Stair Construction

The National Construction Code (NCC) 2022 Part 3.9.1 requires: individual rise height of 130-225mm per step, going (tread depth) of 215-335mm per step, and the product of rise × going must fall between 45,000-48,000mm². All risers and goings on the same flight must be uniform within ±5mm tolerance. Minimum 2 risers and maximum 18 risers per flight.

Per AS 1657:2018 and NCC Part 3.9.2, handrails must be installed at minimum 865mm above the nosing line on stairs, and minimum 1000mm above floor level on landings and platforms. Handrail diameter must be 30-50mm for graspability. A transition zone is permitted between stair height (865mm) and landing height (1000mm). Handrails must extend the full length of the flight.

47.1% of saw injuries are caused by kickback. Prevention measures include: always clamp workpiece securely, use a cutting guide or straight edge, ensure blade is sharp and correct for timber, set blade depth to minimum (no more than 10mm below stock), never force the saw through the cut, let blade reach full speed before starting, use jigsaw for completing internal corner cuts instead of forcing circular saw, and use a drop saw for repetitive straight cuts on treads and risers.

No. Bump-fire mode is prohibited on construction sites. SafeWork SA data shows 77% of serious nail gun injuries over 5 years were to apprentices in residential construction. Apprentices and all workers must use sequential trigger (one-shot mode) only, where the trigger must be reset after each shot. Apprentices require additional supervision during nail gun use.

Stairwell voids exceeding 2m fall height require: temporary guardrails (minimum 1000mm) around the stairwell perimeter before work commences, toe boards (150mm) to prevent falling objects, temporary handrails on at least one side as soon as stringers are fixed, scaffold platforms with guardrails for working within the void, and fall arrest harness systems where guardrails cannot be installed. A fall protection plan and SWMS are mandatory.

Per AS 1657:2018 and NCC Part 3.9.2, balusters must be spaced so that a 125mm sphere cannot pass through any opening when tested above the nosing line. This typically results in maximum 100mm spacing between balusters. This requirement prevents children from getting their heads trapped or falling through openings.

Australian workplace exposure limits (8-hour TWA): hardwood dust 1 mg/m³, softwood dust 5 mg/m³. Wood dust exposure can cause nasal cavity cancer, sinus cancer, asthma, and COPD. Controls include HEPA-filtered dust extraction on all power tools, P2 respirators during cutting and sanding, designated cutting areas, wet cleaning or HEPA vacuuming (no dry sweeping), and limiting continuous cutting sessions to 30 minutes.

Yes. Residential stair construction typically qualifies as high-risk construction work (HRCW) under WHS Regulations due to the risk of falls exceeding 2m from open stairwell voids. A written SWMS must be prepared before work commences, identifying all hazards, risk ratings, and control measures. The SWMS must be available on site and all workers must be briefed before starting work.

Stringers must be temporarily braced with diagonal members after positioning and before permanent fixings are completed. Bracing must prevent lateral movement, rotation, and collapse. A competent person must verify bracing stability before workers load the stairs. Temporary bracing must be inspected daily and after any weather event or vibration that could affect stability. Do not remove bracing until all permanent connections are verified secure.

Minimum requirements: General Construction Induction (White Card — CPCCWHS1001) mandatory for all construction sites, Certificate III in Carpentry (CPC30220) or equivalent trade qualification, Working at Heights training for work above 2m, and power tool safety training. Additionally, nail gun operation training is required, and at least one person on site should hold a current First Aid Certificate. Apprentices require direct supervision during stair construction.