Composite decking in Perth's northern suburbs
Northern Decking Co builds composite decks across the City of Joondalup and the City of Wanneroo. Composite boards do not rot, splinter or need oiling, which makes them the usual pick on coastal lots. Tell us the size and the spot and the contractor will quote it free.
What you get
Boards that suit the coast
Composite decking is a board made from wood fibre and plastic, usually with a hard outer cap. It does not rot, split or splinter, termites have no interest in it, and it never needs oiling. On a lot within a few streets of the ocean, where salt air and sand work on everything, that is why most people choose it.
The board is only part of the job. The frame under a composite deck is still timber or steel, and the fixings and hangers are still metal. Near the coast the contractor uses stainless or heavily galvanised hardware for those, because the board outlasting the frame is no good to anyone.
Joists at the right centres
Composite boards flex more than hardwood between supports, so the board maker sets the joist spacing and it is usually tighter than a timber deck: 400 mm centres is common for boards laid straight, and closer again for boards laid on the diagonal. The contractor builds the frame to the specification of the board you choose, which is one reason a composite deck on an old timber frame often needs extra joists first.
Hidden fixings and clean edges
Most composite boards are grooved on both edges and fixed with hidden clips that screw to the joist and hold the board down without a screw head showing. The gap between boards is set by the clip. Ends are finished with a matching fascia board or a picture-frame border, so no cut ends or hollow cores show.
Composite expands along its length in heat, more than timber does, so the contractor leaves the end gaps the manufacturer specifies and fixes boards while they are at a stable temperature. A board laid tight on a cool morning will push its neighbour on a hot afternoon.
Colour and heat
Capped boards hold their colour. Uncapped boards lighten over their first few months and then settle. Darker boards get hotter underfoot in full sun than timber does, so on a north or west facing deck a lighter colour, or some shade, matters more than the brand.
Where composite makes the most sense
Pool surrounds, decks close to the beach, decks on rentals, and any deck the owner does not want to oil again. Where it makes less sense is a shaded, sheltered spot where hardwood would last well and the owner likes the warmth of timber. If you are weighing the two, our composite versus timber guide sets it out honestly.
How it goes in
-
Joists
Joists go across the bearers at the centres the board maker specifies, typically 450 mm for hardwood and tighter for composite.
-
Boards
Boards are laid from the house out with an even gap, fixed with screws or hidden clips.
-
Finish
Fascia and trims go on and the deck is oiled, or a composite deck settles into its finished colour.
What changes the price
- Size
- More area is more boards, joists and fixings, but the rate per square metre usually falls as the deck gets bigger.
- Height
- A deck over 500 mm needs more structure, probably a balustrade, and may need planning approval and privacy screens.
- Material
- Composite costs more per board than most hardwood, and hidden clip systems add to that, but it is the last money you spend on the surface.
- Access
- A deck at the back of a narrow lot means carrying everything through by hand and takes longer.
- Approvals and engineering
- A building permit, drawings and any engineering for a raised deck are real costs that sit outside the build itself.
We do not publish prices, because two decks of the same size can be very different jobs. Read what affects the cost of a deck, then get a free quote from the contractor.
Approvals
City of Joondalup
- Building permit requirements depend on the deck. Confirm with the City of Joondalup on 9400 4000 before work starts.
- For a single house or grouped dwelling, development (planning) approval is not required for decking 500 mm or less above natural ground level.
- Decking over 500 mm can avoid planning approval if it meets the R-Code setbacks for the lot's density.
- A deck within 7.5 m of a side or rear boundary needs a privacy screen at least 1.6 m high.
City of Wanneroo
- All decking requires a building permit, regardless of height or floor area.
- Planning approval may be required for decking over 500 mm above natural ground level.
- Decking over 500 mm is treated like a balcony, with a 7.5 m setback to side and rear boundaries unless a reduced setback is approved.
Check the DFES Map of Bush Fire Prone Areas for your lot. Decks in a bushfire prone area have to meet the BAL construction requirements of AS 3959. DFES Map of Bush Fire Prone Areas.
Questions people ask
Does composite decking get hot in summer?
Darker composite boards get hotter underfoot than timber in full sun. Lighter colours and shade help. On a north or west facing deck the colour choice matters more than the brand.
Does composite decking need a building permit in Wanneroo?
Yes. The City of Wanneroo requires a building permit for all decking regardless of height or floor area. The material makes no difference.
Can composite boards go over an existing timber frame?
Sometimes. Composite needs tighter joist centres than most timber decks were built with, so the contractor checks the frame first and adds joists or replaces the frame where needed.
Get a free quote
Send your details. The contractor calls you, looks at the site and quotes in writing. No obligation.