Decking Oils, Stains and Treatments: Part 3 – Application & Protection


How to apply decking oils, stains and treatments?

In Part 2 of our Complete Decking Guide, Wood Finishes Direct covered some of the common problems that affect decked areas and gave some handy tips and remedies to help you get it right. In part three, the final part of our decking guide, we look at how to apply decking oils as well as giving more top tips about how to protect decking so it looks fantastic for years to come.

The application techniques we’re going to discuss cover oil-based decking finishes as in our opinion these are much easier to maintain and patch repair. As such this decking maintenance advice is suitable for:

  • new wood
  • preserved new wood
  • wood which only has oil on it

Once your decking is clean, dust-free and physically sound, with any damage mended, you can apply a clear or coloured decking oil.

Oils are easy to apply with no special skill required. It’s simply a case of making sure the oil is ‘pushed’ into the wood rather than leaving it on the surface.

If your decking is smooth, a long-handled microfibre roller is ideal as it works really well with decking oils. If your decking is grooved, you can attach a floor brush head to a wooden handle – the firm texture will help you push the oil into the wood much more effectively.

How many coats of decking oil do I need?

Because it’s the oil content that protects decking against water, sun damage and more, you need to get as much of the product into the wood as possible. It’s important to apply the oil in thin coats because thicker coats can’t penetrate the wood as easily and take ages to dry. It’s much quicker and more effective to apply three thin coats than two thick ones.

There’s no need to use a lot of elbow grease. Just move the oil around the wood and apply a little pressure until it has virtually all sunken into the grain. A well applied coat of oil will comfortably dry in a day.

Are there any exceptions?

Yes – if the wood is already naturally oily such as Teak, Ipe or other exotic hardwood. In which case it might not take in any more oil or might just accept one thin coat. If your wood is already saturated with oil you’ll know because you won’t be able to get it to absorb any more. In which case you can simply wipe the excess off.

What happens if I use too much deck oil?

Sometimes people apply as much oil as they can in the hope that the more they get on the wood the better. All this does, though, is leave deposits of oil on the surface that can take a very long time to dry, often more than forty eight hours. In the worst cases the oil can’t evaporate or sink into the wood and it forms a skin on the surface which can ultimately peel off.

Top tips for decking maintenance with oils

We highly recommend a quality deck oil like Barrettine Decking Oil, also known as The Complete Decking Treatment.  It contains rich resins and waxes and we invariably get excellent feedback about it.

  • Get an idea of how much oil is still in your decking first – if you can’t tell, test a small area with a thin coat of decking oil. If it doesn’t sink in, your wood probably isn’t ready for extra oil yet
  • Try to avoid sealer-type decking finishes. In our opinion, they’re not as good as decking oils
  • Always apply the oil thinly
  • Bear in mind that thin coats enhance the grain structure best
  • As a general rule the darker a finish, the better the UV protection
  • Sweep decking regularly – keeping it clean means it stays in better condition for longer
  • Attend to any visible problems like greying, blackening and dryness promptly and they’ll cause less damage 

How often do I need to oil my decking?

You can play it by ear. Less oily woods tend to need more frequent treatment than oilier woods. Keep a supply of your favourite decking oil handy and test a small patch somewhere unobtrusive every spring. If the oil refuses to sink in or takes ages to dry, you can leave it until it gets ‘hungry’ for more oil. If so, test it again at the end of the summer, just in case it needs to be fed more oil to protect it over the winter.

Colouring your decking

Black finishes on decking are becoming increasingly popular. It’s no surprise when the deep, rich colour complements the vivid greens of plants so beautifully. How do you dye your decking black? The easiest way to achieve the look is a black timber stain. The same goes for other colours. Osmo, for example, feature a vast range of lovely wood colours in oil tint form, from cool, subtle amber to rich gold, bright silver and dramatic white. 

Once you’ve achieved the colour you want, whether it’s black or something else altogether, simply apply two to three coats of good quality clear decking oil on top.

Can I buy non-slip decking oil?

Yes. If you’re concerned about slipping over, Osmo decking oil comes in a special anti-slip variant.

What’s next? Simply enjoy your garden decking!

When your decking has been cleaned, treated and restored, it’ll look beautiful, a real asset to your garden. Now all you need to do is magic up some sunshine, add friends or family, good company, food and drinks and you’re off. Here’s to a glorious summer!

