Douglas fir (Pseudotsuga menziesii) Douglas fir
Wood of Pseudotsuga menziesii: cellulose, lignin and hemicelluloses in a cellular structure
Douglas fir (Pseudotsuga menziesii) is a softwood conifer from western North America.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Density
510 kg/m3
Bending strength
86.2 MPa
Stiffness
12.17 GPa
Hardness
2760 N
Compression and shear
43.1 to 51.2 MPa
Recipe, share of the weight
- not statedCellulose
- not statedLignin
- not statedHemicelluloses
- not statedCellular structure
Best for
Structural construction lumber and plywood where a light-to-medium softwood with a strength close to spruce is needed
Weakest at
Moderate decay resistance in damp service, and it is hard to work with hand tools (FAA)
Risk at a glance
- People Low. Dust and splinters are the reported hazards
- If it fails Moderate. Decay and insect attack in damp service
- Corrosion Moderate. Heartwood is moderately durable against decay but susceptible to insect attack.
Quick facts: Douglas fir
| Property | Value | Basis |
|---|---|---|
| Density | 0.46 to 0.53 g/cm³ | 3 sourced values across conditions |
| Young's modulus | 10.3 to 13.4 GPa | 3 sourced values across conditions |
What is the density of Douglas fir?
Douglas fir has a density of 0.46 to 0.53 g/cm³. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is the Young's modulus of Douglas fir?
Douglas fir has a Young's modulus of 10.3 to 13.4 GPa. The range covers 3 sourced values across the tempers, forms and test conditions the sources report; room-temperature values are used where a source states a temperature.
What is Douglas fir used for?
Uses recorded in the sources include Construction lumber, plywood, piles and engineered wood composites; Aircraft wood structure, as a substitute for spruce; Railroad crossties, poles, mine timbers and fencing.
Why it exists
Douglas fir (Pseudotsuga menziesii) is a softwood from western North America. The Wood Handbook says it is used mostly for building and construction, and the FAA says it may be used as a substitute for spruce in some aircraft wood structures. It is in this collection as a structural timber benchmark, not as a space material: we found no flight data and no space-environment source for it.
Where it's used
Building and construction
The Wood Handbook says Douglas-fir is used mostly for building and construction, as lumber, marine fendering, piles, plywood and engineered wood composites.
Aircraft wood structure
FAA AC 43.13-1B Table 1-1 says Douglas Fir exceeds spruce in strength. It says the species may be used as a substitute for spruce in the same sizes, or in slightly reduced sizes, if the reductions are substantiated. The table prints the older name Pseudotsuga taxifolia.
Railroad ties, poles and fencing
The Wood Handbook says considerable quantities are used for railroad crossties, cooperage stock, mine timbers, poles and fencing.
Recipe
Wood of Pseudotsuga menziesii: cellulose, lignin and hemicelluloses in a cellular structure
Douglas-fir is wood, not a single compound. Its cell walls are built from cellulose, lignin and hemicelluloses, arranged in a cellular structure. The Wood Handbook gives this composition for all wood.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Cellulose | not stated | Long fibres that give the cell walls their tensile strength. |
| Lignin | not stated | Binds the cellulose fibres together and stiffens the cell walls. |
| Hemicelluloses | not stated | Matrix material between the cellulose fibres. |
| Cellular structure | not stated | The hollow cells whose size and arrangement, with the component proportions, make a wood heavy or light, stiff or flexible, and hard or soft. |
Weight shares are as printed in the sources.
What it can do
Density
510 kg/m3
measured
Engineering ToolBox gives 460 to 500 kg/m3 at 12% moisture content for the Douglas-fir regions. A separate table gives 530 kg/m3 for seasoned and dry wood, and the Wood Database gives 510 kg/m3 as average dried weight. The three figures use different moisture conditions, so they are shown side by side.
Bending strength
86.2 MPa
measured
At 12% moisture content, Engineering ToolBox gives 82 to 90 MPa for fibre stress at elastic limit. The Wood Handbook gives 85000 kPa for Coast Douglas-fir, and the Wood Database gives 86.2 MPa modulus of rupture without a moisture condition.
Stiffness
12.17 GPa
measured
The Wood Handbook gives 13400 MPa modulus of elasticity for Coast Douglas-fir at 12% moisture content, and Engineering ToolBox gives a range of 10.3 to 13.4 GPa across the regions.
Hardness
2760 N
measured
The Wood Database gives a Janka hardness of 2,760 N for Douglas-fir.
Compression and shear
43.1 to 51.2 MPa
measured
At 12% moisture content, the Wood Handbook gives 49900 kPa compression parallel to grain for Coast Douglas-fir and 7800 kPa shear parallel to grain. Engineering ToolBox gives 43.1 to 51.2 MPa and 7.8 to 10.4 MPa across the regions.
