How to Apply Decking Oil: Step-by-Step Guide for Australian Timber
Applying decking oil correctly is the difference between a finish that lasts years and one that peels within months. This guide covers how to oil a deck step by step, from preparation to final cure, so your timber deck gets the protection it needs in Australian conditions. It also gives the drying time, number of coats and coverage for each of the three decking oils in this guide.
Ready to buy? EcoGrit stocks the products in this guide and ships Australia-wide. Shop the outdoor timber oil range.
Choose the Right Decking Oil
Not all decking oils perform the same way. For Australian hardwoods and treated pine, you need a product designed for exterior use and UV exposure. This guide covers three exterior oils EcoGrit stocks for decks: WOCA Exterior Wood Oil, and Rubio Monocoat DuroGrit and Hybrid Wood Protector. All three data sheets list built-in UV protection.
Check the product data sheet for compatibility with your timber species. Some oils work better on dense hardwoods like spotted gum or merbau, while others are formulated for softer species like pine or cedar.
If you are still weighing it up, WOCA Exterior Wood Oil is a water-based oil for new and previously oiled decks, applied in 1 to 2 coats. Rubio DuroGrit and Rubio Hybrid Wood Protector each colour and protect exterior timber in a single layer.
Tools You Need
Gather everything before you start. You will need: a stiff broom or blower, 120-grit sandpaper or sanding pad (80-grit for Rubio DuroGrit), the brush or applicator your oil's instructions call for (see Step 3), a paint tray, a measuring cup if you are adding an accelerator, clean lint-free cloths, and the decking oil itself. For decks, Rubio's Hybrid Wood Protector instructions also allow a polishing machine with a beige or red pad to spread the oil.
Step 1: Clean the Deck Thoroughly
Remove all furniture, pots and debris. Sweep the entire deck surface. For decks with mould, algae or grey weathering, use a timber deck cleaner first. Rinse with a garden hose. Rubio Monocoat's Hybrid Wood Protector instructions say never to use a high pressure cleaner. Allow the deck to dry completely. This takes 24 to 48 hours depending on weather.
Do not skip this step. Oil applied over dirt, mould or moisture will not penetrate properly and will fail early.
Step 2: Sand the Surface
If the deck is new, a light sand with 120-grit (80-grit for Rubio DuroGrit) removes mill glaze and opens the timber grain for oil absorption. For weathered decks, sanding removes grey surface fibres and creates a fresh surface.
Sand in the direction of the grain. Remove all sanding dust with a broom and tack cloth before applying oil.
Step 3: Apply the First Coat
Stir the oil thoroughly. Do not shake the tin. Pour a small amount into the paint tray and work in small sections sized to suit your product (see the notes below).
Apply an even coat with the brush or applicator your product specifies. Work the oil into the grain. Avoid puddles or thick spots, as these will become sticky and take longer to cure.
Work with the grain, not across it. Keep a wet edge to prevent lap marks where sections overlap.
WOCA Exterior Wood Oil. Apply an even, thin coat with a brush or WOCA Oil Applicator, treating the end grain first. The wet oil can look white until the water evaporates after a few minutes.
Rubio DuroGrit. Rubio Monocoat Australia recommends adding 10% water to all DuroGrit applications in Australia, whatever the weather. Stir it well before you start and regularly as you go. Brush on a generous coat rather than a thin one, working 1 or 2 boards wide along the full length of each board, and avoid stopping mid-board.
Rubio Hybrid Wood Protector. Stir it until it is even, then add the accelerator (see below). Work in zones of 5 to 10 m²: brush on a small amount, then spread it along the grain with the brush or a polishing machine and pad. Do not thin it with anything else.
Accelerator on decks. For decks, Rubio Monocoat's Hybrid Wood Protector instructions say to add 10% Part B accelerator to the oil. EcoGrit stocks the accelerator as Oil Plus Part B. Once the two are mixed, you have 4 to 6 hours to use them, so mix only what you can apply in that time.
Step 4: Allow Penetration Time
Penetration time varies by product, so check the product instructions for exact timing. Whichever oil you use, wipe off any excess that has not soaked in, using clean, lint-free cloths. WOCA Exterior Wood Oil needs the excess wiped off after no more than 5 minutes, with particular care in joints and grooves. Hybrid Wood Protector is left to react for 10 minutes, smoothed again with the same brush or pad without adding oil, then wiped off after another 5 minutes. For DuroGrit, keep the leading edge wet as you go, then wipe off any excess or pooled oil with a lint-free cloth before it dries.
Excess oil left on the surface will dry as a sticky film that attracts dirt and peels. Removing it is one of the most important steps in the process.
Step 5: Apply a Second Coat Only If Your Oil Needs One
How many coats of decking oil you need depends on the product. WOCA Exterior Wood Oil takes 1 to 2 coats. If the surface does not look saturated once you have wiped off the excess, repeat the application the same way: thin and even, with the excess wiped off within 5 minutes. WOCA's data sheet does not set a waiting time between coats.
DuroGrit and Hybrid Wood Protector are one-layer finishes, so one coat is the normal system. Rubio keeps a second DuroGrit layer for exceptional cases, such as very weathered or highly absorbent boards that colour unevenly, and then thins both layers with 20% water. Extra DuroGrit layers make the finish more film-forming and lengthen the cure.
