Wood is becoming more and more frequently used a preferred material in modern construction applications. The predominant reasons for this are related to environmental friendliness, degradability (after the end of service life), competitive price and renewability. Because of the expensiveness of wood of the highest quality composite materials are used as substitutes. Wood composites are also a constituent of wood based buildings. Wood lower quality and of lower price can be utilized for composite production. Natural wood fibres are subjected to biological degradation by variety of wood pests including wood decay fungi. We determined performance of various lignocellulosic materials against wood decay fungi: Antrodia vaillantii, Gloeophyllum trabeum, Serpula lacrymans, Hypoxylon fragiforme, Pleurotus ostreatus, Trametes versicolor. The samples were prepared from different composite panels and insulation materials. We used OSB, plywood, 3 different wood plastics, insulation boards made of wood fibres and cellulose insulation for blowing. Samples were prepared according to standard EN 113, designed for determining the resistance of wood and wood based materials against wood decay fungi. The results show that resistance of ligno-cellulosic materials varies considerably. Wood plastic composites, cellulose insulation and OSB boards have the best resistance against fungi.