Drainage system

Abstract

A drainage system (1) for installation in a wet area such as a shower stall. The drainage system (1) comprises an outer drainage conduit (2) adapted to extend within a subfloor (100) of a wet area and an inner drainage conduit (3). The conduit (2) comprises a rim (20) and a pipe body (21). The inner drainage conduit (3) also comprises a rim (30) and a pipe body (31). The rim (30) and pipe body (31) are nestable within the outer drainage conduit (2). When nested, the pipe bodies (21, 31) are adapted to be connectively sealed together using sealant, the rims (20, 30) are adapted to hold a waterproofing membrane (107) between the rims (20, 30,) and to be connectively sealed in a water-tight manner to the waterproofing membrane (107) using sealant or, in the absence of a waterproofing membrane (107), the rims (20, 30) are adapted to be connectively sealed together using sealant in a water-tight manner.

Claims

1. A method of installing a drainage system having a central axis, said drainage system comprising: (1) an outer drainage conduit adapted to extend within a subfloor of a wet area, said outer drainage conduit comprising: a rim adapted to be secured to an upper surface of the subfloor, wherein the rim has an inlet for liquid and extends substantially laterally relative to the central axis; and a pipe body extending from the rim and having an outlet for liquid adapted to be connected to a waste pipe riser extending beneath the subfloor, wherein the central axis extends within the pipe body; and (2) an inner drainage conduit comprising: a rim having an inlet for liquid and extending substantially laterally relative to the central axis; and a pipe body having an outlet for liquid and extending from the rim of the inner drainage conduit, and the central axis extends within the rim and pipe body of the inner drainage conduit, wherein: the rim and pipe body of the inner drainage conduit are nestable within the outer drainage conduit such that the pipe bodies are in direct contact with each other, when nested, the pipe bodies are adapted to be connectively sealed together using sealant, and when nested, the rims are adapted to hold a waterproofing membrane in the form of a liner between the rims and to be connectively sealed in a water-tight manner to the waterproofing membrane using sealant, said method comprising the steps of: (1) positioning the outer drainage conduit such that it extends through a subfloor of a wet area requiring drainage; (2) securing the rim of the outer drainage conduit to an upper surface of the subfloor; (3) connecting the pipe body of the outer drainage conduit to a waste pipe riser extending beneath the subfloor; (4) installing a cement bedding floor to the height of the rim of the outer drainage conduit and allowing the bedding floor to set; (5) installing a waterproofing membrane in the form of a liner over the bedding floor and outer drainage conduit but so as to not obstruct the inlet for liquid of the outer drainage conduit; (6) connectively sealing the waterproofing membrane between and to the rims of the outer and inner drainage conduits by applying sealant to both said rims; and (7) connectively sealing the pipe bodies together in a water-tight manner using sealant, wherein steps (1) to (7) need not be carried out in the order listed.

2. The method of claim 1, wherein the waterproofing membrane is a plastic liner.

3. The method of claim 1, wherein the waterproofing membrane is sealed between the rims of the outer and inner drainage conduits using silicone sealant.

4. The method of claim 1, wherein the pipe bodies are connectively sealed together in a water-tight manner using a solvent weld.

5. The method of claim 1, wherein the drainage system further comprises a height adjustable conduit comprising: a rim having an inlet for liquid and extending substantially laterally relative to the central axis and adapted to be sealed with a removable closure, wherein the rim includes at least one drainage opening; and a pipe body having an outlet for liquid and extending from the rim of the height adjustable conduit, and the central axis extends within the pipe body of the height adjustable conduit, wherein the pipe body of the height adjustable conduit is nestable within the inner drainage conduit and friction fits to the pipe body of the inner drainage conduit such that the height adjustable conduit is slidable parallel with the central axis and relative to the pipe body of the inner drainage conduit, and the method further includes a step (8) of nesting the height adjustable conduit within the inner drainage conduit and adjusting the height of the rim of the height adjustable conduit such that it coincides with a desired bedding floor height.

6. The method of claim 5 further comprising a step of installing a cement bedding floor around the rim of the height adjustable conduit.

7. The method of claim 4, further comprising a step of installing a metal mesh within a bedding floor or between bedding floors.

