S23 Plumbing Drainage and Gas

Note: The term contractor is used interchangeably to describe both subcontractors & suppliers


1.0 Scope

  • 1.01 The work of this Section is as specified below and as detailed on drawings and includes but is not limited to, supplying and fixing of a complete system of sewer, sub-drainage and stormwater pipes, pits, tanks covers, waste and vent pipes plus the reticulation of cold water, hot water and gas from the new water and new gas mains, including all associated isolating valves, stop taps and outlets to connect the following items, also supplied and fixed under this contract:
    • 1.01.1 Showers
    • 1.01.2 Bath
    • 1.01.3 Basins
    • 1.01.4 WC pans, seats, cisterns Sinks
    • 1.01.5 Gas hot water unit
    • 1.01.6 Connection to washing machine
    • 1.01.7 Connection to dishwashing machine
    • 1.01.8 Laundry tub
    • 1.01.9 Floor wastes
    • 1.01.10 External hose cocks
    • 1.01.11 Gas outlets, internal and external
    • 1.01.12 Gas cooktop
    • 1.01.13 Landscape irrigation system (if required)
    • 1.01.14 Stormwater re-use tanks Swimming pool Pool equipment (if required)
      • The work also includes supply and installation of a complete stormwater detention/retention system as detailed and specified on the Hydraulic Engineer’s Drawings.
      • Hydraulic Engineer’s drawings and specifications take precedence over architectural documents with the exception of setout.

1.1 Related Work

  • 1.1.1 Excavation
  • 1.1.2 Waterproofing
  • 1.1.3 Ceramic Tile
  • 1.1.4 Finishing Trades
  • 1.1.5 Masonry
  • 1.1.6 Concrete
  • 1.1.7 Roof Plumbing

1.2 Coordination with work by other Trades

  • 1.2.1 Various items of apparatus and equipment will be provided and fixed under other contracts. The Contractor must familiarise himself with the requirements of these contracts and is to examine the plans and specification covering each of these contracts.
  • 1.2.2 It is the responsibility of the Contractor to schedule his work closely so that his work may be installed at the proper time and without delaying the completion of the entire project.
  • 1.2.3 The Contractor must carefully check space requirements with other Contractors to ensure that his equipment, piping, etc. can be installed in the spaces allotted for same.
  • 1.2.4 When equipment and/or installations associated with the work of the contract are installed by other Contractors (e.g. electrical controls, float switches, etc.) the Contractor must attend and coordinate as necessary.

1.3 Quality Assurance

  • 1.3.1 Perform all of the work of this Section using tradesmen whose experience and skills meet the requirements of any controlling statutory authority.

1.4 Reference Standards

  • 1.4.1 Comply with all current editions of the current relevant Australian standards.
  • 1.4.2 Comply with all requirements of any Statutory Authority having jurisdiction.
  • 1.4.3 Comply with applicable “BASIX’ certification requirements.

1.5 Building Code of Australia

  • 1.5.1 Class of Building is Class 1a
  • 1.5.2 Construction shall be carried out in accordance with the “Deemed-to-Satisfy Provisions” of the Building Code of Australia.

1.6 Submissions

  • 1.6.1 Before ordering any scheduled material, submit any required product data to the Principal, particularly where the specified material is not available and alternatives are offered.

1.7 Warranty

  • 1.7.1 Provide the Principal  with warranties covering:
    • Materials: in the form supplied by manufacturers of specified components.
    • Installation, for five (5) years from the date of Completion: the complete drainage and piping installation and the specified components to which it is connected.
    • Equipment: in the form supplied by manufacturers of specified items e.g. hot water units etc.

1.8 Fees

  • 1.8.1 Pay applicable fees to the relevant statutory authorities as required.
  • 1.8.2 Fees nominated to be paid by the Principal shall be paid accordingly by the same.


2.0 Acceptable Manufacturers

  • 2.0.1 Ensure that all items to be installed are approved for installation by Local Authorities before ordering.

