Home / Wood Compare / Thermowood Spruce ThermoD vs Thermowood Western Red Cedar ThermoD
Professional Comparison · Verified Engineering Data · Updated 19 July 2026
Thermowood Spruce ThermoD VS Thermowood Western Red Cedar ThermoD
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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Thermowood Spruce ThermoD
21/100 Library Score
🌲Softwood🌧Outdoor
- Stronger in bending (MOR 60.0 vs 45.0 MPa)
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Thermowood Western Red Cedar ThermoD
18/100 Library Score
🌲Softwood🌧Outdoor
- Lighter (0.38 vs 0.45 g/cm³)
- Solid choice where its profile fits the project
Visual comparison
Thermowood Spruce ThermoDThermowood Western Red Cedar ThermoD
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 Spruce ThermoD |
| Strength (MOR) | Thermowood Spruce ThermoD |
| Stiffness (MOE) | Thermowood Spruce ThermoD |
| Flame spread | Tie |
| Machining ease | Thermowood Western Red Cedar ThermoD |
| Lightness | Thermowood Western Red Cedar ThermoD |
Engineering data
| Property | Thermowood Spruce ThermoD | Thermowood Western Red Cedar ThermoD |
|---|---|---|
| Janka Hardness | 380ITWA lbf | 350ITWA lbf |
| Density | 0.45ITWA g/cm³ | 0.38ITWA g/cm³ |
| MOE | 9.0ITWA GPa | 7.5ITWA GPa |
| MOR | 60.0ITWA MPa | 45.0ITWA MPa |
| Durability | Class 2 Durable (treated) | Class 2 Durable (treated) |
| Stability | Moderate | Moderate |
| Fire (E84) | Class C indicative | Class C indicative |
| Radial Shrink | 1ITWA % | 1ITWA % |
| Tangential Shrink | 2.2ITWA % | 2ITWA % |
| T/R Ratio | 2.2 | 2.0 |
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 Spruce ThermoD | ★★★☆☆ |
| Exterior cladding | 🥇 Thermowood Western Red Cedar ThermoD | ★★★★☆ |
| Flooring / wear surfaces | 🥇 Thermowood Spruce ThermoD | ★☆☆☆☆ |
| Furniture / interior joinery | 🥇 Thermowood Western Red Cedar ThermoD | ★★★★☆ |
| Structural / load-bearing | 🥇 Thermowood Spruce ThermoD | ★☆☆☆☆ |
Advantages & limitations
Thermowood Spruce ThermoD
Advantages
- Rated for exterior exposure (EN 350 Class 2)
- Easy to machine, glue and fasten
- Lightweight — easy handling and installation
Limitations
- Noticeable seasonal movement — allow for it in design
- Soft surface — dents under point loads
Thermowood Western Red Cedar ThermoD
Advantages
- Rated for exterior exposure (EN 350 Class 2)
- Easy to machine, glue and fasten
- Lightweight — easy handling and installation
Limitations
- Noticeable seasonal movement — allow for it in design
- Soft surface — dents under point loads
Recommendation
Choose Thermowood Spruce ThermoD if…
- You want the stronger all-round engineering profile
Choose Thermowood Western Red Cedar ThermoD if…
- Weight matters — ceilings, wall panels, transport
- Its profile matches the application better than a single overall score
Frequently asked questions
Which is more durable, Thermowood Spruce ThermoD or Thermowood Western Red Cedar ThermoD?
Neither — both carry the same EN 350 rating (Class 2, Durable (treated)). For outdoor decisions between them, weigh dimensional stability and hardness instead.
Which wood is better for outdoor use?
They are closely matched outdoors — durability and stability come out almost level. Let the application decide: harder surface for decking traffic, lighter weight for cladding.
Is Thermowood Spruce ThermoD harder than Thermowood Western Red Cedar ThermoD?
Yes — Janka 380 lbf vs 350 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.