8. The method of claim 4, further comprising a step of connecting a grate or strainer to the inlet for liquid of the rim of the height adjustable conduit.

9. The method of claim 4, further comprising a step of installing floor tiles to provide a desired floor finish.

10. The method of claim 1, further comprising a step of installing a test plug within a said drainage conduit, submersing the waterproofing membrane in water and testing for water leakage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an exploded perspective view of a drainage system according to an embodiment of the present invention;

(2) FIG. 2 is a top plan view of the drainage system shown in FIG. 1;

(3) FIG. 3 is a cross sectional view of the drainage system shown in FIG. 2, taken through plane A-A;

(4) FIG. 4 is an underside perspective view of an outer drainage conduit of the drainage system shown in FIG. 1;

(5) FIG. 5 is an underside perspective view of an inner drainage conduit of the drainage system shown in FIG. 1;

(6) FIG. 6 is an underside perspective view of a height adjustable conduit of the drainage system shown in FIG. 1;

(7) FIG. 7 is an underside perspective view of a closure of the drainage system shown in FIG. 1;

(8) FIG. 8 is a perspective view of a grate or strainer of the drainage system, according to an embodiment of the present invention;

(9) FIG. 9 is a perspective view of another type of grate or strainer of the drainage system, according to an embodiment of the present invention;

(10) FIG. 10 is an exploded perspective view of a drainage system according to another embodiment of the present invention;

(11) FIG. 11 is a top plan view of the drainage system shown in FIG. 10;

(12) FIG. 12 is a cross sectional view of the drainage system shown in FIG. 11, taken through plane A-A;

(13) FIG. 13 is an underside perspective view of an outer drainage conduit of the drainage system shown in FIG. 10;

(14) FIG. 14 is a flowchart explaining basic installation steps for the drainage system; and

(15) FIG. 15 is a cross sectional view of the drainage system shown in FIG. 1 when installed in a wet area.

DETAILED DESCRIPTION

(16) In the figures, like reference numerals refer to like features.

(17) Referring first to FIGS. 1 to 7, there is shown a first embodiment of a drainage system 1 for installation within a concrete or timber subfloor 100 (as seen in FIGS. 3 and 15). The drainage system 1 includes an outer drainage conduit 2 (3 inch2 inch), an inner drainage conduit 3, a height adjustable conduit 4 and a closure 5. A central axis 101 is shown in exploded view FIG. 1 extending through the outer drainage conduit 2 (3 inch), inner drainage conduit 3, height adjustable conduit 4 (4 inch3 inch) and removable closure 5 (4 inch).

(18) The outer drainage conduit 2 includes a rim 20 which is adapted to be secured to an upper surface 102 of the subfloor 100. The rim 20 includes an inlet for liquid 23 and extends substantially laterally relative to the central axis 101. The outer drainage conduit 2 also includes a pipe body 21 extending from the rim 20 and is adapted to be connected to a waste pipe riser 103 (see FIG. 3) which extends beneath the subfloor 100. If a wooden subfloor 100, the pipe body 21 may extend through a 3. inch diameter hole. The pipe body 21 includes an outlet 24 for liquid. The central axis 101 extends centrally within and through the rim 20 and pipe body 21. The outer drainage conduit 2 is of unitary construction and is made of polypropylene, with antibacterial properties.

(19) The rim 20 is in the form of concentrically arranged inner 20a and outer 20b rings. Four countersunk openings 25 are positioned equidistantly around the outer ring 20b of the rim 20 and are able to receive screw fasteners 200 to secure the rim 20 to the subfloor 100.

(20) The rim 20 has an upper surface 20c, a sidewall 20d extending downwardly from the upper surface 20c and a lower surface 20e situated opposite the upper surface 20c. The rim 20 has reinforcing ribs 27 extending from the sidewall 20d and lower surface 20e towards the central axis 101. In this way, the upper surface 20c of the rim 20 can be adequately supported at a location above the subfloor upper surface 102 during installation and post-installation.

