How to Make Decking Non-Slip


During the summer your decking dries out. The sun dries up any mildew and mould and the surface provides a decent grip. But the minute it gets wetter and colder, that lethal slipperiness comes back.

If you’ve ever almost killed yourself sliding around on slippery, slimy garden decking you’ll understand how important it is to know how to make decking non-slip. It’s a question we’re asked regularly, and we thought it’d be useful to write a post on the subject.

Beautiful Decking – Ready for Summer
Using the right decking products and keeping it maintained can help to prevent slipping

How to Stop Slippery Decking?

How does one achieve safe non slip decking? There are several anti slip decking products available.

  • Anti slip decking paint
  • Non slip decking varnish
  • Anti slip decking oils & stains

We highly recommend antislip decking oils. Non-slip decking paints and varnishes tend to be prone to cracking, flaking and peeling off over time, whilst anti-slip decking oil and oil-based decking stains do not. In addition, anti-slip decking oils and oil-based stains are also very easy to apply, maintain and patch repair if areas become worn or stained.

Our favourite is the excellent Osmo Anti-Slip Decking Oil, which contains special compressed organic particles evenly dispersed throughout the oil. The product dries to a clear satin-matt finish to deliver a reliable anti-slip surface. It’s made from natural oils and also contains active ingredients designed to protect against mould, algae and fungus.

The great news is that this oil can be used as a top coat over Osmo and many other brands of decking oil, clear and coloured, to add an anti-slip finish. It’s perfect for exterior wooden decking and steps and works wonders on all sorts of woods including Douglas Fir, Bangkirai, Garapa, Massaranduba, Larch and common or garden Pine. And it’s ideal for any kind of decking, from the ribbed and grooved versions to the flat and smooth stuff.

Osmo Anti Slip Decking Oil – Available in clear and a range of attractive decking stain colours

Where to use Osmo Anti Slip Decking Oil?

Osmo Anti Slip Decking Oil is perfect for your home garden decking and equally good for making decked steps safe. But it’s also a great product for commercial decking in places like pubs, cafes, nightclubs and restaurants.

If someone slips on your garden deck at home, it’s unlikely they’ll sue you. But if you run a commercial operation anti-slip decking might prove your undoing, so it’s better to be safe than sorry. It might be a condition of your commercial insurance to make sure your deck is safe, and if it isn’t your insurer might even refuse your claim, leaving you liable for compensating people who have injured themselves because your deck is dangerous.

When is the Product Suitable?

Osmo anti-slip deck oil can be used on new, previously untreated decking. But you need to weather it first, leaving it untreated for 2-4 weeks in the case of softwood decking and 3 months for hard and exotic woods, and after applying 1 coat of your chosen decking oil, be it coloured or clear. This excellent product is also perfect for decking that has been previously oiled. If your deck features an oil-based finish, you’ll need to clean it thoroughly before you begin.

Bear in mind that you can’t use an anti-slip oil on top of painted decking and it won’t work over varnished or coated decks either, including many types of decking stain. If your decking has an existing finish like a varnish or a stain you need to remove it completely, which will involve either stripping, sanding or a bit of both.

When NOT to use it? Osmo Anti Slip Decking Oil isn’t suitable as a stand-alone product. You should always use it with a wood preserver and a primary decking oil.

Anti Slip Decking Stain Preparation in 8 Simple Steps

  1. Always carry out a test first in an area that doesn’t show, so you know how the products you’ve bought work on your particular deck. It makes doing the real thing so much easier when you know what to expect
  2. First clean your deck, sweeping it to get rid of every speck of visible surface debris, dirt and dust
  3. If there’s mould or algae present, you MUST get rid of it first. Jet washing is always a good option before treating the surface with a good quality mould and mildew cleaner
  4. Allow the deck to dry thoroughly
  5. Once treated by the mould and mildew cleaner, apply a good quality exterior wood preservative to help prevent future biological growth. 2 coats of preservative is the norm for exterior wood
  6. Add a single coat of good quality decking oil, either clear or tinted
  7. Apply one coat of anti-slip decking oil, following the instructions on the pack as well as checking those we’ve provided on our product page
  8. Clean your brushes and other equipment with white spirit straight away

The drying time for Osmo Anti Slip Decking Oil is 10-12 hours under normal weather conditions, longer if it’s cool or humid.

