Home / Wood Compare / Cumaru vs Spotted Gum
Professional Comparison · Source-attributed engineering data · Updated 19 July 2026
Cumaru VS Spotted Gum
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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Cumaru
98/100 Library Score
🪵Hardwood🌧Outdoor🔥Low Flame Spread💧Moisture Stable
- Higher durability (EN 350 Class 1 vs Class 2)
- Harder wear surface (Janka 3330 vs 2473 lbf)
- Stronger in bending (MOR 175.1 vs 137.0 MPa)
- Better flame-spread class (Class A vs Class B)
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Spotted Gum
86/100 Library Score
🪵Hardwood🌧Outdoor💧Moisture Stable
- Close second across most categories
- Solid choice where its profile fits the project
Visual comparison
CumaruSpotted Gum
Winner by category
There isn't one universally best wood — there's a best wood for each purpose.
| Category | Winner |
|---|---|
| Durability | Cumaru |
| Stability | Tie |
| Hardness | Cumaru |
| Strength (MOR) | Cumaru |
| Stiffness (MOE) | Cumaru |
| Flame spread | Cumaru |
| Machining ease | Spotted Gum |
| Lightness | Spotted Gum |
Engineering data
| Property | Cumaru | Spotted Gum |
|---|---|---|
| Janka Hardness | 3330WD lbf | 2473WD lbf |
| Density | 0.87WD g/cm³ | 0.85WD g/cm³ |
| MOE | 22.33WD GPa | 20.0WD GPa |
| MOR | 175.1WD MPa | 137.0WD MPa |
| Durability | Class 1 Very Durable | Class 2 Durable |
| Stability | Excellent | Excellent |
| Fire (E84) | Class A indicative | Class B indicative |
| Radial Shrink | 5.3WD % | 4WS % |
| Tangential Shrink | 7.7WD % | 6WS % |
| T/R Ratio | 1.45 | 1.5 |
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 | 🥇 Cumaru | ★★★★★ |
| Exterior cladding | 🥇 Cumaru | ★★★★☆ |
| Flooring / wear surfaces | 🥇 Cumaru | ★★★★★ |
| Furniture / interior joinery | 🥇 Spotted Gum | ★★☆☆☆ |
| Structural / load-bearing | 🥇 Cumaru | ★★★★★ |
Advantages & limitations
Cumaru
Advantages relative to Spotted Gum
- Janka is 3,330 lbf vs 2,473 lbf, about 35% harder
- MOR is 175.1 MPa vs 137 MPa, about 28% higher
- Durability is Class 1 vs Class 2 — one class more durable in exterior and ground-contact service
- Fire (E84) is Class A vs Class B — one class better on flame-spread rating
Limitations relative to Spotted Gum
Spotted Gum
Advantages relative to Cumaru
Limitations relative to Cumaru
- Janka is 2,473 lbf vs 3,330 lbf, about 26% lower
- MOR is 137 MPa vs 175.1 MPa, about 22% lower
- Durability is Class 2 vs Class 1 — one class less durable
- Fire (E84) is Class B vs Class A — one class lower on flame-spread rating
Recommendation
Choose Cumaru if…
- Decking, boardwalks, marine structures and heavy exterior joinery where the higher hardness, bending strength, Class 1 durability and Class A fire class all matter in specification
- Structural components subject to bending loads where the top-tier property combination is what the project needs
Choose Spotted Gum if…
- Decking, cladding and flooring, structural framing, posts and poles where the working properties are sufficient and the Class 2 durability is acceptable for the exposure
- Engineering work including wharves, bridges, railway sleepers, cross-arms and mining timbers, fine furniture, feature walls and charred cladding where the documented Spotted Gum role is what the project is specifying
Frequently asked questions
Which is more durable, Cumaru or Spotted Gum?
Cumaru — 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?
Cumaru — outdoor performance combines decay durability with dimensional stability, and it leads on that combination.
Is Cumaru harder than Spotted Gum?
Yes — Janka 3330 lbf vs 2473 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.