How does timber compare to steel in fire?

Timber performs more predictably than unprotected steel in fire. Steel loses 50% of its yield strength at approximately 550°C (reached within 15–20 minutes in a standard fire) and can collapse suddenly without warning.

Timber performs more predictably than unprotected steel in fire. Steel loses 50% of its yield strength at approximately 550°C (reached within 15–20 minutes in a standard fire) and can collapse suddenly without warning. Timber chars at a predictable rate while the uncharred core maintains full strength and stiffness. A properly designed timber member can maintain structural integrity for 60–90 minutes, while unprotected steel may fail in under 20 minutes.

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

Related questions

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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.