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

Development of an improved model for mould growth: Laboratory and field experiments Kimmo Lähdesmäki(1, Juha Vinha(1, Kati Salminen(1, Tomi Strander(1 Hannu Viitanen(2, Leena Paajanen(2, Hanna Iitti(2, Tuomo Ojanen(2, Ruut Peuhkuri(2 1 Tampere University of Technology (TUT), Department of Civil Engineering, Finland 2 Technical Research Centre of Finland (VTT), Finland ABSTRACT Mould growth in eight construction materials (edge glued spruce board, polyurethane (paper coated and grounded), glass wool, expanded polystyrene, polyester wool, concrete, autoclaved cellular concrete and expanded light aggregate concrete) have been studied in Finland in a study by Tampere University of Technology and Technical Research Centre of Finland. The experiments consist of the tests for the materials and for the exterior wall assemblies in laboratory and in field conditions. A mathematical model of mould growth on pine and spruce sapwood materials has been created in 1990's in Finland by Ph.D. Hannu Viitanen. One of the objectives of this research is to extend the range and reliability of the recent mathematical model. This is achieved by extending the measurement data necessary for the model development by applying several materials, different types of material surfaces and different kinds of fluctuating temperature and humidity conditions. New experimental results from the mould growth on different material surfaces and in exterior wall assemblies are presented in this paper. Experiments and calculation results of mould growth have also been compared. The comparison shows that there are some limitations and unpunctuality in the recent model. The different surface types of wooden materials and also other construction materials need correction coefficients. A more detailed analysis of this comparison and the improvement the recent mathematical model is presented in another paper to this conference.