Any questions?

If you have any questions about garden decking maintenance, we’re always delighted to help –  just give our resident experts a call.


  1. Hi, I laid a hardwood sapelle deck in the summer and gave it 2 or 3 coats of Cuprinol ultimate decking oil in the weeks after. The oil didn’t pond and once it showed signs of not being absorbed I stopped. The deck looked amazing in the summer but as soon as we had persistent rain in the autumn the decking turned milky white in some places and this happens every time we get a down pour now. Once it dries out the milkiness dis appears, but it’s pretty unsightly when wet.

    I’m assuming somethings gone wrong in the oiling but how do I rectify?

    Hoping you can help, thanks in advance.

    • Hi Jonathan,

      This could be a number of things. Sapele is a very dense tropical hardwood and it requires a weathering period in the exterior elements before a product can be applied to ensure that some of the natural oils have dispersed the grain to make room for the new protective oil. We normally recommend at least 6 weeks to weather. It could also be that the timber was still slightly damp when the oil was applied. This is what causes the milky appearance that disappears when it is dry. Moving forward, the oil will need to completely removed by sanding or jet washing. Please bear in mind that jet washing does raise the grain and makes the surface slightly furry. You can then apply a thinner oil that is more suited to Sapele such as this one;

      Please remember to weather the Sapele for at least 6 weeks after stripping as the natural oils will come back to the surface of the wood.

  2. Hi,

    I have just applied one coat of decking oil on my deck thus far as it was getting late in the evening. It has now dried, can a second coat be applied or will the oil not absorb into the wood now and remain sticky on the surface?


    • Hi Ash,

      If the oil is a two coats product that second coat will be required and as long as the first coat was applied correctly the second should be fine even with a slight gap between applications.

      The key is saturate the wood with the oil, but not over apply, all the oil must soak into the woods and this will give a durable protective finish. If you find the oil remains tacky and is slow to dry this is an indication of over application.

      Regular sweeping and cleaning will prolong the life of your finish and if you have any questions at all please do not hesitate to get in touch with one of our friendly team via our contact us page.#

      Kind regards Samantha.

  3. hi, i have 3 year old softwood tanalised decking, starting to age, just cleaned it and applied ronseal decking protector 2 coats, do i need to oil as well?

    • Good Afternoon Steve,

      Thank you for getting in touch with your enquiry. The Ronseal Decking Protector is a finishing product in its own right and does not require any further product applied over the top.

      As with any Decking treatment good maintenance will ensure long protection and top up annually or bi annually when you feel the wood needs it. For further advice please do not hesitate to get in touch via contact us page.

      Kind regards Samantha.

  4. Hi
    We have just had decking put around our static finished yesterday, it’s tantalised. Do we need to oil it now before the bad weather or wait till spring.

    • Good Afternoon Debbie,

      Thank you for getting in touch with your question. It can be difficult this time of year to find a dry period of time for application, but if you can I would advice that you try to get the deck treated before the winter.

      Its fair to say that the decking will essentially be okay over the winter period without any treatment as it is tanalised. It could start to weather over the winter however, silvering slightly and you would need to allow the wood to fully dry out in the spring before then applying a treatment.

      To protect the decking from weathering I would recommend a Decking Oil such as Barrettine Decking Oil which comes in a range of colours and a clear finish. It is a penetrating oil that will help to make the wood moisture repellent and slow down the silvering process.

      I hope that helps and if you have any further questions please do not hesitate to get in touch.

      Kind regards Samantha.

  5. Hi there
    My verandah has been cleaned with a wood cleaner and reoiled at least 6 times over 15 yrs .The timber has slowly darkened to almost black but still in great condition. Should i sand it back to its brown colour and treat it with an antifungal etc and reoil again or just leave it as is? Sonja

    • Good Afternoon Sonja,

      Thank you for getting in touch with your question. Oil will be the best and easiest treatment to use. It is far easier to maintain over time and give a moisture repellent finish. The black you are getting could be a range of things from the type of wood you are treating or the type of oil you are treating it with. Sanding back will bring out the original colour for and you might want to consider applying a preservative first Barrettine Premier Universal Preserver this will help to prevent mould, mildew and rot.