How it compares
Against spruce, the FAA table says Douglas Fir exceeds spruce in strength, but it is harder to work with hand tools and splits more readily. The sources give Douglas-fir values at different moisture contents and test regions, so this profile does not rank Douglas-fir numerically against other timbers. The compare rows below use the 12% moisture values from the regional tables.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details.
| Measurement | Douglas fir |
|---|---|
| Lifetime and stability | |
| Volumetric shrinkage | 11.6 %8 |
| Physical and electrical | |
| Average dried weight | 510 kg/m31 |
| Janka hardness | 2760 N5 |
| Density, four Douglas-fir regions (range) | 460 to 500 kg/m39 |
| Density, seasoned and dry woodPrinted in the Wood Species Densities table | 530 kg/m3 |
| Other measurements | |
| Modulus of rupture (bending strength) | 86.2 MPa2 |
| Elastic modulus | 12.17 GPa3 |
| Crushing strength (compression parallel to grain) | 47.9 MPa4 |
| Radial shrinkage | 4.5 %6 |
| Tangential shrinkage | 7.3 %7 |
| Fibre stress at elastic limit (modulus of rupture) | 82 to 90 MPa10 |
| Modulus of elasticity (range) | 10.3 to 13.4 GPa11 |
| Compressive strength parallel to grain (range) | 43.1 to 51.2 MPa12 |
| Shear strength parallel to grain (range) | 7.8 to 10.4 MPa13 |
| Modulus of rupture, Coast Douglas-fir | 85000 kPa14 |
| Modulus of elasticity, Coast Douglas-fir | 13400 MPa15 |
| Compression parallel to grain, Coast Douglas-fir | 49900 kPa16 |
| Shear strength parallel to grain, Coast Douglas-fir | 7800 kPa17 |
| Specific gravity, Coast Douglas-fir | 0.48 -18 |
Why choose it, and why not
Good for
- Construction lumber, plywood and piles, where a strong softwood is needed (Wood Handbook).
- Aircraft wood structure, where the FAA allows Douglas Fir as a spruce substitute if the reductions are substantiated.
Watch out for
- Moderate decay resistance and susceptibility to insect attack in damp service.
- Splitting and splintering when worked, with large solid pieces hard to inspect.
- Dust from the wood is a reported health hazard, and IARC classifies wood dust as carcinogenic to humans.
A strong, widely used structural softwood. Keep it dry and control its dust and splinters.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Average dried weight | Printed on the Wood Database page as Average Dried Weight, with 32 lbs/ft3 shown alongside | basis average dried weight as printed in the species data tablemoisture no moisture condition stated on the page | — |
| 2 | Modulus of rupture (bending strength) | Printed on the Wood Database species page under Physical and mechanical properties | basis value as printed on the Wood Database page, shown with 12,500 lbf/in2moisture no moisture condition stated on the page | — |
| 3 | Elastic modulus | Printed on the Wood Database species page under Physical and mechanical properties | basis value as printed on the Wood Database page, shown with 1,765,000 lbf/in2moisture no moisture condition stated on the page | — |
| 4 | Crushing strength (compression parallel to grain) | Printed on the Wood Database species page as Crushing Strength | basis value as printed on the Wood Database page, shown with 6,950 lbf/in2moisture no moisture condition stated on the page | — |
| 5 | Janka hardness | Printed on the Wood Database species page as Janka Hardness | basis Janka hardness as printed, shown on the page as 620 lbfmoisture no moisture condition stated on the page | — |
| 6 | Radial shrinkage | Printed on the Wood Database species page under Shrinkage | basis shrinkage as printed; no condition stated on the page | — |
| 7 | Tangential shrinkage | Printed on the Wood Database species page under Shrinkage | basis shrinkage as printed; no condition stated on the page | — |
| 8 | Volumetric shrinkage | Printed on the Wood Database species page under Shrinkage | basis shrinkage as printed; no condition stated on the page | — |
| 9 | Density, four Douglas-fir regions (range) | Range printed in the Wood, Panel and Structural Timber Products table | moisture 12% moisture content (table note: values for wood with 12% moisture content)basis Douglas-fir Coast, Interior West, Interior North and Interior South printed as one range | — |
| 10 | Fibre stress at elastic limit (modulus of rupture) | Range printed in the Wood, Panel and Structural Timber Products table; the column is headed Fibre Stress at Elastic Limit (Modulus of Rupture) | moisture 12% moisture content (table note)basis Douglas-fir Coast, Interior West, Interior North and Interior South printed as one range | — |
| 11 | Modulus of elasticity (range) | Range printed in the Wood, Panel and Structural Timber Products table | moisture 12% moisture content (table note)basis Douglas-fir regions printed as one range | — |
