WoodSense: Spotlight on Western Red Cedar

Most of the cedar you’ll encounter for woodworking hails from the Pacific Northwest. In the trade it’s called western red cedar (Thuja plicata). However, there are other cedars available, too, with a few variations

between them, and, yet, they’re all in the same cypress family.

History in woodworking

Tribes of North America’s Pacific Northwest were using western red cedar long before white explorers came across the tree on Vancouver Island in the late 1700s.  Native carvers shaped it into masks, ceremonial boxes, and totem poles. Split into planks, the lightweight, decay-resistant wood formed their lodges. As hollowed-out trunks, it became ocean-going trade and whaling canoes (also see “It’s a fact that...”) Even the tree’s tough, sinew-like bark provided the raw material for woven baskets, braided rope, and fishing lines.

When white settlers came on the scene, they, too, took advantage of western red cedar’s attributes, making it into shakes, shingles, and siding for their frontier homes. Today, those uses still account for the largest commercial use of the wood, followed by outdoor structures such as decks, gazebos, and fences, as well as patio furniture. (See the arbor and gate on page 22.)

Moving east, across the continent, the history was similar with northern white cedar (Thuja occidentalis). From the Great Lakes to Maine, Native American’s put it to good everyday use, while white men employed it as home construction material. Its use today parallels that of its western cousin, but in far less volume. It’s also more greatly appreciated by boat builders.

Atlantic white cedar (Chamaecyparis thyoides), which grows in fresh water swamps from New England to Louisiana’s Gulf Coast, shares the same characteristics as northern white cedar and small amounts may be mixed with it at local lumberyards.

Note: Eastern red cedar (Juniperus Virginia), the aromatic wood used for chest and closet linings, isn’t suitable for furniture and outdoor projects, so the information here doesn’t pertain to it.

Where it comes from

Western red cedar flourishes in the moist coastal forests that stretch from northern California to southern Alaska, but also grows in commercial quantities in the mountains of Idaho and Montana. Under prime conditions it can attain heights greater than 100' and 10'-diameters.

Northern white cedar is logged from eastern Canada to Maine and along the northern Appalachians, then westward through the northernmost Great Lakes states. The greatest production of Atlantic white cedar centers in North Carolina and along the Gulf Coast to Louisiana.

What you’ll pay

Lumber retailers sell western red cedar in board and timber form as well as shakes, shingles, and siding. The best board grade—kiln-dried clear heart—has no knots or sapwood, and can cost $4 per board foot or more. Most outdoor projects don’t require all-clear lumber, though, so lesser grades containing knots will do.

You’ll find northern white cedar and Atlantic white cedar at small local mills and lumber outlets in its growth range. It sells for about $1 per lineal foot in thicknesses up to 4" and surfaced four sides (S4S). C Select and D Select grades work well for interior trim, cabinets, and outdoor furniture because they are graded for appearance from one side. You also can buy the wood in common and construction grades as well as roughsawn on one face (A). 

It’s a fact that…

• Northern white cedar splits easily by hand, a trait that made it the featured wood for the planking (as little as 1/8" thick), ribs, thwarts, and gunwales of traditional bark canoes.
• Port-Orford cedar, a species that grows along a narrow coastal mountain strip from northern California to southern Oregon, has always furnished the favored wood for archery arrows. 
• The largest of the nation’s western red cedars grows in Olympic National Park, Washington. According to American Forests’ National Register of Big Trees, it stands 159' tall and has a diameter of nearly 20'! In contrast, northern white cedar’s top tree, growing in Michigan, is only 113' tall and about 6' in diameter.

Choose top-quality wood

Due to its variety of possible applications, western red cedar comes in a matching variety of grades, but you need remember only the following simplified guidelines:

The wood offers two basic “appearance” categories—standard clear and standard knotty (both kiln-dried). Standard clear grades, for furniture and cabinets, include clear (finest appearance and highest cost), A-grade, and B-grade. Some dealers may special-order these grades in vertical grain for specialized architectural use.

Non-appearance grades—for decks, fences, and planters—include Select merchantable, Construction, Standard, and Utility knotty grades. Select offers the fewest and tightest knots in the group.

Keep in mind that for projects that come in contact with the ground don’t use material that includes sapwood. Tight knots won’t hurt a thing.

Cedar Finishing Secrets

• Cedar that’s been surfaced (S4S or S2S) should be gone over with 80-grit abrasive before applying a solid, pigmented finish (paint). This helps the finish adhere.
• Extend the life of painted cedar by first applying a paintable water repellant to the bare wood.
• If you want a clear finish on cedar outdoor projects, such as furniture, you’ll be best off with a penetrating one because it’s easily renewed. However, choose a finish that includes ultraviolet ray blockers. Look for “transoxide” pigments in the ingredients on the label.

Working cedar in the shop

One of the lightest softwood species at about 20 pounds per cubic foot, western red cedar (and its relatives) also rates among the most stable, especially when kiln-dried. However, it tends to be brittle which demands attention in machining.

Planing, ripping, and routing. Plane cedar in shallow passes, removing 1/16" or less. Do the same on the jointer.

Due to its straight grain (B), western red cedar rips easily. Crosscut it with a fine-toothed blade to avoid splintering.

Tear-out while routing across the grain is common. Eliminate it with a backing board along the edge where the bit exits.

Adhesives and fasteners. Without sappy pitch to gum up the works, you’ll have little problem joining cedar with the adhesive of your choice. When it comes to fasteners, though, you should use non-corrosive ones of aluminum, brass, or silicon bronze. Screws require pilot holes and should also be about one-third longer than you’d normally use. Rely on zinc-coated nails that are also extra long so they won’t pull out.

Deciding on the right finish

When fresh-cut, western red cedar looks bright, reddish-brown (other cedars appear light tan), but it soon becomes drab brown. Sapwood, by contrast, appears creamy white (C).

Without a finish, all cedars gradually change to a silver gray color (D). Although this aged color is pleasant, it can be uneven. Any type of clear protective finish that’s occasionally reapplied slows the graying process. Without a protective finish the wood also will literally weather away—not decay—over time (about ½" per century).

Cedar, because it contains no pitch or resins, takes paints, stains, and clear finishes well, with the best protection from damaging ultraviolet rays provided by a pigmented coating.