Impregnation the surface of the wood means the wood’s soaking in the industrial bath full of the respective industrial concentrate. An impregnated wood should always be used when the wood is in contact with the ground and water, or if it is not protected from the weather. Under these conditions, on the surface of the wood occurs mold spores and fungus that destroy wood, reduce its volume and density what promote rotting of the wood. If there is condensation and/ or moisture opportunity you need a waterproof timber.