Abstract: Apparatus for testing of the water permeability of samples of building facades comprising a frame (3) on one side of which a sample of the facade to be tested (2) is fixed, and a grid (5) on which nozzles (1) which spray water on the sample of the facade to be tested (2) are arranged, characterized in that said apparatus is equipped with a movement system (4) of the grid (5) from a working position positioned in front of the facade sample to be tested (2) to a rest position positioned behind the frame (3) on the opposite side to that on which is located the sample (2) and that the grid (5) on which nozzles (1) are set up slides on elements of the frame placed at a predetermined distance from the sample to be tested (2).