This European Standard specifies a method for determining the relative protective effectiveness against fungal decay of a wood preservative applied to wood in combination with a subsequent surface coating, exposed to the weather and out of contact with the ground. The effectiveness is evaluated relative to a reference wood preservative. The method is applicable to the testing of commercial or experimental preservatives applied to non-durable timbers by methods appropriate to commercial practice and subsequently coated with a specified coating system. The method is applicable to products and processes used individually or in combination to prevent the development of decay in the wood. The method is also appropriate for factory finishing systems which include wood protection and wood preservation claims.