and reduces installation costs. Summary of the invention The invention provides, in a first aspect, a shower base comprising a unitary moulding that has a plurality of sides and includes: 25 a floor on which a person stands while taking a shower, when the shower base is installed; -4 a thin-walled upstand at at least one of said sides of the base, which upstand is: (i) Of a thickness sufficiently small for the upstand to be accommodated between wall studs and a wallboard attached s directly to the studs at the respective side of the base without either rebating the studs or packing out the wallboard at the studs, and (ii) Of a height great enough to prevent water rising by capillary action behind the wallboard and over the upstand; and 10 a channel in said moulding, immediately adjacent said upstand, to firmly accommodate and seat a lowermost edge of said wallboard. Preferably, said upstand has an outside upright face defining a lateral extremity of the base, for example by being flush with an outside face of said 15 base. Said channel may be formed in a peripheral ledge that extends about, preferably wholly about, the base and said floor. Said channel preferably also extends wholly about said base. Typically, said upstand is provided on one, two or three sides of the 20 shower base according to the intended location of the shower base. Most commonly, the shower base is generally rectangular in plan and designed to be fitted to a wall on one, two or three sides. Typically, said floor will include an opening to receive a drain outlet fitting, and the floor will preferably slope from its outer periphery to the vicinity 25 of this opening. In accordance with a particular preferred aspect of the invention, said floor has a floor surface that includes a plurality of relatively narrow radiating grooves to channel water to said drain outlet fitting. These grooves preferably open into said channel at their outer ends and are provided to 30 ensure that water that seeps through any overlying floor materials such as floor tiles is directed to the drain fitting.

5 Advantageously, at a side not having said upstand, there is a hob for underlying an access doorway to the shower space. The shower base is preferably an injection moulding in a composite polyurethane material. 5 In a second aspect, the invention provides a method of making a shower base according to the first aspect of the invention, comprising injection moulding the shower base in a composite polyurethane material. In a third aspect the invention provides a method of installing a shower base according to the first aspect of the invention, comprising: 10 placing the base onto a floor surface with said upstand substantially abutting a plurality of wall studs; and fastening a wallboard to said plurality of studs substantially without intervening packing so that a lowermost edge of the wallboard is seated in said channel. The method may further include applying a sealant composition along the 15 interface between said wallboard and said channel, and/or along the interface between said wallboard and said upstand. Brief description of the drawings The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: 20 Figure 1 is a three dimensional view of an embodiment of a shower base according to the invention intended for installation in a corner between two walls; Figure 2 is a plan view of the shower base of Figure 1; Figure 3 is an underneath view of the shower base of Figure 1; 6 Figure 4 is a fragmentary cross-sectional view of the shower base of Figure 1 when installed; Figure 5 is a view similar to Figure 1 of a modified embodiment of a shower base in which a wall or wall stud engaging upstand is provided at three sides of the base; 5 Figure 6 is a view similar to Figure 1 of a third embodiment having a hob formation on two of the sides of the base; and Figure 7 is a fourth embodiment combining the modifying features of the embodiments of Figure 5 and 6. Detailed description of the embodiments 10 The embodiment of shower base 10 depicted in Figures 1 to 4 is a unitary or integral injection moulding in a suitable composite polyurethane material. Base 10 is generally rectangular and, in this case, substantially square in profile and defines a floor 12 and, along two of the sides of the floor, respective integrally moulded thin-walled upstands 20a, 20b, that merge at corner 22. Extending about the whole periphery of 15 floor 12 is a continuous channel 25 that lies immediately adjacent upstands 20a, 20b on two sides of the floor, and on the other two sides is separated from the respective edge of the floor by a fine lip 29 of height matching the depth of the channel. Within the ring formed by channel 25, floor 12 defines a floor surface 13 on which a person stands while taking a shower. Floor surface 13 slopes very slightly downwardly 20 to a centrally located opening 30 which in situ mounts a drain outlet fitting 40 (Figure 4) connected to a waste-water pipe. Floor surface 13 is segmented by an array of narrow and shallow grooves 26 that radiate from opening 30. Grooves 26 open at their outer ends into channel 25 and at their inner ends into an annular shallow depression 32 that seats the flange of the drain outlet fitting 40. 25 Upstands 20a, 20b are of a thickness sufficiently small for the upstand to be accommodated between wall studs and a wallboard attached directly to the studs without either rebating the studs or packing out the wallboard at the studs. Further, the 7 height of the upstands 20a, 20b is great enough to prevent water from rising by capillary action between the wallboard and the upstand and escaping over the top edge of the upstand. In addition, channel 25 is of a width selected to firmly accommodate a standard bathroom wallboard to thereby receive and seat a lowermost edge of such 5 wallboard. With these requirements in mind, upstands 20a, 20b may typically be 2.5-3mm in width and have a height of at least 50mm, preferably 65mm or greater. A suitable width of channel 25 is in the range 4 to 8mm, although 6mm would be typical. These ranges are of course not limiting on the scope of the present invention. 10 The underside of the moulding that forms the shower base 10 is depicted in Figure 3. The structure evident is a peripheral ledge 40 and multiple ribs 42 at the locations of grooves 26. These ribs 42 link the peripheral ledge 40 to a central annular land 43 which is the complement of depression 32 about aperture 30. Ribs 42 are of course substantially wider than grooves 26 but are separated by underside shallow 15 recesses 45 designed to minimise the weight of material, and therefore the weight of the moulding, to an extent that does not compromise the ability of the base to bear the weight of a heavy person without fracturing or weakening. This is further guarded against by having the bottom of the moulding as a flat face 15 that rests firmly and evenly on an underlying floor surface. The structure formed by ribs 42 embracing the 20 grooves 26 is thought to enhance the overall weight-bearing strength of the base while minimising the total material requirement. The steps involved in installing the shower base 10 of Figures 1-3 will now be described, with particular reference to Figure 4. The shower base is placed on a floor surface 50 with face 15 flush to the floor surface, and with the respective upstands 20a, 25 20b abutted against wall studs 52 of adjacent wall frames 53 that meet at a corner 54. Respective panels of wallboard 55 are then fastened to the wall studs, e.g. by nailing, screwing or gluing, so that their lowermost margins overlie upstands 20a, 20b and their lowermost edges 62 seat firmly in respective segments of channel 25. Because of the slight flexure of the wallboard panels to accommodate upstands 20a, 20b, the wallboard 30 is biased slightly against the upstands, and this, combined with the sufficient height of 8 the upstands to prevent capillary action between the upstands and the wallboards, means it is not essential to apply sealant at the interface between the wallboards and the channel, or between the wallboards and the upstands. Such sealant may of course be applied if desired for enhanced security against leakage. 5 Glass panel assemblies are placed in the remaining segments of channel 25 at the "open" sides of the base to complete the enclosure. One of these panel assemblies will include a door arrangement. The ease with which the base is installed will have been noted from this description. In particular, relative to traditional installations, checking out or packing of 10 each wall stud has been eliminated, and application of sealant along the wallboard edges is not essential. The shower base may be installed in a mode in which the person using the shower stands directly on floor surface 13. Alternatively, the illustrated embodiment is suited to a mode of installation in which an overlay of floor tiles is placed on surface 13, 15 as depicted in part in Figure 4. In this case, the floor tiles 70 are fixed to floor surface 13 with the usual adhesives and tile grout 72 applied between the tiles. During subsequent use, moisture will inevitably penetrate the grout and adhesive to reach the surface 13, but narrow radiating grooves 26 provide a mechanism by which this penetrating moisture may be directed by capillary action along the grooves to depression 32 and 20 then to the drain outlet. It is significant, though not essential, that base 10 is injection moulded in a composite polyurethane material. Such material is better able to accommodate load stresses and temperature change stresses than the conventional fibreglass-reinforced polymers traditionally employed in the moulding of shower bases. Moreover, injection 25 moulding of composite polyurethane is a feasible mechanism for integrally moulding upstands 20a, 20b to the thickness range required: conventional vacuum moulding processes cannot readily produce projecting elements of such thinness.

