Treated sawn Reg Timber C24 47mm x 150mm (6x2)

Treated structural timber C24 47mm x 150mm (6x2) is a pressure-treated, kiln-dried softwood section strength-graded to BS 4978, suitable for floor joists, rafters, and load-bearing carcassing where longer spans and higher structural performance are required.6m, 4.8m, 6.0m

What it's used for

• Floor joists in new-build and renovation projects where C24 grade is specified by building control
• Roof rafters and ridge construction requiring higher load-bearing capacity
• Decking subframe and structural supporting timbers in external applications
• General structural carcassing where longer spans demand a stronger section than C16

Fitting and handling

Allow this timber to acclimatise on site for 24 to 48 hours before fixing, keeping it stacked flat with spacers and covered to avoid moisture uptake. Use galvanised or stainless steel fixings throughout, particularly in external or damp environments, to maintain the integrity of the tanalised treatment. Cut ends exposed during installation should be field-treated with an end-grain preservative to preserve the protection.

FAQ

What is the difference between C16 and C24 structural timber?

C24 is a higher strength grade than C16, meaning it has been assessed and found to carry greater loads over longer spans. Building regulations or a structural engineer may specify C24 where C16 is not sufficient, for example in floor joists with wider joist centres or longer spans.

Is this timber suitable for external use?

Yes. The tanalised pressure treatment means it is suitable for above-ground external applications such as decking subframes and external carcassing. The treatment penetrates the timber to resist rot and insect attack, and the kiln-dried process helps reduce further shrinkage once installed.

Does 47mm x 150mm C24 meet building regulations for floor joists?

C24 graded timber is widely accepted by building control as structural softwood. Whether this specific section satisfies your joist span requirements depends on joist spacing, load, and span - your structural engineer or building inspector can confirm suitability using TRADA span tables.

Nottage Timber Merchants supply C24 graded structural timber to trade and retail customers across South Wales, with next-day delivery available to the Bridgend area. Browse the full range in our C24 graded timber collection for additional sections and lengths.