What is the charring rate of structural timber?

The design charring rate for softwood (density ≥ 290 kg/m³) is 0.65 mm/min for one-dimensional charring under standard fire exposure (EN 1995-1-2). This means a timber member loses approximately 39 mm of cross-section per exposed face in a 60-minute fire.

The design charring rate for softwood (density ≥ 290 kg/m³) is 0.65 mm/min for one-dimensional charring under standard fire exposure (EN 1995-1-2). This means a timber member loses approximately 39 mm of cross-section per exposed face in a 60-minute fire. The char layer acts as an insulating barrier, protecting the uncharred core which retains its full structural strength. Hardwoods and glulam have slightly different rates depending on density.

Why this matters

This question relates to Fire Resistance of Structural Timber: Charring Rates & Eurocode 5, 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:

→ Fire Resistance of Structural Timber: Charring Rates & Eurocode 5

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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. All technical content is reviewed by qualified timber technologists before publication.