Cedar, Western Red

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Western red cedar is a large softwood that grows in British Columbia and some of the nearby western states of the USA including Washington, Oregon, Montana and Idaho.

Western red cedar will remain dimensionally stable under most weather conditions and is not prone to shrinkage or swelling. Due to its versatility, it can be used for both internal and external applications such as cladding, linings, joinery, windows and roofing shingles. Natural preservatives provide resistance to fungus and insect attack, while its low density offers very good thermal insulation qualities. Western red cedar also delivers impressive acoustic properties.

Visually, western red cedar is favoured for its rich and inviting colours. The heartwood ranges from a pale brown through to a richer dark brown. The sapwood is a paler yellowish white colour. It has a fine texture and straight grain with growth rings often visible.

A durable, yet soft timber, western red cedar has a good workability. It cuts, machines and glues well and can also be painted, stained and polished. Precautions should be taken when sanding western red cedar as the sawdust can cause irritation for some people.

It nails and screws well, however if timber is damp it is corrosive to iron and copper, so hot-dipped galvanised nails/screws should be used where required, and any copper plumbing, fittings or sheathing isolated from contact with the wood.

Western red cedar can be brittle along the end grain and sharp cutters are recommended due to its soft nature. It is not suitable for steam bending.

Western red cedar is commonly available with significant quantities being imported into Australia.

Appearance

Western red cedar is favoured for its rich and inviting earthy tones. The true beauty of this durable softwood is most evident when used for appearance based applications such as external cladding and windows. The heartwood ranges from a pale brown or honey colour through to a richer dark brown, with older growth timber somewhat darker in appearance. The sapwood is a paler yellowish white colour. It has a fine texture and straight grain with growth rings often visible.

Common Applications

Western red cedar is used for applications such as cladding, linings, joinery, windows, doors and roofing shingles. Natural preservatives provide resistance to fungus and insect attack, while its low density also provides good insulation qualities. It can be used in many types of weather conditions due to its natural durability.

Common Form

Sawn

Workability

A durable yet soft timber, western red cedar has good workability. It cuts, machines and glues well and can also be painted, stained and polished. It also nails and screws well, however if timber is damp it is corrosive to iron, so hot-dipped galvanized nails/screws should be used where required.

Western red cedar can be brittle along the end grain and sharp cutters are recommended due to its soft nature. Precautions should be taken when sanding western red cedar as the sawdust can cause irritation for some people. It is not suitable for steam bending.

Origin of Timber

North America

Readily Available

NSW

Availability - Further Information

Western red cedar is commonly available with significant quantities being imported into Australia.

Availability - Further Information

Native Forest

Shrinkage

Very Low Low Medium High Very High

Tangential :

2.30%

Radial:

1.10%

Unit Movement Tangential:

0.23%

Unit Movement Radial:

0.11%

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:

F7

F5

F4

Seasoned:

F8

F7

F5

F4

Density per Standard

Seasoned:

350kg/m3

Unseasoned:

490kg/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:

31-39 (35.9)

Modulus of Rupture - Seasoned:

49-55 (51.7)

Modulus of Elasticity - Unseasoned:

6.3-6.9 (6.5)

Modulus of Elasticity - Seasoned:

6.95-7.7 (7.7)

Maximum Crushing Strength - Unseasoned:

15.5-19.3 (19.1)

Maximum Crushing Strength - Seasoned:

34.6-38.6 (31.4)

Impact - Unseasoned:

Impact - Seasoned:

Toughness - Unseasoned:

Low - up to 15 Nm

Toughness - Seasoned:

Low - up to 15 Nm

Hardness - Unseasoned:

<1.75 (1.2)

Hardness - Seasoned:

<1.75 (1.6)

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:

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:

Average Specific Extinction Area:

<250

Bushfire Resistance:

Not Tested

Shingles and Shakes

Timber shingles and shakes provide eye-catching and practical forms of timber cladding for roofs and walls, on domestic and commercial structures around the world. Most shingles and shakes used in Australia are made from western red cedar and are imported from Canada. Some are also produced locally from species such as rose sheoak and hardwoods.

A shingle, generated from a sawn piece of timber is characterised by its relatively smooth face and back, while in contrast a shake, essentially a split piece of timber, is dominated by a strongly textured surface.

Australian producers generally follow the set standard sizes adopted in North America for western red cedar shingles and shakes. Widths are generally random, with only length and butt thickness specified. The table below provides standard sizing for western red cedar shingles.

Length (mm)

Thickness (mm)

400

10

450

11

600

13

Timber shingles and shakes are most commonly used on roofs as cladding. While they are typically applied in straight single courses, this can be varied to achieve other more decorative effects. Detailed information about the construction of shingle clad roofs is best sought from individual suppliers.

