Hygro-thermal and Mould Growth Risk Analysis of Common Foundation Structures

The presented analysis deals with hygro-thermal numerical simulation and mould growth risk evaluation in cases representing common foundation structures of timber-framed houses in Finland. Three different structural approaches are addressed with estimation of potentially problematic elements during the buildings life cycle that may require special caution in design process. The studied cases include common building materials such as mineral wool, timber, bricks, concrete, EPS, and so on, and the key differences consist of building element configurations. The selected application for mould growth analysis predicts growth initiation and/or its stage in given climate conditions. The size of structural elements and their placement have a significant impact on hygro-thermal performance of a structure, and hence likely on the health of its indoor environment and the sustainability of the building too. Hygro-thermal analyses apply official weather data measured in Oulu region in Finland from 2009 to 2015 representing humid coastal conditions. The long-term analysis depicts hygro-thermal conditions inside the structure and on its layered interfaces and predicts mould growth initiation in selected positions. The numerical simulation indicates that applying less sensitive structural material on top of a building skin to protect timber-frame from humid external conditions would be beneficial. The conditions in wooden elements cause issues at a certain range of thermal conditions and sufficient exposure time. The study highlights problems that may occur in the ambient of foundation structures of common timber-framed houses. (C) 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the organizing committee of the 11th Nordic Symposium on Building Physics.