Anti Slip for Decking – Upkeep and Maintenance

You want the areas of your deck that get particularly heavy foot traffic to stay anti-slip. To stop the effect wearing off we recommend you renovate areas of wear as soon as they start to look tatty, without delay. Luckily it’s really easy – just brush-apply another coat to the worn patch.

Alternative anti-slip decking treatments

Any questions about anti-slip decking?

Need our help with your decking project?

For more information about decking treatments and their uses, contact our team of resident experts who are always on hand to help with project advice and product recommendations. Alternatively, see our decking treatments FAQ page which covers many of the most commonly asked questions about decking treatments.

We love to see before, during and after photos of any decking, project. If you would like to share your pictures with us and our followers, send us your photos or share on our Facebook, Twitter, Pinterest or Instagram pages.

Other great blogs that discuss decking

  • Decking Oil or Stain, Which is Best?
  • Decking Finish Problems: Sticky Issues
  • 7 Common Decking Problems and Solutions

      • Good Morning,

        Please could you give one of our wood care experts a call as I am not sure which particular Anti Slip product you are referring to. We can then definitely point you in the right direction.

    1. Hello, I wonder if you could help me, please. My question is about “Osmo Anti Slip Decking Oil” .

      Can I apply the Osmo anti-slip product as a top coat, once I have applied the wax-enriched “Ronseal Decking Protector”?

      Many thanks in advance.

      • Good Morning Eiligh,

        Thank you for your question. The answer in this case is no, they are not compatible products, the Decking Protector will prevent the oil of the Osmo from soaking into the wood as it needs to do.

        The Ronseal Decking Protector is a finish in its own right and with regular sweeping and the occasional clean to prevent the development of Algae, it should not get slippery.

        If you did need the Anti Slip factor and wanted to use the Osmo Anti Slip Decking Oil you need to apply it of one coat of standard decking oil already applied.

        For more help and advice why not get in touch with your friendly team via our contact us page.

    2. Hi,
      I’m getting a new softwood decking installed and would like to get it right from the beginning but also know how to take care of it in the following years.
      I was thinking of starting with a coat of Barrettine Premier Wood Preserver, then 2 coat of Osmo Decking Oil and on top 1 coat of The Osmo Anti Slip Decking Oil. Can I do this just after installation or should I let it weathered? If yes for how long?
      In the following years, what will be the best way to maintain it? Except regular cleaning, should I reapply yearly a coat of Osmo Decking Oil and a coat of The Osmo Anti Slip Decking Oil?
      Thanks a lot

      • Hello Steph,

        Its great to hear you are keen to look after your deck, so many people apply a product the first year and then forget to take care of the wood. Soft woods do not generally require a period of wethering, although a couple of weeks may be of benefit to the wood settling into its position.

        You have the perfect products there for the best care of your decking, I would just swap out the Premier Wood Preserver out for the Barrettine Premier Universal Preserver, this one has less wax so is less likely to cause any issue with the oil being applied over the top.

        You only need one thin coat of the Osmo Decking Oil and one thin coat of the Osmo Anti Slip Decking Oil for the finish and this will ensure a moisture repellent decking finish. The clear version of this decking oil does not have an UV filter in it and so will allow the wood to silver naturally over time. if you want to slow this down then I would recommend a coloured decking oil, even a very light one will vastly improve the level of UV protection.

        This will then last for around a year and potentially longer, depending on use, weather and general cleaning and care. Regular sweeping to avoid decaying foliage or insects will help an occasional clean with a Decking Cleaner such as the Barrettine Super Concentrated Decking Cleaner and I would also recommend, if you have pots or furniture to move these regularly around the decking, any areas covered for long periods will weather differently to those exposed and you end up with a patchy deck. I speak from experience on this one.