| 12 | Compressive strength parallel to grain (range) | Range printed in the Wood, Panel and Structural Timber Products table | moisture 12% moisture content (table note)basis Douglas-fir regions printed as one range | — |
| 13 | Shear strength parallel to grain (range) | Range printed in the Wood, Panel and Structural Timber Products table | moisture 12% moisture content (table note)basis Douglas-fir regions printed as one range | — |
| 14 | Modulus of rupture, Coast Douglas-fir | Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line | moisture 12%basis clear wood, Coast Douglas-fir (Oregon and Washington west of the Cascade summit), as printed in the metric table | — |
| 15 | Modulus of elasticity, Coast Douglas-fir | Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line | moisture 12%basis clear wood, Coast Douglas-fir, as printed in the metric table | — |
| 16 | Compression parallel to grain, Coast Douglas-fir | Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line | moisture 12%basis clear wood, Coast Douglas-fir, as printed in the metric table; the table footnote calls compression parallel to grain the maximum crushing strength | — |
| 17 | Shear strength parallel to grain, Coast Douglas-fir | Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line | moisture 12%basis clear wood, Coast Douglas-fir, as printed in the metric table | — |
| 18 | Specific gravity, Coast Douglas-fir | Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line | moisture 12%basis table footnote: specific gravity is based on ovendry weight and volume at 12% moisture content | — |
Corrosion and compatibility
What happens when it meets other materials and environments.
| Environment | Concern | What happens |
|---|---|---|
| Damp service where decay fungi and wood-boring insects are present | moderate | Heartwood is moderately durable against decay but susceptible to insect attack.1 |
| # | Environment | Details | Test conditions |
|---|---|---|---|
| 1 | Damp service where decay fungi and wood-boring insects are present | The Wood Database rates Douglas-fir heartwood as moderately durable in regard to decay, but susceptible to insect attack. The page gives no exposure time or test method for this rating. | basis rating as printed on the species page; no exposure test described |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The reported hazards are irritation from dust and splinters, and wood dust is classed as a cancer hazard in occupational exposure.
- Dust
- The Wood Database allergy chart says all inhaled wood dust is hazardous to long-term health. IARC Volume 62 (1995) links occupational wood dust exposure to cancer of the nasal cavities and paranasal sinuses.
- Skin and splinters
- The Wood Database reports skin irritation for Douglas-fir, and says splinters are more likely to become infected. Severe reactions are described as quite uncommon.
- Odour
- The wood has a distinct resinous odour when worked.
If the wood is wet or infested
Douglas-fir heartwood is rated moderately durable against decay and susceptible to insect attack.
- Damp service
- Moisture with decay fungi or wood-boring insects is the main threat to the wood. The Wood Database rates the heartwood moderately durable, which gives no exposure time.
- Splitting
- The FAA says Douglas Fir has some tendency to split and splinter during fabrication, and large solid pieces are hard to inspect.
Test details
The original wording and numbers from the sources, for readers who want them.
Failure risks
| Failure | Trigger and consequence |
|---|---|
| Decay and insect attack in damp servicemoderate severity | Moisture in service together with decay fungi or wood-boring insectsLoss of strength and service life; the sources we hold give no rate of loss |
| Splitting and splintering during fabricationlow severity | Hand-working or machining Douglas-fir stockSplit and splintered parts; the FAA notes large solid pieces are hard to inspect and should be avoided |
Side effects on surrounding parts
| Affects | Effect |
|---|---|
| People working the wood | The wood has a distinct resinous odour when it is worked. |
Handling and storage
- Wood Database allergy page: all woods produce fine dust when worked, so keep dust down when cutting or sanding.
- FAA AC 43.13-1B: Douglas Fir is difficult to work with hand tools and gluing is satisfactory.
Supply and geography
How common the raw materials are and where they come from.
Douglas-fir timber (wood feedstock)
- Recycling
- No recycling figure for Douglas-fir timber was found in the sources we hold.
- Substitutes
- FAA AC 43.13-1B: Douglas Fir may be used as a substitute for spruce in the same sizes or in slightly reduced sizes, providing the reductions are substantiated.
