The Behaviour of Wood Fibre Insulation Systems for Solid Wall Buildings: Lessons from a Long-term Monitoring Study

Abstract

The majority of the traditional building stock in the UK is made of solid brick walls. Internal wall insulation is one of the possible interventions to preserve the external appearance of a building while improving the energy efficiency of its walls. However, it can lead to moisture-related risks, such as excess moisture accumulation and mould growth. This paper presents an overview of the lessons learnt from the long-term monitoring of two case-study solid wall buildings, insulated with wood fibre-based systems and monitored for a year. The aim of this monitoring campaign was to provide evidence on the main moisture transfer and storage mechanisms occurring in solid walls insulated with wood fibre-based systems under actual environmental conditions. Results showed that the dynamic interaction between the insulated wall and moisture sources could be controlled by means of an appropriate specification of the insulation system, considering the influence of orientation, material properties and indoor moisture loads. It was also found that construction moisture influenced the initial conditions of the interface, but mitigation strategies can be considered to reduce mould growth risk during installation and before the drying of construction moisture.