SETTING THE STANDARD
Within Europe there are recognised industry standards relating to the preservative protection of timber. Some relate to the development and testing of wood preservative products to make sure they are effective in extending the service life of timber. Some relate to the end use of the treated timbers which will affect the type and level of treatment required. Some relate to the actual treatment procedures, helping to ensure high quality treatment results and high performance treated timbers.
Across Europe there are different regional authorities that work with the timber protection industry to interpret and implement these standards. For instance the NTR covers Scandinavian markets, the FCBA is the regulatory authority in France and recognized in many western European markets and the Wood Protection Association works with the British Standards Institute in the UK to advise and provide an industry code of practice.
The regional standards will differ as certain species are more prevalent in certain markets and require different approaches to achieve effective preservation results.
One common approach throughout the markets is a move towards ‘results’ based treatments rather than a previous reliance on ‘treatment process’ parameters.
Achieving the Best Result
To meet this ‘results’ based approach, there are 5 general considerations in providing quality preservative treated timbers for market and making sure they perform as they are intended.
- Timber species – Some species are more naturally durable than others whilst some are more permeable and easier to preservative treat and protect. Consideration needs to be given to the most suitable timber species related to the eventual end use of the timber and the level of hazard it faces from decay in that particular situation.
- Timber preparation – All harvested timbers have a natural moisture content that will need reducing to species specific levels to allow the wood preservative to penetrate into the wood structure and be effective in protecting against wood decay organisms. This is usually achieved by natural air drying methods or careful kiln drying.
- Timber preservative – The most appropriate timber preservative needs to considered to meet the requirements of the timber’s eventual end use and the hazards the treated timber is likely to experience. Also timber preservative types relate to particular types of timber components from dimension critical interior construction timbers through to exterior fencing and landscaping timbers where a more robust protection is the key consideration.
- Treated timber use – just like any product preservative treated timbers need to be used and installed correctly to perform at their best. For instance, timbers are generally preservative treated in their final form but installation can mean cutting or notching on-site. These actions need to be carried out correctly and the exposed untreated areas protected by recognized brush-on end grain preservative products to maintain the integrity of the preservative system.