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
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spore: profile
id: douglas-fir
spore_version: '0.2'
family: wood
name: Douglas fir (Pseudotsuga menziesii)
abbreviation: Douglas fir
role: Softwood conifer timber used for construction lumber, plywood and light aircraft wood structure
category: living
type: bio-grown-building-materials
summary: |
Douglas fir (Pseudotsuga menziesii) is a softwood conifer from western North America. At 12% moisture content, Engineering ToolBox gives a density of 460 to 500 kg/m3 for Douglas-fir, and the USDA Wood Handbook gives a modulus of rupture of 85000 kPa for Coast Douglas-fir. Its strength and density vary by growth region, so the figures in this profile are kept side by side rather than merged.
best_for: Structural construction lumber and plywood where a light-to-medium softwood with a strength close to spruce is needed
weakest_at: Moderate decay resistance in damp service, and it is hard to work with hand tools (FAA)
identity:
formula: 'Wood of Pseudotsuga menziesii: cellulose, lignin and hemicelluloses in a cellular structure'
source: vt-dendro
where: 'Title line: Pseudotsuga menziesii (Mirb.) Franco, family Pinaceae; common names list Douglas-fir'
tags:
applications:
- structures
properties:
- benchmark: density
label: Average dried weight
value: 510
unit: kg/m3
scope: material
conditions:
basis: average dried weight as printed in the species data table
moisture: no moisture condition stated on the page
method: Printed on the Wood Database page as Average Dried Weight, with 32 lbs/ft3 shown alongside
status: ground
source: wood-database
where: Species data table, Average Dried Weight row
- benchmark: flexural_strength
label: Modulus of rupture (bending strength)
value: 86.2
unit: MPa
scope: material
conditions:
basis: value as printed on the Wood Database page, shown with 12,500 lbf/in2
moisture: no moisture condition stated on the page
method: Printed on the Wood Database species page under Physical and mechanical properties
status: ground
source: wood-database
where: Physical and mechanical properties, Modulus of Rupture
- benchmark: elastic_modulus
label: Elastic modulus
value: 12.17
unit: GPa
scope: material
conditions:
basis: value as printed on the Wood Database page, shown with 1,765,000 lbf/in2
moisture: no moisture condition stated on the page
method: Printed on the Wood Database species page under Physical and mechanical properties
status: ground
source: wood-database
where: Physical and mechanical properties, Elastic Modulus
- benchmark: crushing_strength
label: Crushing strength (compression parallel to grain)
value: 47.9
unit: MPa
scope: material
conditions:
basis: value as printed on the Wood Database page, shown with 6,950 lbf/in2
moisture: no moisture condition stated on the page
method: Printed on the Wood Database species page as Crushing Strength
status: ground
source: wood-database
where: Physical and mechanical properties, Crushing Strength
- benchmark: janka_hardness
label: Janka hardness
value: 2760
unit: 'N'
scope: material
conditions:
basis: Janka hardness as printed, shown on the page as 620 lbf
moisture: no moisture condition stated on the page
method: Printed on the Wood Database species page as Janka Hardness
status: ground
source: wood-database
where: Physical and mechanical properties, Janka Hardness
- benchmark: shrinkage_radial
label: Radial shrinkage
value: 4.5
unit: '%'
scope: material
conditions:
basis: shrinkage as printed; no condition stated on the page
method: Printed on the Wood Database species page under Shrinkage
status: ground
source: wood-database
where: Physical and mechanical properties, Shrinkage (Radial)
- benchmark: shrinkage_tangential
label: Tangential shrinkage
value: 7.3
unit: '%'
scope: material
conditions:
basis: shrinkage as printed; no condition stated on the page
method: Printed on the Wood Database species page under Shrinkage
status: ground
source: wood-database
where: Physical and mechanical properties, Shrinkage (Tangential)
- benchmark: shrinkage_volumetric
label: Volumetric shrinkage
value: 11.6
unit: '%'
scope: material
conditions:
basis: shrinkage as printed; no condition stated on the page
method: Printed on the Wood Database species page under Shrinkage
status: ground
source: wood-database
where: Physical and mechanical properties, Shrinkage (Volumetric)
- benchmark: density
label: Density, four Douglas-fir regions (range)
value: 460
value_high: 500
bound: range
unit: kg/m3
scope: material
conditions:
moisture: '12% moisture content (table note: values for wood with 12% moisture content)'
basis: Douglas-fir Coast, Interior West, Interior North and Interior South printed as one range
method: Range printed in the Wood, Panel and Structural Timber Products table
status: ground
source: et-timber
where: Clear Wood table, Douglas-fir row, Density column
- benchmark: flexural_strength
label: Fibre stress at elastic limit (modulus of rupture)
value: 82
value_high: 90
bound: range
unit: MPa
scope: material
conditions:
moisture: 12% moisture content (table note)
basis: Douglas-fir Coast, Interior West, Interior North and Interior South printed as one range