2.1 Materials

  • 2.1.1 Tubing for Cold Water Material: Iplex or similar
  • 2.1.2 Jointing: Capillary, Brazed or Compression
  • 2.1.3 Tubing for Hot Water
    • Material: Pre-lagged copper, “Kemlag” or equal
      • Jointing: Capillary, Brazed or Compression
  • 2.1.4 Tubing for Drainage from Fittings
    • Material: UPVC or to match fitting outlet and in accordance with regulations
      • Jointing: Solvent-welded
  • 2.1.5 Tubing for Gas Service
    • Material: Copper
    • Jointing: Capillary, Brazed and Threaded
  • 2.1.6 Chrome Plating (Refer current relevant Australian Standard)
    • Location: All exposed pipes
    • Base Material: Brass or copper
  • 2.1.7 Sewer Drain Pipes:
    • UPVC Sewer grade pipes with solvent joints.
  • 2.1.8 Storm Water Pipes:
    • UPVC stormwater grade pipes with solvent joints.
  • 2.1.9 Pit Covers:
    • Refer to Hydraulic Engineer’s Drawings.
  • 2.1.10 Grated Drains:
    • All grated drains to be fitted with light duty galvanized metal grating or cast-iron grating with longitudinal grate bars. Both types to be provided with cast-in metal frames. Refer External Finishes Schedule.
  • 2.1.11 Patio Drains:
    • Waterproof decks to be provided with metal floor drains of an approved type manufactured for that purpose. “Fulgo”, “C.l. and D” or equivalent.
    • Stormwater Detention Pits and Discharge Control Pits: Refer to Hydraulic Engineer’s drawings.
    • Provide access hatch if required.

2.2 Hot Water Heater

  • 2.2.1 Maximum temperature at ablution outlets : 50’C.
  • 2.2.2 Maximum recommended temperature at kitchen sinks and laundry tubs: 60‘C.

2.3 Tapware

  • 2.3.1 General: Provide the tapware as documented.
  • 2.3.2 Metal heads and handles: Provide brass fittings or suitably bushed to prevent electrolysis and growth.
  • 2.3.3 Plastic heads and handles: Provide break-resistant fittings of a compact nature, to prevent fracture and exposure of jagged or rough edges.
  • 2.3.4 Tap positions: Locate hot tap to the left of or above, the cold tap. If there is sufficient space, install with valve spindles vertical.
  • 2.3.5 Vandal proof heads: If available, provide vandal proof or anti-tampering devices for the designated types.
  • 2.3.6 Water efficiency: Provide water efficient tapware as follows:
    • Shower heads: To current relevant Australian Standard and suitable for the pressures and pressure differences of the supplied water.
    • Water efficient tapware: Tested and labeled with their water efficiency rating to current relevant Australian Standard.

2.4 Thermostatic mixing valves

  • 2.4.1 General: Water temperature regulated by a single hand control, capable of delivering water at the temperature of either of the supply systems and at any temperature in between and suitable for controlling single or multiple outlets, as appropriate.
  • 2.4.2 Controls: Incorporate the following.
    • A temperature sensitive automatic control which maintains temperature at the pre-selected setting and rapidly shuts down the flow if either supply system fails or if the normal discharge water temperature is exceeded.
    • Hot water flush facility.

2.5 Line strainers

  • 2.5.1 Type: Low resistance, Y-form bronze bodied type, with screen of dezincification resistant brass, stainless steel or monel.
  • 2.5.2 Screen perforations: 0.8mm maximum.

2.6 WELS Scheme

  • 2.6.1 WELS – Water Efficiency Labelling and Standards Scheme is a Federal Government initiative.
  • 2.6.2 All water using fixtures sold, bought and installed must comply with the WELS scheme including all showers, taps, spouts, urinals, WCs, etc.
  • 2.6.3 Compliance with the WELS scheme must be produced when requested by the Principal. Any products installed under the WELS scheme must also comply with the current relevant Australian Standards.

