This European Standard defines an additional test method which may be used when assessing the watertightness of curtain walling, both its fixed and openable parts. It is a supplementary test, not required for classification purposes, and it should be used only when the project specifier has determined its necessity. This European Standard describes how the outside face of a curtain walling specimen should be subjected to a continuous spray of water and a turbulent airflow, with continuous pulses of positive air pressure on the outside of the test specimen generated from within the chamber. This European Standard applies to any curtain walling product as defined in EN 13830.