method: Range printed in the Wood, Panel and Structural Timber Products table; the column is headed Fibre Stress at Elastic Limit (Modulus of Rupture)
status: ground
source: et-timber
where: Clear Wood table, Douglas-fir row, Fibre Stress column
- benchmark: elastic_modulus
label: Modulus of elasticity (range)
value: 10.3
value_high: 13.4
bound: range
unit: GPa
scope: material
conditions:
moisture: 12% moisture content (table note)
basis: Douglas-fir regions printed as one range
method: Range printed in the Wood, Panel and Structural Timber Products table
status: ground
source: et-timber
where: Clear Wood table, Douglas-fir row, Modulus of Elasticity column
- benchmark: compressive_strength_parallel_to_grain
label: Compressive strength parallel to grain (range)
value: 43.1
value_high: 51.2
bound: range
unit: MPa
scope: material
conditions:
moisture: 12% moisture content (table note)
basis: Douglas-fir regions printed as one range
method: Range printed in the Wood, Panel and Structural Timber Products table
status: ground
source: et-timber
where: Clear Wood table, Douglas-fir row, Compressive Strength parallel to Grain column
- benchmark: shear_strength_parallel_to_grain
label: Shear strength parallel to grain (range)
value: 7.8
value_high: 10.4
bound: range
unit: MPa
scope: material
conditions:
moisture: 12% moisture content (table note)
basis: Douglas-fir regions printed as one range
method: Range printed in the Wood, Panel and Structural Timber Products table
status: ground
source: et-timber
where: Clear Wood table, Douglas-fir row, Shear Strength parallel to grain column
- benchmark: density
label: Density, seasoned and dry wood
value: 530
unit: kg/m3
scope: material
conditions:
moisture: seasoned and dry wood (page wording)
basis: single Douglas Fir value in the species table
method: Printed in the Wood Species Densities table
status: ground
source: et-density
where: Wood Species - Densities table, Douglas Fir row
- benchmark: flexural_strength
label: Modulus of rupture, Coast Douglas-fir
value: 85000
unit: kPa
scope: material
conditions:
moisture: 12%
basis: clear wood, Coast Douglas-fir (Oregon and Washington west of the Cascade summit), as printed in the metric table
method: Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line
status: ground
source: wh2010
where: Table 5-3a (metric), Douglas-fir Coast, 12% row, modulus of rupture column
- benchmark: elastic_modulus
label: Modulus of elasticity, Coast Douglas-fir
value: 13400
unit: MPa
scope: material
conditions:
moisture: 12%
basis: clear wood, Coast Douglas-fir, as printed in the metric table
method: Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line
status: ground
source: wh2010
where: Table 5-3a (metric), Douglas-fir Coast, 12% row, modulus of elasticity column
- benchmark: compressive_strength_parallel_to_grain
label: Compression parallel to grain, Coast Douglas-fir
value: 49900
unit: kPa
scope: material
conditions:
moisture: 12%
basis: clear wood, Coast Douglas-fir, as printed in the metric table; the table footnote calls compression parallel to grain the maximum crushing strength
method: Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line
status: ground
source: wh2010
where: Table 5-3a (metric), Douglas-fir Coast, 12% row, compression parallel to grain column
- benchmark: shear_strength_parallel_to_grain
label: Shear strength parallel to grain, Coast Douglas-fir
value: 7800
unit: kPa
scope: material
conditions:
moisture: 12%
basis: clear wood, Coast Douglas-fir, as printed in the metric table
method: Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line
status: ground
source: wh2010
where: Table 5-3a (metric), Douglas-fir Coast, 12% row, shear parallel to grain column
- benchmark: specific_gravity
label: Specific gravity, Coast Douglas-fir
value: 0.48
unit: '-'
scope: material
conditions:
moisture: 12%
basis: 'table footnote: specific gravity is based on ovendry weight and volume at 12% moisture content'
method: Printed in the Wood Handbook metric strength table, Douglas-fir Coast row, 12% moisture content line
status: ground
source: wh2010
where: Table 5-3a (metric), Douglas-fir Coast, 12% row, specific gravity column
corrosion:
- environment: Damp service where decay fungi and wood-boring insects are present
headline: Heartwood is moderately durable against decay but susceptible to insect attack.
effect: The Wood Database rates Douglas-fir heartwood as moderately durable in regard to decay, but susceptible to insect attack. The page gives no exposure time or test method for this rating.
rating: moderate
conditions:
basis: rating as printed on the species page; no exposure test described
source: wood-database
where: Decay and durability, Rot Resistance
risks:
hazards:
- text: 'Wood Database: Douglas-fir has been reported to cause skin irritation, nausea, giddiness and a runny nose, and splinters are more likely to become infected. Severe reactions are described as quite uncommon.'
ghs: []
source: wood-database
where: Allergies/Toxicity
- text: 'Wood Database allergy chart: Douglas-fir is listed as an irritant, with giddiness, runny nose, splinters going septic and nausea. The chart also states that all inhaled wood dust is hazardous to long-term health.'