2.7 Equipment

  • 2.7.1 Provide all necessary equipment to effect a complete installation of each part of this Section, including seals, jointing materials, flanges, etc.
  • 2.7.2 For specific items refer to Interior Finishes Schedule.

2.8 Fabrication

  • 2.8.1 Fabricate all components in a manner approved by the Local Authority and the Contractor. Comply with requirements of current relevant Australian Standards where applicable.


3.0 Examination

  • 3.01 Visit the site before delivery of materials, and compare conditions with those shown on Drawings.
  • 3.02 Start of any work means total acceptance of all conditions.

3.1 Installation Piping

  • 3.1.1 General: Install piping in straight lines and to uniform grades. Arrange and support the piping so that it remains free from vibration and water hammer, while permitting thermal movement. Keep the number of joints to a minimum.
  • 3.1.2 Prevent direct contact between incompatible metals.
  • 3.1.3 Concealment: If practicable, conceal piping and fittings requiring maintenance or servicing so that they are accessible within non-habitable enclosed spaces such as roof spaces, sub- floor spaces and duds.
  • 3.1.4 Keep pipelines in sub-floor spaces at least 150mm above ground and ensure access can be provided throughout for inspection.
  • 3.1.5 Provide at least 25 mm clearance between adjacent pipelines (measured from the piping insulation where applicable).
  • 3.1.6 Embedded pipes: Do not embed pipes that operate under pressure in concrete or surfacing material.
  • 3.1.7 Building penetrations: If piping or conduit penetrates building elements, provide metal or PVC-U sleeves formed from oversized pipe sections.
  • 3.1.8 Pipe support materials: To be the same as the piping, or galvanized or non-ferrous metals, with bonded PVC-U or glass fibre woven tape sleeves where needed to separate dissimilar metals.
  • 3.1.9 Cover plates: Where exposed piping emerges from wall, floor or ceiling finishes, provide cover plates of non-ferrous metal, finished to match the piping, or of stainless steel.

3.2 Connections to Network Utility Operator mains

  • 3.2.1 General: Excavate to locate and expose the connection points and connect to the Network Utility Operator mains.
  • 3.2.2 On completion, backfill and compact the excavation and reinstate surfaces and elements which have been disturbed such as roads, pavements, kerbs, footpaths and nature strips.

3.3 Connections to Supply

  • 3.3.1 Principal to arrange with the supply authority, obtain and install any required meter equipment complete with meter housing, and conned in accordance with the Authority’s requirements.

3.4 Trenching

  • 3.4.1 Form straight and true trenches, maintain sides and keep free from water.
  • 3.4.2 Form trenches and bedding to provide constant falls as approved by the local Authorities.
  • 3.4.3 Arrange for inspection by relevant Authority before backfilling.

3.5 Pipe Laying

  • 3.5.1 Lay pipes 600mm clear of walls.
  • 3.5.2 Connect with materials appropriate to the pipes in accordance with manufacturer’s instructions.
  • 3.5.3 Provide inspection openings, bends and junctions required by Authorities.

3.6 Pipes Below Structures

  • 3.6.1 Where sewer or drain pipes are laid below or under structures, comply with requirements of local Authority.

3.7 Connections to Other Services

  • 3.7.1 Conned downpipes to storm water drains with appropriate pre-formed or special upturns, shoes, etc.
  • 3.7.2 Seal thoroughly with water-tight material as recommended by component manufacturer.
  • 3.7.3 Connect new lines to road or street sewer and drainage to the requirements of the relevant Authority.

3.8 Fabrication and Jointing

  • 3.8.1 Fabricate and join all components to the authority’s approval, to applicable current relevant Australian Standards and to the manufacturer’s’ instructions.

