NZ Certificate in Carpentry flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Hierarchy of control

Ranking of hazard controls from most to least effective: eliminate, substitute, isolate or engineer controls, administrative controls, and finally personal protective equipment. PPE is the last line of defence, never the first choice.

Notifiable work threshold

Under NZ health and safety rules, construction work over 5 metres deep, or where a person could fall 5 metres or more, must be notified to WorkSafe before starting.

Fall protection trigger height

Where a person could fall 3 metres or more, fall protection such as guardrails, scaffolds or a harness system must be provided. Ladders are access, not work platforms.

Silica dust control

Cutting concrete, brick or fibre cement releases respirable crystalline silica. Use water suppression or on-tool extraction plus a P2/P3 respirator. Dry sweeping spreads dust and is not acceptable.

Sediment control on site

Silt fences, stabilised entry and exit, covered stockpiles and contained washout water prevent sediment and slurry entering stormwater. Stormwater drains discharge untreated to waterways.

Drawing scale conversion

At 1:100, one millimetre on the drawing equals 100 millimetres on site. At 1:50 it equals 50 millimetres; at 1:20 it equals 20 millimetres. Always confirm the stated scale.

3-4-5 right angle method

A triangle with sides of 3, 4 and 5 units (or multiples such as 6-8-10) has a right angle between the short sides. Used with a string line to set out square corners.

Checking a rectangle square

Measure both diagonals of the set-out rectangle. If the diagonals are equal, the corners are square. Any difference indicates the corners must be adjusted.

Datum and level transfer

A datum is a fixed reference level. Transfer levels with a dumpy or rotary level or total station rather than measuring up from the ground, which accumulates error.

Stair riser and tread limits

For common residential stairs under NZS 3604, riser height is typically 150-190 millimetres and tread depth 250-300 millimetres. Total rise divided by riser height gives the number of risers.

Stud spacing under NZS 3604

Timber wall studs are commonly spaced at 300, 400 or 600 millimetres centres. Closer spacing is required as wind zone, load and bracing demand increase.

Notching and holes in members

Under NZS 3604, notches must not exceed one quarter of member depth. Holes must not exceed one quarter of depth and must sit within the middle third of the depth.

Bracing units (BU)

NZS 3604 rates braced wall elements in bracing units. The total BU required depends on wind zone and floor area, and is distributed across the building's walls.

Truss installation rule

Roof trusses must be installed to the manufacturer's layout and fixing schedule. Top and bottom chords must never be cut or notched without specific engineering approval.

Four Ds of weathertightness

Deflection keeps water off the building, drainage removes water that gets in, drying allows moisture to escape, and durability ensures materials last in the designed exposure.

Cladding cavity requirement

E2/AS1 requires a drained and ventilated cavity, typically 20 millimetres deep, behind most cladding types. Cavity battens create this space and allow water to drain out.

Cladding ground clearance

Under E2/AS1, cladding must finish at least 100 millimetres above paved ground and 175 millimetres above unpaved ground to prevent moisture uptake and capillary rise.

Flashing lap direction

Flashings are lapped shingle-style: the upper flashing laps over the lower one so water runs outward and downward. Head flashings need a minimum 10 millimetre upstand.

Building wrap installation

Wall underlay is installed with laps per the manufacturer, typically 75-150 millimetres, and lapped over flashings so any water drains outward, not into the frame.

Lining fixing centres

Thirteen millimetre plasterboard on walls is fixed to studs at 600 millimetres maximum centres. Ceiling battens are typically at 400-600 millimetres depending on sheet thickness and span.

Level 4 plasterboard finish

Level 4 is the New Zealand standard finish for painted interior walls. Level 5 adds a skim coat over the whole surface for critical lighting or gloss paints.

Wet area lining requirements

Bathrooms and laundries use moisture-resistant plasterboard. Showers require a waterproof membrane under E3/AS1, installed before tiling and turned up walls and over curbs.

Timber treatment classes

H1.2 suits interior dry use, H3.1 and H3.2 exterior above ground, H4 ground contact, and H5 in-ground or marine. Treatment must match the exposure and hazard.

SG8 timber grade

SG8 is the common New Zealand structural grade for radiata pine, with a characteristic bending stress of 8 megapascals. MSG8 and VSG8 denote machine and visual stress grading.

Circular saw blade depth

Set blade depth so the teeth protrude no more than about 5 millimetres below the timber. The retracting guard must return freely before use.

RCD protection on site

Portable electrical tools on construction sites require residual current device protection. 230 volt tools must be RCD-protected, or use 110 volt (SELV) equipment.

Ladder 1 in 4 rule

Set the ladder base one unit out for every four units of height. Secure top and bottom, and maintain three points of contact while climbing.

Site induction purpose

Induction covers site hazards, emergency procedures, first aid arrangements and site rules. Every worker and visitor must be inducted before entering the work area.

Toolbox talk

A short pre-task briefing, usually 5-15 minutes, covering the hazards, controls and any changes to the plan for the work about to start.

Written variation

A variation changes the agreed scope, price or programme. It must be recorded in writing and signed before the work proceeds; verbal instructions should be confirmed by email.

Durability periods under B2

Building Code clause B2 sets durability at 50 years for structural and inaccessible items, 15 years for accessible but not easily replaced items, and 5 years for easily replaced items.

Producer statements

PS1 covers design, PS2 design review, PS3 construction and PS4 construction review. They are issued by suitably qualified people as evidence of compliance with the Building Code.