Sketches should be used to illustrate
answers wherever practicable.
Calculations: Simple calculations
relating to volumes of earthworks (trenches) or shingle.
Materials: Cement sand, shingle, mortar, concrete (selection mixing and use),
calcium chloride, sodium silicate (use of in concrete and water).
Jointing materialsrings, sleeves, mortar, bitumen, clay, cement.
Pipes and fittingsearthenware, concrete, asbestos, cement,
plastics. Ideal qualities of pipes and fittings.
Tools and Equipment: Drainlayers' tools, electrical equipment.
Safety Precautions: Knowledge of dangerous gases as applicable to drains and sewers.
Use of isolating transformers. Rescue breathing.
Principles of Drainage
Design: Planning of drainagedomestic and commercial,
access to and cleansing of drains, manholes and other access openings.
Systems: General knowledge of storm water and foul water
systems, combined systems, separate systems, storm water drain fittings,
oil and petrol traps; sewage tanksNZSS758; septic closets.
Simple understanding of decomposition of sewage and effluent disposal
Drain Jointing: Methods of making flexible
and rigid joints.
The Laying of Drains: Levelling, gradients,
trenching, bedding of drains, back-filling, safety precautions for
earthworks and excavations, the use of simple pumps. Application of
the Construction Regulations 1961 to excavations. Safety measures to protect the public.
Testing of Drains: Air, water, coloured water, mirror, smoke, scent tests.
of Drains: Methods of ventilating with or without the use
of an interceptor trap. Factors influencing flow of air and gases
Regulations: A knowledge of the Drainage and Plumbing Regulations 1959 as applied to drainage work.
Insurance: Types of insurance
applied to the drainlayer.
Practical test of workmanship
Arrangements for a practical test will
be made only after the candidate has passed the written examination
and drawing test. The test shall include such of the following as
the examiner may require to ascertain the competency of the candidate:
Preparing an application for permit
and payment of fees:
information regarding location of junctions on existing sewers:
Locating underground cables, ducts,
to grade and size and protection of trench:
Actual laying of pipes and fittings to include
not less than 20 m of pipe, including four rigid joints:
Bedding and haunching of pipes:
Sealing of inspection openings
and dead ends:
pipes in shallow trench:
Installing and building up gully traps and surrounds:
Building and plastering inspection chambers:
Backfilling trenches and restoring
of drain after completion:
Completing a drainage installation.