ghs: []
source: wood-allergies
where: Allergy and toxicity chart, Douglas-fir row, and the introduction text above it
- text: IARC Monographs Volume 62 (1995) states that occupational exposure to wood dust is causally related to adenocarcinoma of the nasal cavities and paranasal sinuses. The classification applies to wood dust in general, not to Douglas-fir alone.
ghs: []
source: iarc-v62
where: Classification statement on the monograph page
failure_risks:
- mode: Decay and insect attack in damp service
trigger: Moisture in service together with decay fungi or wood-boring insects
consequence: Loss of strength and service life; the sources we hold give no rate of loss
severity: moderate
source: wood-database
where: Rot Resistance
- mode: Splitting and splintering during fabrication
trigger: Hand-working or machining Douglas-fir stock
consequence: Split and splintered parts; the FAA notes large solid pieces are hard to inspect and should be avoided
severity: low
source: faa-ac43-13
where: Table 1-1, Remarks column
side_effects:
- text: The wood has a distinct resinous odour when it is worked.
affects: People working the wood
source: wood-database
where: Odor
handling:
- text: 'Wood Database allergy page: all woods produce fine dust when worked, so keep dust down when cutting or sanding.'
source: wood-allergies
where: Paragraph after the allergy chart introduction
- text: 'FAA AC 43.13-1B: Douglas Fir is difficult to work with hand tools and gluing is satisfactory.'
source: faa-ac43-13
where: Table 1-1, Remarks column
mitigations: []
uses:
- application: structures
device: Construction lumber, plywood, piles and engineered wood composites
example: Douglas-fir is used mostly for building and construction purposes in the form of lumber, marine fendering, piles, plywood, and engineered wood composites.
source: wh2010
where: Chapter 2, Species Descriptions, Douglas-fir paragraph
- application: structures
device: Aircraft wood structure, as a substitute for spruce
example: Douglas Fir exceeds spruce in strength; it may be used as a substitute for spruce in the same sizes or in slightly reduced sizes, providing the reductions are substantiated.
source: faa-ac43-13
where: Table 1-1, Douglas Fir row (printed as Pseudotsuga Taxifolia)
- application: structures
device: Railroad crossties, poles, mine timbers and fencing
example: Considerable quantities are used for railroad crossties, cooperage stock, mine timbers, poles, and fencing.
source: wh2010
where: Chapter 2, Species Descriptions, Douglas-fir paragraph
supply:
- subject: Douglas-fir timber (wood feedstock)
producers: []
critical_lists: []
recycling: No recycling figure for Douglas-fir timber was found in the sources we hold.
substitutes:
- 'FAA AC 43.13-1B: Douglas Fir may be used as a substitute for spruce in the same sizes or in slightly reduced sizes, providing the reductions are substantiated.'
source: vt-dendro
where: 'Distribution paragraph: range from the Rocky Mountains to the Pacific coast and from Mexico to central British Columbia; production from the coast states of Oregon, Washington and California and the Rocky Mountain states'
media: []
documents:
- title: 'Wood Database: Douglas Fir (softwood species profile)'
type: database
url: https://www.wood-database.com/douglas-fir/
- title: 'Wood Handbook: Wood as an Engineering Material (FPL-GTR-190, 2010), copy hosted by California Air Resources Board'
type: report
url: https://ww2.arb.ca.gov/sites/default/files/barcu/regact/2014/capandtradeprf14/usfswoodhandbook2010.pdf
year: 2010
- title: FAA Advisory Circular AC 43.13-1B, Chapter 1 (copy hosted by RAANZ)
type: standard
url: https://raanz.org.nz/techproject/FAA%20AC43.13%20b/Chapter%2001.pdf
year: 1998
- title: 'IARC Monographs Volume 62: Wood Dust and Formaldehyde'
type: report
url: https://publications.iarc.who.int/80
year: 1995
gaps:
- No ageing or weathering data for Douglas-fir (greying, UV, moisture cycling) were found in a source we could open; the one search returned only other species.
- No country-level production shares or current production volumes for Douglas-fir were found, so the supply entry lists feedstock regions only.
- No flight, vacuum, radiation or thermal-cycling data for Douglas-fir were found, and no space application source was found.
- Specific gravity of the other Douglas-fir regions was not recorded, because the Wood Database gives two unlabelled values (0.45, 0.51) and the Wood Handbook regions were not matched to them.
- Shrinkage values in the Wood Handbook Table 4-3 are printed without an explicit unit on the page, so they were left out; the Wood Database shrinkage percentages are recorded instead.
- Thermal conductivity, Poisson's ratio and fatigue strength for Douglas-fir were not recorded from a source we could open.
- Moisture effects away from 12% moisture content were not recorded from a source we could open.
- Combustion and fire behaviour for Douglas-fir were not found in a source we could open.
