Northern white-cedar and Atlantic white-cedar
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There are two separate tree species that are called white-cedar.  Northern white cedar (Thuja occidentalis), also called arborvitae or just cedar (there are over 40  local names), grows in Quebec to Maine to New York and westward to Minnesota as well as down the Appalachian Mountains from Pennsylvania to Tennessee.  Atlantic white-cedar (Chamaecyparis thyoides), also called southern white-cedar and boat cedar, grows in swamps in the coastal regions from Maine to Florida.  Northern white-cedar lumber is manufactured primarily in the Lake States; Atlantic white-cedar in the Carolinas and Gulf States.

The two separate species are not closely related, but sometimes are grouped together, as the properties are almost identical.  The lumber is highly resistant to decay and insects.  The surface is fairly soft, and the strength, overall, is fairly low, compared to other North American species.

In the past, these two species were used for tight cooperage (holding liquids), boat building (northern white-cedar is still a popular choice for canoe ribs), fences and tableware.  Northern white-cedar is often used for log cabin logs today; Atlantic white cedar is used for furniture.  Being a wood that works easily, I am certain that white-cedars have been used locally for hundreds of items and will perform well indeed.  Check the Internet for suppliers.

White Cedar is one of the primordial trees the Ojibway.  Honored with the name Nokomis Giizhig, Grandmother Cedar, the tree is the subject of sacred legends and is considered a gift to humanity for its myriad uses.  Native Americans used the leaves and twigs to treat malaria, coughs, gout, and rheumatism.  This purported medical benefit is most likely the original of the term arborvitae (tree of life) used for this species.  The leaves are reported to be high in vitamin C.  Cedar leaf oil is distilled from boughs and used in medicines and perfumes.  The oil is also suppose to help reduce hair loss. (Even if it doesn’t work, you sure will smell nice!)

PROCESSING SUGGESTIONS AND CHARACTERISTICS

Density.

The density at 9% MC is approximately 20 pounds per cubic foot.  A board foot of 4/4 dried (9% MC) and planed lumber (3/4" thick) will weigh only about 1-1/4 pounds.  This is the lightest weight native American species.

Drying.

The wood is very easy to dry without many defects.  However, if dried under 9% MC or dried at over 180 F, the wood will become quite brittle, which will lead to splits when machining.  This brittleness cannot be removed by increasing the MC after drying is complete.  In practice, this wood is often, inadvertently, over-dried.

Shrinkage in drying is 3% maximum-a very low shrinkage value.

Gluing and Machining.

This is one of the easiest woods to glue and is quite forgiving if gluing parameters are not perfect.  Aged surfaces may have a slight oil accumulation, so always use freshly prepared surfaces.

Machining is very good, although the softness of the wood means that machine pressures must not be excessive.  If over-dried or dried at very high temperatures, the wood will become brittle.  Planer splits and other machining defects will be common.  When these cedars will be used for fine woodworking, it is critical to avoid over-drying.

Stability.

The wood is extremely stable.  It takes over 6% MC change to result in a 1% size change in the tangential direction (the width of a flatsawn piece of lumber) and a 12% MC change in the radial direction.  Note that because of the demand of this wood for boat building, much of the wood is quartersawn, providing excellent stability...better than teak.

Strength.

As with all lower density woods, the mechanical properties are low.  The ultimate strength (MOR) is 6500 psi, the elasticity (MOE) is 800,000 psi, and the hardness is 320 pounds.  As a comparison, the values for Eastern white pine are 8600 psi, 1.24 million psi, and 380 pounds.

Screw, staple and nail holding is quite low, requiring more fasteners with larger diameter shanks and larger heads to develop good fastener strength.

Color and Grain.

The wood color is light brown, perhaps with a little reddish color.  There is a distinctive spicy odor and a bitter taste, similar to the wooden pencil smell and taste (if you are old enough to remember what a cedar pencils is).  The grain is very even and fine, with a little oily feel at times.  Although lacking the heavy grain and appearance of some of the pines, this is a good utility wood and would be a top choice for outdoor furniture, as well as many indoor uses.

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About the author
Gene Wengert

Gene Wengert, “The Wood Doctor” has been training people in efficient use of wood for 45 years. He is extension specialist emeritus at the University of Wisconsin-Madison.