Introduction

EN 16755: Durability of Fire-Retardant Treated Wood

When working with fire-retardant treated wood, safety and durability are essential. EN 16755 s the European standard that defines the durability requirements for wood products treated with fire retardants. The standard ensures that fire performance is maintained throughout the product’s service life, both indoors and outdoors.

At Woodsafe Timber Protection, we go beyond compliance to provide certified and trusted fire-retardant wood solutions that meet the highest European standards, including EN 16755.

What is EN 16755?

EN 16755:2017 is a harmonized European standard that specifies the performance and durability of fire-retardant treatments for wood and wood-based products. It ensures that the fire protection remains effective over time, even when exposed to moisture, humidity, or outdoor weathering.

The standard applies to:

Solid wood
Plywood
Wood-based panels

By ensuring durability, EN 16755 gives architects, builders, and regulators confidence that fire safety is not compromised during the lifespan of a building.

Why EN 16755 Matters

Not all fire-retardant treatments are equal. Some lose their effectiveness when exposed to moisture or humidity, which can be critical in real-world applications.

With EN 16755-certified products, you are guaranteed that:

Fire performance is tested and validated long-term
Wood can be safely used in both interior and exterior applications
Compliance with European building codes and fire safety requirements is ensured

This standard protects not only buildings but also lives.

EN 16755 Classification System

EN 16755 introducerar tre beständighetsklasser beroende på användningsområde:

INT1 – Interior Dry

For heated indoor spaces with low humidity
Example: Offices, living rooms, hotel rooms

INT2 – Interior Humid

For unheated or humid interior spaces
Example: Bathrooms, swimming pool halls, basements

EXT – Exterior Use

For wood exposed to outdoor weathering and rain
Requires the highest level of durability and resistance to leaching
Example: Façades, exterior cladding, walkways

Woodsafe and EN 16755 Certification

Woodsafe Timber Protection is a European leader in durable fire-retardant wood solutions.

Our products certified under EN 16755 include:

Woodsafe PRO™ – For INT1 and INT2 applications, also for EXT but then with requirements for surface treatment
Woodsafe WFX™ – Certified for INT1, INT2 and EXT class, ensuring long-term durability outdoors

We back every product with:

Third-party certification
Continuous quality control
Proven performance in large-scale projects across Europe

EN 16755 vs. EN 13501-1

These two standards work together but cover different aspects:

EN 13501-1: Reaction to fire (how materials behave when exposed to fire)
EN 16755: Durability of fire-retardant treatments (how long protection lasts)

In short: EN 13501-1 tells you how safe a product is today; EN 16755 tells you how safe it will remain in the future.

Applications of EN 16755 Certified Wood

EN 16755-certified fire-retardant wood is used in a wide range of projects, such as:

Schools, hospitals, airports, and public buildings
Hotels, restaurants, and shopping centers
Residential housing and multi-story timber construction
Façades, outdoor decking, and public walkways

What tests are carried out for EN 16755 certification?

EN 16755 requires durability testing that includes:

Accelerated aging to simulate long-term use
Humidity exposure tests for INT1 and INT2 classes
Leaching tests for EXT classification to measure loss of fire-retardant chemicals in rain or moisture

How does EN 16755 benefit architects and designers?

By specifying EN 16755-certified products, architects can:

Ensure compliance with European safety standards
Avoid risk of fire protection loss in humid or outdoor environments
Offer clients peace of mind with a documented, durable solution

Is EN 16755 mandatory?

EN 16755 is not always legally mandatory, but it is increasingly recognized by authorities, insurers, and building regulations as proof of long-term fire safety. Many large-scale projects require it as a condition for approval.

What happens if wood is not EN 16755 certified?

Without EN 16755 certification, there is no guarantee that the fire-retardant treatment will remain effective over time. This can lead to:

Diminished fire safety
Non-compliance with building regulations
Increased liability for contractors and building owners

How does EN 16755 relate to sustainability?

Choosing EN 16755-certified products supports sustainability by:

Extending the service life of wood
Reducing the need for replacement or maintenance
Allowing safe use of renewable timber in challenging environments

Which Woodsafe products are EN 16755 certified?

Woodsafe PRO™ – Certified for INT1 and INT2. Also certified for EXT, but then with with requirements for surface treatment
Woodsafe WFX™ – Certifierad för INT1, INT2, EXT

Both product lines undergo independent third-party testing and comply with EN 16755 requirements.

Does EN 16755 apply outside Europe?

Yes. Although EN 16755 is a European standard, its requirements are internationally recognized. Many projects outside the EU use EN 16755 as a benchmark for fire safety and durability.

Why Choose Woodsafe for EN 16755 Certified Fire Protection?

Market leader in durable fire-retardant timber
Certified solutions for all EN 16755 classes (INT1, INT2, EXT)
Trusted partner in large-scale architectural projects
Sustainability-focused production methods

Understanding EN 16755 is critical for making safe, sustainable, and compliant choices in construction.

Contact Woodsafe today to discuss your project and discover how our EN 16755-certified solutions can meet your fire safety and design needs.

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