The paper presents an overview of preservation methods based on professional, expert assessment and research activity of the Thermal Preservation Methodological Department. It reflects the suitability and usability of available methods for wooden elements of respective type of structure. The methods are represented according to currently available and applied preservation methods. The methods use thermal energy, namely the hot-air sterilisation of wood and microwave technologies. The presented paper specifies conditions under which the methods shall be used so that their application contributes to more efficient protection of the heritage fund. The field of biotic harmful elements includes wood-destroying insects and fungi with special regard to dry rot fungus (Serpula lacrymans).