Carcassing timber is structural softwood used to form the hidden framework of a building or timber structure. Depending on the job, the same type of timber may also be described as structural timber, framing timber or timber joists.
Carcassing timber is used for the structure rather than the finished surface
Common uses include floor joists, roof joists, timber framing, wall plates, decking subframes, garden buildings and other supporting frameworks. The important distinction is that the timber is being chosen for a structural job rather than for its decorative finish.
Treated carcassing is used where added durability is required
Pressure treatment helps protect timber used in suitable external and exposed construction applications. Treatment does not tell you the structural capacity of the timber; section size, span, spacing, loading and the specified structural properties still need to suit the design.
Trade sizes and actual dimensions can differ
Names such as 4x2, 6x2 and 8x2 are common trade descriptions. Always check the metric section listed for the timber you are buying, particularly when matching joists, hangers or an existing structure.
Carcassing, CLS and general treated sawn timber are different buying jobs
Choose treated structural timber for joists, structural framing and treated carcassing. Use CLS Studwork Timber for internal partitions and dry internal framing. For general non-structural treated timber, browse treated sawn timber.
