47mm x 100mm (4 x 2) - Sawn Kiln Dried & Pressure Treated (Tanalised) C24 Graded Timber

47mm x 100mm (4 x 2) Sawn Kiln Dried & Pressure Treated (Tanalised) C24 Graded Timber is a widely used structural softwood section that combines C24 strength grading, kiln drying, and pressure treatment to deliver reliable performance and improved durability on site.

C24 carcassing timber is kiln dried and strength graded to C24 standards, providing known and dependable structural performance for load-bearing applications. Stress grading is carried out either in the country of origin to BS 4978 or visually graded at the sawmill by qualified stress graders.

Kiln dried to a moisture content of 20% or less, this timber offers improved stability, better straightness, and reduced movement once installed, helping to meet current building regulation requirements.

This timber is regularised (planed all round) for consistent sizing, typically finishing approximately 2mm off nominal thickness and 5mm off nominal width. For example, a 47mm × 100mm section will finish at around 45mm × 95mm, with eased edges for safer handling and easier fixing.

Pressure treated under licence using Celcure AC-500, this timber has enhanced resistance to rot and insect attack. The treatment specification corresponds to Use Class 2 (UC2), making it suitable for internal structural use or protected external applications where occasional moisture exposure may occur. In practice, many customers also use treated C24 timber externally where good detailing, drainage, and airflow are provided.

For best long-term performance, all cut ends should be sealed with a suitable preservative after cutting. While treated, this timber is not intended for direct ground contact.

Typical uses include studwork, floor joists, framing, lintels, decking sub-frames, pergolas, garden structures, and general construction, where strength and durability are required in a familiar 4 × 2 format.

About timber sizes:
Although all timber is sold in metric sizes, imperial measurements remain widely used across the trade. We list both metric and imperial equivalents to help you identify the correct product. Always use the metric measurement when measuring timber.

Why choose C24 over C16?
Most CLS timber in the UK is graded to C16, however:

• C24 is graded to a higher strength standard

• Achieved from slower-grown timber with tighter grain

• Approximately 50% stronger than C16

• Better suited to longer spans and heavier loads

Nominal size: 47mm × 100mm (4 × 2)
Finished size: approx. 45mm × 95mm
Grade: C24 strength graded
Treatment: Pressure treated (Tanalised – Celcure AC-500)
Use Class: UC2
Moisture content: Kiln dried to ≤20%