        Then once a year a test area to see if you need a refresher coat or not, its easy to think you should just apply a fresh coat every year, however the wood is not always ready to absorb more oil after a year. You do not want to over apply and end up with the oils drying on the surface of the wood. If after a year the oil is not soaking in then try again in 18 months.

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

        Kind Regards Samantha.

    3. The garden of our newly acquired house has a 4 course oak sleeper retaining wall containing a couple of sleeper steps. These have previously been treated with Bartoline Creocoat so they matched the feather-edge fence colour. Would adding the anti-slip decking oil on the horizontal step surfaces help minimise the likelihood of the steps becoming slippery in the winter, or would the Creocoat treatment prevent it from adhering?

      • Hello Paddy,

        Thank you for getting in touch with your question. Creocote products are very high in wax and so it will repel any thing you now try to apply over the top.

        To avoid the surface of the wood getting slippery, and occasional clean with a decking cleaner is recommended. Wood gets slippery when damp conditions encourage algae to grow and it is the algae that causes the surface to become slippery. Keeping the algae at bay with a product such as the Osmo Decking Cleaner or the Cuprinol Decking Cleaner will help.

        Also regular sweeping to avoid the decay of foliage or insects, which will again encourage the growth of mould and algae.

        I hope that helps and please do not hesitate to get in touch with one of our friendly team if you have any further questions. contact us page.

        Kind regards Samantha.

    4. We got advice from you a few months back and have treated a large area of decking with preserver, 2 coats of oil and now Barrettine anti slip oil. My comment is that it does not cover nearly as many metres as you suggested (and as it says on the tin). Does that mean we have applied too much? It does say ‘apply liberally’ !

      • Good Morning Anne,

        This could be to do with the condition of the wood, if it is aged,very dry or not had a treatment for a while, then uptake can be higher than the guidelines suggests, some softwood may absorb more oil also, these are just a few factors that can have an impact on the oils coverage. As long as the oil has soaked in to the wood well, there should be no problem.

        I hope that helps and if you do have any questions please do not hesitate to get in touch via our contact us page.

        Kind regards Samantha.

    5. Hello Sam,
      Your reply to Carl Richards on 28 Aug., 2015 advised him to use Mould & Mildew Cleaner, then Preservative, & finally Anti- Slip Decking Stain. Could the final step be Anti-Slip Decking Oil?

      • Hello Vincent,

        Thank you for taking the time to read the blog and the advice I have give in the comments. If you have applied the Anti Slip Decking Stain, this is your final coat product and an oil can not be applied over the top, oils and stains are not compatible. The oil cannot penetrate the wood, as it needs to, if a stain or varnish is applied, and a stain or varnish will not adhere to an oil, if that has already been applied.

        Both Anti slip Decking Stain and Anti Slip oils are finishing product in their own right and so you can use one or the other, both have different advantages. If you would like to know which is best for you feel free to get in touch via our contact us page.

        Kind Regards Samantha.

    6. I have just laid 50sq mtrs of Red Cedar decking and have read the feed with interest.

      If I use the barrettine wood preserver and want it to be non slip do i need to use the Osmo Decking Oil first before applying the Osmo Non Slip oil. If so would it be one coat of the oil and an additional coat of Non slip oil. Just need to know for ordering the quantity as it works out quite a lot of cash.

      Many Thanks Richard

      • Good Morning Richard,

        You have the right combination there for sure, so one or two coats of the Barrettine Premier Universal followed by one coat of the Osmo Decking Oil and one coat of the Osmo Anti Slip Decking

        It is recommended with Cedar to allow the wood to weather for 4-6 weeks, this allows it to settle and adjust to its new location and environment, before application and I would also recommend wiping over with Methylated Spirits to remove any excess grease, dirt or natural oils in the wood.

