Douglas fir is a softwood species from the Douglas fir tree (Pseudotsuga menziesii), recognisable by its reddish-brown colour, coarser grain and natural durability. It is one of the most popular wood species for outdoor DIY projects because it lasts 15-20 years untreated.
Characteristics
| Property | Douglas fir |
|---|---|
| Durability class | III (moderately durable) |
| Lifespan outdoors (untreated) | 15-20 years |
| Colour | Reddish-brown (weathers to silver-grey) |
| Density | approx. 530 kg/m3 |
| Hardness | Harder than spruce, softer than oak |
| Resin content | High (natural protection) |
Why is Douglas fir so popular?
1. Naturally durable — No treatment needed for outdoor use
2. Beautiful colour — Warm reddish-brown tone, weathers to stylish silver-grey
3. Stronger than spruce — Higher load capacity at the same dimensions
4. Good value for money — More expensive than spruce, but much cheaper than hardwood
5. European-grown — Not tropical wood, readily available
Applications
| Application | Notes |
|---|---|
| Facade cladding (lap siding) | The number one choice for wooden facade cladding |
| Canopies | Beautiful as exposed structure |
| Sheds and garden buildings | Structural and cladding timber |
| Pergolas | Sturdy posts and beams |
| Fences | More durable than pressure-treated spruce |
| Carports | Visible structure with a natural look |
Douglas fir vs. other wood species
| Douglas fir | Spruce | Larch | Pressure-treated | |
|---|---|---|---|---|
| Outdoor (untreated) | 15-20 years | 2-5 years | 15-20 years | 15-20 years |
| Colour | Reddish-brown | Light yellow | Yellowish-brown | Greenish |
| Price | Medium | Low | Medium | Low |
| Chemicals | No | No | No | Yes |
| Resinous | Yes | Less | Yes | No |
Points to note
- Resin bleeding — Douglas fir contains a lot of resin. In warm weather, resin can seep from the wood (sticky droplets). This stops after 1-2 years. Do not paint while resin is still bleeding.
- Weathering — Untreated Douglas fir weathers to silver-grey. This is normal and protects the wood. Want to keep the reddish-brown colour? Oil with Douglas fir oil (1-2 times per year).
- Pre-drilling — Douglas fir is harder than spruce. Always pre-drill when screwing to prevent splitting.
- European vs. American — European Douglas fir (grown in the Netherlands) is less durable than American (Oregon Pine). For structural outdoor use, American Douglas fir is better.
Related terms
- Larch wood
- Softwood
- Hardwood
- Thermowood
- Lap siding