      You can then follow this with a topcoat of Decking Oil Barrettine Decking Oil this will help to slow down the silvering process caused by UV damage and will give a moisture repellent protective finish.
      If you take a look at these recommendations and feel free to get back to me with any questions you have.

      Kind regards Samantha.

  6. Hi,
    Your guide is very interesting and useful. We’ve just had our decking boards replaced – as it is February it is cold and damp – should we get some oil on immediately or leave until the warmer weather, as recommended? Thanks.

    • Hello Paul,

      Thank you for getting in touch. It would be wiser to wait for slightly warmer dry weather before application. Wood can appear touch dry but it really needs a few days of dry weather to really dry out and if you apply any treatment whilst the wood is still wet you are effectively sealing the moisture into the wood and this over time can result in problems with mould and algae.

      If it is a tropical hard wood such as Balua it will have some natural oils in it to help make the wood moisture repellent and many decking boards will have a be tanalised. So my advice would be to wait a little while until the warmer weather.

      I hope that helps and do let me know if you have any other questions.

      Many Thanks Samantha.

  7. Hi.

    I moved into a new build property with outdoor decking around six months ago. I am not sure which kind of wood, and whilst I am sure it had been treated in some way, it didn’t seem to have been finished as it still had a light, natural colour. A few months in, I cleaned the decking after up-cycling some old chairs (sanding, oiling etc) and wiped it down with a dish cloth. Shortly after black spots appeared on the wood and I read on this blog post (and part 2) that it was probably mould after getting the wood wet.

    It took me a little while to get around to it, but a couple of months later I tried to clean up the spotting with Knock Out Mould & Mildew Cleaner, before treating the decking with Barrettine Wood Preserver and finishing with Barrettine Decking Oil (both clear). The Knock Out cleaner seemed to do the trick – the black spots were significantly improved although not removed entirely. Unfortunately the weather turned so I had to wait a few days for a dry spell before applying the Wood Preserver. I applied to 2 coats (with some more rain in between) and waited for it to dry.

    I’m not sure what has happened, but half the decking looks okay, and the other half is much darker. It’s similar but slightly different to the black spots before, as it is more even and perhaps a little fainter. Has Mould gotten in again and if so what I should I do (bearing in mind it is now sealed with 2 coat of Wood Preserver)?

    My next step would have been to finish with decking oil, but now I’m not sure. Any advice would be appreciated.


    • Hello Nick,

      Are you able to send me some photos of the full decking and the areas effected to It does sound like it could be a moisture problem but without seeing, its difficult to say.

      Kind regards Samantha.

  8. Hi Sam

    I have cleaned old decking and bit confused

    Should I use decking oil first or decking stain first

    Please help !!

    Thank you

    • Hello Jono,

      You should use one or the other but not both together. The Barrettine Decking Oil would be my adviced option. It soaks into the surface of the wood and will not peel and flake over time. Its easy to apply and maintain over time.

      The Ronseal Decking Stain is a surface sealer to give a paint-like effect to the wood.

      I hope that helps and if you have any further questions about either products then please feel free to email me on

      Kind Regards Samantha.

  9. Hello Sam

    Sooo glad I found this site.! Bought my house 6 years ago with a massive deck. As I’m from South Africa and single, I’m totally clueless about decking. I need to replace the decking now as it rotting through in places.

    Do i buy hardwoood or soft wood? i have 50 litres of Sadolin superdeck, 50litres of Ronseal ultimate decking oil but now so confused as it all seems wrong!

    please help! Don’t want to get rid of the deck but just need someone to say hard say hard or soft wood and the name of proper decking oil please!
    Than you in advance!


    • Hello Jenna,

      I can’t help you with the type of wood that you will need I am afraid and my advice would be to go to your local supplier of decking and speak to someone there who should be able to help. If you are able to take a small sample of the decking or a photos this will help them to advice you.

      For the finish however I can help and for decking I would advice the Ronseal Ultimate Decking Oil as good choice. It is designed to soak into the surface of the wood and so will not peel and flake over time. Always try a test area first to ensure you like the finish that will be achieved and there is no adverse reaction.

      If you have any further questions please do not hesitate to let me know.

      Kind Regards Samantha.