Step 6: Allow Full Cure Time
The oil needs time to cure and harden inside the timber. Cure times vary widely, from 24 to 48 hours for WOCA Exterior Wood Oil at 20 °C to 7 days for Hybrid Wood Protector (see the table below). During this period, keep foot traffic to a minimum. Do not place furniture back on the deck until the oil has fully cured.
Check the forecast and the temperature before you open the tin, because each data sheet sets its own limits:
- WOCA Exterior Wood Oil: dry weather only, 15 to 30 °C at about 50% air humidity, out of direct sun and high temperatures.
- Rubio DuroGrit: dry weather only, out of direct sun and off hot boards, and not when rain is expected within 10 hours. Above 30 °C, Rubio Monocoat Australia advises up to 20% water or no more than 10% open time extender. The extender can lengthen full cure to as much as 5 days, so allow the extra time before putting any load or furniture on the deck.
- Rubio Hybrid Wood Protector: 10 to 30 °C in dry weather, never in direct sun. If rain reaches the deck within 24 to 36 hours of oiling, rub the surface dry.
How Long Does Decking Oil Take to Dry?
It depends on the oil and the weather. WOCA Exterior Wood Oil is ready for light use after 24 hours at 20 °C and fully hard after 24 to 48 hours. DuroGrit dries in 3 hours, can take light foot traffic after that, and fully cures in 3 days. Hybrid Wood Protector dries in about 24 hours and fully cures in 7 days. For DuroGrit, Rubio notes that low temperatures, poor ventilation and high humidity slow drying and curing significantly.
| Product | Coats and coverage | Drying and cure |
|---|---|---|
| WOCA Exterior Wood Oil | 1 to 2 coats; 8 to 12 m² per litre | Light use after 24 hours; fully hard after 24 to 48 hours (both at 20 °C) |
| Rubio DuroGrit | 1 layer; 13 to 15 m² per litre on medium to high density timber, 8 to 10 m² per litre on lower density timber, 6 to 10 m² per litre on very weathered boards | Dry in 3 hours; full cure in 3 days, or up to 5 days with open time extender |
| Rubio Hybrid Wood Protector | 1 layer; 15 to 30 m² per litre, depending on the timber and preparation | Dry in about 24 hours; full cure in 7 days |
The DuroGrit water and coverage figures follow Rubio Monocoat Australia's local guidance; Rubio's international data sheet gives a standard spread rate of 8 to 15 m² per litre.
Common Mistakes to Avoid
Applying too thick. More oil does not mean more protection. Thin coats that penetrate the timber last longer than thick coats sitting on the surface. DuroGrit is the exception: Rubio says to apply it generously, because too little product can dry too fast and leave more visible brush marks and start and stop lines.
Oiling in direct sun. The oil dries too fast and does not penetrate properly. Work in the shade or during cooler parts of the day.
Skipping the cleaning step. Oil over dirt equals early failure. Every time.
Maintenance Schedule
How often a deck needs a maintenance coat depends on the weather, exposure, which way the deck faces, the timber and the colour. Whichever oil you use, check the deck every spring, once winter is over, and re-oil when you see the signs: water no longer beads on the boards, the colour has faded, or the surface looks worn.
- Rubio DuroGrit: allow up to 2 years between maintenance coats on decks and other horizontal surfaces, and 3 to 5 years on vertical surfaces such as cladding (3 years in more extreme conditions, such as sites very close to the beach or sea). Rubio's yearly check after winter looks for dirt, green deposits and faded colour.
- Rubio Hybrid Wood Protector: Rubio's data sheet gives no set interval, so use the spring check. When the deck shows a lot of wear and the colour needs repair, clean it and apply a new thin coat in the original colour.
- WOCA Exterior Wood Oil: WOCA says to check the treated surface every year, repair any damage straight away and repeat the oil treatment when required. Around swimming pools, or where chemicals are used, it may need re-oiling more often.
A simple water test tells you when to re-oil: splash water on the deck. If it soaks in immediately, it is time for a fresh coat.
EcoGrit stocks professional decking oils from WOCA and Rubio Monocoat. Browse the Outdoors collection to find the right product for your deck.
See also: timber cleaning products.
See also: oil and stain finishes guide.
See also: sanding grit guide.
Related: Which Decking Oil Reigns Supreme in Australia?
Not sure which oil suits your deck? Call our sales team on 0403 964 703, or technical support on 0401 270 818 for application advice.
Sources
- WOCA Denmark, Exterior Wood Oil, technical data sheet (PDF)
- Rubio Monocoat, DuroGrit, technical data sheet (PDF)
- Rubio Monocoat, Hybrid Wood Protector, technical data sheet (PDF)
- Rubio Monocoat Knowledge Center, Can we apply a second layer of DuroGrit for an even better protection or more intense colour?
Products in this guide
- Outdoor timber oil range - exterior timber oils and protectors
- WOCA Exterior Cleaner - lifts dirt, mould and grey weathering before oiling
- WOCA Exterior Wood Oil - water-based oil for new and previously oiled decks
- DuroGrit - 1L - water-soluble oil that colours and protects exterior timber in one layer
- Hybrid Wood Protector - 1 Litre - one-layer exterior oil; add Oil Plus Part B on decks
All available from EcoGrit, shipped Australia-wide. Trade pricing available for flooring professionals.