When and how often to treat outdoor wood and wooden furniture

22/10/2024

It’s hard to beat the appeal of freshly treated wood furniture, structures, and finishes—inside or out. They catch the eye and complement any setting. Rough, flaky, rotting, or insect-infested wooden furniture, on the other hand…

Although plenty of online guides explain how to treat outdoor furniture, understanding when and how often to treat exterior wood is equally important. While conventional wisdom suggests treating it annually, it's not always that straightforward. Knowing the right timing and frequency can help keep your outdoor wood in tip-top condition for years.

Factors that affect how often you should treat outdoor wood

If you understand the factors that affect the frequency with which your outdoor wood needs treatment, you can apply them to your own needs and avoid both neglect and wasting time and money. The most important factors to consider when deciding how often to treat your outdoor wood are:

How much time has elapsed since the last treatment

Unless the wood in question has been kept out of the rain and direct sunlight, we recommend treating any outdoor wood that hasn’t been treated in 24 months. If you’re not sure whether it’s been treated or not, look for the following signs. If you identify any of these, a round of treatment could help restore your outdoor wood to its former glory.

  • The wood is greying, fading, or developing uneven colours across the surface.
  • The surface is cracking, splitting, or warping.
  • The wood feels dry and splintery. Small splinters easily break off.
  • You notice mould, algae, or mildew spots forming on the wood.

While the treatment for each problem might differ, any of these is a signal that some sort of treatment is required and that the wood is currently degrading. If you purchased raw wood furniture or structures, we strongly recommend treating it ASAP to avoid insect infestation and/or water damage.

Treating your outdoor wood and still missing a few essentials? Get them below and continue reading to discover the best treatments for your needs.

The type of wood you need to treat (hardwood vs. softwood)

All wooden furniture and structures are either hardwood or softwood. Teak, mahogany, oak, and other hardwoods are more expensive; however, they’re less prone to water damage, provide a degree of insect and rot resistance, and are resistant to impact, scratching, and general surface damage. These properties make them good for high-traffic areas such as decks, walkways, and outdoor furniture.

Typically, outdoor hardwood surfaces need refinishing every 24 months or so. Depending on the desired finish, you may need to sand down the surface before applying a fresh coat of stain, wax, varnish, or other finish.

Softwood furniture and surfaces, such as those made from pine, cedar, and Douglas fir, typically need more regular treatments. They’re less dense than hardwoods, making them more susceptible to moisture damage, rot, and insect infestation. They also deteriorate faster than hardwoods and require special preservative treatments to maintain their integrity in the long run.

You should treat your outdoor softwood furniture and surfaces with sealants, stains, and preservatives annually if they are facing direct sunlight and rain, and every 24 months if they are protected from the elements.

The weather

The type of weather your outdoor wooden furniture is exposed to is a major factor in determining how often it will need treatment. A cedar patio set facing Cardiff’s rain for a year and the same set baking in London’s sun are likely to develop completely different sets of problems.

Outdoor wooden furniture and surfaces that get and stay wet for much of the year are likely to rot or develop mould, algae, or mildew. The problem is worse for softwoods. We recommend a water-repellent preservative or sealant that penetrates the wood to protect against moisture absorption every 6 to 12 months. These products often contain mildewcides and fungicides that help prevent the growth of mould and mildew. Checking for signs of algae, mildew, rot, and insects every 3 to 6 months and treating any problems on the spot can significantly extend the expected lifespan of your outdoor wood.

UV exposure causes wood to fade, discolour, dry out, and develop surface cracks. Luckily, these imperfections develop more slowly than the ones caused by excessive moisture and can be addressed every 12 months or so in the case of softwoods and every 24 months for hardwoods.

We hope that you’ve found this guide useful. We recommend these products for your outdoor wood upkeep needs.