Thermowood Decking

Thermowood decking

Thermowood decking is made from timber that has been heated to high temperatures in a controlled process, without chemicals. The heat changes the cell structure of the wood, improving stability and resistance to rot, and darkens it to a rich chocolate brown colour. It is a popular alternative to tropical hardwood.

Benefits

• Good dimensional stability, so less swelling, shrinking and cupping.
• Improved decay resistance compared with untreated softwood.
• A consistent, attractive tone from the outset.
• Typically free of resin bleed, so comfortable underfoot.

Read more about the process on our thermally modified timber page.

Installing

Fix boards across joists at roughly 400mm centres, leaving a 5 to 8mm gap. Pre-drill and use stainless screws, as thermally modified timber is more brittle than untreated wood and can split at the ends. Keep the substructure ventilated and avoid placing boards in direct contact with the soil. Our decking substructure joists are suitable for the frame.

Finishing and care

Without treatment, thermowood will fade to silver grey over time. If you prefer to keep the brown colour, apply a UV-stable decking oil from finishes and treatments once or twice a year. Seal any cut ends.

How much to order

Measure the deck area and add 10% for waste, more if your layout has many angles. Browse the full decking boards category, or consider a planned kit from decking kits. A free sample will show the real colour and grain, see free timber samples.