3.9 Rainwater Tanks and OSD Tank (if applicable)

  • 3.9.1 Accessories: Provide accessories needed to complete the installation and constructed from corrosion resistant material compatible with the tank material. Include the following:
    • Electric pump if required and to Hydraulic Engineer’s specification.
    • Inlet and outlet connections.
    • Floating outlet to draw water from the upper part of the tank.
    • Tight fitting lids or insect proof screens at all openings.
    • Flap valves at every opening to the tank.
    • Calmed inlet to the tank to prevent stirring sediment.
    • Flywire screened overflow siphon to skim surface contaminants.
    • Vermin proof, child proof access hole.
    • Easily cleanable filter prior to the entry to the tank. Mesh size <1 mm.
  • 3.9.2 Refer Hydraulic Engineer’s Specification.
  • 3.9.3 Polyethylene tanks: To current relevant Australian Standard.
  • 3.9.4 Coated steel tanks: Metallic-coated steel with polymer film to current relevant Australian Standard on the inside and pre-painted on the outside.
  • 3.9.5 Bladder tanks: Proprietary plastic bladder type constructed from polymer conforming to current relevant Australian Standard, resistant to puncture and microbial attack.

3.10 First flush diverter:

  • 3.10.1 General: Provide first flush diverters arranged to drain completely and selected for >20L/100 m2 rainwater catchment area.
  • 3.10.2 Construct from corrosion resistant and compatible with the rainwater plumbing and tank.
  • 3.10.3 Discharge waste-water from the first flush diverter either: (if permitted by the local authority) onto grassed areas away from tank and building footings or; to the stormwater installation.

3.11 Installation

  • 3.11.1 General: Provide structural support to withstand the mass of the tank when full without deformation or excessive settling. Support connecting piping independently of the tank.
  • 3.11.2 Provide a 300 mm long section of reinforced flexible Hose to prevent piping exerting a load on the tank.
  • 3.11.3 Pipe overflow to discharge to stormwater line.
  • 3.11.4 Prevent the entry of sunlight to the interior of the tank.
  • 3.11.5 Above ground tanks: Restrain the tank to prevent movement, when empty, caused by wind and other loads. Provide a level base with gaps not exceeding 10 mm, free of sharp projections and projecting beyond the edge of the tank at all points.
  • 3.11.6 Polyethylene tanks: Trim and compact the ground and place a level bed of sand at least 50 mm thick.
  • 3.11.7 Coated steel tanks: Fully support the tank on a self draining timber or concrete base. Prevent contact with dissimilar metals. Arrange so that no part of the tank is below ground level and so that adjacent ground surfaces fall away from the tank. Do not use sharp objects inside the tank. Remove swarf with a magnet if drilling or cutting.
  • 3.11.8 Bladder tanks: Locate on level base free from sharp objects. Install with manufacturer’s supporting frame. Provide over-pressurising relief and air vent.
  • 3.11.9 Cleaning: Flush the rainwater system. Wash and flush tanks to remove manufacturing and other contaminants.

3.12 Gas

  • 3.12.1 To current relevant Australian Standard.
  • 3.12.2 Buried pipes
    • Warning tape: During backfilling, lay plastic warning tape 300 mm above and for the full length of buried gas pipes.
    • Type: Minimum 100 mm wide, with ‘GAS PIPE UNDER’ marked continuously.

3.13 Commissioning

  • 3.13.1 General: On completion of installation and testing, turn on isolating and control valves and purge and charge the installation.

3.14 Capping

  • 3.14.1 Where noted cap lines for future installment of fitments as noted on drawings or instructed by the Contractor.

3.15 Testing

  • 3.15.1 Cover no pipes, joints or connections until tested and passed by the relevant authority, and approved by the Contractor.
  • 3.15.2 Submit to the Principal copies of any and all certificates issued by relevant authorities.

3.16 Protection

  • 3.16.1 Protect all work of this Section from damage until Completion is achieved.

3.17 Cleaning

  • 3.17.1 On completion, remove all debris and clean all visible work to the Contractor’s satisfaction.

3.18 Completion

  • 3.18.1 Complete all contracted work in accordance with contract documents and written instructions issued by the Principal or Building Supervisor.

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