Most lumber available is “flat sawn”. The annual growth rings run roughly parallel to the face of the board. As shown in the illustration,they tend to shrink across the width, and cup.

True quartersawn lumber produces a “vertical grain” where the annual growth rings are vertical to the face of the board. As shown in the illustration, they tend to shrink across the thickness and remain flat.

“Vertical grain” boards are highly stable and show a minimum shrinkage and warpage. This enhances the durability and its ability to hold paints and stains.

Colours – Unfinished cedar has richly textured grain with colours ranging from mellow ambers, reddish cinnamons and rich sienna browns. Its warm coloring is complimented by a uniform, fine-grained texture with a satin luster.

Easy finishing – Because cedar is virtually pitch and resin free, the wood easily accepts a range of finishes, from fine oils and stains, to solid coatings and paint.

Usages – Enhance the beauty and elegance of your home or commerical property with cedar siding, decking, moulding, windows, doors, posts, beams, paneling, outdoor projects, interiors and saunas.

Aroma – Cedar’s unique aroma comes from naturally occurring thujaplicins in its heartwood. These compounds resist moisture and are toxic to decay-causing fungi and insects and preserve the wood to give it long lasting appeal.

Acoustic insulation – Acoustic properties of cedar walls and ceilings provide sound insulation necessary to quieten rooms. Surround yourself in the beauty of cedar.

Knotty Grades
Knotty cedar presents a more rustic appearance and is typically supplied green (unseasoned) in the appearance and structural grades. When required, seasoning is achieved by air-drying except for grades of Light Framing and Structural Joists and Planks which are available kiln-dried.

Playground Structure-Constructed of Appearance Knotty structural timbers, this playground uses cedar’s natural resistance to decay to provide a chemical-free environment for children.

Surface Textures
Saw Textured The saw textured surface, obtained during the milling process which uses either circular or band saws, is present on all four sides.

Rougher Headed The lumber receives its texture from a milling process which uses roughened planer knives. The rough texture is clearly visible on all four sides.
Surfaced Four Sides (S4S) The smooth surface on all four sides presents a uniformly sized product with a high quality appearance. Sizes from 2×4 (51mm x 102mm) up to 6×6 in. (152mm x 152mm) are generally available. Larger sizes are produced on special orders.

More 9info at the WRCLA @ http://wrcla.org/cedarspecs/timbers-landscaping/grades.asp

Specific Reforestation – Public land is quickly reforested with native species suited to meet local ecological conditions. See Biodiversity

Ensured Reforestation – Canadian Forest companies are legally obligated to track and ensure regeneration success. If a newly planted forest fails, the company must replant the area until it is properly reforested. Forest companies remain responsible for a harvested area until the new growth reaches what is called a free-growing state, which means there is assurance the young trees will grow into a new, healthy forest. This usually takes 6 to 12 years.

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Every year, more than 200 million seedlings are planted in B.C. to reforest areas after logging, wildfire or insect infestations.

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On average, each year 650 million trees are planted across Canada in areas where forests have been harvested.

For optimum performance, the WRCLA recommends that Western Red Cedar is preprimed or pre-finished prior to job site delivery. Factory-priming, as the name implies, is performed in an industrial setting where a machine coating process applies a coating to all six sides of each board. The coated boards are then dried prior to shipment to the job sites. Pre-primed siding and trim boards delivered to a job site should be kept dry and clean prior to installation. All field cuts should be re-sealed with a primer prior to the boards being installed. Top coating should be completed as quickly as possible as most primers are not intended to be exposed to natural weathering for more than 90 days.

Factory–finishing is similar to the above process, however, it allows for the additional application of one or two topcoats of acrylic latex paint, solid stains or natural stains in job lot quantities and in the colors selected by the builder/homeowner. It is important not to overdrive nails during installation of factory finished siding, as this will damage the surrounding wood and coating. Overdriven nails must be remedied immediately by filling the depression with exterior grade wood putty specifically designed for this purpose.

Touch-up any repairs or field cuts, taking care not to smear the top coat. Properly done, factory priming/finishing provides:
•the application of a uniform coating at the recommended coverage of the primer/stain to all six surfaces of each piece (face, back, edges andends)
•a controlled environment to permit proper curing of the finish
•the wood with a coating to protect it from exposure to sunlight (UV degradation) and surface contamination by mildew and dirt
•an elimination of lap marks, streaks and shrink lines after installation • an ability to install products at any time of the year
•a product that often comes with a coating warranty

The WCLIB was originally established as the West Coast Lumberman’s Association when four small regional associations in the northwestern part of the U.S. joined forces in 1911. In 1923, the WCLA together with other regional lumber associations, formed the first national committee for lumber standardization under the auspices of the U.S. Department of Commerce. In 1941, the WCLA created a new division, The West Coast Bureau of Lumber Grades and Inspection, to enhance the identity of the grading and inspection services provided by the association. The name was later changed to the West Coast Lumber Inspection Bureau. In 1968, the WCLIB was formally incorporated as an independent organization when the promotional arm of the WCLA was disbanded.

