By Amy Hanlon on 14 Nov 2023
Don’t you just love it when the title of the blog is full of perplexing words like Radiata Pine ThermoWood?
Words that you’ve never seen before. Words that really don’t seem to mean anything!
But give me a few minutes of your time and before you know it you’ll be telling all your pals about this wondrous creation. I’ll get you spouting timber terminology like you were born to the ShedLife! And if you’re in the market for a really great Garden Room, you’ll have something else to look out for as you shop.
Because Radiata Pine ThermoWood is kind of a big deal.
What is Radiata Pine?
Let’s start at the very beginning. Timber gets its name from the species of tree it came from. Sometimes we use generic terms – like Scandinavian Redwood or British Whitewood – but usually, we talk about wood using the tree species.
Radiata Pine (or pinus radiata if you want to get your Latin on) is a species of tree that is native to California and Mexico, but grown all over the world.
The original name for this species was pinus insignis – the remarkable pine.
Why so remarkable?
Radiata is incredibly versatile. It thrives in a wide range of environments. It’s strong and dense, making it suitable for housebuilding, fences, boatbuilding, and many other indoor and outdoor applications. It tends to be tall and straight with few branches, making it excellent for timber production.
Interestingly, the native species has conservation status, but anywhere outside of its original forests, Radiata is plentiful, healthy and sustainable.
One of the reasons for its popularity is its fast growth.
Now if you’ve been paying attention, you may already know a thing or two about timber. You may even know that one of the reasons that we use Scandinavian Redwood is because it’s slow-grown.
What’s the difference between slow-grown timber and fast-grown timber?
Usually, fast-grown timber is poor-quality timber. It’s more likely to warp, bend and shift, and much more likely to cause water ingress in a building. We don’t put up with that sort of thing around here. We know that the best timber makes the best timber buildings.
But the Radiata Pine that we’re introducing breaks all the rules about fast-grown timber.
How come?
Because it’s heat-treated.
What is timber treatment?
People have been treating timber to improve its natural qualities for thousands of years. The Ancient Romans boiled wood in oil to strengthen it. In Scandinavia, pine tar was the timber treatment of choice. 17th-century Japanese builders even used heat treatment to make their timber durable. All of these methods had one common goal – to make timber strong, long-lasting and more weatherproof.
What is ThermoWood® ?
Perfected in Finland in the early 90s, the ThermoWood process uses pressure, heat and steam to treat timber.
Phase 1: High-temperature drying.
The process starts by placing the timber in a kiln and rapidly heating it to 100°C. The temperature then slowly increases to a maximum of 212°C. This phase dries the timber, reducing its moisture content from around 20% to 0.
Phase 2: Thermal modification.
Next, the high temperature is maintained. This permanently modifies the chemical structure of the wood and removes extractives like resins and tannins from the timber.
Insects and fungi feed on sugars in the timber, damaging the structure of the wood. This phase of heat treatment breaks down these sugars, protecting the timber from insect damage, mould, and decay. It also changes the appearance of the wood, giving it a beautiful toffee-coloured finish.
Phase 3: Conditioning and cooling.
Water sprays then lower the temperature of the timber. Once the timber cools, steam and water bring the moisture content of the wood up to 4-7%.
Timber needs some moisture content for stability, and so it can be machined. The ThermoWood process brings the moisture content of the timber much lower than other treatment methods. This makes the timber extremely weatherproof and resistant to shape changes or shifting.
What are the benefits of Radiata Pine ThermoWood?
ThermoWood lets us combine the many benefits of Radiata with the many benefits of heat treatment. It’s a win-win! Radiata Pine ThermoWood is a fast-grown, easily sourced, high-quality timber that is as stable, durable and weatherproof as less traditional alternatives like composite cladding.
Radiata Pine ThermoWood is five times more expensive than the Scandinavian Redwood we use for our Sheds. It’s a seriously long-lasting, low-maintenance product.
You can paint ThermoWood, but it’s not a necessary protection. Instead, you can coat it with a clear UV-protectant to maintain its gorgeous toffee colour or leave it to weather to a silvery grey. For the longest life we recommend using at least a clear UV protectant. While the silver grey is a beautiful finish, this colour change happens when the outer surface of the timber is degraded by the weather.
We use Radiata Pine ThermoWood cladding on our Under 12m2 Garden Rooms as standard. This cladding option is also available as an upgrade on our larger Blackstone Garden Rooms and our Garages.
Want to know more? Pop in and see us at our Show Area here in Errol. Or, if all this timber-chat has you raring to go for the ShedLife, book a consultation with one of our team. Don’t forget to tell them that you’ve done your homework and that you know all about the benefits of Radiata Pine ThermoWood.
