Following on from Part 1 of our Decking Guide, in Part 2 Wood Finishes Direct talk about some of the more common problems that can affect decking maintenance. We also take a look at the various types of decking treatments on the market and the differences between them.
Common garden decking problems
- Wood blackening happens when fungus forms on the surface of the wood, usually because water has penetrated the wood and reacted with the brown tannin it contains. Different woods have different levels of tannin, but fungal blackening can be removed with a special mould and mildew cleaner.
- Greying or silvering occurs when the wood has been damaged by water and sun, but the effect can be reversed with oxalic acid. There’s a great product from Osmo called Wood Reviver Gel, which contains the acid to help restore the natural colour of the wood. Just like magic – it’s such an amazing transformation!
Grey decking is a common issue that can be quickly and easily resolved
How long does a garden decking finish last?
Decking is one of the most difficult areas in a garden to keep in good order. During the year it gets a lot of foot traffic in all weathers, and it’s open to the elements, insects, leaves and mud, all of which can remove the finish a little at a time. When the biggest contributing factor is the weather, life becomes very unpredictable. That’s why it’s difficult for manufacturers to give accurate timescales for how long a particular finish will last.
As a general rule, the most exposed parts of your wooden decking suffer the worst weather damage, needing more maintenance and more frequent attention. The bottoms of decking spindles get all dry or go black or grey, suffering more than the tops because running water gradually wears the finish off. Decking oil comes into its own here, with the affected areas easily rubbed down with steel wool or sandpaper and repaired seamlessly by treating them with a fungicidal wash (if required), then using more oil.
Once it’s finished, one of the easiest ways to extend the life of your decking is regular sweeping. Other than that, regular use of a specialist decking cleaner will do the trick.
Decking treatment terminology
The wood finishing industry’s terminology is full of inconsistencies. Most people don’t know that a lacquer and a varnish are the same thing, for example, and pigments are often confused with dyes. So we thought it’d be useful to clear up a few popular misconceptions:
Decking stains – A normal water-based wood stain is purely a colour, usually a liquid. It doesn’t give the wood a sheen or protect it. It just colours the wood, and you need to add a protective finish on top. Decking stain is different. It’s more than a colouring liquid, with added protection. But there’s more…
Take Ronseal. They’re one of Britain’s leading suppliers of decking finishes, yet they have two different decking products, both called a stain but both very different. The product they call Ronseal Decking Stain falls into the sealer category, a paint-like material which does nothing to enhance the grain and will likely start to peel and flake over time as the product degrades. Their Advanced Decking Stain was far superior and oil-based. In our opinion, neither qualifies as a decking stain.
- Ronseal Decking Stain is actually a coloured decking treatment.
- Ronseal Advanced Decking Stain, now discontinued, was actually a coloured decking oil.
What is decking oil? – If it’s called a decking oil, it is probably exactly that. In our experience, it’s always a good choice when made by a reputable company like Barrettine or Ronseal.
What is wooden decking treatment? ‘Treatment’ can mean either an oil or a surface coating. Be sure to find out which to make sure it meets your requirements.
What is a garden decking finish? As above, a ‘finish’ could mean more or less anything. Proceed with caution.
Next time, in the final part of our complete garden decking treatment guide, we’ll take a look at how best to apply decking treatments, plus top tips about decking maintenance and making the most of your beautiful decking all year round.
26 comments
Hi there. Last year we treated and coloured a large south-facing deck with Manns Premier UV Decking Oil, Dark Oak. It looked great but after a winter with several ‘sahara sand’ rainstorms it needs washing off before re-oiling with the same Manns product. The issue I have is that when we washed off the deck last summer, it left limescale stains because we are in a hard water area (Hampshire). Any thoughts on how we can clean it without leaving stains or should we just go ahead an re-oil it after a thorough sweeping?
Regards,
Paul
Reply to Paul Archer:
Morning Paul, thank you for getting in touch.
When it comes to cleaning decking, we would normally recommend a decking cleaner as these products are designed to help clean decking. Our friendly experts will be happy to give you further advice.
hi there
I would REALLY appreciate your help after googling and finding not much help anywhere else! We had decking laid in May (UK summer time) and now in October the last couple of months we have seen the wood has gotten water logged in various patches, and is blackening and white specs of fungi are growing on top of these water logged patches. I just cant seem to get the wood to dry out, which I think is what is causing the white fungi to grow.
We did seal it twice with a ronseal wood oil, so I don’t understand what we have done wrong. The only thing I can think is that our neighbour who laid the decking, cut pieces in half so I wondered if the freshly cut ends have got water in them and that is what is causing them to never be able to dry out, and then the white mould/black spots start appearing?
