C16 Timber vs C24 Timber: What’s the Difference and Which One Should You Use?

When shopping for structural timber, you’ll often come across two grades: C16 timber and C24 timber. Both are widely used in construction and DIY, but they aren’t the same. Knowing the difference can save you money, ensure safety, and help you pick the right timber for your project.

C16 / C24 Timber

What Do C16 and C24 Mean?

The “C” stands for coniferous (softwood), and the number refers to the strength grade. The higher the number, the stronger and more reliable the timber is.

• C16 Timber – the standard grade used across the UK.

• C24 Timber – a premium grade, stronger and more durable.

Both are stress-graded timber, meaning they’ve been tested for load-bearing strength and approved for structural use.

Key Differences Between C16 and C24 Timber

1. Strength and Load-Bearing

• C16 timber is strong enough for most domestic projects, including flooring, walls, and roofs.

• C24 timber has fewer knots, higher density, and greater bending strength, making it ideal for heavy loads and longer spans.

2. Appearance and Quality

• C16 may contain more natural defects like knots and splits.

• C24 is visually cleaner, straighter, and more consistent in quality.

3. Durability and Lifespan

• C16 performs well in most standard builds.

• C24 offers added reliability, especially in projects where long-term durability is critical.

4. Price

• C16 timber is cheaper and widely available in UK builders’ merchants.

• C24 timber costs more due to stricter grading and often being imported (commonly from Scandinavia).

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When Should You Use C16 Timber?

Choose C16 timber if:

• You’re working on general building projects (floors, walls, roof joists).

• The spans are relatively short.

• You want a cost-effective option.

👉 Browse our C16 timber range here

When Should You Use C24 Timber?

Choose C24 timber if:

• You need stronger support over longer spans.

• You’re building decking, extensions, or loft conversions.

• You want higher quality timber with fewer defects.

👉 View our C24 timber products here

Which Timber Is Right for You?

• For everyday DIY and small builds, C16 timber is usually enough.

• For heavier structural work, C24 timber is worth the extra investment.

  
  

Final Thoughts

The difference between C16 and C24 timber comes down to strength, quality, and price. C16 is the standard choice for most domestic projects, while C24 is a premium option for when you need extra reliability.

When in doubt, always follow your project’s building regulations or ask your supplier for guidance—choosing the right timber grade ensures your structure is both safe and cost-effective.

✅ At AGABOS, we supply both C16 and C24 timber across the UK, delivered straight to your site.👉 Shop structural timber online at agabos.co.uk