Woodsafe® WFX™
Advanced Polymer-Based Fire Protection for Exterior Timber
WFX™ is Woodsafe's high-performance fire protection system for naturally weathered timber façades and demanding exterior applications.
Developed to combine the natural weathering of wood with documented, durable fire performance—verified for use class EXT in accordance with EN 16755 and manufactured under continuous third-party supervised Factory Production Control (FPC).
EN 16755 EXT · ASTM D2898 · CE / EN 14915 · RISE 0402 · TG 0263-08
Woodsafe® WFX™ – Developed for timber that is exposed to the elements and evolves over time
Timber used in exterior environments naturally changes over time. UV radiation, rain, moisture, temperature fluctuations, and natural weathering gradually affect the surface and appearance of the wood.
For fire-retardant treated timber, this means that fire performance must not only be documented at the time of delivery—it must also be possible to verify the durability of that performance following defined weather exposure.
Woodsafe® WFX™ has been developed specifically for these conditions.
Through Woodsafe's industrial impregnation, fixation, and drying process, the fire protection is permanently integrated into the wood's cellular structure. The system is designed for exterior applications where the natural character of the timber, architectural expression, and documented fire performance must work together over the long term.
WFX™ is documented for a wide range of natural, thermally modified, and chemically modified timber species, providing architects, specifiers, and contractors with extensive design freedom when creating modern timber façades.
WFX™ at a Glance
| Application | Fire-retardant treated timber for exterior façades and other documented outdoor applications. |
| Natural Weathering | Verified for EN 16755 use class EXT without requirement for a protective surface coating, within the documented field of application. |
| Fire Classification | Depends on the timber species, dimensions, profile, and installation method. Select the appropriate solution based on the applicable Classification Report and Declaration of Performance (DoP). |
| Wood Species | Documented solutions are available for, among others, spruce, cedar, ThermoWood®, and Accoya®. Check which timber species are covered for your project. Check which wood species are covered for your project. |
| Verification | CE marked in accordance with EN 14915, continuous Factory Production Control (FPC) supervised by RISE, and covered by Swedish Type Approval TG 0263-08. |
Documented Fire Performance After Weather Exposure
WFX™ is developed for exterior timber applications where the durability of the fire performance must be verifiable even after exposure to weather and climatic conditions.
The product is supported by testing, certification, and continuous third-party supervised Factory Production Control (FPC).
The documentation covers both fire performance and the verified durability of that performance for exterior applications.
EN 16755
Durability of Fire Performance
Verification of the durability of the fire performance following defined weather exposure.ASTM D2898, ASTM E2768
Accelerated Weathering
Supplementary verification of the product's performance following exterior exposure.CE / EN 14915
AVCP System 1
The product and its manufacturing are covered by the European system for Assessment and Verification of Constancy of Performance (AVCP).RISE 0402
Third-Party Supervised Production
Continuous surveillance by a Notified Body.TG 0263-08
Swedish Type Approval
Documented use within the scope of the Type Approval.
Woodsafe® WFX™
Advanced Polymer-Based Fire Protection for Exterior Wood
What Does EN 16755 EXT Mean?
For fire-retardant treated wood intended for exterior applications, it is not sufficient to demonstrate fire performance on a newly manufactured product. Documentation is also required to demonstrate how the fire performance is maintained following relevant weather exposure.
Use class EXT in accordance with EN 16755 is used to verify the durability of the fire performance of fire-retardant treated timber products following defined accelerated weathering for exterior service conditions.
For WFX™, the documented durability is based on Woodsafe's industrial impregnation and fixation process and, within the product's documented field of application, does not depend on a protective surface coating to maintain the verified durability of the fire performance.
This allows the timber surface to weather naturally and develop its own character over time, while the product's fire performance is supported by documented and verified performance.
This is WFX™
This is WFX™
WFX™ is Woodsafe's advanced polymer-based fire protection system for exterior timber, developed for applications where the durability of the fire performance must be documented even after weather exposure.
