Material reference · specification & sourcing
Cedar Wood: Western Red Cedar, Grades & Applications
Western red cedar is Thuja plicata. Cedar trade names cover different species, so identify the wood and specify grade, heartwood, profile and exposure for your project.
By Lumberama · Updated November 11, 2026 · Editorial standards
Selection at a glance
| Item | Meaning | What to verify |
|---|---|---|
| Western red cedar | Thuja plicata | Siding, trim and exterior products |
| Eastern redcedar | Juniperus virginiana | Aromatic products; different species |
| Northern white-cedar | Thuja occidentalis | Confirm local product specification |
| Clear versus knotty | Appearance selection | Not a substitute for structural grade |
Which cedar are you specifying?
Western red cedar (Thuja plicata), eastern redcedar (Juniperus virginiana) and northern white-cedar (Thuja occidentalis) are different trees. Eastern redcedar is often associated with aromatic interior products; that does not make it a direct substitute for a western red cedar siding specification.
The word cedar alone is insufficient for comparing quotations. Ask the supplier to identify the species and the grade rule used. Keep species identity separate from a coating color called cedar or a pressure-treated product stained to resemble it.
Clear, knotty and structural grades
Clear and knotty selections serve different visual goals. Ask about permitted knots, repairs, edge defects, grain orientation and the appearance of the exposed face. For a structural member, the specified structural grade and design requirements still apply; a clear appearance label is not a structural approval.
Plan visible joints and color distribution before installation. An approved sample should illustrate expected variation rather than only the best board. State whether selection applies to a single face, both faces, or all exposed edges.
Heartwood, moisture and exterior performance
Natural durability descriptions generally concern heartwood and do not make all sapwood equally resistant. Specify acceptable sapwood and assess wetting, drainage and drying opportunities in the assembly. Cedar can still move, check and decay under unsuitable conditions.
Condition boards for the intended installation and follow the product’s moisture requirements. Store them above the ground and protect them from direct wetting without trapping condensation. Avoid a universal acclimation duration; use measurements and the manufacturer’s guidance.
Siding, fencing, trim and decking
Specify actual dimensions, coverage width, profile, exposed face and finish for siding or trim. A nominal 1×6 board does not necessarily cover six inches after laps or tongues are accounted for. For fencing, clarify rails, posts, pickets and ground-contact requirements separately.
Use the approved fastening and support details for the selected product and exposure. Fastener appearance, corrosion compatibility and staining potential matter on exposed cedar. A wood species choice does not determine a universal support spacing or connection schedule.
Finishes and maintenance
Choose between a weathered appearance and a maintained color or coating. Surface preparation, end-grain treatment where specified and coating compatibility affect results. Test the system on representative material and follow the manufacturer’s recoat criteria rather than a fixed calendar promise.
At inspection, distinguish surface discoloration from soft, decayed areas and failed connections. Maintenance should include drainage paths, joints and fasteners as well as the finish. Record the product and coating used so later repairs can match the assembly.
Build your supplier specification
Enter what is known. Unspecified details stay marked for confirmation. Nothing is submitted until you review and send the sourcing request.
Review specification text
Material: Cedar Wood Application and exposure: To confirm Actual dimensions and lengths: To confirm Grade, faces and selection: To confirm Profile / milling / core: To confirm Moisture or bond classification: To confirm Quantity and unit: To confirm Delivery location, date and access: To confirm
Sources and verification
Reference guidance describes material selection, not a product inspection or engineering approval. Confirm the supplied product, current manufacturer instructions and project requirements. No stock, price, fire rating or service-life guarantee is implied.