CPCCCA3003 — Install flooring systems

◈What this unit is about

This unit covers building a house floor from the ground up — setting out and installing the supports, bearers and joists, then fixing strip or sheet flooring on top, all to the drawings, the National Construction Code and the manufacturer's specifications. Everything else in the build stands on this floor, so a frame that is level, square and properly protected from damp and termites is the difference between a sound job and years of callbacks.

The load path, top to bottom: flooring → joists → bearers → ant cap and damp proof course → stumps or piers → footings. Every layer has a job.

What assessment looks like: you'll be expected to build a bearer and joist system on supports (at least 30 m², carrying external walls and internal walls parallel to joists) including deck/balcony fixings and deep joists, plus lay a tongue and groove strip floor (≥5 m²), an approved wet-area floor system (≥5 m²) and a sheet platform floor (≥10 m²).

1Plan and prepare

Start with the paperwork. Read and interpret the drawings, specifications and work instructions, then plan the sequence of work before anything gets cut.
Know what "compliant" means for this job. Plan all work to meet the laws and regulations, the National Construction Code (NCC), relevant Australian Standards, WHS and environmental requirements, manufacturers' specifications and your workplace's own requirements — the drawings and specs tell you what right looks like.
Tools before task. Select the tools and equipment the job needs, check each item is serviceable, and report anything faulty — tag it out, don't work around it.
PPE per stage. Select and use the PPE each stage of the task calls for — cutting, nailing and adhesive work all demand different protection.
Walk the site first. Inspect the work area, locate services, assess hazards and put risk controls in place, including any signage and barricades required.
Materials ready to go. Select the right materials, calculate quantities from the plans, handle them safely and stack them positioned ready for use.

On site: the sequence matters — supports, then bearers, then joists, then flooring. Planning the order (and material deliveries to match) is half the job.

2Set out and install the support structure

Transfer the drawings to the ground. Position stumps, piers or posts exactly to the set-out lines, drawings and specifications — spacing and alignment come from the documents, not from habit.
Install to spec. Footing depth, embedment, packing and fixings all follow the specification for the support type being used.
Check before you build on it. Every support gets checked for level, plumb and square. An error here multiplies through every layer above it.

3Install bearers

Joins land over supports. Mark and cut bearer material to lengths so that every join sits over a stump, pier or post — never mid-span.
Damp and termite protection go in first. Arrange for the damp proof course and termite shields (ant caps) to be installed wherever the regulations require them — before the bearers go down, because you can't slide them in afterwards.
Fix, then verify. Locate and fix the bearers, then check and adjust for square, in-line and level along the full run.
Decks and balconies: fix waling plates to the external walls exactly to the connection detail. Deck attachment is specifically covered by the NCC — this connection failing is how decks collapse.

4Install floor joists

Set out the spacings from the documents. Mark joist positions at the spacings shown on the drawings and specification (450 mm centres is common — but the documents rule, not the rule of thumb).
Sight every joist. Check each one for straightness, install crowns facing up, then fit and fix to line and level.
Support the openings. Fit and fix supporting blocks and trimmers around doorways and other openings so nothing is left hanging.
Support the sheet joints. Cut, fit and fix trimmers wherever sheet-flooring joints will land between joists — every sheet edge needs solid support underneath it.

5Install flooring

Check materials for suitability first. Right product for the area (wet-area rated where the specs say so), undamaged, dry, and properly acclimatised to the site before fixing.
Measure the floor as built, not as drawn. Confirm the actual measurements on site, then cut and prepare the flooring to install with a minimum of waste — plan your cuts so offcuts get used.
Fix to the manufacturer's specifications. Fastener type and spacing, adhesives, expansion gaps, joint layout — the manufacturer's instructions are part of compliance, not a suggestion.

6Clean up

Leave the site right. Clean up meeting all legislative and workplace requirements for safety, waste disposal and materials handling — sort and dispose of waste correctly, recycle or reuse where you can, and stack leftover materials safely.
Look after the gear. Check, maintain and store tools and equipment properly, and report any faults so the next person isn't handed a problem.