During the industrial treatment process, the timber is impregnated with fire-retardant chemicals that, through a controlled fixation and curing process, form a stable polymer structure within the wood. The technology is developed to provide durable fire performance in exterior applications, and WFX™ is verified for EN 16755 use class EXT.
Unlike systems where the durability of the fire protection depends on a protective surface coating, WFX™ is designed to allow the timber to be naturally exposed to the elements and weather over time within its documented field of application. The timber surface may change through exposure to UV radiation, rain, moisture, and temperature fluctuations without a protective surface coating being required to maintain the verified durability of the fire performance.
WFX™ is documented for a wide range of natural, thermally modified, and chemically modified timber species, including spruce, cedar, ThermoWood®, and Accoya®.
The result is a fire protection system for modern timber architecture that combines material freedom, natural weathering, and documented fire performance in exterior façade applications.
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Material Properties After Fire-Retardant Treatment
Material Properties After Fire-Retardant Treatment
WFX™ is applied through an industrially controlled vacuum-pressure impregnation process in which the fire-retardant chemicals are introduced into the wood's cellular structure and subsequently fixed through a defined drying and curing process.
The treatment introduces moisture into the wood before it is dried back to the specified delivery moisture content. Because wood is a natural, hygroscopic material, the process may result in minor changes to its dimensions, shape, and surface characteristics compared with its original condition.
The extent of these changes depends on several factors, including the timber species, density, grain orientation, dimensions, profile, initial moisture content, and the quality of the raw material. As a result, even timber within the same grading category may respond differently during the impregnation and subsequent drying process.
For planed timber products and plywood, dimensional changes following treatment may result in final dimensions that differ from the tolerances applicable before impregnation. This is a natural consequence of carrying out the impregnation and drying process after the original machining.
Selecting the appropriate timber quality and dimensions prior to treatment is therefore essential to achieving a predictable final result.
When specifying and ordering fire-retardant treated timber, consideration should be given to the timber species, dimensions, profile, machining, and any requirements for final dimensions. For projects with particularly tight dimensional tolerances, Woodsafe or the responsible project partner should be consulted before production to confirm the applicable conditions.
EN 16755 – Verified Durability of Fire Performance
EN 16755 – Verified Durability of Fire Performance
Woodsafe® WFX™ has been assessed and documented by RISE in accordance with EN 16755:2017, the European standard for the durability of the fire performance of fire-retardant treated wood products.
WFX™ complies with the requirements for DRF-classes INT1, INT2 and EXT, covering applications ranging from dry and humid interior environments to exterior conditions with direct weather exposure.
For EXT, the standard verifies that the fire performance is maintained within the specified acceptance criteria following the prescribed accelerated weathering procedure and subsequent fire testing.
The RISE Assessment and Type Approval Certificate TG 0263-08 confirm the documented DRF classification of the WFX™ system and specify the timber species, products, and conditions of use covered by the approval.
DRF INT1 · DRF INT2 · DRF EXT
Verified by RISE · Documented Durability · Exterior Applications
All timber species covered by the current RISE Assessment and Type Approval for WFX™ are documented for DRF classes INT1, INT2, and EXT in accordance with EN 16755:2017.
Let yourself be inspired by Woodsafe® WFX™
Botanikern
One of Uppsala's first apartment buildings with a wooden frame, which won the city's architecture award 2020. Thermowood fire-impregnated with Woodsafe® WFX™.
Universeum Gothenburg
Sweden's national science center, world-unique visualization lab and visualization court. Cedar shavings impregnated with Woodsafe® WFX™.
Cederhusen Stockholm
One of the world's largest wooden house projects in an inner-city environment, which won construction of the year 2022. Cedar shavings (red/yellow) fire-impregnated with Woodsafe® WFX™.
