Western Red Cedar - Heavy Timber Specifications

Western Red Cedar 6x6 Heavy Timbers
Cross cut Western Red Cedar log with red heartwood and growth rings
Freshly harvested old growth Western Red Cedar logs
Cedar logs stacked
Pacific Northwest old growth Western Red Cedar forest
Western Red Cedar
Cedar forest
Cedar leaves

Summary Description

Western Red Cedar (WRC) 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. It is commonly known as Red Cedar or Giant Cedar (as distinct from Inland Red Cedar). WRC is known for its extremely fine and even grain, its flexibility strength-to-weight ratio. WRC maintains dimensional stability under most weather conditions, and resists shrinkage and swelling. The lumber can be used in a myriad of ways. Due to high impermeability to liquids and a saturation of natural phenol preservatives, WRC is ideally suited for exterior use, and/or interior use where high humidity is present.

Old Growth Western Red Cedar is highly resistant to decay, because of its slow growth, dense fiber, and natural oily extractions. WRC has a rich coloring, which ranges from a light milky straw color in the sapwood to a vanilla-chocolate in the heartwood. It seasons easily and quickly, with a very low shrinkage factor, and high stability. It contains no pitch, creating excellent finishing characteristics.

Western Red Cedar is used for applications such as cladding, linings, joinery, windows, doors and roofing shingles, as well as in siding patterns, paneling patterns, and boards for board-on-board siding, trim, and fascia. Other common uses are timber entryways, outdoor decks, pavilions, pergolas, saunas, decorative posts, and fencing. Natural preservatives provide resistance to fungal and insect invasion, while its low density also provides good thermal insulation qualities. WRC also provides excellent sound insulation and impressive acoustic properties. It is inherently very durable, and can be used in many types of weather conditions.

Interior Uses

• Boxes, crates, linings, joinery, windows, doors, linen closets, saunas, and musical instruments.

Exterior Uses

• Heavy timber post-and-beam framing, shingles, exterior siding and cladding, entryways, decks, pavilions, fencing, boat building.

Western Red Cedar Properties

Moisture Content:

12%

Durability:

Above ground: Highly Durable – Class 2 – Life expectancy 15-40 years
In ground: Moderately Durable – Class 3 – 5 to 15 years

Structural Rating:

F5

Color/Appearance:

Heartwood reddish to pinkish brown, often with random streaks and bands of darker red/brown areas. Narrow sapwood is pale yellowish white, and isn’t always sharply demarcated from the heartwood.

Grain/Texture:

Straight grain with a coarse texture and moderate natural luster.

Endgrain:

Resin canals: absent
Tracheid diameter: medium to medium-large
Earlywood to latewood transition: usually abrupt (or gradual if growth rings are more widely-spaced)
Grain contrast: high
Parenchyma: none

Rot Resistance:

Western red cedar has been rated as durable to very durable with regard to decay resistance, though it has a mixed resistance to insect attack.

Flame Spread Rating:

45 (Class II)

Stability:

Cedar is the most stable softwood species.

Workability:

Works easily with both hand and machine tools, though scratches and dents very easily due to its softness, and sanding may produce uneven results due to the density difference between the earlywood and latewood zones. Accepts glues and finishes well. Iron-based fasteners can become corroded, potentially staining and discoloring the wood, especially in the presence of moisture. Hot-dipped galvanized nails and screws are recommended. Can be brittle along the end grain and sharp cutters are recommended due to the soft wood. Take precautions when sanding, as the sawdust is an irritant for some people. Not suitable for steam bending.

Odor:

Although severe reactions are quite uncommon, western red cedar has been reported as a sensitizer. Usually most common reactions simply include eye, skin, and respiratory irritation, as well as runny nose, asthma-like symptoms, and nervous system effects.

Allergins/Toxins:

Acute reactions are rare, though has been reported to cause skin irritation, nausea, light-headedness, runny nose, and an increased probability of infections from splinters.

Acoustical Properties:

An important acoustical property of wood is its ability to damp vibrations. Wood has a cellular network of minute interlocking pores which converts sound energy into heat by frictional and viscoelastic resistance. Because of the high internal friction created by the cellular pore network, wood has more sound damping capacity than most structural materials. Floor, ceiling and wall assemblies of wood can provide effective economical sound insulation and absorption when properly utilized. Western Red Cedar is particularly effective in this regard and can be used to help reduce noise or to confine it to certain areas.

Price/Availability:

Should be moderately inexpensive for construction-grade lumber, though higher grades of clear, straight-grained, quartersawn lumber can be more expensive.

Sustainability:

Not listed in the CITES Appendices, and reported by the IUCN as a species of least concern.

Applications:

Shingles, exterior siding and lumber, boatbuilding, boxes, crates, linen closets, saunas, and musical instruments.

Seasoned Density:

350kg/m³

Unseasoned Density:

490kg/m³

Technical Specifications 

Additional Articles

Western Red Cedar Designer Handbook

A comprehensive guide to this species, including physical properties, base design values, span tables, shrinkage, and more.

Published by the Western Red Cedar Lumber Association (WRCLA). (18 pages)

Resources Quick Links

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General Construction Techniques

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Western Red Cedar - A Giant Among Giants

A summary of the wood's properties, the different grades, and how it is used commercially. Includes a table of comparative physical properties of various coast species.

Published by the Coast Forest Products Association (now the BC Council of Forest Industries [COFI]). (4 pages)

Resources Quick Links

Construction

General Construction Techniques

Lumber Data & Specifications

Connection Guides

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How to Specify Western Red Cedar

 A guide to the properties and uses of WRC for siding, trim boards, decking, timbers, fences & gates.

Published by the Western Red Cedar Lumber Association (WRCLA). (52 pages)

Resources Quick Links

Construction

General Construction Techniques

Lumber Data & Specifications

Connection Guides

Engineering

Properties

Performance

Douglas Fir

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Western Red Cedar - An American Wood

A vintage US Forest Service guide to the species, including growth distribution, production, properties, uses, and more.

Published by the US Forest Service. (7 pages)

Resources Quick Links

Construction

General Construction Techniques

Lumber Data & Specifications

Connection Guides

Engineering

Properties

Performance

Douglas Fir

Western Red Cedar

Eastern White Pine

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Growth, Properties & Uses of Western Red Cedar

An exploration of the species, detailing aspects as a forest resource, and the raw material for building and construction, with a list of physical, chemical and mechanical properties.

Published by the Forintek Canada Corp, Western Red Cedar Lumber Association, and Western Red Cedar Export Association. (51 pages)

Resources Quick Links

Construction

General Construction Techniques

Lumber Data & Specifications

Connection Guides

Engineering

Properties

Performance

Douglas Fir

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Western Red Cedar Quick Facts

Features, properties, fastening, shrinkage, and grading.

Published by the Western Red Cedar Lumber Association (4 pages)

Resources Quick Links

Construction

General Construction Techniques

Lumber Data & Specifications

Connection Guides

Engineering

Properties

Performance

Douglas Fir

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Western Red Cedar

A summary sheet with physical and mechanical properties, resistance to pests and climate, drying, sawing and machining, and more.

Published by Tropix 7 (4 pages)

Resources Quick Links

Construction

General Construction Techniques

Lumber Data & Specifications

Connection Guides

Engineering

Properties

Performance

Douglas Fir

Western Red Cedar

Eastern White Pine

Specialty Timbers