The WCLIB is currently one of only seven organizations in the United States accredited by the American Lumber Standard Committee to write and promulgate lumber grading rules, and provide grade inspection and supervision services. The WCLIB is also accredited by the ALSC to provide heat treating inspection and supervisory services for manufacturers of wood pallets and crating.

The WCLIB provides grade inspection and supervision services to member mills in the western states, and throughout the continental U.S. and Europe. WCLIB has a total of approximately 190 member lumber mills plus 180 pallet and heat treating associate members. WCLIB is governed by a Board of Directors composed of twenty persons elected from the membership.

For centuries builders and artisans have valued Western Red Cedar for its natural beauty and durability.

Architectural design – Cedar compliments any architectural design – from turn-of-the-century to contemporary.

Colours – Unfinished cedar has richly textured grain with colours ranging from mellow ambers, reddish cinnamons and rich sienna browns. Its warm coloring is complimented by a uniform, fine-grained texture with a satin luster.

Easy finishing – Because cedar is virtually pitch and resin free, the wood easily accepts a range of finishes, from fine oils and stains, to solid coatings and paint.

Usages – Enhance the beauty and elegance of your home or commerical property with cedar siding, decking, moulding, windows, doors, posts, beams, paneling, outdoor projects, interiors and saunas.

Aroma – Cedar’s unique aroma comes from naturally occurring thujaplicins in its heartwood. These compounds resist moisture and are toxic to decay-causing fungi and insects and preserve the wood to give it long lasting appeal.

The National Lumber Grades Authority (NLGA) was incorporated in 1971 and is the organization responsible for the establishment, issuance, publication, amendment and interpretation of Canadian lumber grading rules and standards. NLGA is the only recognized rules writing body for lumber grades and standards in Canada.

The NLGA Grade Rule is approved and enforced by the Canadian Lumber Standards Accreditation Board (CLSAB) and by the American Lumber Standard Committee, Incorporated (ALSC) Board of Review. This approval enables acceptance of the NLGA Grade Rule under Canadian and American building codes.

The NLGA Grade Rule incorporates the National Grade Rule (NGR) standards for all North American dimension lumber. The NGR establishes standard lumber grades and grade names for all commercial species of dimension lumber, thus assuring lumber users of uniform design criteria and performance throughout North America.

The membership of NLGA consists of all the independent lumber grading agencies in Canada (which are accredited by the CLSAB and ALSC) that oversee the grading activities of certified Canadian lumber producing facilities.

One of the lightest commercial softwoods, the density of Western Red Cedar at oven-dry conditions is approximately 21 pounds per cubic foot with a relative density (specific gravity) of 0.32. Comparative oven-dry densities of cedar and some other softwood species are given in the Table 1.

Cedar’s low density enhances its insulation value and makes it an easy wood to transport and handle.

Dimensional Stability

Like all woods, Western Red Cedar is hygroscopic and will absorb or discharge moisture to attain equilibrium with the surrounding atmosphere. However, it has a very low shrinkage factor and is superior to all other coniferous woods in its resistance to warping, twisting and checking. The size differential between dry and unseasoned Western Red Cedar is given in Table 2. Shrinkage in both the radial and tangential directions is given in Table 3.

Thermal Conductivity

Wood is an excellent thermal insulator. This is an important characteristic since good thermal insulators help keep buildings cool in the summer and reduce heating costs in the winter.

The conduction of heat in wood is directly related to its density. Woods with low density have the highest thermal insulating value because such woods contain a high proportion of cell cavities. In dry wood, these cavities are filled with air which is one of the best known thermal insulators.

With its low density and high proportion of air spaces, Western Red Cedar is the best thermal insulator among the commonly available softwood species and is far superior to brick, concrete and steel. It has a coefficient of thermal conductivity (k value) at 12% mc of 0.74 BTU inch/ft2h degrees F. The R value (the reciprocal of k) for Western Red Cedar is 1.35″ (34mm) of thickness.

Acoustical Properties

An important accoustical 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.