(21) The upper surface 20c of outer ring 20b extends substantially perpendicularly relative to the central axis 101 and the upper surface 20c of the inner ring 20a extends from the upper surface 20c of the outer ring 20b downwardly towards the central axis 101.

(22) The pipe body 21 is cylindrical and has an outer wall and inner wall, and the inner wall faces the central axis 101. The outer and inner walls extend substantially parallel with the central axis 101. The pipe body 21 has a lower pipe portion 21a at which the outlet for liquid 24 is located, and an upper pipe portion 21b between the lower pipe portion 21a and rim 20 that is of greater diameter than the lower pipe portion 21a. The upper pipe portion 21b extends from the inner ring 20a of the rim 20. The pipe body 21 has a stepped periphery.

(23) The waste pipe riser 103 friction fits within a free end of the lower pipe portion 21a and sealant is used to fix the waste pipe riser 103 within the free end.

(24) The pipe body 21 include a sloping sidewall or shoulder 21c between the upper pipe portion 21b and lower pipe portion 21a. The lower pipe portion 21a has an internally extending shoulder 21d against which the waste pipe riser 103 abuts when being fixed in place within the lower pipe portion 21a. The internally extending shoulder 21d is in the form of a circular flange or ring.

(25) The inner drainage conduit 3 includes a rim 30 that extends substantially laterally relative to the central axis 101. The rim 30 includes an inlet for liquid 33. The inner drainage conduit 3 also includes a pipe body 31 extending from the rim 30 and includes an outlet 34 for liquid. The central axis 101 extends centrally within and through the rim 30 and pipe body 31. The inner drainage conduit 3 is of unitary construction and is made of polypropylene, with antibacterial properties.

(26) The rim 30 is in the form of concentrically arranged inner 30a and outer 30b rings. The rim 30 has an upper surface 30c, a sidewall 30d extending downwardly from the upper surface 30c and a lower surface 30e situated opposite the upper surface 30c.

(27) The outer ring 30b extends substantially perpendicularly relative to the central axis 101 and the inner ring 30a extends from the outer ring 30b downwardly towards the central axis 101.

(28) The pipe body 31 is cylindrical and has an outer wall and inner wall, and the inner wall faces the central axis 101. The outer and inner walls extend substantially parallel with the central axis 101. The pipe body 31 has a lower pipe portion 31a at which the outlet for liquid 34 is located, and an upper pipe portion 31b that extends from the inner ring 30a of the rim 30.

(29) As seen in FIG. 3, the rim 30 and pipe body 31 of the inner drainage conduit 3 are nestable within the outer drainage conduit 2. When nested, the pipe bodies 21, 31 are adapted to be connectively sealed together using sealant. When nested, the rims 20, 30 are adapted to hold a waterproofing membrane 107 between the rims 20, 30 and to be connectively sealed in a water-tight manner to the waterproofing membrane 107 using sealant or, in the absence of a waterproofing membrane, the rims 20, 30 are adapted to be connectively sealed together using a solvent weld in a water-tight manner.

(30) The height adjustable conduit 4 includes a rim 40 that extends substantially laterally relative to the central axis 101. The rim 40 includes a main inlet for liquid 43 and four drainage openings 48. The height adjustable conduit 4 also includes a pipe body 41 extending from the rim 40 and includes an outlet 44 for liquid. The central axis 101 extends centrally within and through the rim 40 and pipe body 41. The height adjustable conduit 4 is of unitary construction and is made of polypropylene.

(31) The pipe body 41 is nestable within the inner drainage conduit 3 and friction fits to the pipe body 31 of the inner drainage conduit 3 such that the height adjustable conduit 4 is slidable parallel with the central axis 101 and relative to the pipe body 31 of the inner drainage conduit 3.

(32) The rim 40 includes a circular flange 40a that extends from the pipe body 41 concentrically with the central axis 101. The circular flange 40a slopes downwardly towards the central axis 101 so as to encourage water run-off.

(33) The rim 40 includes an upstanding sidewall 40b that extends substantially parallel with the central axis 101. The sidewall 40b extends upwardly from the circular flange 40a. The sidewall 40b is annular in shape when viewed from above.

