Why does outdoor wood change colour?

One characteristic that is challenging when working with wood is the spectrum of colours you find within a single species.

All woods will vary in color throughout the process from sawmill to finished task. Wood continues to change colour years down the road.

It fades from exposure to sunlight, but some woods also undergo chemical transformations that change the wood colour.

The one thing you can count on is the wood colour will definitely change. Further, expect that matching an existing wood may take months or years to do as the wood ages.

Why Timber Changes Colour?

  • Exposure to weather, including UV and rain

UV exposure from Sunshine, rain, snow, mist and fog are the culprits for outer woodwork misery, and we get a bunch of them here.

Source: silvatimber

Under this continuous battering, wood operates very much like human skin. When sunburn and windburn peel, dead skin chips off, and gives way to new skin, and the gloomy grey patina you get on untreated or overlooked wood is caused by those layers of dead wood fibres.

Even sealed wood will go silvery grey with time and since deadwood can’t restore fresh fibres, you must do the job on its behalf. But do you really have to? Can you just leave your wooden decking, fences, shacks and so on to age gracefully, or is it necessary to keep up a decent standard of upkeep and try to prevent the wood from going grey?

  • Chemical reactions within the wood resins a.k.a extractives

The colour of timber is driven by natural pigments. This is determined by a group of chemicals known as quinones and polyphenolic compounds. Quinones are the true pigments, as the polyphenolic compounds are clear. However, they can become significant over time. All timber contains what is commonly referred to as “extractives”.

When polyphenolic compounds are exposed to air and a little UV, they oxidise to form quinones. So they go from being clear to a specified colour. This darkens the wood over time. Exposure to light, even ambient light, causes tannins to slowly oxidise. This can create a yellowed formation over time. It is very ordinary in light-coloured timber.

Introduction of alkali or acidic material like glue or finishes can cause unpredictable reactions with various components of extractives. Leaching of extractives can cause watermarks on timber, particularly when freshly cut. The water draws out and consolidates the extractives on the wood surface.

Why Timber Changes Colour
Source: preschem.com

Can I protect my outdoor wood?

Well, the only answer is, no. However, you can slow down the greying process by using UV-resistant wood finishing products and maintaining the finish of your exterior wood in good shape. These UV-resistant creations are excellent for providing additional protection for wooden cladding, garden sheds, wooden decking and garden furniture against harmful components.

Protect Exterior Wood

How to control and treat grey wood?

While it seems that quitting wood silver-grey doesn’t necessarily curtail the wood’s valuable life, what if you sense it’s more sloppy than chic, favouring gleaming, new, colourful wood in all its glory? Here are some tips and directions about how to protect wood’s magnificent natural colour and shine.

Graying Wood Deck
Source: timbertown

Preserving new timber colour

  • Keep in mind that most brand new timber comes pre-treated to one extent or another. It must be pre-protected with a suitable wood preserver or wood oil.
  • If so, it allows knowing precisely what it’s treated with so you can use a compatible product when the actual finish wears off.
  • If not, you can utilise decking oil to treat fences and sheds since it’s so water-resistant, adaptable and usually comes with built-in UV protection. Most wood preservers, if over-coated with some kind of decking oil or different exterior wood oil will last for up to 5 years. Most exterior wood oils including decking oil will require a top-up every 1 to 3 years, relying on how much wind, rain and sun the surface of the timber receives.
  • Fence stains are rather good for water protection but in our climate, they’re not as good as oils. When water doesn’t sit on the surface and bead anymore, it is just the time to use another coat.
  • Wood sealing products work sufficiently but like stains, they’re not quite as satisfactory as wood oils. If it’s specifically wet where you live you’ll have to restore it more often than usual.

Restoring old timber

  • A power washer is an effortless mode to take off layers of dead fibres and expose the fresh wood underneath. They’re readily available at most tool hire stores.
  • Use a tough bristle brush first to get rid of stubborn stuff like dirt and bird poop.
  • Treat mildew – green and black – with a good quality mould and mildew cleanser which will kill it off correctly as well as get rid of the stain.
  • Sanding makes the surface smooth, getting rid of slivers and rough scraps and giving your finish the best chance of a long life.
  • A wood reviver gel is your best friend.
  • Allow the wood to dry for 48 hours then apply a suitable exterior wood oil.

Pro Tip: The more silver-grey your outdoor wood is, the more elbow grease and extra applications you’ll need. Like so much in life, upkeep and maintenance is the key!

Why should wood be impregnated?

There’s a reason you’ve bought that front door because you like how it looks, so why let the weather and chemicals let it turn it grey? proPERLA® Wood Impregnator won’t change the natural colour of the wood or yellow over time and it protects from whatever the weather can throw at it.

proPERLA® Wood Impregnator is a water-based solution developed with the latest nanotechnology. It guards wooden surfaces such as hardwood terraces, beams or wooden boards against any premature ageing. Thanks to its extreme beading effect, it effectively prevents the shrinkage, splitting of wood and greying. As the surface remains constantly dry, microorganisms can not adhere and green growth of green is also drastically minimised.

  • It is Super-hydrophobic

You will realise the excellent water repellent properties of its beading behaviour. It will make the surface dry and incredibly resistant to biological threats, mould, mildew, etc. A dry surface will enhance the thermal resistance, control frost damage, lessen the growth of microbial spores and maintain the fresh vibrant colour of your wood.

Water Repellent Effect
  • Has a Self-cleaning effect

Dirt particles are unable to obtain a hold on the proPERLA® coated surface and will merely flow off with rainfall. The surface remains clean and pleasing, even on sides that are especially exposed to the weather, as well as in areas with high air humidity or sea salt infiltrated air.

We could make something great together. Get in touch.

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proPERLA® offers a range of exterior super hydrophobic waterproof paints & coatings designed to reduce energy costs and protect homes.

Through our official network of applicators, we provide services to end customers, ensuring the correct application of our products for your benefit.

Whether you are a professional interested in working with our products, or a customer looking for solutions, contact us for more information.

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