Flame Spread Rating

Flame spreading ratings describe the surface burning characteristics of interior finishes. They are used to regulate the use of interior finish materials to reduce the probability of rapid fire spread. Materials are burned in a test furnace for a relative assessment of flammability. The lower the flame spread rating, the more the material resists the spread of fire.

Building codes in North America generally define as interior finish any exposed material that forms part of the building interior. This usually includes interior wall and ceiling finishes, flooring, windows, doors and other wood products. US codes set the maximum flame spread rating for interior wall and ceiling finishes in most buildings at 200. The flame spread rating for Western Red Cedar is 69 (Class II rating).

Smoke developed classifications reflect the amount of smoke released by burning material. They are used in conjunction with flame spread ratings to regulate the use of interior finish materials where the potential to generate smoke or control smoke movement is of major fire safety importance.

US codes set the maximum smoke developed classification for interior wall and ceiling finishes in most buildings at 450. The smoke developed classification for Western Red Cedar is 98.

Western Red Cedar’s flame spread rating and smoke developed classification compare well with the ratings of many other species of both softwood and hardwood. Because of its favorable performance, Western Red Cedar can be used for interior finish in some building applications where other species would not be permitted.

Durability

Historically, native peoples of the Pacific coast prized cedar for its long lasting qualities and used wood and bark from cedar trees for most of their building needs. Evidence of cedar’s durability are the many cedar artifacts still in good condition today.

Properly finished and maintained, cedar will deliver decades of trouble-free service. If exposed for prolonged periods to conditions where decay could be a factor, such as where the wood is in contact with the ground, cedar should be treated with suitable wood preservatives.

Fastening

Western Red Cedar has good fastening properties but its natural preservatives have a corrosive effect on some unprotected metals in close contact, causing a black stain on the wood. Fasteners should be corrosive resistant such as aluminum, brass, silicon bronze, hot-dipped galvanized or stainless steel.

Nails and screws used to fasten Western Red Cedar should be about one-third longer than those used to fasten hardwood species.

Because it is free of pitch and resin, Western Red Cedar has excellent gluing properties, comparable to those, for example, of old growth Redwood and American Chestnut. It works well with a wide range of adhesives.

Finishing

Although cedar is a naturally durable species, leaving it untreated is not recommended because a finish or protective coating will greatly increase its service life. Cedar is free of pitch and with its high degree of dimensional stability, it is the best of the softwoods for accepting paints, stains, oils and other coatings. For a detailed discussion, see Finishing Western Red Cedar (3MB pdf) published by the Western Red Cedar Lumber Association.

Workability

With its straight grain and uniform texture, Western Red Cedar is among the easiest and most rewarding woods to work with. It takes a fine finish in all hand and machine operations, takes fasteners without splitting and is easily sawn and nailed. When working with Western Red Cedar, sharp cutters are recommended.

Products, Grades and Sizes

There are few more versatile building materials than Western Red Cedar which is ideal both for indoor and outdoor uses. Western Red Cedar lumber is available in visual stress grades for construction and finishing uses in a range of lengths, widths and thicknesses. It is available in clear or knotty grades with smooth surfaced, combed or rough sawn finishes; kiln dried or unseasoned (green); flat grain and vertical grain.

For nominal widths, thicknesses and grades of some commonly available Western Red Cedar lumber products, see the Cedar Products section.

Western Red Cedar is used to manufacture a range of specialty products such as wood siding, wood paneling, structural decking and outdoor decking. Detailed product information is available from the Western Red Cedar Lumber Association.

Cedar produced by the Western Red Cedar Lumber Association includes specialty end use grades as well as products graded to National Lumber Grading Authority (NLGA) rules. NLGA grades are approved by the American Lumber Standards Board of Review and are accepted under all US building codes.
Table 1. Comparative Softwood Densities (pcf)
Western Red Cedar
Table 2. Size Differential Between Unseasoned and Dry Lumber
Nominal Dimension (inches)
Size Differential Between Unseasoned and Dry Lumber After Surfacing (inches
Table 3. Shrinkage of Western Red Cedar
Shrinkage in Percentage
From green (25% or greater moisture content) to:
From kiln dried (15% average moisture content) to:
Notes:
1.Radial shrinkage applies to the width of vertical grain lumber: tangential to the width of flat grain lumber.
2. Shrinkage does not begin until the fiber saturation point is reached.
3. 15% is the average equilibrium moisture content of wood during the summer in the Pacific Northwest.
4. 12% is the summer average equilibrium moisture content in dry areas of the US.
5. 6% is the average equilibrium moisture content for interiors of heated buildings.
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Overview
Cedar Properties