- No UNS, EN or other standard grade designation applies to Douglas-fir timber, so none is listed.
sources:
wood-database:
title: Douglas Fir, Wood Database (softwood species profile)
id: Wood Database, Douglas fir page
url: https://www.wood-database.com/douglas-fir/
kind: database
license: cited, not reproduced
wood-allergies:
title: Wood Allergies and Toxicity, Wood Database
id: Wood Database allergy and toxicity chart
url: https://www.wood-database.com/wood-allergies-and-toxicity/
kind: web
license: cited, not reproduced
et-timber:
title: Wood, Panel and Structural Timber Products - Mechanical Properties (Engineering ToolBox)
id: Engineering ToolBox, Clear Wood table
url: https://www.engineeringtoolbox.com/timber-mechanical-properties-d_1789.html
kind: web
license: cited, not reproduced
et-density:
title: Density of Wood Species (Engineering ToolBox)
id: Engineering ToolBox, Wood Species - Densities table
url: https://www.engineeringtoolbox.com/wood-density-d_40.html
kind: web
license: cited, not reproduced
wh2010:
title: 'Wood Handbook: Wood as an Engineering Material, General Technical Report FPL-GTR-190 (2010 edition)'
id: USDA Forest Service Forest Products Laboratory, FPL-GTR-190
url: https://ww2.arb.ca.gov/sites/default/files/barcu/regact/2014/capandtradeprf14/usfswoodhandbook2010.pdf
year: 2010
kind: report
license: US government publication
vt-dendro:
title: Pseudotsuga menziesii (Mirb.) Franco, Douglas-fir wood technology sheet (Virginia Tech Dendrology)
id: Virginia Tech Dendrology, woodtech sheet
url: https://dendro.cnre.vt.edu/DENDROLOGY/woodtech/pseudotsuga_menziesii.pdf
kind: report
license: cited, not reproduced
faa-ac43-13:
title: 'FAA Advisory Circular AC 43.13-1B, Chapter 1, Table 1-1: Selection and Properties of Aircraft Wood'
id: AC 43.13-1B, dated 9/8/98
url: https://raanz.org.nz/techproject/FAA%20AC43.13%20b/Chapter%2001.pdf
year: 1998
kind: standard
license: US government publication
iarc-v62:
title: 'IARC Monographs Volume 62: Wood Dust and Formaldehyde (1995)'
id: IARC Monographs Volume 62
url: https://publications.iarc.who.int/80
year: 1995
kind: report
license: IARC, cited
license: CC-BY-4.0
updated: '2026-11-02'
review:
status: draft
method: assistant
checked_values: 19
unreachable: 0
caveats: 2
note: Read by an AI assistant on 2026-11-02 from the cited pages and PDFs. Regional values are kept separate; the Wood Database averages are not merged with the regional tables.
story:
recipe:
line: Douglas-fir is wood, not a single compound. Its cell walls are built from cellulose, lignin and hemicelluloses, arranged in a cellular structure. The Wood Handbook gives this composition for all wood.
parts:
- name: Cellulose
role: Long fibres that give the cell walls their tensile strength.
source: wh2010
where: Chapter 1, composition sentence
- name: Lignin
role: Binds the cellulose fibres together and stiffens the cell walls.
source: wh2010
where: Chapter 1, composition sentence
- name: Hemicelluloses
role: Matrix material between the cellulose fibres.
source: wh2010
where: Chapter 1, composition sentence
- name: Cellular structure
role: The hollow cells whose size and arrangement, with the component proportions, make a wood heavy or light, stiff or flexible, and hard or soft.
source: wh2010
where: Chapter 1, composition sentence
risk_groups:
- title: For people
level: 1
verdict: Dust and splinters are the reported hazards
lead: The reported hazards are irritation from dust and splinters, and wood dust is classed as a cancer hazard in occupational exposure.
points:
- label: Dust
line: The Wood Database allergy chart says all inhaled wood dust is hazardous to long-term health. IARC Volume 62 (1995) links occupational wood dust exposure to cancer of the nasal cavities and paranasal sinuses.
- label: Skin and splinters
line: The Wood Database reports skin irritation for Douglas-fir, and says splinters are more likely to become infected. Severe reactions are described as quite uncommon.
- label: Odour
line: The wood has a distinct resinous odour when worked.
- title: If the wood is wet or infested
level: 2
verdict: Moderately durable against decay; susceptible to insects
lead: Douglas-fir heartwood is rated moderately durable against decay and susceptible to insect attack.
points:
- label: Damp service
line: Moisture with decay fungi or wood-boring insects is the main threat to the wood. The Wood Database rates the heartwood moderately durable, which gives no exposure time.
