Wood was treated with hydrophobic plasma polymers to reduce the water penetration. Due to the released water vapour and/or molecular weight components from wood under low pressures the efficiency of the plasma treatment was dependent on the evacuation time before plasma treatment. A long evacuation for the efficient treatment could be avoided by increasing the monomer pressure. Adhesion of a paint onto the hydrophobized wood was poor. The adhesion was improved by hydrophilic post-treatment at a sacrifice of the reduction of water penetration. However, a large reduction of water penetration and a good adhesion to a