Public defence in civil engineering, Klaus Viljanen, M.Sc.
When
Where
Event language(s)
Hygrothermal performance of wood-framed, mineral-wool-insulated walls and roofs with low thermal transmittance
The level of thermal insulation in the building envelope has increased significantly in Finland in the 21st century. Highly insulated buildings support sustainability but the long-term durability of structures may deteriorate by the increasing level of insulation. This thesis assessed the hygrothermal performance of highly insulated external walls exposed to significant amounts of moisture and evaluated the functionality of the ventilation cavity of walls and roofs by a mainly experimental approach. The goal was to ensure the functionality of the building envelope and to propose structural solutions to support this target.
Based on the results received, highly insulated external walls function well even when subjected to significant moisture loads. It is of paramount importance to ensure the airtightness of the external wall and to use vapour-open and insulating wind barrier. As the high level of insulation in modern buildings efficiently isolates the external parts of the building envelope from the heat of the indoor air, the hygrothermal conditions in the ventilation cavity are close to the level of the outdoor air. The results show that performance of the ventilation cavity of highly insulated roofs is significantly worse compared to roofs with less insulation. The moisture safety of the ventilation cavity may be improved by using moisture resistant materials in the cavity, by optimising the ventilation rate of the structure and by increasing the thermal resistance outside the ventilation cavity.
Opponen: Professor, PhD Targo Kalamees, Tallinn University of Technology, Estonia
Custos: Professor Jari Puttonen, Aalto University School of Engineering, Department of Civil Engineering
Contact information of the doctoral student: Klaus Viljanen, klaus.viljanen@aalto.fi
The public defence will be organised on campus (auditorium R1, Rakentajanaukio 4).
The thesis is publicly displayed 10 days before the defence in the publication archive Aaltodoc of Aalto University.