This part of EN 927 specifies a natural weathering test for exterior wood coating systems mainly intended for decoration and protection of planed and sawn wood. The test provides a means of evaluating the performance of a wood coating system during outdoor exposure. It forms the basis for the performance specification in accordance with EN 927-2. This document (EN 927-3:2012) has been prepared by Technical Committee CEN/TC 139 "Paints and varnishes", the secretariat of which is held by DIN (Germany). The work has been carried out by Working Group 2 "Coating systems for wood" of CEN/TC 139, the chairmanship of which is held by DIN (Germany). The responsible German standardization committee is Working Committee NA 002-00-15 AA "Bautenbeschichtungen" ("Coatings for masonry") of the Coatings and Coating Materials Standards Committee (NAB).