Yellow Cedar
Yellow-cedar (Chamaecyparis nootkatensis) grows along British Columbia’s coastal region. It is a medium-sized tree growing up to 24 metres tall and 90 cm in diameter when mature. It often grows singly or in small clumps in a mixture with conifers such as amabilis fir and western hemlock. It is a beautiful tree that is tough, solid and extremely durable.
Common Uses
Yellow-cedar is one of the world’s most durable woods with exceptional longevity. Due to this attribute it is used for shingles, posts, poles, marine pilings, small boat hulls, oars and paddles, water and chemical tanks, exterior doors, and window boxes. Structural grades are commonly used for exterior applications such as bridges, decking, stairs and for landscaping. It is sometimes used in specialty construction projects such as temples and shrines.
Unlike most softwoods, density across single growth rings is quite uniform making this a very good carving and woodworking species. This effect also accounts for the lack of visual grain. This wood is incredibly easy to work and, therefore, is prized for applications such as joinery and carpentry, decorative panelling, furniture, mouldings and cabinetwork. Its fine, even texture makes it a top choice for carvings and turnings.
Yellow-cedar lumber is often sold green due to its unique properties. When dried, lumber is dried according to end-use and customer specifications. Kiln drying inhibits natural staining of the wood, improves its strength and stiffness, enhances its appearance, and increases its resistance to decay and attack by insects.
| Physical Properties |
|---|
| Density (kg/m3) | Green | 419 |
| Air Dry | 431 |
| Specific Gravity (12% M.C.) | Standard | 0.42 |
| Hardness (N) | Side | 2510 |
| End | 3960 |
| MOE (Mpa) | Green | 9240 |
| Air Dry | 11000 |
| MOR (Mpa) | Green | 45.8 |
| Air Dry | 79.7 |
| Compression Parallel (Mpa) | Air Dry | 45.9 |
| compression Perpendicular (Mpa) | Air Dry | 4.74 |
| Shear (Mpa) | Air Dry | 9.21 |
| Cleavage (N/mm Width) | Air Dry | 45.4 |
Shrinkage
OD=oven dry
air=air dry 12% | Radial (OD) | 3.7% |
| Tangential (OD) | 6.0% |
| Volumetric (OD) | 9.4% |
| Volumetric (air) | 5.0% |
| Tang / Rad ratio | 1.6 |
Working Properties
Yellow-cedar is considerably harder when dry than most commercial softwoods so it is strong. It is known for its exceptional working properties and can be easily machined and finished. It turns, planes and shapes well and can be sanded to a smooth finish. The wood glues satisfactorily, has moderate nail and screw holding ability, and takes a good finish.
| Process | Performance | Comments |
|---|
| Machining |
|---|
| Planing | Excellent planing quality | Recommended planer settings: 20o hook and 8, 12, 16, or 20 kmpi (knife marks per inch). No major defects. Slight dulling effect on cutting tools. |
| Turning | Medium to high surface quality | Good surface quality when turned using a rotary knife lathe. |
| Sawing | Easy to work with tools | Known for its exceptionally good working qualities. |
| Boring | Moderate | Much better boring quality with brad point bits than with single twist bits. |
| Mortising | Good to moderate | Excellent mortising quality is found with a hollow chisel mortise. |
| Shaping | Good shaping quality | Recommended: The use of a counter piece for end-grain shaping. |
| Veneering | N/A | |
| Sanding | Excellent | |
| Fastening |
|---|
| Screwing | Moderate | Average screw retention: 476 lb. |
| Lateral Nail Holding | N/A | |
| Nail Retention | Good | Equivalent to Douglas-fir. |
| Gluing | Satisfactorily | Bonds satisfactorily with good-quality adhesives under a moderately wide range of bonding conditions. |
| Finishing |
|---|
| Staining | Moderately easy | Natural finish looks best. As stain gets darker, uneven colour is pronounced. A wash coat would even out colour differences. |
| Painting | Moderate paint holding ability | Older wood should be wiped with paint thinner to remove surface "greasyness". |
| Lacquering | Good to moderate | Reasonably smooth results with only two topcoats. |
| Waxing | Good | Good results are obtained when using light- to medium-coloured waxes (e.g. Mellow Pine, Chestnut). |
| Drying |
|---|
| Ease of Drying | Moderately easy | Dries without difficulty, but there is a tendency for surface checking to occur in thick stock with some end splitting if the drying is forced. |
| Durability |
|---|
| Natural Decay Resistance | Durable | Appropriate for outdoor usage. |
| Treatability | Impermeable | Can be improved by incising. |
Commercial Availability
In North America structural grades are in accordance with the National Lumber Grades Authority (NLGA) rules for dimension lumber. Yellow-cedar is currently marketed under the Northern Species group making its official structural design value lower than SPF, Hem-Fir, or DFir-Larch. However, yellow-cedar is used structurally for its appearance and for its decay resistance.
Yellow-cedar is commonly produced in appearance grades according to NLGA rules. Clears, shop lumber and moulding stock are most common. Yellow-cedar is also offered in export grades for Japan and other markets.
Sources
BC Wood Specialties Group, www.bcwood.com
Coast Forest Products Association, www.coastforest.org