Thuja plicata heartwood is generally a pinkish salmon to red colour but can also be chocolate brown. The sapwood is narrow and almost white. WR Cedar is dimensionally very stable. The texture is fine but uneven due to the prominent growth rings and the grain is straight. 

Uses and applications: WR Cedar, with its attractive appearance, is suitable for panelling and joinery. However, because the timber is soft it is subject to indentation and therefore should not be put in applications requiring hard-wearing timber. WR Cedar is ideal for exterior cladding, provided only heartwood is used. 

Physical and Mechanical Properties: WR Cedar is a low-density softwood. It is not a structural timber, being considerably weaker than pine. 

Galvanised fixings are recommended for exterior uses because unprotected iron nails stain the timber. Alternatives include stainless steel, silicon bronze or copper. Nail holding is poor to medium and annular grooved nails or special fasteners may be required to ensure a strong assembly.  

Not suitable for applications subject to loads or surface abrasion (wear), because of its low density and softness. Subject to surface erosion from exposure to weather. 

WR Cedar is easily worked. Since WR Cedar is very soft there is a risk when dressing it that the cutters may compress the softer earlywood which will later recover to produce a ridged surface. Thus sharp cutters are required. Sanding dust can be very irritant to the breathing passages so a well-ventilated workshop is essential. 

WR Cedar takes glue, stain and paints well.

  • Category
    Wall Panels & Cladding , Timber, Flooring

Botanical Name
Thuja Plicata 

Other Names
Cedar, Giant Arbor Vitae, Red Cedar 

North America

Scope of use


  • Structure
  • Wall/Ceiling
  • Furniture
  • Mouldings 


  • Structure
  • Wall/Cladding
  • Door/Windows
  • Mouldings

Natural durability
WR Cedar heartwood is not ground-durable. It is durable in above-ground exposure conditions and is suitable for exterior applications such as cladding. Sapwood is perishable but is suitable for use indoors. 

It is one of our three most highly recommended species for weatherboards! 

Board lengths range from 1.8m to 6m


Certifications Available
PEFC/40-31-26 Promoting Sustainable Forest Management

Smaller sizes dry easily, larger boards need extra care to prevent internal checking and collapse. Almost no tendencies to warp and check once dry with little swelling or shrinking movement. 

Working Qualities
The timber is easily worked, but its brittle nature can cause splintering also its soft character can lead to chip-bruising. Care should be taken when planning and moulding, sharp cutters will also help create a nice finish. Stains and paints well. 

Interior panelling, fine furniture, interior and exterior joinery, weatherboards and cladding.

Basic Info

Durability Above Ground Durable 

Density Air Dry 380 kg/m3 

Shrinkage Radial 2 %
Shrinkage Tangental 5 % 

Stability Kiln Dry Very Stable
Stability Green Stable

Mechanical Properties

Janka Hardness 1.6 kN
Modulus of Rupture 53 MPa
>Modulus of Elasticity 7.7 GPa
Max Crush Strength 35 MPa
Strength Group UnseasonedS7
Streanth Group SeasonedSD7
Comp Strength Perp to Grain3.4 MPa
Shear Strength Parallel to Grain 11.6 MPa 

NZAS Ignitability 14
NZAS Flame Spread 10
NZAS Heat Evolved 9
NZAS Smoke Developed 4<
ASTM Flame Spread 70
ASTM Smoke Developed 213

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ITI Timspec is a wholesaler supplier for the Trade. For all non-trade pricing enquiries, please contact your preferred Timber supply Merchant.
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Timspec was established in 1990 as a wholesaler of specialty timber and was wholly New Zealand owned. In March 2019 Timspec was acquired by ITI Australia and became ITI Timspec LTD.  

Today we import, export, and wholesale a huge range of timber to builders, joiners, home owners, floor layers, landscape builders and furniture manufacturers. We pride ourselves on being environmentally responsible and strive to source the most sustainable timber options available. Timber stocked includes species from North America, South America, Europe, Africa, South East Asia, Australia, and New Zealand's exotic as well as indigenous species. 

The ITI Timspec team are extremely knowledgeable about the various types of timber, treatments and uses available and are happy to help you in choosing the right product for your project.