The unfavourable effects of the weather on unprotected wood and timber products can cause changes to the mechanical and chemical properties of the wood, and if unchecked can do irreversible damage. The sheathing of wooden buildings must always be supplemented with surface treatments, and in a large number of cases a contact thermal insulation system is used. The paper presents research focused on the possibility of using a commonly used cement adhesive for bonding thermal insulation to the substrate formed by oriented strand boards. The substrate is provided with several types of penetration coatings or bonding primers and subsequently their influence on the adhesion of the cement adhesive is monitored. The best values were achieved when treating the surface treatment with a modified dispersion with quartz sand. On the other hand, the penetration coating of a mixture of water, nanodispersion of styrene-acrylate copolymer and additives is inappropriate treatment.