Walls made of bricks, ceramic and silicate blocks, cellular concrete blocks, as well as walls and ceilings made of prefabricated concrete components. Old, not weathered cement-lime plasterwork, ALPOL AT 303 underlay plaster.
The substrate must be clean, sound, dry and free from dirt, dust and grease. Remove paint coats from old and durable plasters, patch irregularities and chipped plaster with ALPOL AZ 130 quick-setting mortar or ALPOL AZ 135 levelling mortar. Treat loose plaster with ALPOL AG 700 deep penetrating primer or, if highly absorptive, with ALPOL AG 703 primer for absorbing substrates, or apply initial scratch coat using ALPOL AT 303 plaster. Moisten dry substrate with plenty of water before applying the initial scratch coat. Treat substrates of prefabricated concrete and formwork systems with ALPOL AG 702 primer. Surfaces exposed to scratching, e.g. adjacent structural material, corners of door/window openings etc., should be strengthened with 10 mm fibre-glass reinforcing mesh, by embedding it in ALPOL AZ 130 quick-setting mortar or ALPOL AZ 135 levelling mortar.