Sergelhuset Stockholm
Unique remodeling/renovation project awarded LEED Building/Project of the Year 2020. Cedar shavings impregnated with Woodsafe® WFX™.
FAQ Woodsafe® WFX™
Is Woodsafe® WFX™ organic fire protection?
No. Worth mentioning is that there are no fire retardants that are organic. Claims of natural and organic fire retardant are a marketing strategy that sounds good, but it is not true.
Is Woodsafe® WFX™ toxic?
No, the product is not classified as hazardous to health or the environment.
Can Woodsafe® WFX™ be used indoors?
Yes, but it is mainly used in environments with very high humidity.
Can Woodsafe® WFX™ be surface treated?
Yes, but only in the factory with a special tinting system. Tinting means that the product can be colored in a thin layer, such as transparent lasering in several shades, for example green, silver, grey, black, sooty black, brown and driftwood. Cover painting is not recommended, nor is surface treatment in the workplace due to adhesion problems with standard products.
Does Woodsafe® WFX™ contain substances included in the REACH CLP list?
Yes. In the concentrate and process liquid there is formaldehyde, which is classified Muta. 2; H341 and Carc. 1B; H350.In the fixing process, the fire retardant is hardened into a stable polymer where the levels are below the limit level for emission E1 (EN717).
Can I treat with silicon such as Organowood, Sioox, iron vitriol?
No. The treatment does not provide the effect that the supplier markets, such as gray tinting or water repellency. The wood naturally turns gray over time, in any case when it is broken down by UV light and more.
Can fire retardants based on iron phosphate, di-ammonium, ammonium phosphate be compared to WFX™'s properties?
No, that is not possible. They are completely different types of composition chemicals, where function and properties cannot replace or equate as equivalent to Woodsafe® WFX™.
Is Woodsafe® WFX™® WFX™ type-approved?
Yes, since 2018. Included in type approval certificate. Ref. no: 0263-08. Approved properties are SP FIRE 105, EN 16755 INT1, INT2 and EXT.
Is Woodsafe® WFX™ CE certified?
Yes, since 2015. CE certificate no: 0402-CPR-SC0260-15 (EN14915:2013).
Can I buy the product directly from you?
No, we sell through partners who are more than happy to help you. Click here to get to resellers.
Does Woodsafe® WFX™ have fire resistant properties?
Yes, it is suitability tested and approved according to EN 16755 INT1, INT2, EXT. The properties are verified by RISE in type approval certificate TG0263-08.
Does Woodsafe® WFX™ contain hygroscopic substances such as ammonium phosphate?
No.
What sets Woodsafe® WFX™ apart from other fire retardants?
Woodsafe® WFX™ is a multi-component fire retardant that in the process hardens into a long-lasting stable polymer (a bit like 2-component glue, put simply). In comparison with other fire retardants based on hygroscopic easily soluble substances, such as di-ammonium, monoammonium, ammonium, iron (III) phosphate, urea, polyammonium phosphate, which cannot be used without an approved surface treatment in, for example, an exterior environment. WFX™ is the only approved exterior fire-impregnated wood product with no requirements for surface treatment according to EN 16755 EXT and American standard ASTM D2898.
Some operators claim that their product is maintenance-free because the type of wood is impregnated, is that correct?
No, through impregnation in relation to the properties of the fire retardant are two completely different things. Claims that fire retardants containing ammonium have equivalent properties to Woodsafe® WFX™ are completely unfounded.
In addition, many types of wood cannot be impregnated as it is claimed. Types of wood such as spruce, larch, cedar and oak are some examples of types of wood that cannot be impregnated through, as a fire protection impregnation.
About Woodsafe® WFX™
Woodsafe® WFX™ combines Hoover's proprietary polymer technology with verified EN 16755 use class EXT and performance verified in accordance with ASTM D2898. The system is developed for natural weather exposure, allowing timber to weather naturally while maintaining documented and verified durability of the fire performance.