(34) The drainage openings 48 are spaced equidistantly along the sidewall 40b and enable the ingress of moisture or liquid into the pipe body 41 once the drainage system has been installed (as seen in FIG. 15).

(35) A strainer 180 or grate 181 (as seen in FIGS. 8 and 9) can be fitted to the rim 40, as seen in FIGS. 9 and 15. The sidewall 40b of the rim 40 can snugly receive and support the strainer or grate, such as a collar 180a of a circular grate 180, or a draining pan 181a of a strainer or grate 181.

(36) The pipe body 41 is cylindrical and has an outer wall and inner wall, and the inner wall faces the central axis 101. The outer and inner walls extend substantially parallel with the central axis 101, and the central axis 101 extends centrally of the pipe body 41.

(37) The pipe body 41 has a lower pipe portion 41a at which the outlet for liquid 44 is located, and an upper pipe portion 41b that is of greater diameter than the lower pipe portion 41a. The upper pipe portion 41a extends from the circular flange 40a. The pipe body 41 has a stepped periphery.

(38) The lower pipe portion 41a includes a sloping sidewall or shoulder that slopes towards the central axis 101. The lower pipe portion 41a friction fits to the pipe body 31 of the inner drainage conduit 3 by way of a deformable skirt 47 (deformable flanges 47) that extends from the lower pipe portion 41a and bears against the pipe body 31 of the inner drainage conduit 3. (Spaces between the deformable flanges 47 act as weep holes such that water can seep into the pipe body 21.) In this way, the height adjustable conduit 4 is slidable parallel with the central axis 101 and relative to the pipe body 31. The rim 40 of the height adjustable conduit 4 can be raised relative to the other conduits 2, 3 such that cement bedding 201 may set around the rim 40 and to the height of the rim 40 or just below the height of the rim 40 (if floor tiles are to be installed), and between that rim 40 and the rim 31 of the inner drainage conduit 3 (as seen in FIG. 15).

(39) The removable closure 5 can seal the inlet for liquid 43 of the rim 40 of the height adjustable conduit 4 as well as the four drainage openings 48 by friction fitting to the sidewall 40b of the rim 40.

(40) The closure 5 is of unitary construction and is made of polypropylene.

(41) The closure 5 is in the form of a cap 5 having a top surface 50 and a sidewall/collar 51 which extends downwardly from the top surface 50. The top surface 50 extends substantially perpendicularly of the central axis 101, whereas the sidewall 51 extends substantially parallel with the central axis 101. The sidewall/collar 51 is recessed relative to the top surface 50. The sidewall/collar 51 friction fits within the sidewall 40b of the rim 40 of the height adjustable conduit 4 and prevent the ingress of dirt and debris into the height adjustable conduit 4. The cap 5 includes two openings 50a in the top surface 50 that are initially sealed with a thin plastic or paper liner (not shown), and that can be pierced using a finger or instrument. Once pierced, the openings 50a can allow for easy removal of the cap 5 from the rim 40 of the height adjustable conduit 4, after installation/tiling has been completed (as seen in FIG. 15).

(42) The drainage system 1 may be utilised in a wet area such as a bathroom, laundry or shower area as follows, with the basic steps being described in FIG. 14. As seen in FIGS. 3 and 15, the outer drainage conduit 2 is either installed in a pre-formed circular opening in a concrete or timber subfloor 100, or the conduit 2 is installed during the pouring of a concrete slab. Screws 200 are used to fasten the rim 20 of the conduit 2 to an upper surface 102 of the subfloor 100. During this step of installation, the inner drainage conduit 3 and height adjustable conduit 4 together with the cap 5 may be partially nested within the outer drainage conduit 2 so as to prevent the accidental ingress of debris (such as cement) into the conduit 2 or waste pipe riser 103 (substantially as shown in FIG. 3). The lower pipe portion 21a is designed to receive a 2 inch waste pipe riser 103 and to be welded thereto with solvent cement (solvent weld).

