The main focus is the following research questions:

• How do constructions consisting of protected or exposed CLT contribute to the fire development in a room?
• How can contribution to the fire development from detailing of CLT be avoided?

Results from large scale fire tests and other studies in the period 2010 – 2018 are presented in this report, and recommendations regarding protection of CLT structures and detail solutions are given.

There is an increasing desire to use wooden structures in tall buildings, as a substitute for more traditional construction materials. However, when designing tall and complex timber buildings, it must be taken into account that a fire involving a timber construction may have more severe consequences than in buildings with constructions of steel or concrete, if the fire design of the construction and detail solutions is insufficient.

In recent years, there has been extensive research on charring rates, delamination and auto-extinction, and how exposed, or insufficiently protected, CLT affects the fire development in a room. The research is, however, based on few large fire experiments, and the literature is still pointing to several knowledge gaps. 

The report is in Norwegian with an English summary, and may be downloaded here: