1. Establish the application use class of the component(s) you need before ordering.
2. Tell your supplier, in writing, that the wood must be treated to comply with BS8417 for this use class.
3. Specify the desired service life you require for the wood – 15, 30 or 60 years.
4. Incising (piercing the surface of a component) is used increasingly to enhance preservative penetration. Expect to see it on sawn posts treated for the 30-years specification in BS8417.
5. Ask your supplier to verify (on the delivery note and invoice) or provide a treatment certificate that the wood supplied meets your specification.
6. When buying from stock, always verify which use class and desired service life the wood has been treated for.
7. Never substitute wood treated for an indoor application for an external application – failure is inevitable.
8. For wood in permanent ground contact, Use Class 4 levels of protection must be achieved. Anything less and service life, structural safety and customer satisfaction will be compromised.
9. Always use end grain preservative for sealing untreated wood exposed when cross-cutting, notching or boring treated products during installation.
10. When third-party reassurance of fitness for purpose is required, ask for treated wood certificated under the WPA Benchmark quality scheme which verifies compliance with BS8417.
See more <here>