(43) The rim 20 of the conduit 2 stands proud of the subfloor 100 so that a cement bedding floor 106 may be poured (as seen in FIGS. 3 and 15). The conduits 3 and 4 (with cap 5) are nested within the conduit 2 to prevent the accidental ingress of debris (as shown in FIG. 3). A cement bedding floor 106 is poured to the height of the rim 20 of the conduit 2, screeded and allowed to set/dry thoroughly. For wet areas such as showers, the bedding floor 106 is pre-sloped to encourage water to flow to the conduit 2. The other conduits 3, 4 are then removed from engagement with the conduit 2. A waterproofing liner/membrane 107 is extended and positioned over the bedding floor 106 and the conduit 2. A suitable liner is the PVC shower pan liner sold under the trademark Oatley, which is fixed in place using bonding adhesive (Oately X-15). A circular hole (is cut in the liner 107 such that the liner 107 overlaps essentially the entirety of the upper surface 20c of the rim 20 of the conduit 2.

(44) The conduit 3 is then used to sandwich/hold the liner 107 between the rims 20, 30 of the conduits 2, 3. The sloping rims 20, 30 enable the conduit 3 to be almost fully nested within the outer drainage conduit 2 even when holding the liner 107 between them. The rim 30 of the conduit 3 has been graded to allow for the positive draining of water from the liner 107. In practice, sealant, such as silicone sealant ( inch bead), is applied to the upper surface 20c of the rim 20 of the conduit 2 and the lower surface 30e of the rim 30 of the conduit 3. Solvent cement (solvent weld) is applied to the inner wall of the pipe body 21 of the conduit 2 and outer wall of the pipe body 31 of the conduit 3 such that the conduits 2, 3 are welded together. After placing the liner 107 between the conduit rims 20, 30, the conduit 3 is forced into engagement with the conduit 2 with a slight twisting motion of the conduit 3. In effect, this creates a triple-seal connection between the rims 20, 30, the liner 107 and the conduits 2, 3.

(45) At this stage, the shower pan liner and connection can be water tested. This may involve installing a 2 inch test plug or a 2 inch pump up test plug into the bottom of the 2 inch pipe connection, fill the shower pan liner with water to just below the top of the curb, and testing for approximately four hours. If any leaks, these can be repaired.

(46) The triple seal connection is formed because of interlocking of: the lower surface of the rim 30e of the conduit 3 to a top side of the liner 107 via a bead of silicone sealant (first seal); an underside of the liner 107 to the upper surface 20c of the rim 20 of the conduit 2 via a bead of silicone sealant (second seal); and solvent welding of the pipe body 31 of the inner drainage conduit 3 to the pipe body 21 of the outer drainage conduit 2 (third seal). The third seal prevents waste water (such as shower wastewater) from flowing back up between the conduits 2, 3 which could otherwise undermine the liner connection and create leaks.

(47) The height adjustable conduit 4 (with cap 5) is partially nested within the inner drainage conduit 3 and then raised to the appropriate height for bedding. The skirt 47 of the conduit 4 initially holds the conduit 4 at the desired height. An external of the rim 40 of the conduit 4 is partially or fully embedded with newly poured cement bedding 201 (as seen in FIG. 15), which bedding 201 may also incorporate a metal mesh (galvanised reinforcement mesh or metal lath mesh, generally in the areas labelled 220). The rim 40 of the conduit 4 is held in place by the bedding 201 and the bedding also penetrates the openings 48 in the rim 40 (which are sealed at an inner end of the openings 48 by the cap 5). The bedding 201 further fills any space between the lower surface 40a of the rim 40 and the upper surface 30a of the rim 30 of the inner drainage conduit 3. The pipe body 41 of the conduit 4 has an extended length so as to provide extra working height for floor bedding levels. If for example, floor tiles were to be laid, then the bedding would be laid to a height just below the top of the rim sidewall/collar 40b (to allow for tile thickness), so that the tiling can lay flush with an installed strainer or grate 180, 181 (or the top of the cap 5).

(48) Cement bedding mix 201 and floor tiles 203 would be installed to provide the desired floor finish (as seen in FIG. 15). Following removal of the cap 5, the rim sidewall/collar 40b of the conduit 4 is able to receive a strainer or grate 180, 181. A collar 180a or draining pan 181a of the strainer or grate 180, 181 is snugly received within the rim sidewall/collar 40b, thereby creating a free-flowing connection between the tiled floor and waste pipe riser 103. The strainer or grate 180, 181 can be held in place within the rim 40 using additional grout and/or tiling glue.