When applied to walls, shingles and shakes are generally fixed over solid or spaced sheathing. 9mm or thicker exterior grade plywood provides a smooth, even base for fixing. The inherent strength of plywood also offers the added benefit of giving increased structural rigidity to the building.

For long term durability shingles and shakes can be dipped in a water repellent preservative formulation prior to installation. On roofs they are often given no further treatment and will subsequently weather to a soft silver-grey tone. On walls, where access for maintenance may be easier, pigmented stains are often used to retain a natural looking colour.

Joinery

Timber joinery products offer a classic, unique and stylish touch to any interior or exterior design. The products are produced for a variety of internal applications including door and window frames, cabinetry, skirtings, mouldings and architraves. When looking to the outdoors, joinery products range from decorative eaves and posts to eye-catching railings.

Many timber species are suitable for joinery products and care should be taken in selecting the perfect timber for the particular product and its intended finish. Rare and exotic species such as Teak and Rosewood can generate pieces of outstanding beauty but material cost and availability are also important considerations.

Commercially available species like Tasmanian oak, Australian cypress, spotted gum and the like, often make the more practical choice, with the added benefit that they can be easily matched with other timber products within the building, like flooring.

Solid timber for joinery products is generally supplied as ‘clear finish grade' but ‘paint grade' options are available and these are usually comprised of a composite material like MDF or glulam.

A large number of specialist suppliers and producers offer the consumer extensive choice of profiles for all of the most common and popular joinery products. Choice is in many cases, limited only by imagination.

Cabinetry is often associated with joinery and most typically includes, cupboards, benches and other similar ‘built in' furniture. Like joinery, cabinetry is generally specified as either paint or clear finish grade and naturally for clear finish grade timbers, appearance and surface finish are critical in achieving a successful application.

 

Doors

Whether manufactured from solid or engineered timber, there are many stylish and practical options that won't compromise on strength and structural performance. A distinctive timber door can also create visual impact, adding value to any commercial or domestic building.

Timber makes an attractive choice for door design and construction, offering a strength, flexibility and versatility that other materials find hard to match. 

Protected from moisture, a timber door will perform satisfactorily for the life of any building. With regular maintenance, carefully designed and finished timber doors can perform in the toughest external environment and if required, can be refurbished or updated easily and effectively.

This application guide outlines the common elements involved in specifying and finishing timber internal and external doors.

Panelling, Interior

Internal panelling, also known as appearance boards and linings, is not just a practical means of covering one or more walls and ceilings in a building, its inclusion in a room's interior design can generate looks that are both dramatic and stylish. Internal paneling comes as either solid natural timber paneling or as sheets of engineered wood products that provide a durable and hardwearing surface for areas subject to high impact. As they typically function as appearance products they generally have no structural requirements. This guide describes the variety of panelling products available and outlines the straightforward process of installing them.

Fencing

The inherent appeal and strength of timber makes it the obvious choice for fencing. Timber fencing not only provides a natural look in keeping with the outdoor environment but it also enables the construction of a long lasting, durable property boundary. Fences come in many forms including the traditional paling, picket, post and railing styles. Most rely on a structural frame of posts embedded into the ground and two or more rails spanning between the posts. The ultimate selection of a suitable fence type or style is determined by application and aesthetics. A fence can serve a variety of purposes, including the provision of security, privacy and safety in addition to defining property boundaries. Specification for durability is important, especially for posts, given their exposure to high moisture in the ground.

This section provides an overview to best practice methods in specifying, installing and finishing a timber fence.

Cladding, External

No other cladding material can offer the design freedom, ease of handling, range and natural beauty of timber. Timber cladding can create a building to suit almost any environment, taste or style.

Timber cladding has an inbuilt flexibility that provides natural advantages on sites subject to high winds, extreme climate, highly reactive soils, subsidence or earth tremors. And unlike masonry and other rigid materials, the natural resilience and high strength to weight ratio of timber enables it to withstand far greater stresses and movement.

Modern finishes give a long lasting and attractive appearance to timber cladding and can be used to change the colour and style of the building, making it a versatile material that will keep pace with changing tastes and fashions.

 

Windows

Timber windows are usually supplied as joinery items with a primer or base coat, as factory glazed components requiring site finishing or as fully glazed and finished windows.

Demand is ever increasing for high performance windows that promote efficient energy use in buildings. Careful window selection and placement is rightly viewed as a means of reducing demand for artificial light and climate control. Timber is an ideal material when considering these aspects as it is a material that is light, strong, natural and renewable. It can be moulded to any shape, so will meet the thermal, acoustic and design requirements of even the most unusual window.

This guide discusses the common elements involved in specifying, constructing and installing timber windows

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