  10. Hi, we just put up the new decking next to our house. The decking boards are from Wicks which are pre-treated. I would like to ask if we can straight away apply decking oil during the dry day or its better to wait until next year. We were told that for the new decking, leave it until next year to apply the treatment and therefore confused. Many thanks, Fang

    • Hello Fang,

      It may also depend on the type of wood the decking is made from. If it is a tropical hardwood such as Iroko or Balau then it may have some natural oil still in the wood. And if this is the case then you can leave it until next year. If you have a some standard timber decking then treating with a decking oil can only be a good thing.

      The oil still allows the wood to flex and move in the changing temperatures and will give better protection over the winter months. You could have a look at Manns Premier UV Decking Oil, which is a good option and will help to prevent silvering in the sun. Feel free to let me know if you have any further questions or quires about the type of wood or the best way to treat.

      Kind regards Sam.

  11. Hi, I am replacing 2/3rds of my decking with new. Do I use oil on the old decking, seal the new decking boards with s sealer and then use a stain to make it all the same colour? Or will a decking oil do it all? I’m confused. Please help

    • Hello Alison,

      You could have a look at using the Osmo Wood Reviver Gel for the older decking to restore it back to an original condition. This will bring it closer together for the finish although is unlikely to match exactly and there may be colour variances when applying an oil.

      But you can usually working it by adding an extra coat of oil to the older wood, but you will need carry out some test areas to check what colours you are going to get. I would recommend a Preservative first to protect against mould, mildew and rot. And then either a Decking Oil from Barrettine or this one from Ronseal.

      I hope that is of some help and if you have any further questions please do let me know.

      Kind Regards Sam.

    • Hi Kate,

      Decking should be dry before applying a decking oil, I would say at least 2 or 3 days and nights of dry warm weather. The reason for this is that if the decking timber contains a high moisture content it can make it more difficult for the oil to fully penetrate in to the timber. Another issue is that trapped moisture can still rise up to the surface after it has been oiled which can give the oiled finish a milky or cloudy appearance. This can rectify itself but may require long periods of warm, dry weather.

      I hope this helps but please feel free to contact us again if you have any further questions.

  12. Thanks for the excellent articles.
    Quick query. I have just had new, tanalised pine decking installed under pine trees. We get a lot of pine needles and heavy shade. What treatment would you recommend tostain, help protect the wood, reduce algal blooms and lastly what top coat would make it non slip?

    • Hello Bob,

      The first thing that I would recommend would be Barrettine Premier Wood Preservative. This will help protect against mould, mildew and rot.

      The a top coat treatment of Osmo Anti Slip Decking Oil will help with water repellency.

      The key to keeping your deck in good condition once treated, is regular sweeping. Leaving leaves, needle or dirt build up on the surface will make the treatment deteriorate much quicker. And then regular maintenance top ups with the oil. Annually or Bi annually depending on when the wood needs it.

      Do let me know if there is anything else I can help with.

      All the Best Sam.

  13. Thanks for this valuable guidance about the deck protection treatments. These precautions and measures help to keep the beauty of the deck last long. I am looking for the whole process of the deck oiling and staining. Great efforts. Will surely follow your advice.

    • Hello,

      I would not recommend using a the Decking stain over the top of an oil. I would instead recommend using a Dark decking Oil such as Barrettine Decking Oil in Dark Oak. But a test area would be required to ensure that firstly the original and the new decking oil are compatible and that another coat of Oil will absorb in to the wood.

  14. Last Autumn I treated my new pine decking with Cuprinol Decking Stain, not realising it gave a largely surface coat. I was not that happy with the finish, and with the benefit of hindsight (and reading your articles) realise that oil would have been a better option. If I was to now just thoroughly jet wash my deck to remove the bulk of the stain and then retreat it with oil would that work, or will I have to use a special varnish stripper? Thanks for you help.


    • Hello Mark,

      A jet wash may be a good way to remove the stain but if you have any stubborn areas it may be worth considering the Cuprinol Stain Stripper which will make the stain bubble up to be scrapped off. Always try a test area first. If you don’t wish to use the stripper then it would need to be sanded. Once you have got all the stain off then a Decking Oil treatment such as Barrettine Decking Oil can be used.

  15. Thank you for your useful guide to restoring my decking I will be ordering some of the recommended products.

    • Thank you Amanda, and we always love to see photos of customers projects if you get a chance to send some that would be great !!


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