(49) If installing grate 181 of FIG. 9, then it would stand proud of the rim 40 and would need to be fixed in place with additional bedding mix.

(50) The drainage system has two-tier weep holes (openings 48 and between skirt flanges 47, as seen in FIG. 10), allowing for water seepage to escape into the waste pipe riser 103.

(51) The drainage system 1 may also be utilised in a slightly different manner. The outer and inner drainage conduits 2, 3 are first solvent cement welded together and the outer drainage conduit 2 is fastened to the subfloor 102 using screws as described above.

(52) The height adjustable conduit 4 (with cap 5) is nested within the inner drainage conduit 3 to prevent the accidental ingress of debris. Cement bedding 106 is poured and screeded to the height of the rims 20, 30 of the conduits 2, 3. Once dried, a paintable waterproofing membrane (liner) 107 is applied to the bedding as well as to upper surfaces 20c, 30c of the rims 20, 30 of the conduits 2, 3, and slightly further along the inner wall of the pipe body 31 of the inner drainage conduit 3.

(53) The height adjustable conduit 4 (with cap 5) is then raised relative to the inner drainage conduit 3 and fixed in place with concrete bedding 201, as described above. The floor can then be finished/tiled as described above.

(54) Referring now to FIGS. 10 to 13, there is shown a second embodiment of a drainage system 7 for installation within a concrete or timber subfloor 100. The drainage system 7 includes an outer drainage conduit 8, a height adjustable conduit 4a and a closure/cap 5a. The height adjustable conduit 4a and enclosure/cap 5a are substantially identical to the height adjustable conduit 4 and closure/cap 5. A central axis 101 is shown in exploded view FIG. 10 extending through the outer drainage conduit 8, height adjustable conduit 4a and cap 5a.

(55) The outer drainage conduit 8 includes a rim 80 which is adapted to be secured to an upper surface 102 of the subfloor 100. The rim 80 includes an inlet for liquid 83 and extends substantially laterally relative to the central axis 101. The outer drainage conduit 8 also includes a pipe body 81 extending from the rim 80 and is adapted to be connected to a waste pipe riser 103 (see FIG. 12) which extends beneath the subfloor 100. The pipe body 81 includes an outlet 84 for liquid. The central axis 101 extends centrally within and through the rim 80 and pipe body 81. The outer drainage conduit 8 is of unitary construction and is made of polypropylene, with antibacterial properties.

(56) The rim 80 is in the form of a ring 80a. Four openings 85 are positioned equidistantly around the ring 80a and are able to receive screw fasteners 200 to secure the rim 80 to the subfloor 100.

(57) The rim 80 has an upper surface 80c, a sidewall 80d extending downwardly from the upper surface 80c and a lower surface 80e situated opposite the upper surface 80c. The upper and lower surfaces 80c, 80e of the ring 80a extend substantially perpendicularly relative to the central axis 101.

(58) The pipe body 81 is cylindrical and has an outer wall and inner wall, and the inner wall mostly faces the central axis 101.

(59) The pipe body 81 has a lower pipe portion 81a at which the outlet for liquid 84 is located, an intermediate pipe portion 81b immediately adjacent the lower pipe portion 81a that is of greater diameter than the lower pipe portion 81a, and an upper pipe portion 81c immediately adjacent the rim 80 that is of greater diameter than the intermediate pipe portion 81b. The upper pipe portion 81c extends downwardly from the ring 80a of the rim 80. The pipe body 81 has a stepped periphery and two shoulders 81e, 81f.

(60) The waste pipe riser 103 friction fits within a free end of the lower pipe portion 81a and sealant/a solvent weld is used to fix the waste pipe riser 103 within the free end.

(61) Shoulder 81f slopes from the upper pipe portion 81c towards the central axis 101 to the intermediate pipe portion 81b. The lower pipe portion 81a has an internally extending shoulder 81h against which the waste pipe riser 103 abuts when being fixed in place. The internally extending shoulder 81h is in the form of a circular flange or ring.

