Published 12 November 2026
When a wash is still enough
If the timber is sound, the old oil has simply faded, and there is no peeling film, a timber clean and brightening wash followed by a maintenance coat is often enough. The boards may look tired and slightly grey, but the surface is still firm, there are no splinters you would not walk on, and water marks lift with a proper clean. That is the point of regular maintenance, described in our guide to how often to re-oil a coastal deck.
A specialist can often test a small patch: clean it, let it dry, and see how much colour returns. If the timber comes back and the grain is sound, you can usually avoid a sand this time.
Signs a sand is the better next step
These are the usual signs that a wash will not do the job:
- •The old coating is peeling, flaking or coming off as a film — typical of acrylic stains and paints
- •Greying is deep, and a clean leaves the boards still dull and fibrous
- •Splinters, a furry surface, or boards that are rough underfoot
- •Cupping (boards drying with a curve) or raised grain that a mop will not settle
- •Patchy, failed oil with bare timber beside shiny, peeling areas
- •Previous coats stacked on top of each other, especially if they were not the same type of product
At that point, new oil sits on a weak surface and tends to fail early. Sanding takes off the oxidised fibres and the old coating so the new oil can soak into fresh timber. That is the work on our deck sanding page.
Peeling stain and paint are a special case
Film-forming coatings sit on top of the timber. Once moisture gets underneath, they lift, and a new coat on top usually fails the same way. Those decks often need chemical stripping as well as sanding, which takes longer than sanding an old oil finish. See peeling stain and paint removal, and our separate guide to dealing with peeling deck stain.
If you have been painting your deck, say so when you enquire. It changes the method and the time on site.
What a typical sand involves
A typical restoration, described in more detail on our 4-stage process page, starts with punching nails below the surface and securing loose boards, then coarse sanding to strip the weathered face, then a finer sand for a smooth, barefoot-friendly finish. Edges and stairs are done with smaller machines. Dust is vacuumed from between the boards, the timber is cleaned, and moisture is often checked with a meter before any oil goes on.
Sanding makes dust. Specialists usually use machines with dust collection — dust-controlled — and you should close nearby windows and move furniture before they arrive. The process is typical, not identical on every deck: a small, already-bare balcony is a different day from a large, painted deck with many stairs.
Coastal details worth mentioning
Decks around Kiama, Shell Cove and the Village take a lot of UV and salt, so coatings fail in a familiar pattern: the seaward or western edge first, then the traffic path. Stainless fixings are common on the coast when old nails have rusted; replacing boards and fixings belongs before the sand, so the whole deck can be finished together. If the frame feels bouncy or posts look rotten, that is a structural question for a builder, not a sanding question.
Kiama is in the Municipality of Kiama, a separate council from the City of Shellharbour. That does not change how you sand a deck, but it can matter if you are also altering a structure or a balustrade.
Repairs before you sand
Proud nails, loose boards and rotten treads should be dealt with first. Sanding over them leaves an uneven floor and can tear a belt. Our board and step repairs page covers replacements and stainless fixings, which are a common upgrade on the coast when old nails have rusted. Mention any bounce in the frame as well: that may be the joists, not the boards, and it should be checked before anyone starts sanding.
How long will the deck be out of use?
It depends on the size, the old coating and the weather. Oil needs dry conditions between coats, so a wet week on the coast will stretch the job. The specialist should give you a timeframe with the quote, including when you can walk on the boards in shoes and when furniture can go back. Plan around that rather than around a generic “one-day” promise, especially if stairs are the only way into the house.
If the deck is a front entrance, ask whether work can be staged so a path stays open. That is a practical question, not a standard package, and it is fair to raise it before they start.
Price, honestly
We have not put a square-metre rate in this article. A wash and a full sand are different jobs, and painted decks take longer than oiled ones. The specialist you are matched with will quote after seeing the deck. Call 0415 770 509 with your suburb, a rough size, the timber if you know it, and a couple of photos of the worst boards. Shellharbour Deck Care is a lead-matching service; the specialist quotes, does the work and is responsible for it.
If you are unsure whether your deck needs a sand or a wash, call 0415 770 509 and we will match you with an independent local specialist who can tell you on site.