Decking in Adelaide (2026)
Adelaide is the cheapest mainland capital to build a deck, with its reactive clay the one thing to engineer around.
| 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 Adelaide
Adelaide's affordable trade labour and lower disposal costs feed straight through to a deck quote, so a standard ground-level or low-rise deck on a conventional home is usually the best value of any mainland capital. Generally accessible single-storey housing stock keeps the build simple, with room to deliver materials and work without the access premiums the eastern capitals carry.
The one factor that must be respected is the notorious reactive clay across much of the city, which is hard on footings and will heave a deck that is not founded properly, so posts need to reach stable ground and be set for movement. The dry Mediterranean climate is otherwise kind to exterior timber, with low salt exposure away from the gulf suburbs, so finishes last and recoating is less frequent than in the humid or coastal capitals.
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.