Resistance of pine and spruce heartwood against decay - the effect of wood chemical composition and coating with water-borne wood oil product. Document No IRG/WP-10597. 37th Annual Meeting of the International Research Group on Wood Preservation, Tromso, Norway, 18-22 June 2006 - Viitanen, H.; Metsä-Kortelainen, S.; Laakso, T.