★Know this cold

The knowledge an assessor will expect you to carry in your head:

The rules of the game: NCC compliance requirements — including deck attachment — plus the relevant Australian Standards, NASH standards for steel-framed housing, and the regulatory requirements that apply to floor framing and flooring.
Your workplace's quality policies and standards for flooring work, and the safety requirements that go with installing flooring systems.
Damp proofing and termite barriers: what's required, where they go, and how they're arranged and installed.
Floor and flooring system types — their characteristics, construction methods and installation techniques.
Floor framing options and where each is used: premanufactured joists · conventional bearers and joists · drop-in (in-line or deep) joist construction · timber or steel sub-floor frames · sub-floor support construction.
Support systems: concrete stumps · timber stumps · masonry piers · steel posts · patented adjustable supports · timber or brick walls.
Flooring materials and their uses as required by the NCC and other legislation:

Material	Typical use	Watch for
T&G strip flooring	Finished timber floors, fitted board by board	Acclimatisation; expansion allowance; fixing pattern
Floorboards	Traditional board floors over joists	Cupping if laid too wet; crown and grain direction
Engineered products	Engineered flooring and framing members made to spec	Manufacturer's span tables and fixing details rule
Sheet products (particleboard, plywood)	Platform floors laid before the walls go up	All joints supported; wet-area rated sheets where specified; glue and fix to spec

Acclimatisation of flooring materials — why timber must adjust to the site's conditions before fixing.
Imposed loads — the types of loads a floor carries in service (people, furniture, fittings) and their effects on the structure.
Insulation products — the types used with floor systems.
Plans, drawings and specifications — reading and applying them for flooring work.
Tools and equipment used to install flooring systems, and what each is for.
Calculating material quantities from the plans so waste is minimised.
Setting out and levelling techniques — string lines, levels, laser levels, checking square by diagonals.

!Where people slip up

✗ Laying strip flooring straight off the truck.

✓ Acclimatise it first, to the manufacturer's specification. Timber that hasn't adjusted to the site's moisture conditions will cup, gap or buckle after it's fixed — and by then it's too late.

✗ Fixing joists without sighting them — or with crowns facing down.

✓ Sight every joist along its length and install the crown facing up. Load will settle a crown flat; a crown fixed down reads as a permanent dip in the finished floor.

✗ Treating ant caps and the damp proof course as optional extras.

✓ They're regulatory requirements, and they go in before the bearers. Don't puncture, bend flat or bridge them — a damaged shield or DPC quietly defeats the whole system.

✗ Letting sheet flooring joints land unsupported between joists.

✓ Every sheet edge sits on a joist or a trimmer. If the layout puts a joint mid-span, cut and fix a trimmer under it — a bouncing joint becomes a squeaking, cracking floor.

✗ Attaching a deck with a few screws through the cladding.

✓ Deck attachment has specific NCC requirements. The waling plate is fixed to the building's structure with the specified fixings and flashing — this is a life-safety connection, not a convenience one.

AaMini-glossary

Bearer: The horizontal member sitting on the stumps or piers that carries the joists.
Joist: The horizontal members fixed across the bearers that carry the flooring, spaced to the drawings.
Stump / pier: Vertical supports — concrete, timber, masonry, steel post or patented adjustable — carrying the sub-floor frame down to the footings.
Waling plate: A plate fixed to an external wall to carry the joists of a deck or balcony.
Trimmer: A short member fixed between joists to support an opening or a sheet-flooring joint.
Crown: The natural bow along a timber member — always installed facing up so load straightens it.
Damp proof course (DPC): An impervious layer that stops moisture rising from the ground or masonry into the frame.
Ant cap (termite shield): A metal cap on top of stumps and piers that forces termites out into the open where activity can be spotted — a detection aid, not a barrier on its own.
Tongue and groove (T&G): The strip-flooring profile where each board's tongue locks into the groove of the next.
Platform flooring: Sheet flooring fixed across the whole floor frame before the walls go up, creating a safe working platform.
Deep (drop-in / in-line) joists: Deeper joists installed in line with the bearers rather than over them, reducing overall floor depth.
Acclimatisation: Letting flooring materials adjust to the site's temperature and humidity before they're fixed.
Imposed load: The loads a floor must carry in service — people, furniture, fittings — on top of its own weight.
Set-out: Transferring positions from the drawings to the site using lines, measurements and levels.
NCC: The National Construction Code — sets the minimum construction requirements, including for deck attachment.
NASH: National Association of Steel-Framed Housing — its standards apply to steel-framed floor systems.

✓That's the lot

Sequence in your head, documents in your hand, checks at every layer. Come back to these notes before your practical check.

Sections viewed: 0 of 10