        A test area is recommend with full coats first to ensure that firstly the wood will accept all the coats with out issue and also to ensure that you like the finish that will be achieved as these products will darken the wood very slightly and enhance the natural tones of the wood.

        And if you have any questions at all please do not hesitate to let me know.

        Kind regards Samantha.

      • Hello Peter,

        If the Decking currently has no treatment on it then the Barrettine Premier Universal is a good option to start with. Although if using an Osmo Decking Oil Osmo would recommend the Osmo WR Basecoat as a more suited option.

        These two together will keep the wood from moisture damage and will allow the wood to silver naturally in the sun.

        To avoid silvering you can apply a coloured Decking oil as the pigments act as UV filters or you could consider the Barrettine Decking Oil in clear as this does contain some UV filters to slow down the silvering process and maintain the natural colour.

        For more advice or information please do not hesitate to get int ouch via our contact us page or give us a call on 01303 213838.

        Many Thanks Samantha.

    7. Hi, I plan to build some raised beds with softwood sleepers. I also plan to use the sleepers as stepping stones with gravel between. After reading your informative site I have come to the conclusion of using a wood preservative followed by a coloured oil. For the stepping stones I would then add the clear anti slip oil? Some areas mentioned are in shade so I expect mould will become present quicker. Would I just clean and recoat with the coloured oil? Also would you recommend I treat the inside of the raised beds with the coloured oil? And would you recommend using a membrane inside the raised bed?

      Thanks in advance

      • Hello Rob,

        Thank you for getting in touch with your enquiry. I would say that you will benefit from both option. A membrane is a must, to keep contact between wood and soil to a minimum, this avoids continuous contact. That said over time it is possible that moisture can build up between the membrane and the sleepers and so a treatment of Barrettine Premier Wood Preservative will help to prevent mould, mildew and rot.

        For the exposed areas of wood the oil will help to maintain some repellency and regular cleaning and top up with the oil will help protection of the wood longer and applying a coloured oil will also increase the UV protection that the oil has.

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

        All the Best Samantha.

    8. Hi Samantha

      There is a lot of concern at the moment about microbeads and plastic in the environment. The Cuprinol anti-slip product uses these I read. What does the Osmo product use? The literature is obscure.

      • Hello Nigel,

        Great question, I can tell you that the description on the Product information says it ‘contains a special highly compressed organic non-slip additive, which is evenly distributed in the coating and prevents slips when dry.’ I have been in contact with Osmo to get a little more information on this as I suspect that it could be a questions that comes up regularly in the future. Once I hear back from them I will add the information for you.

        If there is anything further that I can help with in the meantime please do not hesitate to get in touch or email to

        Kind regards Samantha.

        • Hello Nigel,

          Apologies for the delay in getting back to you. I have heard back from Osmo in regards to this question and I can confirm that the additive that creates the non slip finish is Polypropelene Co poly. This does sound like a plastic to me and so this product is potentially not what you would be looking for.

          All the Best Samantha.

    9. Hi, I wonder if the Osmo anti slip decking oil is suitable to treat the floors of a kids playhouse? It is pressure treated softwood and has not been varnished or painted so far. I do have some leftovers of Osmo oil varnish in red from treating the outside of the house, could this be used underneath the anti slip oil?

      • Good Morning Christine,

        Thank you for getting in touch with your enquiry. I can not recommend the use of an exterior product for an interior project. The two products that you are asking about will both contain Biocides and this is one of the reasons they are for exterior use.

        That said many of our customers will use such products for interiors of log cabins, sheds and summer houses as once fully dry the products are both human and animal safe. So if you choose to use the products moving forward, then one coat of the coloured oil followed by one coat of the Anti Slip will work together. Always try a test are a first and if you have any further questions please do not hesitate to get in touch.

        Kind regards Samantha.

    10. My deck is 2 years old and has already been painted gray or maybe it’s a stain. Can this product be applied over old paint?

