Fire classes for construction materials

Fire classes for construction materials

There are several fire classes in construction related to fire of a building e.g.:

  • Fire class for different materials reaction to fire, which is mainly used in walls, ceilings and floors.
  • Fire classes for façade materials, which measures fire spreading, heat radiation and temperature.
  • Fire classes for the fire resistance of structural elements.

Fire class for fire resistance e.g. wall elements that must be able to withstand fully developed fire and meet REI functional requirements, such as load bearing capacity (R), integrity (E) and insulation (I).

Here at Forum for Fire Retardant Wood (FBT), the aspects of classification system for the reaction to fire performance of construction products is being discussed.

The European classification system for the reaction to fire performance of construction products is often called the Euroclass system and consists of two subsystems, the first of which is being discussed at the Forum for fire retardant treated wood:

  • A system for all construction products except floorings, i.e. mainly for surface layers of walls and ceilings.
  • Another similar system designed for floorings.


The testing method for classifying construction products other than floorings is described in Svensk Standard SS-EN 13823 Single Burning Item (SBI) with the title ”Reaction to fire testing of construction products - Construction products except floorings that are subject to the thermal influence of a single burning object". This standard also forms the basis for the CE markings of the field.

The products are then classified according to the SS EN13501-1. This European standard contains the classification method for fire emergency procedures for all construction products, including products that are part of the construction elements. The products are assessed in relation to their end-use implementation.

The classification of wood, according to the SS EN13501-1, entails preliminary type testing according to test method SS EN13823 for Euroclass B and C corresponding with a particular type of wood. Mounting conditions are then taken into account; options include A2 substrates with or without air gap as well as underlying D-s2, d0 substrates with or without air gap. The test results form the basis for the product / wood classification according to the SS EN13501-1 standard within performance groupings B, C, D, and F.

Please note that, for construction documents, regulatory procedures should not aim at classification according to standard SS EN13501-1. Regulatory procedures must be in accordance with harmonized product standards where the EU has set a requirement for the CE marking of solid wood and wood-based boards in accordance with EN14915:2013+A1:2017 or EN13986:2004+A1:2015.

Regulatory procedures for fire class B and C include mandatory requirements for CE marking and declaration of performance (DoP).

IMPORTANT to know is that fire tests (fire reports) and classification (classification reports) are not equal to the certification of the product or manufacturer process. A product classification only shows the product's performance, while a certification such as the CE marking is the official driving license that includes the entire production chain and control system. However, on-site treatments are not included as they cannot be CE marked. A CE certification also does not mean that national building regulations have been met with; this must be checked against the BBR and PBL

REMEMBER that industrially impregnated and painted products are always covered by a CE certification and a declaration of performance when marketed as Euroclass B or C. Fireproof wood products without a CE marking must not be marketed nor used, according to the EU Construction Product Regulation 305/2011.