Hemlock, Western

Home » Hemlock, Western

Western hemlock is a valuable tree with many commercial uses. It is often marketed as Hem-fir, as it has similar design values to the true firs: California red, grand fir, noble fir, Pacific silver fir and white fir. It is one of ten hemlock species and is considered a premium timber.

 

Western hemlock is an evergreen tree from North America. It grows prolifically from the coastline of northern Sonoma County, California, north to the Kenai Peninsula, Alaska and east to Idaho and Montana, and is widely harvested in these regions.

Growing from 30 to 50 metres tall, trees are characterised by small oval cones and flat, short needles. Their cinnamon coloured bark is furrowed and attractive.

The timber is used in construction but as a softwood is not durable and requires treatment for external use. External and interior construction applications include joinery, cabinetry, flooring, and ceilings. It also is a popular choice for creating doors, windows, parts of staircases, ladders, flooring, paneling, broom handles, crates, pallets and packing cases as well as other architectural millwork items.

Western hemlock is one of the best pulp woods for paper and paperboard products. Traditionally, however, Indigenous artisans used the easily worked timber for carving into spoons, combs, roasting spits and giant feast dishes.

In agro-forestry, western hemlock is used to help reduce stream bank erosion, and increase biodiversity. It has been used to produce dimethyl sulfide, the substance that gives an odour to natural gas, which could otherwise go undetected; and conidendrol, produced from Hemlock wastes, which slows oxidation.

 

Appearance

Timber of the western hemlock has a natural lustre. The tree's heartwood has a pale, cream colour with distinctive growth marks and a fairly even texture. This beautiful pale timber produces few knots and displays a uniform, attractive grain. Sometimes western hemlock can display a slight lavender cast, especially around the knots and in the transition area between the spring and summerwood growth rings. Attractive, delicate, dark grey or black streaks may be apparent in the wood. There is little variation in colour between the heartwood and sapwood, and they are often indistinguishable from one another.

 

Common Applications

Western hemlock timber is used in construction but is not recommended for external use without treatment. Preservative pressure-treated timber products are both visually appealing and strong, and among the more economical species for decks and other outdoor amenities. Internal uses include joinery and cabinetry. 

Some timbers of this species are fine grained and even textured, lending themselves to attractive wood paneling and trims, windows, parts of staircases, and flooring. Handsome solid wood doors, louvers, shutters, moulding and furniture can all be manufactured from Western Hemlock.

The timber has been used to make broom handles, and case goods such as crates, pallets and packing cases and other architectural millwork items. It is one of the best pulp woods for paper and paperboard products.

Lower-grade knotty products are useful for those utilitarian applications in construction where economy governs, such as stud walls.

Common Form

Sawn

Workability

Light in weight and straight in grain, western hemlock's workability has been compared to that of pine, although it does weigh 480kg/cubic metre when seasoned. Builders favour this species because it is resistant to splitting, holds nails and screws securely and saws easily without splintering.

 

The initially high moisture content of western hemlock demands careful drying to avoid surface checking and ensure uniform drying in thick stock.

The wood has an even grain and resists scraping, which makes it easy to machine. Western hemlock timber has a moderate steam-bending rating and works well with both hand and machine tools with little dulling of cutting edges. This timber has medium bending and crushing strength. It is not hard or stiff, giving it low durability. Timber of this species can be easily glued, stained, painted or varnished.

 

Origin of Timber

North America

Readily Available

NSW

Availability - Further Information

Western hemlock has limited availability in all states except Queensland, Victoria and New South Wales, where it is common.

Availability - Further Information

Native Forest

Shrinkage

Very Low Low Medium High Very High

Tangential :

4.90%

Radial:

2.50%

Unit Movement Tangential:

0.27%

Unit Movement Radial:

0.14%

Strength Group

Very High

High

Reasonably High

Medium High

Medium

Reasonably Low

Low

Very Low

Unseasoned:

S1

S2

S3

S4

S5

S6

S7

Seasoned:

SD1

SD2

SD3

SD4

SD5

SD6

SD7

SD8

Stress Grade

Structural
No. 1
Structural
No. 2
Structural
No. 3
Structural
No. 4
Structural
No. 5

Unseasoned:

F8

F7

F5

F4

Seasoned:

F14

F11

F8

F7

F5

Density per Standard

Seasoned:

505kg/m3

Unseasoned:

780kg/m3

Joint Group

Very High

High

Reasonably High

Medium

Low

Very Low

Unseasoned:

J1

J2

J3

J4

J5

J6

Seasoned:

JD1

JD2

JD3

JD4

JD5

JD6

Colour

  White, yellow, pale straw to light brown Pink to pink brown Light to dark red Brown, chocolate, mottled or streaky
   

Mechanical Properties

Modulus of Rupture - Unseasoned:

46

Modulus of Rupture - Seasoned:

78

Modulus of Elasticity - Unseasoned:

9

Modulus of Elasticity - Seasoned:

11.3

Maximum Crushing Strength - Unseasoned:

23

Maximum Crushing Strength - Seasoned:

49

Impact - Unseasoned:

Impact - Seasoned:

Toughness - Unseasoned:

Low - up to 15 Nm

Toughness - Seasoned:

Low - up to 15 Nm

Hardness - Unseasoned:

1.8

Hardness - Seasoned:

2.4

Durability

Low Moderate Reasonably High High
(0 - 5 yrs) (5 - 15 yrs) (15 - 25 yrs) (more than 25 yrs)

In-Ground:

(0 - 7 yrs) (7 - 15 yrs) (15 - 40 yrs) (More than 40 yrs)

Above ground:

(0 - 20 yrs, usually < 5) (21 - 40 yrs) (41 - 64 yrs) (More than 60 yrs)

Marine Borer Resistance:

Lyctid Borer Susceptibility:

Not Susceptible

Lyctid Borer Susceptibility - Other:

Termite Resistance:

Not Resistant

Fire Properties

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

EFH Ignitibility:

0 1 2 3 4 5 6 7 8 9 10

EFH Spread-of-Flame Index:

EFH Smoke-Developed Index:

1 - non-combustible 2 - reasonably non-combustible 3 - slightly combustible 4 - combustible

Fire Properties Group
Number:

Group Number - Other:

3 if used on MDF or particleboard ≥12mm; veneer thickness 0.6-0.85mm

Average Specific Extinction Area:

<250

Bushfire Resistance:

Not Tested

Are you looking for a supplier?