Development of an improved model for mould growth: Laboratory and field experiments

This paper deals with the present results of some on-going mould growth experiments from a project “A Mathematical Modelling of Moisture Behaviour and Mould Growth in Building Envelopes”. The work has been done in collaboration with Tampere University of Technology, Finland (TUT) and Technical Research Centre of Finland (VTT). The material experiments and experiments for exterior wall assemblies are performed both in laboratory and in field conditions. Mould growth on the surface of a material is detected using either microscope or visually with a naked eye. Determination of mould index depends on area of mould growth and type of mould growth. Experiments started in 2005 and will be going on at least until end of 2008. The experimental results are used for further development of a present mould growth predicting model developed at VTT. The original model is based on numerous laboratory experiments on pine and spruce. The present model is improved in respect to expanded climatic conditions and for a greater variety of materials. Also the impact of naturally sedimented dirt and contact of other materials are studied. The results until now show generally less mould growth than expected according to the original model based on pine and spruce sapwood.