      • Hello Joanne,

        Which product are you looking to apply over the current finish ? And I would need to know the current finish to be able to advice whether a product can be applied over the top of it. If you are able to find out please feel free to email with details or even send through some photos and I will be happy to take a look.

        Kind regards Samantha.

    11. Please could you tell me if the satin-matt decking oil leaves a slight sheen?
      I have a large area of decking under a balcony with 2 steps whcih i used an anti slip coating on which was satin (wish I had just used these products now). I want to do the decking area in the oil but I require a slight sheen. thanks

      • Hello Karen,

        Thank you for your enquiry, the Osmo Anti Slip Decking Oil is unlikely to have any shine to it. As an exterior oil it will be a matt finish, as will all other decking oils, any sheen is only likely to show up under direct light, if at all. And the oil will need application to bare wood or any pre existing treatment removed first. I hope that helps and if you have any other questions please feel free to let me know.

        Kind Regards Samantha.

    12. in a post from march last year you suggested cuprinol anti slip oil (although i think you meant stain) as an alternative to using a decking oil followed by osmo antislip oil. I have been looking at reviews on other websites and several have mentioned that the cuprinol product doesnt last very long and soon flakes. Lots of pictures back this up. Do you have any experience with this? They do some nice colours but we have brand new decking being installed and want to get it right from the start.

      • Hello Teresa,

        The feedback for this product from our customers is generally good. It is a surface treatment and so over time may peel and flake over time as all paint and varnishes will. However it will offer a slip resistant deck and can be easily repaired with a single top up coating as required.

        For an alternative product and something that we regularly recommend you could have a look at a Decking Oil this will soak into the surface of the wood give water repellency and protection. It will not peel and flake and you can simply top up with a fresh coat of oil annually or bi annually depending on how exposed the decking is.

        If you have a read up of the product and feel free to get back to me if you have any further questions.

        Kind Regards Samantha.

    13. Hi Samantha, (same as my daughter)
      I intend to have a short pathway made as an extension to a patio. I will only be 1000mmx1500mm long and made from pretreated softwood with a 12- year guarantee for rot and fungal attack.
      Please advise the correct procedure to follow and what quantity of anti- slip I will need of your Anti-Slip treatment.
      Very Best Regards Ian

      • Hello Ian,

        The Osmo Anti Slip Decking Oil is an ideal product for an area that needs that bit extra protection. It is a top coat product and so you will need to add a coat of decking oil first, if you have some already, just check for compatibility of the two oils, by carrying out a test area.

        If you do not have any then the Osmo Decking Oil is ideal and the good news is for such a small area you will just need the 125ml sample tins of each product.

        If you have a look at the recommendations and I am happy to help further should you have any further questions.

        Kind regards Samantha.

    14. Hi, I’m just about to put down around 30m2 of new treated softwood decking and this time we are laying it smooth side up to give a contemporary look. I’m worried about the decking being slippery so would like to use your anti-slip decking oil.

      Reading the other posts, would we still need to use a wood preservative first given that our wood is treated? We also want to colour the wood, so can we use a tinted decking oil first and then put the anti-slip oil on top? Originally we were going to use a deck stain but it looks like this will not work with your anti-slip oil, so we are now considering the Ronseal Decking Oil in teak. Also, is there any advice on leaving treated wood for a period before carrying out all of this?

      Thank you.

      • Hello Belinda,

        Thank you for your inquiry. We do tend to advice a coat of preserver, even if the wood is ‘treated’ as it is not always known what the existing treatment protects against. Barrettine Premier Wood Preservative will protect from mould, mildew and rot and is a good option should you choose to apply a preservative first.

        The combination or the Ronseal Decking Oil and the Osmo Anti Slip Decking Oil would be ideal. Test areas are always recommended and if you have any further questions please do not hesitate to let me know.

        Kind Regards Sam.

    15. Hi,

      If I’m applying preservative to a new deck followed by the cuprinol anti slip decking oil as suggested above, would you recommend going with a clear preservative followed by a coloured anti slip decking oil?

