This document specifies a method for determining the effect on bond strength of damage to wood fibres caused by the action of acids from the adhesive or primer used in the gluing process during climatic cycling. It is suitable for the following applications: a) for assessing the compliance of adhesives with EN 301, EN 15425 and EN 16254; b) for assessing the suitability and quality of adhesives for load-bearing timber structures; c) for determining if the adhesive after bonding has a damaging influence on the strength of the wood due to chemical action. This test is intended primarily to obtain performance data for the classification of adhesives for load-bearing timber structures according to their suitability for use in defined climatic environments. This test is carried out on Norway spruce (Picea abies L.) or Beech (Fagus sylvatica L.). This method is not intended for use to provide numerical design data and does not necessarily represent the performance of the bonded member in service.