Decking in Perth (2026)
Perth's sandy soil makes footings cheap, but isolation and double-brick walls shape the rest of a deck quote.
| Decking boards (140mm hardwood) | 35 lengths | $1,663 |
| Joists | 15 | |
| Bearers | 4 | |
| Posts / footings | 10 | |
| Decking screws | ≈840 | |
| Substructure & fixings | $1,482 | |
| Installation labour | $3,840 |
or from $33/week over 5 years , indicative finance
How we estimate this
The number of decking boards depends on your deck area, board width and the gap between boards. This calculator allows ~10% for cutting waste and works out the supporting joists, bearers and posts as well.
Pricing reviewed: June 2026.
What a decking costs in Perth
Perth's free-draining sandy soils are quick and cheap to dig, so deck footings go in easily and a ground-level build on a modern slab home is among the more affordable in the country. Where a deck has to tie into a double-brick house, fixing a ledger into solid masonry is more involved than screwing into a timber frame, so that connection detail carries more labour than an eastern-states equivalent.
Isolation is the quiet cost: composite boards, specialist hardwoods and fixings often freight in from the eastern states, adding lead time and dollars that Perth builders price in. The dry Mediterranean climate and hot summers mean a deck gets heavy use but also bakes, so a UV-stable finish matters, and coastal suburbs add salt that favours corrosion-resistant screws and brackets.
Compare against the national picture: Decking in Australia →
Decking in other cities
Frequently asked questions
How many decking boards do I need?
It depends on the deck size, board width and gap. As a guide, 140mm boards with a 4mm gap cover about 7 lineal metres per square metre. The calculator works out the exact count plus waste.
How far apart should deck joists be?
Joists are commonly spaced 450mm apart for residential decks, closer for some composite boards. Always check the board manufacturer’s span requirements and Australian standards.
How much does decking cost per square metre?
Decking typically costs $200–$350 per square metre installed in 2026, depending on material. The calculator separates materials, substructure and labour.