Home / Species / Douglas Fir

By Deepak Kumar · Founder, Vriksai

North America

Douglas Fir

Pseudotsuga menziesii

Also known as Oregon pine, British Columbian pine · Botanical Pseudotsuga menziesii

Last updated: 15 July 2026Reviewed by: Vriksai editorial team — timber trade professionalsEditorial policy

Revision history

17 July 2026 — Data re-verified in site-wide audit (formulas, sources, durability classes)
15 July 2026 — Working properties and comparable-species data cross-checked against listed sources

🌲Softwood💧Moisture Stable

Janka Hardness

620WD

lbf

Janka (metric)

2758calc

Hardness Class

Softcalc

Density

0.48fpl

g/cm³

MOE

13.4fpl

GPa

MOR

85.0FPL

MPa

Durability

Class 3

Moderately Durable

Fire (E84)

Class C

indicative

Thermal k

0.135

W/m·K

Green MC

85FPL

Fiber Saturation

28FPL

Radial Shrink

4.8WD

Tangential Shrink

7.6WD

T/R Ratio

1.58derived

Stability

Excellentcalc

About the fire rating. Indicative only, derived from density and published data — not a certified rating. Real performance depends on product, thickness, coating and installation. What our ratings do and do not certify.

Compare this wood:⚖ vs African Mahogany ⚖ vs Scots Pine ⚖ vs Southern Yellow Pine ⚖ vs Sweet Chestnut All comparisons →

About Douglas Fir

Douglas Fir (Pseudotsuga menziesii) is a soft timber that works easily but bruises and dents in service, with a Janka hardness of 620 lbf (2,758 N) and a density of about 0.48 g/cm³. It grows in North America.

Radial 4.8% against tangential 7.6% is an unusually even T/R ratio of 1.58 — Douglas Fir shrinks close to uniformly, which is why it holds a flat panel in interior joinery and furniture. Its fibre saturation point is near 28%. Below it this timber moves a great deal — 7.6% tangential — but evenly, at a T/R ratio of 1.58. Wide boards need genuine expansion room; they are less likely to cup than to simply change width. — wide boards need real expansion room, not a token gap.

At 480 kg/m³ a cubic metre of Douglas Fir weighs about 480 kg air-dry — that figure, the 7.6% tangential and 4.8% radial movement and the 620 lbf hardness are the three inputs the calculators below actually consume. Select Douglas Fir in any of them to get species-specific results for weight, moisture, shrinkage and hardness.

Working properties

How Douglas Fir behaves at the bench and on the machine, drawn from the USDA Forest Products Laboratory and North-American softwood references.

MachiningMachines, turns, planes and shapes well and sands smooth, with only a moderate blunting effect. Two quirks: the latewood bands are much harder than the earlywood, so it can splinter and break out; and if dried below about 9% moisture it turns brittle and machines poorly.

FasteningModerate nail-holding and good screw-holding — sound for framing and structural fixing.

GluingGlues without much difficulty, which is why it is a mainstay of glulam and plywood.

FinishingTakes stain and finish well. Because earlywood and latewood absorb differently, a sanding sealer first prevents blotching; clear or oil-based finishes show the grain best.

Steam bendingNot a bending timber.

DryingA real strength — it dries rapidly with small dimensional movement and little tendency to check, and once dry it stays put even through large humidity swings.

Durability & use classification

Douglas Fir heartwood is rated moderately durable (EN 350 Class 3) and is difficult to treat with preservative, so exterior work needs proper detailing or treated stock. Its real claim is mechanical: an exceptional strength-to-weight ratio, and it is among the hardest and heaviest softwoods in commercial North-American supply. Note a documented safety quirk — Douglas fir splinters are unusually prone to going septic.

Typical applications & suitability

Indoor Outdoor — The structural benchmark. Strength, straightness and easy fabrication make it a first choice for engineered and load-bearing timber; outdoors it wants treatment or good detailing rather than reliance on natural durability.

