Grundlagenuntersuchungen für einen Vorschlag zur Überarbeitung der Muster-Holzbaurichtlinie

Investigations for a proposal to revise the model guideline for fire protective requirements on multi-storey timber buildings.

With the 2004 model guideline for fire protective requirements on multi-storey buildings made of timber it is now possible to construct buildings out of timber up to a height of 13 m. The building code requires for these types of houses, that the load bearing timber elements are protected by a non-combustible cladding against ignition over a standard fire exposure of 60 minutes (classification K260). Furthermore, combustible insulation materials are not allowed inside the timber frame construction.
Multi-storey timber buildings which were built in the last few years often had significant differences to these regulations. To evaluate these differences on the basis of scientific research many fire tests and theoretical considerations were made at the iBMB which resulted in a catalogue of minimum requirements for the constructions. With a risk index method it was analyzed how it is possible to reduce the non-combustible cladding of the timber elements so the fire risk of the building does not increase. Based on these studies, different fire safety concepts for timber structures have been elaborated which compensate for a decrease of the cladding and the related increase of the fire risk by other preventive measures and therefore avoid a reduction of the presently accepted fire safety level. The results are summarized in a proposal to rework the model guideline for fire protective requirements on multi-storey buildings made of timber.