Certificate III in Carpentry flashcards

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

Hierarchy of control

Ranked risk controls from most to least effective: eliminate, substitute, engineering, administrative, then PPE. Controls higher in the list are preferred because they protect everyone without relying on individual behaviour.

Safe work method statement

A written document listing high-risk construction work, the hazards involved, the controls to be applied and how they will be monitored. It must be reviewed when the work or conditions change.

Fall arrest threshold

Fall protection is required where a person could fall two metres or more, or any distance onto a hazardous surface. Edge protection and covers are preferred over harness systems.

Four-to-one ladder rule

The ladder base is set out one unit horizontally for every four units of height. This gives roughly a 75-degree angle, which keeps the ladder stable under load.

Roof pitch ratio

Pitch expressed as rise over run, such as 1:4. Convert to degrees with the tangent: tan(angle) = rise ÷ run, so 1:4 gives about 14 degrees.

Three-four-five method

A squaring check using a triangle with sides in the ratio 3:4:5. Measure 3 and 4 units along two lines; if the diagonal is 5 units, the corner is square.

Nominal versus actual timber

Nominal size is the rough sawn dimension used to name the timber; actual size is the smaller dressed dimension after planing. Span tables and loads use the actual size.

Drawing scale calculation

Real length equals drawing length multiplied by the scale factor. At 1:100, one millimetre on the drawing represents 100 millimetres, or 0.1 metre, on site.

Timber moisture content

The mass of water in timber as a percentage of its dry mass. Framing is typically installed near 10 to 15 percent so shrinkage and movement after installation stay small.

Formwork concrete load

Normal-weight concrete weighs about 24 kilonewtons per cubic metre, so a 200 mm slab imposes roughly 4.8 kilopascals of dead load on formwork before live loads are added.

Formwork stripping rule

Formwork is removed only when concrete has gained enough strength to carry itself and construction loads. Sides may come off early; soffits and props stay until the specified strength is verified.

Stair rise-going formula

A comfortable stair satisfies 2 x rise + going between about 550 and 700 millimetres. Typical values are a 150 to 190 millimetre rise with a 240 to 300 millimetre going.

Equal risers requirement

Every riser in a flight must be the same height, because unequal risers are a major trip hazard. Total rise divided by the number of risers gives the individual rise.

Common rafter length

The common rafter true length equals half the span divided by the cosine of the pitch angle. The rafter is then reduced for the ridge and extended for the eaves overhang.

Hip rafter multiplier

A hip or valley rafter is longer than a common rafter by dividing by the cosine of the plan angle. For a square hip at 45 degrees, multiply the common rafter by about 1.414.

Cavity and weep holes

A drained cavity behind cladding lets water escape and air circulate. Weep holes at the base and open joints at the top allow drainage and drying, reducing moisture trapped against the frame.

Flashing lap direction

Flashings must lap so the upper piece overlaps the lower piece, keeping the lap in the direction of water flow. Reverse laps trap water and lead to leaks and decay.

Fascia and overhang set-out

Fascia height is set from the top plate plus the birdsmouth seat cut. The overhang is measured horizontally from the wall line, so the rafter tail length must be calculated, not guessed.

Door and window squaring

Openings are set from a datum and checked for plumb, level and square by comparing diagonals. Equal diagonals confirm a true rectangle before the frame is fixed.

Bearer and joist relationship

Bearers are the lower members supported on posts or piers; joists sit across the bearers and carry the decking or floor. Decking boards then run across the joists.

Area and volume formulas

Area equals length times width; volume equals area times thickness. Keep all dimensions in metres so the result is in square or cubic metres for ordering.

Waste allowance

Extra material added to a take-off to cover cutting, breakage and defects. Sheet goods and framing commonly use 5 to 10 percent, with more for complex cut-heavy work.

Concrete order volume

Calculate length times width times depth in metres, add about 5 to 10 percent for compaction and spillage, then round up. Concrete is ordered and charged in full cubic metres.

Total cost build-up

Total price equals materials plus labour hours times rate, plus plant, subcontractors, overheads and margin. Contingency is shown as its own line rather than buried in rates.

PCBU primary duty

The person conducting a business or undertaking must manage health and safety risks so far as is reasonably practicable, consulting workers and providing information, training and supervision.

Notifiable incident

A death, serious injury or illness, or dangerous incident arising from work must be reported to the regulator immediately, and the site must not be disturbed until released.

Silica dust controls

Cutting silica-containing products requires water suppression or on-tool extraction, plus fit-tested respiratory protection. Dry sweeping and compressed air spread respirable dust and are avoided.

Sediment control principle

Sediment fences and traps are placed downslope of disturbed ground so runoff slows and drops soil before reaching drains. Stormwater carries pollution directly to waterways.

Written variation

Any change to scope, time or price should be documented and confirmed in writing before work proceeds. Undocumented verbal instructions are difficult to prove and often unpaid.

Site diary purpose

A daily record of weather, labour, deliveries, visitors, instructions and delays. It provides contemporaneous evidence for extensions of time, variations and disputes.

Hold point inspection

A stage of work that cannot proceed until an inspection is passed, such as slab, frame or waterproofing. Covering work before inspection may require it to be opened up.