This standard defines the method to be used to check for any points of water leakage that may occur in curtain walling when installed on a building. It is a supplementary test not required for classification purposes. It is intended for use primarily where water leaks have already occured. It may also be used on new installations, when specified.It describes how an area of curtain walling that is installed on a building shall be subjected to a continuous film of water over its outside faceWindows and doors incorporated into the curtain walling may be similarly tested.This standard applies to any curtain walling product as defined in prEN 13830.NOTE An alternative, more exhaustive test for watertightness of curtain walling, installed on a building, may be carried out. (See annex B).