Do you have any advice as to how to fix this problem? We have tried using two types of algae/mould cleaner and its not solving the problem. It just keeps returning. And we are not even in the depths of winter yet so I can only imagine the problem getting much worse.
We are doing everything we can to prevent wood rot and don’t want to waste money spent on this lovely decking we have been looking forward to enjoying for so long!!
Thank you so much in advance for your help.
Reply to Joanna:
Good Afternoon Joanna,
Decking is one of the hardest areas of exterior wood to protect and keep looking good. It is usually totally exposed to all the elements, sun which causes UV damage, rain which causes moisture ingress that leads to mould or rot, wind which leads to foliage bowing onto and decaying on the surface and lots of other factors on top of this.
As well as good, protective treatments we also recommend regular sweeping and cleaning to help protect the wood from as much as possible. If you would like to get in touch via our contact us (https://www.wood-finishes-direct.com/pages/contact) page with details of the type of wood and the exact product you have used and I can advice further. Also if you are able to send any photos in of the decking this may help.
Kind Regards Samantha.
hi, I am about to oil my decking but I cant decide which oil to use. I have read that the Ronseal oil has good reviews however whenever I have purchased paint from that manufacturer I have been most disappointed.
I recently purchased some Barrettine and I found the quality to be very good although the coverage wasn’t great and I needed several coats to achieve the colour promised on the tin.
what brand of oil would you recommend for my decking ?
Reply to greg:
Good Afternoon Greg,
Thank you for getting in touch with your enquiry, the Barrettine Decking Oil (https://www.wood-finishes-direct.com/products/barrettine-decking-oil) is very popular and a good choice for sure. It is solvent based and will nourish and protect the wood. It also has UV stabalisers to slow down UV damage and even more so if you use a coloured oil.
Another good alternative is the Manns Premier UV Decking Oil (https://www.wood-finishes-direct.com/products/manns-premier-uv-decking-oil) that is suitable for both softwood and hardwood.
The Barrettine comes in a 1 litre tin also unlike the Manns and so gives a little bit of variation in coverage requirements.
I hope that helps, as always test areas are recommended and if you have any questions please get in touch via our contact us (https://www.wood-finishes-direct.com/pages/contact) page.
Kind Regards Samantha.
Hi .l have decking which was laid last year . I have just jet washed it and it’s come up like new . I now want to treat it for the first time , my wife wants it coloured slate grey and l want to treat it with oil , any help advise would be very much appreciated . Kinds regards Chris r
Reply to Chris rush:
Good Afternoon Chris,
Thank you for getting in touch with your enquiry. Grey is a very popular colour choice this year and one of the few brands that have twigged on to this is Osmo and there is a grey in their Osmo Decking Oil (https://www.wood-finishes-direct.com/products/osmo-decking-oil) range which may suit your needs. It just requires two thin coats for application and as always I do recommend a test area first to ensure that you like the finish to be achieved.
For further information or to order please feel free to call in an speak to one of our friendly team on 01303 213838.
Many Thanks Samantha.
Hi,
I laid a deck down around 18 months ago to cover my flat concrete courtyard.
Unfortunately, during the winter months, the area doesn’t get enough sun and certain areas take a looong time to dry, this is made worse by my poor decision to go for wider, 140mm boards which seem to encourage water pooling..
I went for a local hard wood, spent a lot of money on the construction and oiled thoroughly, but unfortunately the finish has deteriorated very quickly! Now have fungus marks and a lot of faded areas. What can I do to prolong its life apart from mopping every time it rains (which is driving me crazy) and re-oiling? Whats the best way to protect the specific areas that consistently pool during winter and need extra protection?
thanks for any help, Chris
Reply to Chris:
Hello Chris,
Decking is the hardest exterior wood to protect, it is exposed to every element and because it is horizontal surface is susceptible to surface water resulting in water ingress. Even the best products have trouble standing up to all weather battering that decking gets. The key is keeping the decking swept and clean and then regular maintenance with the oil and this will all help to keep the wood looking fresh and protected.
For cleaning the areas effected by Algae and mould I would recommend the Cuprinol Decking Cleaner (https://www.wood-finishes-direct.com/products/cuprinol-decking-cleaner). And then a fresh coat of Barrettine Decking Oil (https://www.wood-finishes-direct.com/products/barrettine-decking-oil).
I hope that helps and if you have any further questions please do let me know.
Kind Regards Samantha.