Assessment of wind load resistance of external thermal insulation systems during the renovation of a large panel dwelling building

The paper presents a practical example related to determining the required number of insulation anchors for ETICS during the renovation of a large-panel residential building constructed using the OS-Gl-68 system in Sofia, Bulgaria. The thermal insulation of the façade walls is planned to be carried out using a 12 cm thick layer of expanded polystyrene (EPS). The mechanical fastening elements consist of plastic insulation anchors with driving plastic pins. The required number of insulation anchors is determined based on wind load calculations that account for both the pull-out resistance of the insulation anchors from the base material and the pull-through resistance of the thermal insulation layer. Based on the experimental investigations and calculations, the required number of insulation anchors per square meter has been determined as follows: For Zone A – a minimum of 8 insulation anchors per 1 m²; For Zone B and Zone C – a minimum of 6 insulation anchors per 1 m². The widths of the respective zones are defined individually for each façade, based on the geometric dimensions of the building and the specific characteristics of the wind loads.