9 Figures 5, 6 and 7 depict respective modifications of the embodiment of Figures 1 to 4. The Figure 5 embodiment varies only in that the upstands 20 include a further segment 20c on a third side of the shower base: this base is suited for installation in a cubicle having walls on three sides. 5 Figure 6 depicts a modification of Figure 1 in which the two "open" sides of the base have a raised flat-topped hob 80 as an additional barrier against escape of water from floor surface 13 and to facilitate mounting of a glass frame including a door at the two open sides. Figure 7 simply depicts a similar modification of the embodiment of Figure 5 with a hob 80 at the single open side of the base. 10 It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

1. A shower base comprising a unitary moulding that has a plurality of sides and includes: 5 a floor on which a person stands while taking a shower, when the shower base is installed; a thin-walled upstand at at least one of said sides of the base, which upstand is: 10 (i) of a thickness sufficiently small for the upstand to be accommodated between wall studs and a wallboard attached directly to the studs at the respective side of the base without wither rebating the studs or packing out the wallboard at the is studs, and (ii) of a height great enough to prevent water rising by capillary action behind the wallboard and over the upstand; and a channel in said moulding, immediately adjacent said upstand, to 20 firmly accommodate and seat a lowermost edge of said wallboard.

2. A shower base according to claim 1, wherein said upstand has an outside upright face defining a lateral extremity of the base. 25

3. A shower base according to claim 1 or 2, wherein said channel is formed in a peripheral ledge that extends about the base and said floor.

4. A shower base according to claim 3, wherein the peripheral ledge extends wholly above the base and said floor. 30

5. A shower base according to claim 4, wherein said channel extends wholly about said base. - 11

6. A shower base according to any one of the preceding claims, wherein said upstand is provided on one, two or three sides of the shower base according to the intended location of the shower base. 5

7. A shower base according to any one of the preceding claims, wherein the shower base is generally rectangular in plan and designed to be fitted to a wall on one, two or three sides.

8. A shower base according to any one of the preceding claims, wherein 10 said floor includes an opening to receive a drain outlet fitting, and the floor is sloped from its outer periphery to the vicinity of this opening.

9. A shower base according to any one of the preceding claims, wherein said floor has a floor surface that includes a plurality of relatively narrow is radiating grooves to channel water to said drain outlet fitting.

10. A shower base according to claim 9, wherein the grooves open into said channel at their outer ends. 20

11. A shower base according to any one of the preceding claims, wherein at a side not having said upstand, there is a hob for underlying an access doorway to the shower space.

12. A shower base according to any one of the preceding claims, wherein 25 the shower base is an injection moulding in a composite polyurethane material.

13. A shower base substantially as described herein with reference to Figure 4 of the accompanying drawings. 30

14. A method of making a shower base according to any of claims 1 to 3, comprising injection moulding the shower base in a composite polyurethane material. -12

15. A method of installing a shower base according to any one of claims 1 to 3 comprising: placing the base onto a floor surface with said upstand substantially 5 abutting a plurality of wall studs; and fastening a wallboard to said plurality of studs substantially without intervening packing so that a lowermost edge of the wallboard is seated in said channel. 10

16. The method of claim 15, further including applying a sealant composition along the interface between said wallboard and said channel, and/or along the interface between said wallboard and said upstand. I5 A.C.T. Ltd. By Their Patent Attorneys EKM patent& trade marks