Documented end-uses: structural and construction lumber, glulam beams and roof trusses, timber framing, plywood and veneer (a dominant use), poles, piles and marine pilings, railway crossties and mine timbers, sashes, doors and windows, general millwork, flooring, furniture and cabinets, ships and boats, and boxes, pallets and crates.

Comparable species

Species closest to Douglas Fir by density, hardness, stiffness and bending strength, computed directly from the Vriksai species dataset rather than hand-picked.

Western Hemlock450 kg/m³ · 540 lbf European Larch550 kg/m³ · 530 lbf Scots Pine490 kg/m³ · 540 lbf Hem-Fir450 kg/m³ · 500 lbf

Trade alternatives. Its usual structural substitutes are Hem-Fir, SPF and Southern Yellow Pine, while European Larch and Scots Pine fill the same niche in Europe.

Alternatives to Douglas Fir

Douglas Fir measures 620 lbf Janka at 0.48 g/cm³, EN 350 durability Class 3, movement rated Excellent. Douglas Fir is rated Excellent for movement, which is usually why it was specified — so nothing below trades that stability down. Read the numbers against the Janka scale and EN 350 durability classes.

Step up — harder than Douglas Fir

For furniture and interior joinery that needs to survive handling as well as humidity. Harder resists denting; check the movement figures have not worsened with it.

Sweet Chestnut680 lbf · 0.56 g/cm³ · Class 2+10% Janka · 0.56 g/cm³ · exterior-rated ThermoWood Radiata Pine Thermo-D710 lbf · 0.50 g/cm³ · Class 2+15% Janka · exterior-rated · modified timber Accoya Acetylated Radiata Pine710 lbf · 0.51 g/cm³ · Class 1+15% Janka · more stable (Exceptional) · exterior-rated

Step down — softer than Douglas Fir

Easier to machine and to hand-finish, for interior work where the surface is not taking abuse.

ThermoWood Pine Thermo-D540 lbf · 0.48 g/cm³ · Class 2-13% Janka · exterior-rated · modified timber Scots Pine540 lbf · 0.49 g/cm³ · Class 4-13% Janka Western Hemlock540 lbf · 0.45 g/cm³ · Class 4-13% Janka

Similar, but more dimensionally stable

Already well behaved — these are the few in our library that are measurably steadier still. Size the gaps with the shrinkage predictor and EMC calculator.

Accoya Acetylated Radiata Pine710 lbf · 0.51 g/cm³ · Class 1stability gained by modification, not by species · rated Exceptional vs Excellent · 0.7% radial movement vs 4.8%

Closest overall match

If Douglas Fir is unavailable and the specification cannot change, these are the nearest substitutes across hardness, density, movement, stiffness, bending strength and durability class together — not on any single property. Lower distance means a closer match.

European Larchmatch 1.20740 lbf · 0.55 g/cm³ · Class 3740 lbf vs 620 · 0.55 vs 0.48 g/cm³ Black Walnutmatch 1.441,010 lbf · 0.55 g/cm³ · Class 31,010 lbf vs 620 · 0.55 vs 0.48 g/cm³ American Cherrymatch 1.76950 lbf · 0.50 g/cm³ · Class 3950 lbf vs 620 · 0.50 vs 0.48 g/cm³

More durable for exterior use

Douglas Fir is EN 350 Class 3, so untreated exterior service is not advisable. These reach Class 1–2 at comparable hardness.

Accoya Acetylated Radiata Pine710 lbf · 0.51 g/cm³ · Class 1EN 350 Class 1 vs Class 3 · modified timber Burma Teak Premium Grade1,070 lbf · 0.66 g/cm³ · Class 1EN 350 Class 1 vs Class 3 Teak1,070 lbf · 0.55 g/cm³ · Class 1EN 350 Class 1 vs Class 3

Computed from measured properties only — hardness, density, movement, stiffness, bending strength and EN 350 class. Price, availability and appearance are never inputs. Figures are representative values, not consignment absolutes: two species within a few percent are equivalent until verified on the material. Full method and the rules the engine cannot break.