- label: Splitting
line: The FAA says Douglas Fir has some tendency to split and splinter during fabrication, and large solid pieces are hard to inspect.
why: 'Douglas fir (Pseudotsuga menziesii) is a softwood from western North America. The Wood Handbook says it is used mostly for building and construction, and the FAA says it may be used as a substitute for spruce in some aircraft wood structures. It is in this collection as a structural timber benchmark, not as a space material: we found no flight data and no space-environment source for it.'
uses:
- where: Building and construction
line: The Wood Handbook says Douglas-fir is used mostly for building and construction, as lumber, marine fendering, piles, plywood and engineered wood composites.
- where: Aircraft wood structure
line: FAA AC 43.13-1B Table 1-1 says Douglas Fir exceeds spruce in strength. It says the species may be used as a substitute for spruce in the same sizes, or in slightly reduced sizes, if the reductions are substantiated. The table prints the older name Pseudotsuga taxifolia.
- where: Railroad ties, poles and fencing
line: The Wood Handbook says considerable quantities are used for railroad crossties, cooperage stock, mine timbers, poles and fencing.
can_do:
- label: Density
benchmark: density
line: Engineering ToolBox gives 460 to 500 kg/m3 at 12% moisture content for the Douglas-fir regions. A separate table gives 530 kg/m3 for seasoned and dry wood, and the Wood Database gives 510 kg/m3 as average dried weight. The three figures use different moisture conditions, so they are shown side by side.
- label: Bending strength
benchmark: flexural_strength
line: At 12% moisture content, Engineering ToolBox gives 82 to 90 MPa for fibre stress at elastic limit. The Wood Handbook gives 85000 kPa for Coast Douglas-fir, and the Wood Database gives 86.2 MPa modulus of rupture without a moisture condition.
- label: Stiffness
benchmark: elastic_modulus
line: The Wood Handbook gives 13400 MPa modulus of elasticity for Coast Douglas-fir at 12% moisture content, and Engineering ToolBox gives a range of 10.3 to 13.4 GPa across the regions.
- label: Hardness
benchmark: janka_hardness
line: The Wood Database gives a Janka hardness of 2,760 N for Douglas-fir.
- label: Compression and shear
benchmark: compressive_strength_parallel_to_grain
line: At 12% moisture content, the Wood Handbook gives 49900 kPa compression parallel to grain for Coast Douglas-fir and 7800 kPa shear parallel to grain. Engineering ToolBox gives 43.1 to 51.2 MPa and 7.8 to 10.4 MPa across the regions.
compare: Against spruce, the FAA table says Douglas Fir exceeds spruce in strength, but it is harder to work with hand tools and splits more readily. The sources give Douglas-fir values at different moisture contents and test regions, so this profile does not rank Douglas-fir numerically against other timbers. The compare rows below use the 12% moisture values from the regional tables.
compare_rows:
- label: Density at 12% moisture
benchmark: density
- label: Bending strength
benchmark: flexural_strength
- label: Stiffness
benchmark: elastic_modulus
handling:
- Keep dust down when cutting or sanding. The Wood Database allergy page says all woods produce fine dust when worked.
- Douglas-fir splits and splinters during fabrication, and it is hard to work with hand tools, according to the FAA.
- Keep the wood dry where you can. Decay is the main risk in damp service, and the heartwood is only moderately durable.
good_for:
- Construction lumber, plywood and piles, where a strong softwood is needed (Wood Handbook).
- Aircraft wood structure, where the FAA allows Douglas Fir as a spruce substitute if the reductions are substantiated.
watch_out:
- Moderate decay resistance and susceptibility to insect attack in damp service.
- Splitting and splintering when worked, with large solid pieces hard to inspect.
- Dust from the wood is a reported health hazard, and IARC classifies wood dust as carcinogenic to humans.
verdict: A strong, widely used structural softwood. Keep it dry and control its dust and splinters.
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| Douglas Fir, Wood Database (softwood species profile) | database | 12 values | ||
| Wood Allergies and Toxicity, Wood Database | web | 2 values | ||
| Wood, Panel and Structural Timber Products - Mechanical Properties (Engineering ToolBox) | web | 5 values | ||
| Density of Wood Species (Engineering ToolBox) | web | 1 value | ||
| Wood Handbook: Wood as an Engineering Material, General Technical Report FPL-GTR-190 (2010 edition) | report | 2010 | 7 values | |
| Pseudotsuga menziesii (Mirb.) Franco, Douglas-fir wood technology sheet (Virginia Tech Dendrology) | report | 2 values | ||
| FAA Advisory Circular AC 43.13-1B, Chapter 1, Table 1-1: Selection and Properties of Aircraft Wood | standard | 1998 | 3 values | |
| IARC Monographs Volume 62: Wood Dust and Formaldehyde (1995) | report | 1995 | 1 value |
Updated