Douglas fir and Siberian larch are two of the most popular timber cladding species in the UK market. Both are strong-performing softwoods suitable for exterior facades, but they behave differently in the UK climate and suit different project types. This guide gives you a definitive side-by-side comparison covering durability, cost per m², weathering, maintenance, available profiles, and which species to choose for your specific project.
Douglas fir cladding — a strong, stable softwood with a clean straight grain and warm reddish-brown tones.
For most UK residential projects, Siberian larch is the safer default choice — it has better natural decay resistance, ages beautifully without treatment, and is available in a wider range of profiles from stock. Douglas fir is the better choice where a cleaner, more uniform grain is needed, particularly for contemporary rainscreen cladding on south and west-facing elevations where appearance consistency matters most.
At a Glance: Douglas Fir vs Larch Cladding UK
Full Comparison: Douglas Fir vs Larch Cladding UK (2026)
| Criteria | Douglas Fir | Siberian Larch | Winner |
|---|---|---|---|
| Natural durability | Moderate — needs treatment | Good — high resin content | Larch |
| Expected lifespan (UK) | 20–30 years (treated) | 25–35 years (untreated) | Larch |
| Appearance | Clean, straight grain, reddish-brown | Golden-brown, more knotty | Preference |
| Weathering | Silvers unevenly without treatment | Weathers to consistent silver-grey | Larch |
| Typical cost per m² | £40–£75 | £35–£70 | Larch |
| Maintenance | Regular oiling required | Low — can leave untreated | Larch |
| Workability | Easy — straight grain, lower density | Moderate — denser, more resinous | Douglas fir |
| Takes factory coating | Excellent | Good | Douglas fir |
| Fire treatment compatible | Yes — Euroclass B available | Yes — Euroclass B available | Equal |
| Profile availability | Rainscreen, shiplap | Shadow gap, shiplap, loglap, rainscreen | Larch |
| Best for | Contemporary rainscreen, clean facades | Most UK residential & commercial | Project dependent |
Douglas Fir Cladding: Detailed Overview
Douglas fir is a strong, moderately durable softwood with a distinctive straight grain and warm reddish-brown colouration. Native to North America, it has become an increasingly popular choice for UK exterior cladding — particularly on contemporary projects where a clean, uniform board appearance and consistent profile alignment are priorities.
Its primary strength is workability. Douglas fir machines cleanly, holds fixings well, and takes exterior finishes and factory coatings exceptionally well — making it a strong choice for projects where a pre-finished, site-ready board is preferred. The straight grain also makes it particularly suited to rainscreen profiles where long, consistent board runs are required without visual interruption from knots.
The main limitation of Douglas fir is its natural durability. Without preservative treatment or a quality exterior finish, it is susceptible to rot and biological attack in UK conditions — more so than Siberian larch. For this reason, douglas fir cladding should always be specified with either a factory-applied coating, a site-applied exterior oil, or fire retardant treatment that also enhances durability. With correct specification and maintenance it is an excellent long-term cladding material.
Siberian Larch Cladding: Detailed Overview
Siberian larch cladding — naturally durable, widely available in the UK, and one of the most versatile species for exterior facades.
Siberian larch is the most widely specified natural timber cladding species in the UK market. Its combination of natural decay resistance, attractive appearance, availability in a wide range of profiles, and competitive price point make it a strong default choice for the majority of UK residential and commercial cladding projects.
Larch's high resin content gives it natural resistance to moisture, fungi, and insects — significantly better than Douglas fir without treatment. This means larch cladding can be left unfinished on sheltered elevations with minimal maintenance, gradually weathering to a consistent silver-grey patina over time. For many architects and homeowners this natural weathering is a deliberate design choice rather than a compromise.
The main trade-off with larch is its knotty, more characterful appearance. Siberian larch typically has more knots than Douglas fir, giving it a more rustic, textured look. On contemporary projects where strict visual uniformity is required, this can be a disadvantage — though premium clear grades are available that significantly reduce knot frequency. For maintenance guidance see our timber cladding maintenance guide.
Cost Comparison: Douglas Fir vs Larch Cladding UK (2026)
Both species sit at a similar price point in the UK market. The cost difference between Douglas fir and Siberian larch is modest — typically £5–£10 per m² — and is a less significant factor than profile choice, treatment specification, and whether factory coating is included. For a full breakdown of timber cladding costs by species see our timber cladding cost per m² guide.
| Species & Spec | Typical Material Cost (per m²) | Maintenance Cost (10yr) | Overall Value |
|---|---|---|---|
| Douglas fir — untreated | £40–£75 | High — regular oiling required | Moderate |
| Douglas fir — factory coated | £70–£110 | Low — planned recoat cycles | Good |
| Siberian larch — untreated | £35–£70 | Low — can leave to weather | Very good |
| Siberian larch — factory coated | £65–£105 | Low — planned recoat cycles | Excellent |
| ThermoWood (alternative) | £55–£95 | Very low | Excellent long-term |
Also Worth Considering: ThermoWood
If you are comparing Douglas fir and larch, it is also worth considering ThermoWood thermally modified timber as a third option. ThermoWood offers better dimensional stability than both Douglas fir and larch, significantly reduced moisture movement, and a longer expected service life — without the natural decay resistance limitations of Douglas fir. It sits at a similar price point to treated Douglas fir and is available in a wide range of shadow gap and shiplap profiles. See our full comparison at ThermoWood vs larch cladding.
Which Should You Choose?
Douglas Fir Cladding
Rainscreen profiles available from UK stock. Nationwide delivery 7–14 days.
Browse Douglas Fir →Siberian Larch Cladding
Shadow gap, shiplap, loglap & rainscreen profiles. Nationwide delivery 7–14 days.
Browse Siberian Larch →Both are strong performers for UK exterior cladding. Larch has a natural advantage in decay resistance due to its high resin content, making it slightly more forgiving on exposed elevations without treatment. Douglas fir offers a cleaner, more uniform appearance with a straight grain that is easier to work with and takes finishes well. For most UK residential projects Siberian larch is the more popular choice, but Douglas fir is increasingly specified on contemporary projects where a clean rainscreen profile is required.
When correctly detailed with a ventilated rainscreen cavity, Douglas fir cladding can achieve 20–30 years of service life in UK conditions. With fire retardant treatment or factory coating the lifespan increases. Untreated Douglas fir requires regular oiling or staining to maintain appearance and resist decay.
Siberian larch cladding typically lasts 25–35 years in UK conditions when correctly installed. Its naturally high resin content gives it better untreated decay resistance than Douglas fir. Left unfinished it weathers to a consistent silver-grey patina. With regular oiling the original golden-brown colour can be maintained for longer.
Siberian larch cladding typically costs £35–£70 per m² for materials in the UK. Douglas fir cladding is broadly similar, typically £40–£75 per m² depending on profile and grade. The cost difference between the two is modest — the bigger cost drivers are profile complexity and whether treatment or factory coating is specified.
Untreated Siberian larch cladding does not require preservative treatment due to its natural resin content. It can be left to weather naturally to a silver-grey finish with no maintenance, or oiled every 2–3 years to retain its original golden-brown colour. A UV-stable exterior oil is recommended for south and west facing elevations where UV exposure is highest.
Need help choosing? Talk to our team
We supply both Douglas fir and Siberian larch cladding across the UK from stock, with delivery in 7–14 days. Our team can advise on species, profile, treatment and fixing for your specific project.
