Hygrothermal risk assessment of retrofit of external insulated facadesystems (EIFS) to non-traditional wall types in an Irish context using the glaser method and numerical modelling

Up to 80% of building failures can be attributed to moisture [1]. Failure in EIFS is usually due to moisture ingress at interfaces. The Irish Government seeks ambitious levels of EIFS retrofit but, to date, is not support this in guidance provided. An hygrothermal risk assessment of different EIFS on three non-traditional wall types, in Dublin, Belfast and Belmullet, was undertaken using transient numerical simulation and Glaser method calculations. Whereas the Glaser simulations show no risk, the transient numerical simulations show a significant impact of location, driving rain and the kind of physical failures that commonly occur. Cases with mineral wool and mineral render are low risk, most cases with acrylic render were high risk. The case for updating guidance to reflect the scale and urgency of the retrofit programme planned is clear.