Home / Wood Compare / ThermoWood Ash Thermo-D vs ThermoWood Pine Thermo-D
Professional Comparison · Source-attributed engineering data · Updated 19 July 2026
ThermoWood Ash Thermo-D VS ThermoWood Pine Thermo-D
Which wood is better for your project? Scores are computed from the verified figures on each species page — how we score.
🥇
ThermoWood Ash Thermo-D
56/100 Library Score
🪵Hardwood🌧Outdoor💧Moisture Stable
- Better dimensional stability (Good vs Moderate)
- Harder wear surface (Janka 1320 vs 540 lbf)
- Stronger in bending (MOR 90.0 vs 65.0 MPa)
🥈
ThermoWood Pine Thermo-D
32/100 Library Score
🌲Softwood🌧Outdoor
- Easier to machine and fasten
- Lighter (0.42 vs 0.55 g/cm³)
- Solid choice where its profile fits the project
Visual comparison
ThermoWood Ash Thermo-DThermoWood Pine Thermo-D
Winner by category
There isn't one universally best wood — there's a best wood for each purpose.
| Category | Winner |
|---|---|
| Durability | Tie |
| Stability | ThermoWood Ash Thermo-D |
| Hardness | ThermoWood Ash Thermo-D |
| Strength (MOR) | ThermoWood Ash Thermo-D |
| Stiffness (MOE) | ThermoWood Ash Thermo-D |
| Flame spread | Tie |
| Machining ease | ThermoWood Pine Thermo-D |
| Lightness | ThermoWood Pine Thermo-D |
Engineering data
| Property | ThermoWood Ash Thermo-D | ThermoWood Pine Thermo-D |
|---|---|---|
| Janka Hardness | 1320UNV lbf | 540UNV lbf |
| Density | 0.55ITWA g/cm³ | 0.42ITWA g/cm³ |
| MOE | 13.3ITWA GPa | 9.3ITWA GPa |
| MOR | 90.0ITWA MPa | 38.1ITWA MPa |
| Durability | Class 2 Durable (treated) | Class 2 Durable (treated) |
| Stability | Good | Moderate |
| Fire (E84) | Not classified | Not classified |
| Radial Shrink | 1.7ITWA % | 1.2ITWA % |
| Tangential Shrink | 3.2ITWA % | 2.5ITWA % |
| T/R Ratio | 1.88 | 2.08 |
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 | 🥇 ThermoWood Ash Thermo-D | ★★★★☆ |
| Exterior cladding | 🥇 ThermoWood Pine Thermo-D | ★★★☆☆ |
| Flooring / wear surfaces | 🥇 ThermoWood Ash Thermo-D | ★★★☆☆ |
| Furniture / interior joinery | 🥇 ThermoWood Pine Thermo-D | ★★★☆☆ |
| Structural / load-bearing | 🥇 ThermoWood Ash Thermo-D | ★★☆☆☆ |
| Sauna / wet interiors | 🥇 ThermoWood Ash Thermo-D | ★★★★☆ |
Advantages & limitations
ThermoWood Ash Thermo-D
Advantages relative to ThermoWood Pine Thermo-D
- Janka is 1,320 lbf vs 540 lbf, about 2.4× harder
- MOR is 90.6 MPa vs 38.1 MPa, about 138% higher
- MOE is 13.3 GPa vs 9.3 GPa, about 43% higher
Limitations relative to ThermoWood Pine Thermo-D
ThermoWood Pine Thermo-D
Advantages relative to ThermoWood Ash Thermo-D
Limitations relative to ThermoWood Ash Thermo-D
- Janka is 540 lbf vs 1,320 lbf, about 59% lower
- MOR is 38.1 MPa vs 90.6 MPa, about 58% lower
- MOE is 9.3 GPa vs 13.3 GPa, about 30% lower
Recommendation
Choose ThermoWood Ash Thermo-D if…
- Decking (a signature application), exterior cladding and interior flooring where the higher hardness and bending strength are what the piece must deliver
- Garden furniture and joinery where dent resistance in service matters
Choose ThermoWood Pine Thermo-D if…
- Saunas (a signature use — low thermal conductivity and no resin bleed after modification) and rain screens where the modified profile matches the specification
- Exterior cladding and garden structures where cost or the lighter softwood profile is acceptable and the piece will not see hard wear
Frequently asked questions
Which is more durable, ThermoWood Ash Thermo-D or ThermoWood Pine Thermo-D?
Neither — both carry the same EN 350 rating (Class 2, Durable (treated)). Outdoors, movement will not separate them either — 3.2% against 2.5% tangential. The practical difference is weight: ThermoWood Ash Thermo-D runs 0.55 g/cm³ against 0.42, so ThermoWood Pine Thermo-D is the easier fix overhead and the cheaper one to freight.
Which wood is better for outdoor use?
ThermoWood Ash Thermo-D — outdoor performance combines decay durability with dimensional stability, and it leads on that combination.
Is ThermoWood Ash Thermo-D harder than ThermoWood Pine Thermo-D?
Yes — Janka 1320 lbf vs 540 lbf.
How we score. Scores shown are percentile ranks within our library, weighted towards durability and dimensional stability. They shortlist; they do not decide. Full weighting and what it excludes.
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