BS EN 338:2016 - TC

What is BS EN 338 - Strength classes of structural timber about?  

This European standard assists its users to identify suitable timber structures for their construction projects.  

BS EN 338 establishes a system of strength classes for general use in design codes. 

BS EN 338 gives characteristic strength and stiffness properties and density values for each class to which EN 14081-1 refers. 

BS EN 338 is applicable to all softwood and hardwood timber for structural use, within the scope of EN 14081-1. 

Who is BS EN 338 - Strength classes of structural timber for? 

BS EN 338 on strength classes of structural timber is useful for: 

• Architects 
• Civil engineers 
• Timber graders 
• Sawmills 

Why should you use BS EN 338 - Strength classes of structural timber?  

A strength class system groups together grades, species and sources with similar strength properties thus making them interchangeable. This then permits an engineer to specify a chosen strength class and use the characteristic strength values of that class in design calculations. 

BS EN 338 classifies structural timbers based on their strength properties, stiffness properties, and density values. These classifications help you to identify suitable structural timbers based on their bending resistance and load-bearing capacity, thereby ensuring the structural integrity of the building.  

What’s changed since the last update? 

BS EN 338:2016 supersedes EN 338:2009. Compared to EN 338:2009, the following modifications have been made in BS EN 338:2016: 

• New table of strength classes for softwood species based on tension tests 
• Extension with new classes in the table of strength classes for hardwood species based on edgewise bending tests 
• Modification of some characteristic values for strength, stiffness and density 
• Equations to determine the characteristic values of other strength properties from the grade determining properties has been transferred to EN 384