What does "pressure-treated garden green" mean?
The timber has been treated with chemical preservatives forced deep into the wood under high pressure. The "garden green" tint comes from the treatment process, which helps protect the softwood against rot, fungal decay, and insect attack.
Do I need to paint or stain treated decking?
No, pressure-treated decking is already protected against the elements and can be left untreated, in which case it will naturally weather to a silvery-grey over time. However, you can apply a colored exterior decking oil, stain, or water-repellent finish if you want to preserve or change its color.
Which side of the decking board faces upwards?
Most decking boards are ribbed or grooved on one side and smooth on the other. It is generally recommended to install the grooved side facing downwards (to allow better airflow and drainage underneath) and the smooth side facing upwards, as smooth boards are much easier to clean, less slippery when wet, and less prone to holding moisture and collecting algae.
How far apart should my support joists be spaced?
For standard 28mm thick decking boards, the supporting timber joists should typically be spaced no more than 400mm to 450mm apart (centre-to-centre) to prevent the boards from flexing or bouncing underfoot.
What kind of fixings should I use?
Always use exterior-grade, corrosion-resistant screws (such as stainless steel or specially coated green decking screws). Standard steel screws will react with the treatment chemicals and rust quickly, causing black stains and loose boards.
How should I treat cuts or notches made during installation?
Whenever you cut, drill, or notch a treated decking board, you expose untreated wood at the core. You should apply a dedicated end-grain preserver or timber treatment fluid to all fresh cuts before screwing the board down to maintain its rot resistance.
