What should a timber specification include?

A comprehensive timber specification must include the species or strength class (e.g. C24), moisture content requirements (typically ≤18% for structural, ≤12% for joinery), certification standard (FSC or PEFC chain of custody), preservative treatment class (EN 335 use class), dimensional tolerances (EN 336 class 1 or 2), surface finish requirements, and marking/labelling expectations.

A comprehensive timber specification must include the species or strength class (e.g. C24), moisture content requirements (typically ≤18% for structural, ≤12% for joinery), certification standard (FSC or PEFC chain of custody), preservative treatment class (EN 335 use class), dimensional tolerances (EN 336 class 1 or 2), surface finish requirements, and marking/labelling expectations. Each element should reference the applicable European or national standard to remove ambiguity from the tender process.

Why this matters

This question relates to How to Write a Timber Specification for Construction Tenders, which covers the broader topic in detail. Understanding this specific aspect helps architects, builders, and timber dealers make informed specification decisions.

For full context and additional technical detail, see our comprehensive guide:

→ How to Write a Timber Specification for Construction Tenders

Related questions

• How do I specify timber grade in a tender document?
• What moisture content should I specify for structural timber?
• Should I specify FSC or PEFC certification?

About this answer

This answer is part of the PuurModulair Knowledge Base — comprehensive timber specification guidance for architects, builders, and dealers across the UK, EU, and Scandinavia.