CLS Studwork Timber | Treated Timber | Timber | CLS Wood

CLS Studwork Timber – Strong, Reliable Timber for Internal Framing

CLS studwork timber is one of the most widely used structural timber solutions in modern construction. Designed for internal framing, partition walls, and general carcassing, CLS timber offers a smooth, planed finish with rounded edges—making it safe, easy to handle, and quick to install.

Manufactured from kiln-dried softwood such as spruce, pine, or fir, CLS timber provides excellent dimensional stability, meaning it resists warping, twisting, and shrinkage over time. Whether you're building stud walls, boxing in pipework, or creating timber frameworks, CLS timber delivers consistent performance across a wide range of projects.

What is CLS Studwork Timber?

CLS stands for Canadian Lumber Standard, a widely recognised grading system for structural timber. It is typically machine-planed on all sides and features eased (rounded) edges for improved safety and ease of installation.

Unlike rough sawn timber, CLS timber is:

• Smooth and uniform for precise construction
• Kiln-dried to reduce moisture and movement
• Strength graded (C16 or C24) for reliability
• Ready to use without additional preparation

This makes it ideal for first fix construction, where accuracy and speed are essential.

Key Features of CLS Timber

• Smooth Planed Finish – Easier to work with and safer to handle
• Kiln-Dried Stability – Reduces warping, twisting, and shrinkage
• Strength Graded Options (C16 & C24) – Suitable for different load requirements
• Versatile Sizes & Lengths – Common sizes include 38x63mm and 38x89mm
• Pressure Treated Options Available – Protection against moisture, insects, and decay
• Sustainably Sourced – Often FSC or PEFC certified

Common Uses of CLS Studwork Timber

CLS timber is primarily used for internal structural applications, including:

• Stud wall framing and partition walls
• Floor joists and ceiling frameworks
• Door and window framing
• Boxing in pipes and services
• Roof carcassing and loft structures

Its consistent sizing and ease of cutting make it a go-to choice for both professional builders and DIY users.

CLS Timber Sizes & Grades Explained

Standard Sizes

Typical CLS timber sizes used in the UK include:

• 38 x 63mm (ideal for lightweight partitions)
• 38 x 89mm (standard stud wall size)
• 38 x 140mm (for heavier-duty applications)

Strength Grades

• C16 Timber – Cost-effective, suitable for most internal framing
• C24 Timber – Higher strength for load-bearing and structural use

Choosing the right size and grade ensures your project meets both structural and insulation requirements.

CLS Wood – A Reliable Choice for Modern Construction

CLS wood is a highly versatile and widely used timber solution in the UK construction industry, particularly for internal framing and studwork applications. Known for its smooth planed finish and rounded edges, CLS wood is easy to handle, cut, and install, making it ideal for both professional builders and DIY projects. Typically kiln-dried to reduce moisture content, it offers excellent stability and minimises the risk of warping or shrinkage over time. Available in strength grades such as C16 and C24, CLS wood provides dependable structural performance for partition walls, ceilings, and general carcassing. Its consistent sizing and quality make it a cost-effective and efficient material for achieving precise, long-lasting results in modern building projects.

Benefits of Using CLS Timber

• Easy Installation – Clean edges and consistent dimensions speed up construction
• Cost-Effective – Minimal waste due to standardised sizing
• Reliable Performance – Strong and durable for long-term use
• Versatile Application – Suitable for multiple construction tasks
• Professional Finish – Smooth surfaces improve final build quality

Choosing the Right CLS Timber for Your Project

When selecting CLS studwork timber, consider:

• Wall Type – Lightweight partitions vs structural walls
• Load Requirements – Choose C24 for heavier loads
• Space Availability – Thicker timber allows more insulation but reduces room size
• Moisture Exposure – Use treated timber in damp areas
• Length Requirements – Standard lengths range from 2.4m to 4.8m

Planning ahead helps reduce waste, improve efficiency, and ensure a high-quality finish.

Internal Links (Recommended Placement Section)

For a complete build solution, explore related categories:

• Complete your framing with a high-quality Sheet Materials collection for wall lining and structural boarding.
• Pair your timber framework with a reliable Plasterboard collection to achieve a smooth interior finish.
• Improve thermal and acoustic performance with our range of Insulation collection suitable for stud walls and partitions.

Why Choose Build4Less for CLS Studwork Timber?

At Build4Less, we supply high-quality CLS timber designed to meet the demands of both trade professionals and DIY users. Our range includes multiple sizes, grades, and lengths to suit any project, all sourced from trusted manufacturers to ensure durability and consistency.

With competitive pricing, reliable stock availability, and fast UK delivery, Build4Less makes it easy to get the materials you need—when you need them.

Frequently Asked Questions (FAQs)

What is CLS timber used for?

CLS timber is mainly used for internal framing such as stud walls, partitions, floor joists, and general carcassing in construction projects.

What does C16 and C24 mean?

C16 and C24 refer to the strength grading of timber. C16 is suitable for most internal applications, while C24 offers higher strength for structural and load-bearing uses.

What size CLS timber should I use for stud walls?

The most common sizes are 38 x 63mm for lightweight walls and 38 x 89mm for standard stud walls, depending on strength and insulation requirements.

Is CLS timber suitable for outdoor use?

CLS timber is primarily designed for indoor use. However, pressure-treated CLS can be used in certain external or damp environments.

Can CLS timber be cut to size?

Yes, CLS timber is easy to cut and shape, making it highly adaptable for different construction needs.