Fixing and buying guide
4.8Mtr X 47 X 125mm C24 Treated Regularised KD Carcassing Timber
Selecting the right size
This 47 × 125mm section is a standard carcassing size suitable for floor joists, roof battens, stud walls, and decking frames. The 4.8 metre length offers flexibility for most residential and light commercial applications. Consider your span requirements and load conditions when determining whether this section meets your structural needs. For longer spans or heavier loads, you may need to increase the section size or reduce spacing between supports.
- 47 × 125mm is a common section for residential joists and stud work
- 4.8 metre length suits standard room widths and building layouts
- Check your structural design or building regulations for required section sizes based on span and load
Understanding C24 grading
C24 is a strength grade that indicates this timber has been visually or machine-graded to meet specific strength and stiffness requirements. C24 timber offers enhanced stability, fewer knots, and improved strength compared to lower grades such as C16. This makes it suitable for structural applications where reliability and load-bearing capacity are important.
- C24 is strength-graded to BS EN standards
- Superior load-bearing performance compared to C16
- Fewer knots and better overall quality
Pressure treatment and durability
This timber is pressure-treated with preservative to protect against rot, fungal decay, and insect infestation. The treatment penetrates the wood to provide long-term protection, making it suitable for use in damp conditions and outdoor applications. Treated timber requires no additional on-site treatment, though cut ends and drilled holes should be sealed with appropriate timber preservative to maintain protection at these vulnerable points.
- Pressure-treated for rot and decay resistance
- Suitable for both indoor and outdoor use
- Seal cut ends and drilled holes with timber preservative
Moisture content and handling
This timber is supplied kiln-dried (KD), meaning it has been dried in a kiln to reduce moisture content. Kiln-dried timber is more stable, easier to work with, and less prone to movement than green timber. Store it in dry conditions and allow it to acclimatise to the building environment before installation. Avoid prolonged exposure to weather or damp conditions during storage.
- Kiln-dried for improved stability and workability
- Store in dry conditions before use
- Allow acclimatisation time in the building environment
Fixing and installation
Use appropriate fixings for your application: galvanised or stainless steel nails, screws, or bolts to prevent corrosion and maintain the integrity of the treated timber. Ensure fixings are driven fully home without splitting the timber. For structural applications such as joists, follow building regulations and structural design specifications for spacing, support, and bracing requirements.
- Use corrosion-resistant fixings (galvanised or stainless steel)
- Drive fixings fully home to avoid splitting
- Follow building regulations for spacing and support requirements