prEN 350

Biological durability of wood and wood-based products - Testing and classification of the durability against biological agents of wood and wood-based materials prEN 350

Publication date:   Aug 6, 2026

Scope

This document gives guidance on methods for determining and classifying the durability of wood and wood-based materials against biological wood-destroying agents.
The methods can be applied to individual wood species and processed wood-based materials, including thermally and chemically modified, and water-repellent impregnated wood. Examples of wood-based materials are oriented strand boards (OSB), particle boards, fibre boards, laminated veneer lumber (LVL), and plywood. However, this document is not intended to give guidance on methods for determining and classifying the durability of wood products, coated wood, and wood polymer composites.
Preservative-treated wood is not within the scope of this document, since requirements for the effectiveness of wood preservatives and durability requirements of wood treated with preservatives are regulated in several other European standards. However, this does not apply to modified wood, which is why it is included in the scope of this document.
The wood-destroying agents considered in this document are:
— wood-decay fungi (basidiomycete and soft-rot fungi);
— beetles capable of attacking dry wood;
— termites;
— marine organisms capable of attacking wood in service.
Data on the biological durability of the heartwood of selected wood species considered of economic importance in European countries are presented in Annex A (informative), which also provides information relating to their geographical origin, density, sapwood width and treatability.
NOTE Treatability, durability to disfiguring fungi, permeability to water and performance in use of wood and wood-based materials are also important issues. However, because standardized methods aiming to assess and classify these factors do not exist and/or have not been extensively experienced yet, preliminary guidance is given in Annex B (informative) for the classification of wood treatability with aqueous wood preservatives, Annex C (informative) for the classification of the permeability to water, and Annex D (informative) for the durability to disfiguring fungi.