Substitution is a match on durability class, movement and strength — not on colour or grain. Where two candidates are close, compare them directly before specifying.

Compare Douglas Fir side by side

These comparisons turn on movement and finish quality more than on raw strength. Every pairing shows the measured figures side by side; full matrix in the comparison index.

Douglas Fir vs Sweet ChestnutSide-by-side data · 680 lbf Douglas Fir vs Scots PineSide-by-side data · 540 lbf Douglas Fir vs Southern Yellow PineSide-by-side data · 870 lbf Douglas Fir vs African MahoganySide-by-side data · 1,070 lbf

Calculators relevant to Douglas Fir

Weighted towards joinery and finishing, where Douglas Fir is normally used. Full set in the tool index.

Wood Acclimation Time CalculatorWood Science Wood Moisture Content TrackerWood Science Timber Screw Spacing Calculator (EC5 & IS 883)Joinery Shelf Sag CalculatorJoinery Cabinet Hardware Placement CalculatorManufacturing Box Joint CalculatorJoinery Bark Deduction CalculatorMeasurement Doyle Log Rule CalculatorMeasurement

Understand the figures

Moisture content — EMC, FSP and service conditions · Strength properties — MOR, MOE and what they govern · Durability & fire — EN 350 classes and E84 ratings · Thermal conductivity — k-value and insulation behaviour.

Further reading. What is ThermoWood? · Wood moisture content explained · How to calculate board feet.

Common questions about Douglas Fir

Is Douglas Fir strong enough for furniture or flooring?

It's a softer timber at 620 lbf (2,758 N), so it dents more easily than oak or teak and isn't the first choice for high-traffic flooring. Where it shines is lighter work — panels, mouldings, interior joinery and anywhere low weight and easy machining matter more than bruise resistance. Match it to the job and it performs nicely.

Is Douglas Fir suitable for outdoor projects?

It's moderately durable (Class 3, EN 350), which puts it in the 'fine outdoors with a bit of care' bracket. For anything in ground contact or constantly wet, you'll want a preservative treatment or a coating you keep up. For covered or well-drained outdoor use it does well, especially if you cut away the non-durable sapwood and let air move around the timber.

Does Douglas Fir move much once it's installed?

It's one of the more stable timbers, which is part of its appeal. Radial 4.8% against tangential 7.6% is an unusually even T/R ratio of 1.58 — Douglas Fir shrinks close to uniformly, which is why it holds a flat panel in interior joinery and furniture. You'll still want it dried to the right moisture content for your climate, but cupping and gaps are less of a worry than with a less stable wood.

unverified no published source for this figure · FPL USDA FPL Wood Handbook GTR-190 · WD The Wood Database (Eric Meier) · calc derived from the figures above

Tools that use this species

Janka Database ToolHardness for 60 species Green Weight CalculatorWeight of green timber Shrinkage PredictorDimensional movement EMC CalculatorEquilibrium moisture content Fiber Saturation CalculatorFSP by species Volume Converterm3, CFT, board feet

Sources & references

The Wood Database (Eric Meier) — compiled species data, one of the references behind the panel above. Which figure comes from which reference is not recorded field by field. Spot checks show the numbers do trace to published sources, but not all to the same one: strength values for US species follow the USDA FPL Wood Handbook exactly, while European species draw on European references instead. So a figure that disagrees with any single reference here is not necessarily wrong — different bodies measure specific gravity and shrinkage on different bases. If a number matters to your work, check it against the reference you intend to rely on.
USDA Forest Products Laboratory — softwood tech sheet (Pseudotsuga menziesii) & Wood Handbook · mechanical values, uses, toxicity
North-American softwood references — naturally:wood and AHEC-equivalent species data · working, drying, gluing, finishing
EN 350 — European standard for natural durability of wood · durability class

Updated 15 Jul 2026 Values are representative; wood varies with provenance, age and grade. Confirm critical structural or fire figures against a test report for your actual product.