Cedar is a wonderfully versatile wood used in many different exterior applications. Most cedar is sourced in Canada, with smaller amounts in Washington and Oregon states. Current production in British Columbia, Canada is using only 1/3 of 1% in annual harvest. Western Red Cedar (WRC) (Thuja plicata) is one of North America’s great renewable resources.
Slow growing and naturally durable.
Western Red Cedar has one of the longest life spans of any North American softwood. It produces long lengths of timber with true, straight grain. It is free from pitch and its heartwood has natural decay resistance. Its low density gives it an insulation value superior to most other species. Cedar is lightweight, easy to work, easy to finish, possessing outstanding dimensional stability. Western Red Cedar is a preferred wood for nearly all purposes where attractive appearance or resistance to weather is important. The cedar lumber mill association has a great website that covers product, installation, finishing, grades and more: www.wrcla.org.
Cedar is one of the most confusing woods to purchase since beyond clear and vertical grain, most other grades are proprietary. This translates to the mills or distributors assigning whatever name they choose. Cedar, like all wood boards, is graded to one side and two edges only. In the specific case of cedar, it is graded to the rough side only (i.e. S1S2E ). However, a few general terms are universal:
Clear: No knots, cedar is graded to the rough sawn side (as applicable). All grading applies to just one side and one or two edges.
Select Knotty (or STK - Select Tight Knot): Not in any grade book. It refers to boards that are chosen for their general good appearance with solid, tight knots that should not fall out.
Rough Sawn: Milling process leaving the wood rough–typically the treatment most people identify with cedar.
Smooth Sawn: Milling boards to a smooth appearance.
S1S2E: One side and two edges are smooth, leaving the opposing side “rough”.
No Hole: Generally refers to pickets where the picket—when graded—had no open knotholes, although with no gaurantee the knots could fall out in the future, leaving a hole.
Green: Wood of any species that has not been dried during the milling process.
Dried: Wood of any species that has been allowed to give up the moisture in the cell structure. The processes include kiln dried, heat treated, air dried and partially air dried.
Western Red Cedar: The most common and readily available.
Alaskan Yellow Cedar: Actually a type of Cypress.
Inland Red Cedar: A form of Western Red Cedar growing in different locations. Log quality and size are limited for consistency.