      • Hello Matt,

        As long as the preservative is wax free such as the Barrettine Universal Premier Preservative then it will be suitable, clear or coloured essentially would be fine but the base colour will have an effect on the top coat oil, so it is probably easier to stick to a clear preservative and a coloured oil. Feel free to let me know if you have any further questions.
        Kind Regards Sam.

    16. My decking becomes incredibly slipping after rain, snow or any other way coming into contact of the wood. Would to osmo anti slip oil prevent this? or at least improve the conditions of the decking’s slipperiness?

      • Hello Peter,

        Could You clarify which product you are asking about please and i will happily check for you.

        Kind regards Sam.

      • Hello Joan,

        Thank you for your question, the answer will very much depend on the product that you have applied. If you would like to email me with details of the current ‘Stain’ and water proof coating that you have applied and hopefully I will be able to help. You can email me at

        Kind regards Sam.

      • Hello Nick,

        It is always quite difficult to give a definitive answer to how long products will last before they need re doing or need to have top up coat. But it would be fair to say that I would expect an Anti Slip Oil to last around 2 years before needing re applying. Bear in mind however that lots of regular use, extreme weather (including sunshine) and not looking after the surface generally (sweeping and cleaning) can shorten the life of the decking treatment.

        Preserving the decking with a product such as Premier Wood Preservative before treating with an Oil can also prolong the life and protection of the wood. if you have any other questions please feel free to get in touch.

        All the Best Ben.

    17. Hi, I’m having decking fitted this weekend as it is new I would like to use anti slip from the start. What’s the best way to go about this its standard soft wood decking, what to use first and finish with.

      • Hello Mal,

        I would always recommend starting with a Preservative as this will protect against mould, mildew, and rot. Once this has dried you can look at a couple of Anti slip products, the first being Osmo Anti Slip Decking Oil which comes highly recommended and will make the wood water repellent. The down side to this product is that as a clear oil it doesn’t offer any UV protection and so the wood will naturally silver, but is easy to maintain by simply apply more coats when required. An alternative product to look at would be the Cuprinol Anti Slip Decking Oil which comes in a range of colours and so will offer much better UV Protection. I hope this helps and please let me know if you have any further questions – All the best Ben

      • Hello Bob,

        The Barretttine Premier Wood Treatment which is the new name for the Premier Wood Preservative can be Spray applied, but be aware that if you are using a pump sprayer the solvent in the treatment may cause the seals to perish. The Osmo Anti Slip Decking Oil product can not be sprayed as it contains tiny particles that create the anti slip and these are likely to clog in any spray applicator. Please let me know if you have any other questions.

        Kind Regards Sam.

    18. Hi. Looking to treat a new deck area. Reading this it looks like a coat of preservative then a coat of oil before the anti slip coating is the best way forward. Can i mix suppliers or do Osmo do all the products required. Thanks.

    19. Hi,
      I have a section of soft wood decking which has been down for some seven or eight years. When wet it is very slippy, it had a clear weather coating several years ago. I now want to apply a good anti slip coating on it. Advise please. The surface area is approximately 12 x 8 foot.
      Many thanks
      Carl R

      • Hello Carl,

        I’m assuming that if the decking was last treated 7 or 8 years ago, the finish has since worn or weathered away to expose bare wood? If there are any remaining patches of the original finish which seems unlikely, it should be stripped to expose bare, untreated wood.

        Give the Decking a good clean with a stiff brush or broom to remove all traces of surface dirt, debris and biological growth such as mould and algae. Use a decking cleaner like Barrettine Mould and Mildew Cleaner to clean and kill mould and algae spores in the timber. If the wood is or has been heavily soiled, a second application may be required.

        Once the decking is cleaned and dry then a good quality wood preservative will help to prevent mould, mildew or algae issues from coming back. Once cleaned and preserved, treat the deck with Cuprinol Anti Slip Decking Stain which comes in clear and coloured finishes or an alternative anti-slip decking treatment.


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