The German standard DIN 4102 covers fire classifications F30, F60, F90 and F120 and distinguishes between Class A (incombustible) and Class B (combustible).
The meaning of these classifications is that the supporting structure must be able to withstand the effects of fire for at least 30, 60, 90 or 120 minutes. Here it is also necessary to distinguish between an attack of fire from above, from the side or from below, and it is necessary to appreciate the temperatures that are reached by the various components, or rather, when they are going to fail or what the residual load bearing capacity will be.
The Elascon timber+concrete-composite structure must always be allocated to fire Class A, because of the timber content of the structure. Escape routes and staircases etc. should predominantly be constructed to meet Class A requirements. The greater the number of floors of a building, the more stringent the fire protection requirements. Unless exemption is granted (provisions for existing buildings) roof extensions of buildings with several floors must generally be built as class F90 B structures, especially from buildings in category 4 onwards.
Apart from Euro Code 5.1.2. Appendix B, measurements for hot sizing, our company has access to a large number of standard superstructures, inclusive of test certificates for these. They will enable the specialist to obtain the figures applicable to important superstructures. Questions such as the true fire resistance value of, for example, an old straw/rendering/mud ceiling, can be answered, and we should be able to make specific recommendations on methods for the avoidance of the need for the installation of a fire protection lining underneath (Promat or the like) .
Jointly with a well known industrial partner for plaster products, Elascon has obtained a large number of test certificates for different timbered ceiling superstructures. You, too should therefore benefit from working with us for optimising fire protection in existing buildings.