Experimental results are reported which the author conducted in the Laboratoire de Recherche des Monuments Historiques (LRMH), Paris. The wall bases stood in a tank in which water was filled to a constant level to bring about capillary action. The height of water ascent and the moisture content of the wall surface were determined. Salt efflorescence found on the surface of most of the walls was powdered lime. Among the examined techniques (buon fresco, fresco-secco, detrempe), buono fresco without lime-water coatings proved most resistant against efflorescence and formation of cracks. See AATA 17-1035.