Can I use C16 for floor joists?

C16 can be used for floor joists in limited circumstances (short spans, light loading), but C24 is the standard specification for domestic floor joists in the UK and Europe. Building regulations and approved documents (e.g.

C16 can be used for floor joists in limited circumstances (short spans, light loading), but C24 is the standard specification for domestic floor joists in the UK and Europe. Building regulations and approved documents (e.g. UK Approved Document A) typically reference C24 as the minimum for structural floor members.

Why this matters

This question relates to C24 vs C16 vs C30 Timber Grading — What Architects Need to Know, 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:

→ C24 vs C16 vs C30 Timber Grading — What Architects Need to Know

Related questions

• What does C24 mean in timber?
• Is C24 better than C16?
• When should I specify C30 instead of C24?

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.