The aim of this investigation, which was carried out with financial support from the Nordic Innovation Centre (Project no 1628-03) and the Nordic Wood Preservation Council, was to study the Nordic rules for quality control and certification of preservative-treated wood and to identify in what respect they were interpreted differently by the inspectors in Denmark, Norway and Sweden, and thus where there was a need for clarifying guidance.
The major items identified for further consideration were:
- Selection of the batch from which samples then shall be taken.
- Sampling from batches (commodity, dimension, boring, cross-cuts etc).
- Determination of penetration – difficulties to judge the penetration for the new copper-based preservatives.
- Determination of retention – use of nominal densities when calculating retentions.
- Determination of retention for borings – use of a correction factor (“gradient factor”)?
- Analysis of wood preservative treating solutions.
The project has given useful information and knowledge for Nordic input in the CEN/TC 38 project of revision of EN 351 which is assumed to be completed in 2005-2006.