Salt air, hard sun and heavy summer rain are tough on decks. None of this is complicated, but doing it on a schedule is the difference between a deck that ages well and one that needs replacing in ten years.
Timber decks
- Sweep grit off regularly — it holds moisture and scratches the coating.
- Wash annually with a deck cleaner and a stiff broom, not a high-pressure lance on full power.
- Re-oil every 12 to 18 months on exposed decks, every two years on covered decks.
- Coat before the timber greys off; once it's checked, you'll need to sand back first.
- Keep pot plants on feet so water isn't trapped against the boards.
Composite decks
- Wash down with soapy water a couple of times a year.
- Clear the board gaps so water drains and leaves don't compost in there.
- Treat oil and sunscreen spills promptly rather than letting them sit.
- No oiling or sealing — most warranties specifically exclude coatings.
The annual structural check
- Look at post bases and bearer-to-wall junctions for moisture and rot.
- Check for rust stains or screws sitting proud, especially near the coast.
- Confirm water drains away under the deck and airflow isn't blocked by garden beds or screening.
- Test balustrades for movement — they're a safety item, not a cosmetic one.
Common questions
Can I pressure wash my deck?
- Gently, with a wide fan at low pressure and the tip kept well back. High pressure tears the soft fibre out of timber and leaves permanent lap marks.
What's the best oil for a hardwood deck?
- A quality penetrating decking oil suited to the species, applied in dry, mild conditions. What matters most is coating on schedule rather than which brand you pick.
Do composite decks need sealing?
- No. Sealing or oiling composite boards can void the manufacturer's warranty — cleaning is all they need.