Home / Wood Compare / Douglas Fir vs Sweet Chestnut
Professional Comparison · Source-attributed engineering data · Updated 19 July 2026
Douglas Fir VS Sweet Chestnut
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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Douglas Fir
66/100 Library Score
🌲Softwood💧Moisture Stable
- Stronger in bending (MOR 85.0 vs 71.4 MPa)
- Easier machining and fastening (lower density/hardness)
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Sweet Chestnut
51/100 Library Score
🪵Hardwood🌧Outdoor💧Moisture Stable
- More durable (Class 2)
- Solid choice where its profile fits the project
Visual comparison
Douglas FirSweet Chestnut
Winner by category
There isn't one universally best wood — there's a best wood for each purpose.
| Category | Winner |
|---|---|
| Durability | Sweet Chestnut |
| Stability | Tie |
| Hardness | Tie |
| Strength (MOR) | Douglas Fir |
| Stiffness (MOE) | Douglas Fir |
| Flame spread | Sweet Chestnut |
| Machining ease | Douglas Fir |
| Lightness | Douglas Fir |
Engineering data
| Property | Douglas Fir | Sweet Chestnut |
|---|---|---|
| Janka Hardness | 620WD lbf | 680WD lbf |
| Density | 0.48FPL g/cm³ | 0.56WD g/cm³ |
| MOE | 13.4FPL GPa | 8.61WD GPa |
| MOR | 85.0FPL MPa | 71.4WD MPa |
| Durability | Class 3 Moderately Durable | Class 2 Durable |
| Stability | Excellent | Excellent |
| Fire (E84) | Class C indicative | Class B indicative |
| Radial Shrink | 4.8WD % | 4.2WD % |
| Tangential Shrink | 7.6WD % | 6.9WD % |
| T/R Ratio | 1.58 | 1.64 |
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 | 🥇 Sweet Chestnut | ★★★★☆ |
| Exterior cladding | 🥇 Sweet Chestnut | ★★★★☆ |
| Flooring / wear surfaces | 🥇 Sweet Chestnut | ★★★☆☆ |
| Furniture / interior joinery | 🥇 Douglas Fir | ★★★★☆ |
| Structural / load-bearing | 🥇 Douglas Fir | ★★★☆☆ |
Advantages & limitations
Douglas Fir
Advantages relative to Sweet Chestnut
- MOR is 85 MPa vs 71.4 MPa, about 19% higher
- MOE is 13.4 GPa vs 8.6 GPa, about 56% higher
Limitations relative to Sweet Chestnut
- Durability is Class 3 vs Class 2 — one class less durable in exterior service
- Fire (E84) is Class C vs Class B — one class lower on flame-spread rating
Sweet Chestnut
Advantages relative to Douglas Fir
- Durability is Class 2 vs Class 3 — one class more durable in exterior and moderate-exposure service
- Fire (E84) is Class B vs Class C — one class better on flame-spread rating
Limitations relative to Douglas Fir
- MOR is 71.4 MPa vs 85 MPa, about 16% lower
- MOE is 8.6 GPa vs 13.4 GPa, about 36% lower
Recommendation
Choose Douglas Fir if…
- Structural and construction lumber, glulam beams and roof trusses, plywood and veneer, timber framing where the higher stiffness is what the span or loading demands
- Poles, marine pilings and railway crossties where structural performance under load is the specification
Choose Sweet Chestnut if…
- External cladding, decking and fencing where the Class 2 durability and Class B fire class both matter in specification
- Posts and utility poles (30-40 year documented service), interior joinery and cooperage where the natural durability rating is what the piece needs
Frequently asked questions
Which is more durable, Douglas Fir or Sweet Chestnut?
Sweet Chestnut — it carries the better EN 350 rating (Class 2 vs Class 3). Lower class numbers mean higher natural durability.
Which wood is better for outdoor use?
Sweet Chestnut — outdoor performance combines decay durability with dimensional stability, and it leads on that combination.
Is Douglas Fir harder than Sweet Chestnut?
No — Sweet Chestnut is harder (Janka 680 vs 620 lbf).
How we score. Each Library Score is a weighted composite of the verified figures above, expressed as a percentile against our 60-species library. Cost is handled qualitatively, never scored. Full weighting and what it excludes.