Home / Wood Compare / Accoya Acetylated Radiata Pine vs Sweet Chestnut
Professional Comparison · Verified Engineering Data · Updated 19 July 2026
Accoya Acetylated Radiata Pine VS Sweet Chestnut
Which wood is better for your project? Scores are computed from the verified figures on each species page — how we score.
🥇
Accoya Acetylated Radiata Pine
68/100 Library Score
🌲Softwood🌧Outdoor💧Moisture Stable🌿Sustainable
- Higher durability (EN 350 Class 1 vs Class 2)
- Better dimensional stability (Exceptional vs Excellent)
🥈
Sweet Chestnut
51/100 Library Score
🪵Hardwood🌧Outdoor💧Moisture Stable
- Close second across most categories
- Solid choice where its profile fits the project
Visual comparison
Accoya Acetylated Radiata PineSweet Chestnut
Winner by category
There isn't one universally best wood — there's a best wood for each purpose.
| Category | Winner |
|---|---|
| Durability | Accoya Acetylated Radiata Pine |
| Stability | Accoya Acetylated Radiata Pine |
| Hardness | Tie |
| Strength (MOR) | Sweet Chestnut |
| Stiffness (MOE) | Sweet Chestnut |
| Flame spread | Sweet Chestnut |
| Machining ease | Accoya Acetylated Radiata Pine |
| Lightness | Accoya Acetylated Radiata Pine |
Engineering data
| Property | Accoya Acetylated Radiata Pine | Sweet Chestnut |
|---|---|---|
| Janka Hardness | 710 lbf | 680WD lbf |
| Density | 0.51 g/cm³ | 0.56WD g/cm³ |
| MOE | 8.5 GPa | 8.61WD GPa |
| MOR | 60.0 MPa | 71.4WD MPa |
| Durability | Class 1 Very Durable (treated) | Class 2 Durable |
| Stability | Exceptional | Excellent |
| Fire (E84) | Class C indicative | Class B indicative |
| Radial Shrink | 0.7 % | 4.2WD % |
| Tangential Shrink | 1.5 % | 6.9WD % |
| T/R Ratio | 2.14 | 1.64 |
Figures carry the same source status as the species pages they come from — verified where cited, indicative where marked.
Best for
| Application | Recommended | Suitability |
|---|---|---|
| Outdoor decking / pergola | 🥇 Accoya Acetylated Radiata Pine | ★★★★★ |
| Exterior cladding | 🥇 Accoya Acetylated Radiata Pine | ★★★★★ |
| Flooring / wear surfaces | 🥇 Accoya Acetylated Radiata Pine | ★★★☆☆ |
| Furniture / interior joinery | 🥇 Accoya Acetylated Radiata Pine | ★★★★☆ |
| Structural / load-bearing | 🥇 Sweet Chestnut | ★☆☆☆☆ |
| Sauna / wet interiors | 🥇 Accoya Acetylated Radiata Pine | ★★★★★ |
Advantages & limitations
Accoya Acetylated Radiata Pine
Advantages
- Rated for exterior exposure (EN 350 Class 1)
- Very low movement in service
Limitations
- Soft surface — dents under point loads
Sweet Chestnut
Advantages
- Rated for exterior exposure (EN 350 Class 2)
- Very low movement in service
Limitations
- Soft surface — dents under point loads
Recommendation
Choose Accoya Acetylated Radiata Pine if…
- The project lives outdoors and service life is the priority
- You need minimal movement (doors, decking, panelling)
Choose Sweet Chestnut if…
- Its profile matches the application better than a single overall score
Frequently asked questions
Which is more durable, Accoya Acetylated Radiata Pine or Sweet Chestnut?
Accoya Acetylated Radiata Pine — it carries the better EN 350 rating (Class 1 vs Class 2). Lower class numbers mean higher natural durability.
Which wood is better for outdoor use?
Accoya Acetylated Radiata Pine — outdoor performance combines decay durability with dimensional stability, and it leads on that combination.
Is Accoya Acetylated Radiata Pine harder than Sweet Chestnut?
Yes — Janka 710 lbf vs 680 lbf.
How we score. Each wood gets a weighted composite of the verified figures shown above: durability 22%, stability 18%, hardness 12%, bending strength 12%, machining ease 12%, stiffness 8%, flame spread 8%, lightness 8%. The Library Score is that composite's percentile rank within our 60-species library — 50 means the library median, 90 means it outperforms nine of every ten species we cover. No price data is scored — cost guidance is qualitative. The score summarises the data; it does not replace judgement about your specific application.