(62) As mentioned for the other embodiment, a strainer 180 or grate 181 can be fitted to the rim 40 of the height adjustable conduit 4.

(63) The rim 40 of the height adjustable conduit 4 can rest against the shoulder 81f extending between the upper 81c and intermediate 81b pipe portions, when fully nested within the outer drainage conduit 8. As with the other embodiment, the pipe body 41 friction fits to the pipe body 81 of the outer inner drainage conduit 8 by way of a deformable skirt 47 (deformable flanges 47, again providing weep holes there between) that extends from the lower pipe portion 41a and bears against the pipe body 81 of the outer drainage conduit 8. In this way, the height adjustable conduit 4 is slidable parallel with the central axis 101 and relative to the pipe body 81. The rim 40 of the height adjustable conduit 4 can be raised relative to the other conduit 8 such that concrete bedding may set around the rim 40 and to or near to the height of the rim 40, and between that rim 40 and the rim 80 and upper pipe portion 81c of the outer drainage conduit 8.

(64) The drainage system 7 may be utilised in a wet area such as a bathroom, laundry or shower recess/stall as follows. The outer drainage conduit 8 is either installed in a pre-formed circular opening in a concrete or timber subfloor 100, or the conduit 8 is installed during the pouring of a concrete slab. Screws 200 are used to fasten the rim 80 of the first conduit 8 to the upper surface 102 of the subfloor 100, as seen in FIG. 12. During this step of installation, the height adjustable conduit 4a together with the cap 5a may be partially nested within the outer drainage conduit 8 so as to prevent the accidental ingress of debris (such as cement) into the first conduit 8 or waste pipe riser 103. The lower pipe portion 81a is designed to ultimately receive a 2 inch waste pipe riser 103 and to be welded thereto with solvent cement.

(65) The rim 80 of the first conduit 8 stands slightly proud of the subfloor 100 or can extend within a recess as shown in FIG. 12.

(66) A paintable waterproofing membrane (liner) 107 is applied to the subfloor upper surface 102 as well as to the upper rim surface 80c of the conduit 8, as well as further downwardly along upper pipe portion 81c towards the shoulder 81f.

(67) The height adjustable conduit 4a (with cap 5a) is partially nested within the outer drainage conduit 8 and then raised to the appropriate height for bedding (substantially as shown in FIG. 15). The skirt 40b of the height adjustable conduit 4a initially holds that conduit 4 at the desired height. The rim 40 of the conduit 4 is partially or fully embedded with newly poured cement bedding, which bedding may also incorporate a metal mesh (galvanised metal mesh or metal lath meshnot shown). The rim 40 is held in place by the bedding and the bedding also penetrates the openings 48 in the rim 40 (which are sealed at an inner end of the openings 48 by the cap 5a). The bedding further fills any space between an underside of the rim 40 and the rim 80a of the outer drainage conduit 8.

(68) Concrete bedding mix and floor tiles would be installed to provide the desired finish (substantially as shown in FIG. 15). Following removal of the cap 5a, the rim 40 is able to receive a strainer such as a collar of a circular grate or a draining pan of a strainer (as seen in FIGS. 8 and 9). The collar or draining pan is snugly received within the rim of the height adjustable conduit 40, thereby creating a free-flowing connection between the tiled floor surface and waste pipe riser. The strainer or grate 180, 181 can be held in place within the rim 40 using additional grout and/or tiling glue.

(69) If installing grate 181 of FIG. 9, then it would stand proud of the rim 40 and would need to be fixed in place with additional bedding mix.

(70) The foregoing embodiments are illustrative only of the principles of the invention, and various modifications and changes will readily occur to those skilled in the art. The invention is capable of being practiced and carried out in various ways and in other embodiments. It is also to be understood that the terminology employed herein is for the purpose of description and should not be regarded as limiting.

(71) In the present specification and claims (if any), the word comprising and its derivatives including comprises and comprise include each of the stated integers but does not exclude the inclusion of one or more further integers.

(72) Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases in one embodiment or in an embodiment in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

(73) In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

(74) Any reference to a publication cited in this specification is not an admission that the disclosure constitutes common general knowledge.