Home / Wood Compare / Accoya Acetylated Radiata Pine vs ThermoWood Radiata Pine Thermo-D
Professional Comparison · Source-attributed engineering data · Updated 19 July 2026
Accoya Acetylated Radiata Pine VS ThermoWood Radiata Pine Thermo-D
Which wood is better for your project? Scores are computed from the verified figures on each species page — how we score.
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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 Moderate)
🥈
ThermoWood Radiata Pine Thermo-D
19/100 Library Score
🌲Softwood🌧Outdoor🌿Sustainable
- Close second across most categories
- Solid choice where its profile fits the project
Visual comparison
Accoya Acetylated Radiata PineThermoWood Radiata Pine Thermo-D
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) | Tie |
| Stiffness (MOE) | ThermoWood Radiata Pine Thermo-D |
| Flame spread | Tie |
| Machining ease | Tie |
| Lightness | ThermoWood Radiata Pine Thermo-D |
Engineering data
| Property | Accoya Acetylated Radiata Pine | ThermoWood Radiata Pine Thermo-D |
|---|---|---|
| Janka Hardness | 710 lbf | 710UNV lbf |
| Density | 0.51 g/cm³ | 0.44ITWA g/cm³ |
| MOE | 8.5 GPa | 16.9ITWA GPa |
| MOR | 60.0 MPa | 60.6ITWA MPa |
| Durability | Class 1 Very Durable (treated) | Class 2 Durable (treated) |
| Stability | Exceptional | Moderate |
| Fire (E84) | Not classified | Not classified |
| Radial Shrink | 0.7 % | 1.2ITWA % |
| Tangential Shrink | 1.5 % | 2.6ITWA % |
| T/R Ratio | 2.14 | 2.17 |
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 | 🥇 ThermoWood Radiata Pine Thermo-D | ★☆☆☆☆ |
| Sauna / wet interiors | 🥇 Accoya Acetylated Radiata Pine | ★★★★★ |
Advantages & limitations
Accoya Acetylated Radiata Pine
Advantages relative to ThermoWood Radiata Pine Thermo-D
- Durability is Class 1 vs Class 2 — one class more durable in exterior and ground-contact service
Limitations relative to ThermoWood Radiata Pine Thermo-D
ThermoWood Radiata Pine Thermo-D
Advantages relative to Accoya Acetylated Radiata Pine
Limitations relative to Accoya Acetylated Radiata Pine
- Durability is Class 2 vs Class 1 — one class less durable in exterior and ground-contact service
Recommendation
Choose Accoya Acetylated Radiata Pine if…
- Exterior windows and doors (the timber's flagship application), wide-board cladding and rainscreens where Class 1 durability from acetylation is the specification
- Bridges, civil works and shou-sugi-ban cladding where the modified dimensional stability is the working requirement
Choose ThermoWood Radiata Pine Thermo-D if…
- Exterior cladding, rain screens, decking and garden structures where Class 2 durability is acceptable for the exposure and cost profile is a factor
- Interior panelling and joinery where the thermal-modification profile suits the piece
Frequently asked questions
Which is more durable, Accoya Acetylated Radiata Pine or ThermoWood Radiata Pine Thermo-D?
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 ThermoWood Radiata Pine Thermo-D?
They measure the same on the Janka scale (710 lbf each) — effectively equal in surface hardness.
How we score. Both Library Scores above are percentile ranks inside our 60-species library, from a weighted composite led by durability (22%) and dimensional stability (18%). Price is deliberately not scored. Full weighting and what it excludes.