Part C2 Sanitary drainage system
Introduction to this Part
This Part sets out the requirements for the design, construction, installation, replacement, repair, alteration and maintenance of any part of a sanitary drainage system of a property including from sanitary fixtures and appliances to an approved disposal system.
The Objective of this Part is to—
- safeguard people from illness, injury or loss (including loss of amenity) due to the failure of a sanitary drainage installation; and
- ensure that a sanitary drainage installation is suitable; and
- conserve water and energy; and
- safeguard the environment; and
- safeguard public and private infrastructure; and
- safeguard people from illness caused by the discharge of swimming pool waste water; and
- protect other property from damage caused by the discharge of swimming pool waste water; and
- ensure that a sanitary drainage installation is designed and is capable of being maintained so that throughout its serviceable life it will continue to satisfy Objectives (a) to (g).
Sanitary fixtures and sanitary appliances must be provided with an adequate disposal system that does not impact adversely on occupants of the premises, property, the environment or the Network Utility Operator's infrastructure.
CP2.1 Design, construction and installation
A sanitary drainage system must ensure the following:
Access for maintenance and clearing blockages.
Ventilation to avoid foul air and gases accumulating in the sanitary drainage and sewerage system.
Protection against internal contamination.
A sanitary drainage system must avoid the following:
Damage from root penetration, superimposed loads or ground movement.
Entry of water, foul air and gases from the system into buildings.
Damage to existing buildings or site works.
CP2.2 Swimming pool drainage
CV2.1 Velocity and liquid-to-air ratio
a liquid-to-air ratio of between 1:1 and 0.65:0.35; and
a minimum velocity of 0.8 m/s; and
a maximum velocity of—
2 m/s under normal operating conditions; and
3.5 m/s under surge conditions.
CV2.2 Pressure testing
C2.2 Invert levels
The invert level of a trap or gully weir must be a minimum of 10 mm higher than the soffit of the pipe to which it connects.
C2.3 Swimming pool drainage
C2.4 General requirements
Explanatory information: Cross-volume considerations
NCC Volume One Class 2 to 9 buildings
NCC Volume Two Class 1 and 10 buildings
Excavations for pipework adjacent to a building and footings
Termite management for attachments to buildings and penetrations through a slab
Penetrations for pipework through a vapour barrier
Pipework in timber bearers and joists of solid timber or engineered wood products
Fittings, fixtures and pipework installations in steel framed construction
Penetrations through a fire-resisting wall or floor