The Story
Treated sawn C24 timber 47mm x 50mm is a structural softwood strength-graded to BS 4978, kiln dried, and pressure treated (Tanalised) for long-term performance. Suitable for framing, decking subframes, and general structural work where a verified grade and treated timber are specified.
Specifications
| Material | Structural softwood |
| Grade | C24 to BS 4978 |
| Treatment | Pressure treated (Tanalised) |
| Finish | Regularised (planed all round) |
| Nominal Size | 47mm x 50mm |
| Finished Size | Approximately 45mm x 45mm after regularising |
| Length | 4.8m (16ft) |
| Profile | Sawn, regularised |
| Use Class | UC3 (above ground, exposed) |
What it's used for
- Decking subframes and joist structures where treated timber is a specification requirement
- Stud partitioning and timber-framed wall construction
- Roof tiling battens and general structural framing
- Outbuilding and garden structure framing where ground or weather exposure is likely
Fitting and handling
Store timber flat and off the ground on level bearers, under cover where possible, to prevent bowing or moisture uptake before installation. Allow the timber to acclimatise to site conditions for at least 48 hours before fixing, particularly in heated internal environments. Use hot-dip galvanised or stainless steel fixings throughout, as standard bright steel fixings can react with the preservative treatment and corrode prematurely.
FAQ
What is the difference between C16 and C24 graded timber?
C24 has a higher strength classification than C16, meaning it can span further and carry greater loads for the same cross-section. For decking joists, rafters, or any structural application with demanding load requirements, C24 is the specified grade under current building regulations guidance.
Is 47mm x 50mm the finished or nominal size?
47mm x 50mm is the nominal (sawn) size. Because this timber is regularised, the finished dimension will be approximately 2mm less on thickness and 5mm less on width, giving a finished size of around 45mm x 45mm. Always account for this when setting out structural work.
Can I use Tanalised C24 timber outdoors without further treatment?
Yes. Pressure treatment (Tanalisation) protects the timber against rot, fungal decay, and insect attack, making it suitable for exterior use in above-ground applications. Cut ends exposed during installation should be treated with an end-grain preservative to maintain protection at those points.
Browse the full range of C24 graded timber at Nottage Timber Merchants. We supply trade and retail customers across South Wales, with next-day delivery available to the Bridgend area and surrounding postcodes. Contact us for a quote on larger volumes.
Description
Treated sawn C24 timber 47mm x 50mm is a structural softwood strength-graded to BS 4978, kiln dried, and pressure treated (Tanalised) for long-term performance. Suitable for framing, decking subframes, and general structural work where a verified grade and treated timber are specified.
Specifications
| Material | Structural softwood |
| Grade | C24 to BS 4978 |
| Treatment | Pressure treated (Tanalised) |
| Finish | Regularised (planed all round) |
| Nominal Size | 47mm x 50mm |
| Finished Size | Approximately 45mm x 45mm after regularising |
| Length | 4.8m (16ft) |
| Profile | Sawn, regularised |
| Use Class | UC3 (above ground, exposed) |
What it's used for
- Decking subframes and joist structures where treated timber is a specification requirement
- Stud partitioning and timber-framed wall construction
- Roof tiling battens and general structural framing
- Outbuilding and garden structure framing where ground or weather exposure is likely
Fitting and handling
Store timber flat and off the ground on level bearers, under cover where possible, to prevent bowing or moisture uptake before installation. Allow the timber to acclimatise to site conditions for at least 48 hours before fixing, particularly in heated internal environments. Use hot-dip galvanised or stainless steel fixings throughout, as standard bright steel fixings can react with the preservative treatment and corrode prematurely.
FAQ
What is the difference between C16 and C24 graded timber?
C24 has a higher strength classification than C16, meaning it can span further and carry greater loads for the same cross-section. For decking joists, rafters, or any structural application with demanding load requirements, C24 is the specified grade under current building regulations guidance.
Is 47mm x 50mm the finished or nominal size?
47mm x 50mm is the nominal (sawn) size. Because this timber is regularised, the finished dimension will be approximately 2mm less on thickness and 5mm less on width, giving a finished size of around 45mm x 45mm. Always account for this when setting out structural work.
Can I use Tanalised C24 timber outdoors without further treatment?
Yes. Pressure treatment (Tanalisation) protects the timber against rot, fungal decay, and insect attack, making it suitable for exterior use in above-ground applications. Cut ends exposed during installation should be treated with an end-grain preservative to maintain protection at those points.
Browse the full range of C24 graded timber at Nottage Timber Merchants. We supply trade and retail customers across South Wales, with next-day delivery available to the Bridgend area and surrounding postcodes. Contact us for a quote on larger volumes.
