Fixing and buying guide
5.4Mtr X 75 X 225mm (9" x 3") C24 Treated Regularised KD Carcassing Timber
Selecting the right size
This 75 × 225mm section is a versatile carcassing size suitable for floor joists, roof battens, stud walls, and decking frames. The 5.4 metre length provides good coverage for most standard building applications. Consider your span requirements and load conditions when determining whether this section meets your structural needs. C24 timber offers enhanced strength compared to C16 grade, making it suitable for applications requiring higher load-bearing capacity.
- 75 × 225mm section is commonly used for residential floor joists and wall framing
- 5.4 metre length suits standard building layouts with minimal waste
- C24 grade provides superior strength and stability for structural work
- Regularised finish means consistent sizing across all pieces for easier installation
Moisture content and storage
This timber is supplied kiln-dried (KD), meaning it has been dried to a controlled moisture content. Proper storage on-site is essential to maintain this condition and prevent movement or warping after installation.
- Store horizontally on level ground with adequate ventilation underneath
- Keep timber covered to protect from rain and direct sunlight
- Allow air circulation between layers using timber spacers
- Avoid storing in damp conditions or against external walls before use
Pressure treatment and durability
The timber is pressure-treated with preservative to protect against rot, fungal decay, and insect attack. This treatment extends the service life significantly, particularly in applications exposed to moisture or outdoor conditions. The treatment is integral to the timber and does not require additional on-site application.
- Suitable for both internal and external structural applications
- Pressure treatment provides long-term protection without additional coating
- Meets current BS EN standards for treated timber
- No further treatment required unless specified by structural design
Fixing and installation
Standard fixing methods apply to C24 carcassing timber. Use appropriate fasteners for your application, ensuring they are compatible with treated timber and suitable for the load conditions.
- Use stainless steel or galvanised fasteners to avoid corrosion with treated timber
- Follow structural engineer specifications for spacing and fixing centres
- Ensure adequate bearing and support at all connection points
- Cut ends should be treated with preservative if exposed to weather