It seems that it will happen after all, will Europe apply the handbrake? The famous CWFT table to declare wood in accordance with the accessible fire reaction class D without having to test it will probably be amended with one word. That one word is 'Untreated' and has far-reaching consequences. Paulussen Houthandel has been passionate about wood and fire reaction classes for years and has put the facts side by side.

What is 'CWFT'?

The CWFT table stands for 'Classified Without Further Testing'.
This is a standardized solution (EN 14915) to declare wood under a few conditions in accordance with the accessible fire reaction class D.

The conditions are just as easily summarized: A closed facade system with a minimum thickness of 18mm and minimum density of 390kg/m3.

If the cladding does not meet these conditions, you must test it.
If the cladding does meet these conditions, but you expect and/or hope to end up higher, you can of course also test it.

This standardized solution was created to give the wood world space and not have it tested for every facade.

So what exactly changes?

The possible adjustment of the European CWFT table can better be described as a 'clarification'.

The current CWFT table, like the future standard solution, is only valid for untreated wood.
The problem that the EU is addressing is that the current standardized rule has been frequently misinterpreted.

You will find an interesting part of the memorandum about this:

"Thereby, the current table does not explicitly specify that the proven stable and predictable performance concerning the reaction to fire of those products is, under the set conditions, only guaranteed for untreated wood pieces. However, it has been clarified, as also supported by the relevant Technical Committee of CEN(3) and the Guidance of the Group of Notified Bodies(4) , that Table 2 of Annex to Commission Decision 2006/213/EC is to be applied only to untreated(5) solid wood paneling and cladding ."

The EU has now completed a draft version in which a very limited adjustment has been made, only the word 'Untreated' has been added.
Both the current and the future CWFT table therefore only apply to untreated wood and this 'clarification' excludes any chance of misinterpretation.
All 'treated wood types' fall outside this standardized solution.

Are all treatments excluded from the CWFT table?

Only the well-known 'Kiln Drying' or 'oven drying' is also considered untreated wood.
Please note: This only concerns a limited drying process and no thermal modification.

Why is this changing and is this decision well-founded?

We must conclude that the adjustment of the CWFT table is well-founded.

The standardized solution of the CWFT table is based on scientific research in which series of fire tests were performed and the results were analyzed. These tests indicated that untreated wood had stable and predictable performance in response to fire.

Both the current and the future CWFT table were only valid for untreated wood.
The fact that treated wood types or wood products are equated with fire reaction class D in accordance with this CWFT table due to misinterpretation is unfounded.

Adjusting all kinds of variables (profiling, type of modification, etc.) is impossible to map correctly with a standard solution.
The different variables usually have a different impact on the growth of the fire (FIGRA) and influence each other at the same time.

Our own fire research gives identical results and by doing a lot of testing ourselves, we have a model that can accurately predict results.

The description of the current CWFT table would, purely hypothetically, allow a certain softwood species to be impregnated with Kerosene.

Isn't this possible adjustment very 'sudden'?

Here too I must report that this did not come out of the blue.

The previous CWFT table was also only based on untreated wood, but the description left the possibility of misinterpretation.
In recent years, the EU has communicated several times with, for example, the necessary Guidance Papers to emphasize that it was only valid for untreated wood.

The reality, however, is that not everyone is a fire expert and many market participants did not come into contact with the supporting parties.
Several designing parties / wood producers misinterpreted the current CWFT table.
This misinterpretation ensured that several combinations of products/wood types/profiles were equated with fire reaction class D, while reality says otherwise.

Will this adjustment have a major impact?

The clarification of the CWFT table will have a major impact.
Many manufacturers of treated and/or modified wooden cladding will have to officially test their products.

At the same time, the EU's proposed adjustment implies that not all products will achieve the minimum (low-threshold) values for fire reaction class D.
Paulussen Houthandel's own research has now also shown that it will be difficult for a surprising number of treated wood types and/or profiles.

There is also a significant extra difficulty.

Paulussen Houthandel has been testing treated and untreated wood in all kinds of profiles for many years.

Our own research has shown that not only does the treatment (thermal or chemical modification, surface treatment, etc.) often have a negative impact on the growth of the fire (FIGRA), the profiling of the facade profile also has a major impact.

If a treated wood type were to successfully achieve fire reaction class D in a flat, closed profile, this does not mean that all other thicknesses and profiles also apply.
Nowadays you have all kinds of block profiles where the flammable surface area and number of corners (points of action) are greatly increased and push the growth of the fire (FIGRA) upwards.

Then we are not yet talking about the method of installation.
A thicker ribbed profile mounted horizontally will not achieve the same values as the same vertical variant.


The current CWFT table will probably be adjusted to reduce the risk of misinterpretation.

This adjustment is well-founded and certainly did not come out of the blue.

The impact will be major and will reshape the world of wooden cladding.
Where one wood product will be used less, another product will see its sales grow.

At the same time, this decision also has advantages:

As a manufacturer of facade cladding, we can only encourage such initiatives that are good for safety.
The chance of misinterpretation is smaller and our sector can further innovate within a well-defined framework.

Innovations with an Achilles heel in terms of flammability will now have to innovate further to improve their Achilles heel.
The wood world has already shown several times that it can handle a lot in terms of innovation.