Terminology fire safe wood wool insulation 

Fire safety terminologies



There are several criteria that you should consider when determining the total fire safety of insulation materials and construction elements:

  • Fire resistance
  • Fire classification
  • Smoke formation
  • Drop formation

If you compare building materials to these criteria, building materials react differently in the event of a fire. How materials score together on all these criteria determines to what extent you can speak about a fire safe material.


Fire resistance


Whenn looking at fire resistance, we look at how building parts that have been installed in a certain way behave in the event of a fire. This is different from the fire class where we look at the individual properties of materials. The fire resistance describes the period for which a construction can withstand exposure to a fire load while maintaining its shape and function.

The fire resistance is also expressed in different classes. When a material is resistant to exposure to fire for 30 minutes, this is expressed in REI30. REI stands for:

Load bearing capacity (R) (how does the structural part retain its load bearing capacity)
Integrity (E) (where does the spread stop)
Thermal insulation (I) (how is the temperature rise on the other side of the building part limited)
Most victims in a fire, however, do not get injured because they come into contact with flames, but through smoke poison. When selecting building materials, it is therefore important that you do not only consider the fire class, but also take into consideration the smoke formation and drop formation.


Fire classification materials

What exactly does the fire classification of materials mean? This term describes the fire Deze term beschrijft de flammability characteristics of building materials. It is the properties of the building material itself.

Heraklith delivers wood wool boards with fire classification A2 and fire classification B. This comes down to practically non-combustible (A2) and very difficult to burn (B), as shown below:


Fire classifcation materials

A1 Non- flammable
A2 Practically non - flammable
B Extremely low flammability
C Flammable
D Easily flammable
E Highly flammable
F Extremely flammable, not tested

Smoke formation insulation

Smoke formation is divided into different classes. The wood wool cement boards from Heraklith fall into the class S1: low smoke development. The smoking classes are divided as follows:

Smoke class
S0: no smoke production
S1: slight smoke production
S2: average smoke production
S3: high smoke production

Drop formation insulation

Drop formation is regarded as a specific hazard because burning droplets of building materials can fall and as a result are more likely to cause burns and other injuries. Heraklith supplies wood wool boards that show no drop formation at all. These fall into the drop class D0. 

Drop class

D0: burning droplets are not produced
D1: droplets burn shorter than 10 seconds
D2: droplets burn longer than 10 seconds 

Fire safe constructions with wood wool

Heraklith leads the way regarding outstanding fire classification and fire resistance for its wood wool boards. We are happy to advise you on the correct installation and fixing materials for fire resistant applications. In case you want to know which insulation material works best for your project, please contact us.