Surface condensation risk pre- and post-retrofit at suspended timber ground floors and external wall junctions

Insulating below suspended timber ground floors affects heat transfer at the ground floor to external wall junction, which can affect the risk of surface condensation occurring. In this project, we investigate the impact of installing mineral wool insulation, between joists, below suspended timber floors in 3 solid walled homes. TRSICO is used to calculate surface temperature factors at this junction pre- and post-retrofit. Alternative retrofit scenarios of different combinations of suspended floor and solid wall insulation are also modelled to determine which minimises condensation risk. The results suggest the floor and wall junction will have surface condensation risk when uninsulated. Installing suspended floor insulation increases risk, while installing internal or external wall insulation, with or without floor insulation, reduces risk.