How to Protect Wood from the Elements – A Definitive Guide


Weathering is a natural process that effectively breaks down wood (and many other materials) over time. Exposure to water, biological components and atmospheric changes will all get the wheels turning on this process. 

For homeowners, exterior wood is most hindered by this process. Rain, UV rays and the intrusive nature of wood-boring insects are all damaging realities faced. If left untreated and uncovered, the impact of these elements can be costly. No one wants a fading garden aesthetic, so it pays to act fast.

An extremely weathered park bench. Photo credit to: Couleur

In addition, it always helps to understand the natural elements that play in your garden and just how they can affect exterior wood. In that regard, you’ll know better just how to act and what steps and treatments products you can turn to provide a helping hand. As always, we’re here with some expert guidance.

The Elements

We’ll start with rain. Rain causes rot in wood that lacks the natural oils required to resist it. This is because the influence of moisture creates the conditions for microorganisms to flourish. Species such as teak, cedar and redwood contain these natural oils, however, it’s worth noting that even these can become vulnerable if exposed to extremely wet, shady environments. This can also create the conditions for surface growth of algae and even fungi. 

In most cases, a finish is required to properly protect your exterior wood. A wood oil will provide the necessary means to resist water intake, whilst aiding the natural character of the wood. A quality varnish can also be used to grant a tough, waterproof seal. 

Without such protection, moisture will absorb into the cells of the wood, causing them to swell and expand. Exposure to heat and warmth will, in turn, cause the cells to shrink. This natural, back and forth movement can lead to timber warping and cracking if the cells dry unevenly.  

Rain, a frequent menace to untreated exterior wood. Photo credit to: Schwoaze

Prolonged influence from the sun and, in particular, UV rays can also be very detrimental. If left untreated, UV radiation can actually damage the wood fibres, making them less durable and more susceptible to cracking. 

The first change you will likely see, though, will take the form of an unappealing colour change. Wood is photosensitive and reacts to light. UV rays penetrate the surface and induce a grey patina into the wood that causes a dull, discolouring effect. Finishing products with UV inhibiting features are your go-to here for preventing this process. 

Lastly, it’s also worth considering the impact of the life that exists in your garden. Wood-boring insects, as the name suggests, are insects that feed and nest inside untreated timber. are a known component of weathering that can cause lasting damage to timber. They like to make their homes in areas with high humidity and low ventilation. 

A high-quality wood preserver provides the means to protect your wood from this reality. Preservers contain biocides and insecticides that penetrate the grain, protecting it from biological threats. We always advise keeping your wood away from any damp, shaded conditions. Primarily dry timber is much, much more resistant to insect attack. 

This swing has seen better days. Photo credit to: manfredrichter

Products to Prevent

Manns Premier UV Decking Oil 

This product is ideal for protecting decking. Its multi-purpose capabilities also render it incredibly useful for protecting many other forms of exterior wood, including pergolas, sheds and fences. 

What you get here is ultimately a 2 in 1 deal. A unique, UV formula expertly resists the greying effects of the sun, whilst simultaneously providing superb protection from weathering. Results such as these reduce the risk of timber warping and cracking. Moreover, it’s even safe for animals and plants when dry!

Osmo UV Protection Oil 

Osmo’s leading exterior-based product is perfectly suited for protecting vertical surfaces such as cladding and window frames. Like Manns Premier UV Decking Oil, it offers outstanding protection from weathering and UV rays. To complete the package, special biocides contained within effectively protect algae and fungal attacks. 

All in all, this product presents excellent value for money. It can be used as both a top coat and foundation in one, while an amazingly high coverage makes it tremendously easy to apply, as well as maintain, bonus! 

Barrettine Wood Protective Treatment 

This high-performance preserver creates a film biocide that protects against wood-boring insects, algae and other surface growth. It’s also harmless to bees and other beneficial insects, making it perfect for use across the garden.

Its deeply penetrating formula contains fade-resistant colour pigments that protect against sun damage. 8 delightful shades offer aesthetic variety while it can also be used as a base for an additional top-coat finish.

Cuprinol Garden Shades 

A lick of paint is a simple approach that provides colour and weather-resistant properties. Garden Shades is a great example that offers long-lasting protection and a variety of exuberant shades.

Its use brings out the natural texture of the grain and dries to a natural matt finish in just an hour. That finish will last as well, with up to 6 years of protection. 

Final Thoughts

Weathering is a component of life that simply is. In this country of ours, seasons come and go with distinction and variety, it’s why many people choose to move here. 

While there’s no getting away from the elements and their impact, we’re fortunate enough to live in a time with access to remedies in the form of finishes and treatments. With a bit of knowledge and a bit of patience, your exterior wood can be protected all year round, no matter the weather.

Strive for a well-oiled surface, resistant to weathering.

Need help with your exterior wood?

Contact our team of resident experts who are always on hand to help with project advice and product recommendations. Alternatively, see our FAQ page which covers many of our most commonly asked questions.

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

Other great blogs that discuss exterior wood

  • Osmo – Wood Meets Colour
  • Outdoor Projects – Which Wood to Use?
  • A History of Garden Furniture

    1. We have new garage doors, the manufacturers recommending application of water based Sikkins – colourless – maintenance coat once a year. We have been unable to find the product either on line or via local supplies in Hampshire UK.

      • Good Afternoon,

        Although there are clear products available for exterior project, and many will slow down UV damage and repel moisture, it is always better to apply colour to your exterior wood. And Sikkens believe in this in particular and is why they do not supply many clear options.

        If you think in terms of sun cream to protect our skin when outside, a clear product is the equivalent of a factor 10, it will help, a little, but for a short period only before a top up is required.

        If you add a little colour, something light, this will be more like a factor 30, a more standard level of protection to prevent sun damage, the darker you go the higher the factor and the better the protection.

        Sikkens is a very good brand to consider and for your garage door the Sikkens Cetol HLS Plus is ideal and requires three coats to give a long lasting and durable finish.

        There are alternative you could consider also, if the Sikkens does not have the desired colour result. Sadolin for example have a great range of colours Sadolin Extra Durable Woodstain could be considered.

        And if you are still unsure we have a great team of advisers who are always happy to help with tips and recommendations for your project. Just get in touch via our contact us page and they will be happy to help.

        Kind regards Samantha.


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