Technical information and regulations

Below you’ll find information about features and regulations with regard to the use of Ekki, with reference to various official documents. Due to licensing laws, we cannot make copies of these standards available to you through the website. If you have any questions, please do not hesitate to contact us.


Sustainability certification

Ekki is highly sustainable (class I) in (fresh) water. The transition zone between the heartwood and sapwood falls into sustainability class II. This is based on research done by SHR Houtresearch. Tests carried out were all in accordance with the European test methods laid down in ENV 807, method 2. Ekki is highly resistant to shipworms in brackish and salt water, as well as acids and other chemicals. It is therefore often used in construction and civil, road and hydraulic engineering for support structures in installations used in the chemical industry.

Damwand (azobe)


In the Netherlands, the European strength classes are used according to NEN-EN 338. A strength class is indicated with the letter C for softwood and D for hardwood, followed by a number. That number relates to the representative value for the flexural strength parallel to the fibre (material property). These values are the starting point for the contractor to determine the design value of the material. For class A/B, Ekki is classified in class D70. This makes it one of the woods with the highest calculation values for bending, tensile and compressive strength, elastic modulus, and so on.

View our declaration of performance here


Ekki is divided into three quality classes: A, B and C (NEN 5480). Class A sets the highest requirements for strength and/or appearance such as thread progression, knots, cracks and deformations.

In the Dutch Standard NEN 5493 (formerly NPR 5493), 8 application categories are laid down in terms of quality requirements for hardwood in civil, road and hydraulic engineering works and other applications involving construction:

  •  – Walking decks
  • – Bridge decks and planks for jetties
  •  – Construction wood
  •  – Sheet piling and sheeting
  •  – Horizontal railings
  •  – Studded posts
  •  – Sawed posts
  •  – Round posts

Each category classifies the imperfections that may occur and to what extent. Imperfections such as heart, brushes, mechanical damage, cracks, spider mites and deformation measured over the entire length. Standards have also been laid down for the moisture content and the results of batch inspections.

Fire regulations

The Building Decree imposes requirements on the fire resisting properties of building materials in order to limit the chances of a fire breaking out and the extent to which it spreads, as people must be given sufficient time to evacuate. There are different fire safety requirements for products with or without CE marking. Products with CE must comply with a Euro fire safety class according to NEN-EN 13501-1. Products without CE must either comply with a Dutch fire safety class according to NEN 1775 or a Euro fire safety class.

There are seven Euro classes for both floor surfaces and non-floor surfaces: A1, A2, B, C, D, E and F. For floors, each class is followed by a subscript fl (= floor). A1 is the highest class – the products covered do not contribute in any way to a fire. When a product has not been tested or does not comply with class E, it is classified in F. In addition to the classification for the start and spread of fire, information about the classification for smoke buildup must also be verified.

Azobe steiger

Ekki floors, stairs, escape routes and fire safety

The basic requirement for walkable surfaces is at least Euro fire class Dfl. For escape routes to remain usable, the spread of fire must be restricted in these spaces. The materials must therefore meet stricter conditions with regard to fire resisting properties (Euro class Cfl standard).

The fire class of a wooden floor surface depends on various aspects such as volumetric mass, thickness and possible finish. For wood types with a specific weight above 790 kg/m³, which Ekki falls into, it is very likely that they comply with NL fire class Cfl. Research has shown that with a thickness of 45 mm Ekki can comply with fire class B-s1.

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