Natural durability evaluation of Cypress (Cypress sempervirens L.) solid wood and mixed heartwood-sapwood Cyrpess plywoods

The goal of this study was to produce plywoods with enhanced natural durability compared to the solid wood from which they were made of in order to upgrade the use of biodiversity. The case of Cypress timber (Cupressus sempervirens L) is presented here. The natural durability of Cypress heartwood and sapwood was determined according to the EN 350-1 towards Basidiomycete fungi (Coriolus versicolor, Coniophora puteana) and against termite (Reticulitermes santonensis). Different pure and mixed (sapwood-heartwood) Cypress plywoods were laboratory made and their natural durability was also evaluated using the guidelines of XP ENV12038 and EN117. The biological resistance of both wooden materials are compared. Moreover, for the plywoods, the influence of plies thickness (2.6 nun and 1.3 mm), number of glue lines (melamine-urea-formol resin), percentage of heartwood plies integrated to sapwood plies in the mixed plywood (0%, 40%, 60%, 100%) and finally the way of integration of durable plies (heartwood) into non-durable plies (sapwood) has been evaluated. (Résumé d'auteur