Thermally Modified Larch VS ThermoWood Radiata Pine Thermo-D
- Stronger in bending (MOR 75.0 vs 62.0 MPa)
- Lighter (0.44 vs 0.55 g/cm³)
- Harder wear surface
- Solid choice where its profile fits the project
Visual comparison
Winner by category
There isn't one universally best wood — there's a best wood for each purpose.
| Category | Winner |
|---|---|
| Durability | Tie |
| Stability | Tie |
| Hardness | ThermoWood Radiata Pine Thermo-D |
| Strength (MOR) | Thermally Modified Larch |
| Stiffness (MOE) | ThermoWood Radiata Pine Thermo-D |
| Flame spread | Tie |
| Machining ease | Tie |
| Lightness | ThermoWood Radiata Pine Thermo-D |
Engineering data
| Property | Thermally Modified Larch | ThermoWood Radiata Pine Thermo-D |
|---|---|---|
| Janka Hardness | 530UNV lbf | 710UNV lbf |
| Density | 0.55ITWA g/cm³ | 0.44ITWA g/cm³ |
| MOE | 11.0ITWA GPa | 16.9ITWA GPa |
| MOR | 75.0ITWA MPa | 60.6ITWA MPa |
| Durability | Class 2 Durable (treated) | Class 2 Durable (treated) |
| Stability | Moderate | Moderate |
| Fire (E84) | Not classified | Not classified |
| Radial Shrink | 1.3ITWA % | 1.2ITWA % |
| Tangential Shrink | 2.8ITWA % | 2.6ITWA % |
| T/R Ratio | 2.15 | 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 | 🥇 Thermally Modified Larch | ★★★☆☆ |
| Exterior cladding | 🥇 ThermoWood Radiata Pine Thermo-D | ★★★☆☆ |
| Flooring / wear surfaces | 🥇 ThermoWood Radiata Pine Thermo-D | ★★☆☆☆ |
| Furniture / interior joinery | 🥇 Thermally Modified Larch | ★★★☆☆ |
| Structural / load-bearing | 🥇 Thermally Modified Larch | ★★☆☆☆ |
Advantages & limitations
Thermally Modified Larch
Advantages relative to ThermoWood Radiata Pine Thermo-D
- MOR is 75 MPa vs 60.6 MPa, about 24% higher
Limitations relative to ThermoWood Radiata Pine Thermo-D
- Janka is 530 lbf vs 710 lbf, about 34% lower
ThermoWood Radiata Pine Thermo-D
Advantages relative to Thermally Modified Larch
- Janka is 710 lbf vs 530 lbf, about 34% harder
Limitations relative to Thermally Modified Larch
- MOR is 60.6 MPa vs 75 MPa, about 19% lower
Recommendation
Choose Thermally Modified Larch if…
- Exterior cladding and rain screens, decking, garden structures where the higher bending strength matters in specification
- Interior panelling and flooring where the modified larch profile is the specification
Choose ThermoWood Radiata Pine Thermo-D if…
- Exterior cladding and rain screens, decking, garden structures where the higher hardness matters in service
- Interior panelling and joinery where the modified radiata pine profile matches the specification
Frequently asked questions
Which is more durable, Thermally Modified Larch or ThermoWood Radiata Pine Thermo-D?
Neither — both carry the same EN 350 rating (Class 2, Durable (treated)). Outdoors, movement will not separate them either — 2.8% against 2.6% tangential. The practical difference is weight: Thermally Modified Larch runs 0.55 g/cm³ against 0.50, so ThermoWood Radiata Pine Thermo-D is the easier fix overhead and the cheaper one to freight.
Which wood is better for outdoor use?
Both are EN 350 Class 2, and tangential movement runs 2.8% for Thermally Modified Larch against 2.6% for ThermoWood Radiata Pine Thermo-D — close enough that decay resistance will not choose between them, and ThermoWood Radiata Pine Thermo-D holds its dimension marginally better. ThermoWood Radiata Pine Thermo-D gives the harder wearing surface at 710 lbf; ThermoWood Radiata Pine Thermo-D is the lighter section at 0.50 g/cm³ — traffic favours the first, cladding and handling the second.
Is Thermally Modified Larch harder than ThermoWood Radiata Pine Thermo-D?
No — ThermoWood Radiata Pine Thermo-D is harder (Janka 710 vs 530 lbf).