NZ Certifying Drainlayer flashcards
NZ Certifying Drainlayer · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Building Code clause G13
- Foul water clause requiring safe removal of foul water from buildings to an appropriate outfall without nuisance, hazard, or objectionable odour affecting people or property.
- Plumbers, Gasfitters and Drainlayers Act 2006
- Statute requiring drainlayers to be registered and licensed by the Plumbers, Gasfitters and Drainlayers Board before carrying out or supervising drainlaying work.
- Trade waste bylaw
- Territorial authority regulation controlling discharge of industrial liquid waste into the public sewer; a written trade waste consent is normally required before discharging.
- AS/NZS 3500.2
- Joint Australian and New Zealand standard for sanitary plumbing and drainage covering design, gradients, venting, materials, installation and testing of below-ground and above-ground systems.
- Gradient as a percentage
- Fall divided by length multiplied by one hundred; a 1:60 grade equals about 1.67 percent fall across the run.
- Self-cleansing velocity
- Minimum velocity of roughly 0.6 metres per second at peak dry weather flow that keeps solids moving and stops sediment depositing in the drain.
- Trap seal depth
- Minimum 50 millimetres of water held in a trap; correct venting protects the seal from siphonage and pressure changes caused by discharge.
- Discharge units
- Relative flow values assigned to each fixture type and used with standard tables to size drains, stacks and vents correctly.
- Minimum pipe cover
- Typically 300 millimetres of soil over a private drain in landscaped ground, increased under driveways and vehicle areas where loads are greater.
- Trench width rule
- Commonly pipe outside diameter plus 300 millimetres, with a 600 millimetre practical minimum, allowing room to haunch and compact beside the pipe.
- Expansive clay
- Soil that swells and shrinks as moisture changes, moving pipes and requiring specific bedding, pipe class and often greater cover.
- Percolation test
- Falling head test in a trial hole measuring how quickly water drains through the soil, used to size on-site effluent application areas.
- SN stiffness class
- Ring stiffness rating of uPVC sewer pipe, such as SN4, SN8 or SN16; higher classes resist greater soil and traffic loads.
- Butt fusion joint
- Polyethylene joining method where squared pipe ends are heated and pressed together, producing a joint as strong as the parent pipe.
- Roll-on rubber ring joint
- Concrete pipe joint where a lubricated rubber ring on the spigot rolls into the socket, giving a flexible, sealed connection.
- Solvent cement joint
- uPVC joint made by priming and cementing cleaned, chamfered surfaces, then pushing fully home with a quarter turn and holding until set.
- Socket facing upstream
- Laying rule where sockets point against the direction of flow so spigots enter downstream, helping joints resist root entry and debris.
- Inspection point
- Access fitting required at the foot of stacks, at sharp bends, on long runs and near boundaries so the drain can be rodded and inspected.
- Thrust block
- Concrete block cast against a bend or tee on a pressure main to absorb unbalanced hydraulic thrust and stop joints pulling apart.
- Compacted side support
- Backfill placed and compacted evenly in layers on both sides of a flexible pipe, which is what allows the pipe to carry load.
- Water test
- Drain plugged at the low end and filled with water to the required head, commonly at least 1.5 metres above the highest point, then checked for leakage.
- Pre-cover inspection
- Building consent authority check of drainage before backfilling, confirming alignment, gradient, bedding and jointing match the approved plans.
- Mandrel deflection test
- Test pulling a mandrel or deflectometer through a flexible pipe after backfill to confirm it has not been flattened beyond permitted limits.
- Grease interceptor
- Chamber that separates and retains fats, oils and grease from kitchen trade waste before the sewer, and must be regularly pumped out.
- AS/NZS 1547
- Standard for on-site domestic wastewater management covering treatment system selection, land application area sizing and required setback distances.
- pH discharge limit
- Trade waste consents typically restrict discharge to a pH range of roughly 6 to 10 to protect sewers, treatment plants and workers.
- Invert level
- Level of the inside bottom of a pipe; burial depth is calculated as surface level minus invert level using one datum.
- Longitudinal section
- Profile drawing of a drain showing chainages, invert levels and grades between structures, used to confirm the fall achieved on site.
- Record of work
- Certification issued by a licensed drainlayer confirming the work complies with the applicable standard and falls within their licence class.
- 1.5 metre rule
- Excavations deeper than 1.5 metres must be shored, benched or battered and inspected by a competent person before entry.
- Notifiable event
- Death, serious injury or dangerous incident that must be reported to WorkSafe New Zealand as soon as practicable and then investigated.
- Site-specific safety plan
- Document identifying site hazards, controls, emergency arrangements and responsibilities, prepared before drainage work starts on the contract.