Wood preservative coatings are essential indoors and outdoors to extend the service life of timber structures, facades, furniture, and parquet floors. A distinction is made between film-forming coatings such as varnishes and paints, and penetrating agents such as oils, waxes, and impregnation agents. Preventive wood protection is classified into protection classes chosen according to environmental conditions. Natural alternatives to biocide-rich products are gaining importance as environmental and health aspects receive more attention. Surface pretreatment, especially sanding and degreasing, is crucial for the adhesion of the coating. Regular maintenance and renewal of the coating ensure long-term protection.