Description
Our treated structural timber is a pressure-treated softwood range for joists, carcassing, framing, decking subframes and general construction work.
The range includes common sections such as 2x2, 3x2, 4x2, 6x2, 8x2 and 9x2, with lengths up to 6.0m depending on the section selected. Customers may describe these products as timber joists, treated timber joists, carcassing timber or structural softwood.
Choose the section and length that suits the job rather than relying on one size name alone. If a project requires a specific grade, certificate or documented specification, please confirm the current stock and suitability before ordering.
For stud walls and internal partition work, our CLS studwork timber may be the better fit. For decking structures, pair the correct timber section with suitable joist hangers, fixings and treatment details for the intended use.
Which timber should I use for a decking subframe?
For a straightforward low-level garden deck, our Decking Calculator uses 47 × 100mm treated structural timber (commonly called 4×2) for the main subframe, with joists planned at up to 400mm centres.
The right section still depends on the deck depth, support positions and layout. Use our Decking Joist Calculator to check common joist centres, clear spans and support lines before ordering the frame.
For the surface itself, shop treated timber decking boards, then add suitable decking screws and structural fixings for the chosen frame.
