Description

4.8m x 150mm x 47mm C24 Structural Timber – Pressure Treated

High-strength, treated timber for decking frames, joists, and outdoor structures

This 4.8m x 150mm x 47mm timber is a C24 structural grade, kiln-dried and pressure treated to enhance durability, strength, and resistance to fungal decay. It’s the ideal timber for decking subframes, floor joists, garden rooms, and heavy-duty framing where structural integrity and long life are essential.

Perfect for use in professional landscaping or self-build projects, this size balances strength and handling convenience. Pair it with our range of decking boards for complete structural builds, and extend its life with accessories like Joist Flashing Tape and ForgeFast Timber Screws.

Specifications

• Size: 4.8m (length) x 150mm (width) x 47mm (depth)

• Grade: C24 structural timber

• Finish: Kiln-dried and pressure treated

• Edge: Planed all round with eased edges

• Use: Indoor and outdoor structural projects

Common Applications

Decking Subframes

Ideal for medium-span decking bases. Use with Joist Flashing Tape to shield joists from rain exposure and ForgeFast Screws for secure, high-load fixings.

Garden Structures & Framing

Suitable for timber outbuildings, pergola beams, raised planter boxes, and more — thanks to its dimensional stability and strength rating.

Roofing & Flooring Support

C24 grading provides load support that suits loft joists and flooring frames where certified strength is needed.

Materials related to “C24 Structural Timber”

• Decking Boards – Compatible finish to complete timber-framed decks

• Joist Flashing Tape – Preserves timber from weather damage

• ForgeFast Timber Screws – Durable, torx-compatible screws ideal for structural fixing

• Sleepers – Additional timber components for structural and decorative builds

• Roofing Timber & Ply – Support your construction projects

• Full C24 Range – See other available dimensions

What’s the difference between C24 and C16 timber?

To understand why C24 timber is a popular choice for outdoor and structural builds, read our in-depth blog:
What is C24 Timber? C24 vs C16 Explained – we cover grading, span length, structural use cases and when to choose one over the other.

How do you install C24 structural timber?

Lay on a flat, prepared surface or concrete base. Secure with ForgeFast Timber Screws and apply Joist Flashing Tape along the top surface of joists for weather protection and added longevity.