Moisture protection capability of organic coatings for wooden facades. The moisture protection capability of some organic coating systems for exterior wood has been assessed from measurements of the moisture content of painted wooden facades during outdoor exposure for a time period of four years. Altogether six coating systems were studied, namely: (a) Priming oil / alkyd primer / acrylic latex top coat, (b) Linseed oil primer / linseed oil top coat, (c) Priming oil / alkyd primer / alkyd top coat, (d) Priming oil / alkyd primer / alkyd oil modified acrylic latex top coat, (e) bare panelling, (r) Swedish farm paint. To find the most relevant measure of moisture protection capability an effective critical time of high moisture level occurrence was defined taken into account the variation in the growth rate of wood rot with temperature and water content of wood. All six coating systems exhibited a sufficient moisture protection capability near the end-grain when compared with the reference system (a). However, on the linseed oil system, although having the best moisture protection capability, discoloration occurred caused by growth of micro organisms on the surface of panel. The panel treated with the Swedish farm paint, Alcro Pulvo rödfärg, was discoloured because of heavy chalking and erosion.