CLS Timber
(12 Products)CLS timber, short for Canadian Lumber Standard, is a widely used softwood timber, particularly valued in woodworking and structural projects. It is predominantly sourced from coniferous species such as spruce, pine, or fir. CLS timber undergoes kiln-drying to reduce moisture content, ensuring stability, durability, and resistance to warping or shrinkage over time. Its surfaces are planed smooth with rounded edges, enhancing its aesthetic quality and making it safer to handle.
What Is CLS Timber?
CLS Timber (Canadian Lumber Standard) refers to a widely used type of kiln-dried softwood timber that meets specific grading and manufacturing standards, making it ideal for a variety of construction applications.
Originating under the Canadian Lumber Standard, CLS timber is commonly sourced from species such as spruce, pine, or fir, collectively referred to as SPF. These species are favoured for their strength, workability, and cost-efficiency. CLS timber undergoes kiln drying to achieve a consistent moisture content, which minimises warping and shrinkage over time, ensuring long-term stability in structural applications.
A hallmark of CLS timber is its smooth, planed finish with eased corners, which enhances safety during handling and provides a polished appearance suitable for interior applications. The standard dimensions of CLS timber, such as 38mm x 63mm or 38mm x 89mm, are tailored for use in framing, partitioning, stud walls, and other structural purposes. Lengths typically range from 2.4 metres to 4.8 metres, accommodating diverse project requirements.
Because of its versatility and durability, CLS timber is highly favoured in modern construction, particularly in the UK and Europe, where its dimensions align well with metric building practices. It is also treated to resist decay and pests, making it suitable for interior framing and even some external uses when appropriately protected.
CLS timber’s compatibility with various fastening systems and its ease of cutting and shaping further contribute to its widespread adoption in construction projects, from residential buildings to commercial frameworks.
Where is CLS Timber Used?
- Framing and roofing applications
- Carcassing
- Timber framework construction
- Wall construction, particularly partition walls
- Interior framing and finishing
- Skirting boards
- Architraves
- Decorative features
CLS Timber Benefits
- Pressure treated - resists insects, mould and rot
- Slow grown and kiln dried
- Sustainably sourced
- Strength class: typically graded to C16 - although sometimes available in C24
- Exceptional strength and resilience
- Suitable for a wide range of applications
CLS Meaning
CLS stands for Canadian Lumber Standard, which refers to the size and grade of the timber produced for construction use.
The origins of CLS timber can be traced back to Canada, where this standardized size and grade of timber was first developed. Over time, it has become a popular choice in the construction industry globally.
Frequently Asked CLS Timber Questions
What Is The Difference Between C16 And C24 CLS Wood?
The European Standard BS EN519 grading system divides CLS timber into two strength categories: C16 and C24. Although they are of a similar appearance, the latter is more robust in nature — an attribute which can be seen in its often higher price tag.
How Does CLS Timber Compare To Other Types Of Timber?
CLS timber is often preferred over other types of timber for load-bearing applications because of its strength and stability. On top of its many benefits, its consistent dimensions and smooth surface texture also make it easier to work with and provide a polished finish.
Can You Use CLS For Stud Wall Applications?
When it comes to interior stud walling, CLS is an obvious choice due to its structural integrity and stability.
Whether you need a partition or batten wall design, this type of timber will always ensure optimum precision for your project.
Can CLS Timber Be Used Outside?
To ensure the longevity of CLS timber, it is essential that it has been treated prior to outdoor usage. Otherwise, external conditions can cause rot and decay over time.
Before considering CLS timber for external use, it is critical to ensure that the wood has been adequately safeguarded against moisture and other environmental elements. Although this type of timber is an excellent option for internal structures, its resilience outside depends on adequate protection and treatment.
How Does CLS Wood Contribute To The Circular Economy?
The circular economy is an economic model that seeks to minimise waste and promote the efficient use of resources by keeping them in use for as long as possible.
In the context of construction, the circular economy involves designing buildings and infrastructure to be durable, adaptable, and easy to disassemble and reuse. It also involves using materials that are renewable, recycled, or biodegradable to minimise the environmental impact of construction.
CLS wood contributes to the circular economy by being a renewable resource that can be recycled or reused at the end of its useful life. Additionally, the use of CLS timber in building construction can promote sustainable building practices and reduce waste.
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C16 vs C24 – What’s The Difference?
