Coating’s resistance to natural outdoor UV (ultra violet) radiation is described through UV resistance categories Ruv1 – Ruv4 in accordance with EN10169. UV resistance describes how well the coating is able to keep its original colour and gloss levels in outdoor conditions. Coatings in Ruv1 category have very weak UV resistance and should only be used in indoor conditions. Coatings in Ruv4 category have strong UV resistance and are therefore recommended to outdoor use.
Atmospheric gasses and electrolytes react with all façade materials. The rate and effects of those reactions depend on two factors, the atmospheric conditions (e.g. wetness, salinity, sulfur dioxide) and the material in questions. Both vary extensively. For design purposes the atmospheric conditions have been divided into categories (C1-C5) based on their aggressiveness in accordance with EN 12944. Material and coating suppliers can then assess the suitability of their products in each category for normal service life, but the designers will still have to take into account any building specific factors when making the final decisions on façade materials.
||Heated buildings with clean atmospheres, e.g. offices, shops, schools, hotels.
||Atmospheres with low level of pollution. Mostly rural areas.
||Unheated buildings where condensation may occur, e.g. depots, sports halls.
||Urban and industrial atmosphere, moderate sulfur dioxide pollution. Coastal areas with low salinity.
||Production rooms with high humidity and some air pollution, e.g. food-processing plants, laundries, breweries, dairies.
||Industrial areas with moderate salinity.
||Chemical plants, swimming pools, coastal ship- and boatyards.
||Industrial areas with high humidity and aggressive atmosphere.
||Buildings or areas with almost permanent condensation and with high pollution.
||Coastal and offshore areas with high salinity.
||Buildings or areas with permanent condensation and with high pollution.