What is CLS Timber?

What is CLS Timber?

Working on a construction project and considering CLS timber for the job? Strong, durable and well-shaped for a variety of uses, CLS timber has become a popular choice for many internal structuring jobs. To help you decide whether it best suits your purposes, here at Arnold Laver, we’ve broken down all you need to know about the popular timber wood, including its characteristics, its qualities and its most common uses within the construction industry.

What is CLS Timber? 

First thing’s first, what is CLS timber? CLS timber is created from woods such as kiln-dried fir, pine or spruce. During the manufacturing process, it is planed, treated and shaped with four smoothed surfaced sides and distinctive rounded (or radiused) edges.

What Does CLS Timber Stand For? 

CLS stands for ‘Canadian Lumber Standard’, as it was originally manufactured in Canada and used for building sturdy timber-framed houses there before it became a popular option in the UK, too.

The benefits of CLS Timber 

When it comes to CLS timber, there are several key benefits to consider. One of its main advantages is its exceptional strength and the fact it has superior durability over other types of wood timber, thus making it ideal for construction and internal structural work.

Due to its rounded edges, CLS timber is also particularly easy to transport and safe to handle. As CLS timber has a lack of large knots on its edges, it’s also better able to reduce the spread of potential fire outbreaks.

Another benefit to consider is the fact that CLS timber is available in a variety of widths and lengths to choose from, making it a great option for not only minimising time spent on cutting it to size but for reducing the cost from timber wastage.

What is CLS Timber Used For? 

CLS timber is a versatile timber typically used for a variety of internal structural projects. Alongside the obvious advantages from its strength and durability, the fact that it is shaped with four surfaced sides and rounded edges makes it particularly ideal for jobs such as:

  • Timber frame home construction
  • Creating internal partitioning walls
  • Interior framing
  • Stud walling
  • Carcassing 

You’ll typically find CLS timber strength-graded as either C16 or C24. Both are similar in appearance, but C24 is the stronger of the two and this is often subsequently reflected in the cost.

Can CLS Timber Be Used Outside? 

CLS timber should only be used outside if it has been treated, in order to ensure it is suitably resistant to external climate conditions that can cause issues such as rot and decay. 

While CLS timber is an excellent choice for internal structuring, it is important to check it has been sufficiently protected against moisture exposure and other external factors before considering it for outside use.

Think CLS timber could be right for your project? Within our sawn timber department here at Arnold Laver, you can find PEFC-certified, responsibly sourced CLS timber in a variety of dimensions to choose from.