BS EN 338:2016

Structural Timber Strength Classification with BS EN 338:2016

BS EN 338:2016 is the essential British Standard for classifying the strength properties of structural timber. This standard provides a comprehensive system for determining the mechanical and physical characteristics of wood products used in construction, ensuring they meet rigorous safety and performance requirements.

Comprehensive Strength Grading System

At the core of BS EN 338:2016 is a detailed strength grading system that categorizes timber into 12 different strength classes based on the following key parameters:

• Bending Strength (Modulus of Rupture)
• Tensile Strength (Parallel to Grain)
• Compressive Strength (Parallel to Grain)
• Shear Strength
• Modulus of Elasticity
• Density

This comprehensive grading system ensures that structural timber used in construction projects meets stringent safety and performance criteria, providing architects, engineers, and builders with the confidence that the wood materials they specify are fit for purpose.

Ensuring Structural Integrity and Safety

Compliance with BS EN 338:2016 is essential for the safe and reliable use of structural timber in a wide range of construction applications, including:

• Residential and commercial buildings
• Bridges and other civil engineering structures
• Timber frame construction
• Roof trusses and beams
• Flooring and decking

By adhering to the strength classification system outlined in this standard, construction professionals can be assured that the timber they use will withstand the expected loads and stresses, minimizing the risk of structural failure and ensuring the safety of occupants and the general public.

Detailed Technical Specifications

BS EN 338:2016 provides a comprehensive set of technical specifications for each of the 12 strength classes, including:

• Characteristic values for bending strength, tensile strength, compressive strength, and shear strength
• Modulus of elasticity values (both mean and 5th percentile)
• Characteristic density values
• Guidance on the appropriate use and application of each strength class

These detailed technical specifications enable construction professionals to select the most suitable timber products for their projects, ensuring that the structural integrity and safety of the final construction are maintained.

Compliance and Regulatory Requirements

Compliance with BS EN 338:2016 is a critical requirement for the use of structural timber in construction projects in the United Kingdom and across Europe. This standard is referenced in various building regulations and codes, including:

• Eurocode 5: Design of Timber Structures
• UK Building Regulations
• National Annexes for Eurocode 5

By adhering to the requirements of BS EN 338:2016, construction professionals can ensure that their projects meet the necessary regulatory and compliance standards, reducing the risk of costly delays or non-compliance issues.