Western Red Cedar

Western Red Cedar


  • Light, though relatively solid, resilient North American softwood
  • Durable and highly resistant to rot and weathering
  • Unique colour variations: from light yellowish-brown to pinkish-brown and salmon-coloured to chocolate brown
  • Suitable for innumerable exterior applications, such as shingles and shakes, profiles, wall cladding, eaves, window frames, pergolas, terraces, conservatories and light constructions.
  • No 2 Clear and Better and No 4 Clear both guarantee outstanding quality
  • Easy to work
  • Often used untreated outside, where it naturally turns a beautiful silver-grey


Western Red Cedar is the commercial name for the botanical species Thuya plicata, which belongs to the Cupressaceae family. It grows between the 39th and 57th latitudes, the major growing zone being the Canadian province of British Columbia. Its distribution area runs as far as Alaska in the north and California in the south. Western Red Cedar also grows to the west of the Cascade Mountains, in rainforests along the coast and up to the Rocky Mountains. The many primeval forests in that area are highly varied due to the favourable climate. They constitute an important ecological reserve and consist of 40% Western Red Cedar and 60% Hemlock.



In favourable conditions, the Western Red Cedar can easily attain a height of 70 metres and a diameter of 4 metres at chest height. In less favourable conditions, it reaches an average of 25 to 40 metres, with a diameter of 1.5 to 2.5 metres. Striking is the rapid tapering of the diameter. The useful trunk length is approximately 25 metres. The Western Red Cedar lives to great ages, sometimes over a 1,000 years. Old specimens often have thick buttress roots and sometimes a hollow heart.

Colour and figures

Western Red Cedar has innumerable colour variations: from light yellowish-brown to pinkish-brown and salmon-coloured to chocolate brown. The heartwood is darker than the almost white sapwood. The sapwood zone is no wider than 2 to 3 cm. Light and dark bands alternate, giving a varied figure. The colour differences fade under the influence of light. On the quarter sawn surface, the colour contrast between early and late wood give a clear striped figure. The growth rings of the Western Red Cedar are generally fine, with several rings per mm. The lumber sometimes nevertheless has a coarse structure with growth rings up to 5 mm wide.


The heartwood is durable (natural durability class II).


Western Red Cedar is imported in various qualities:

  • No 2 Clear and Better: virtually defect free with smooth lined figures
  • No 4 Clear: has a number of defects that can easily been sawn out, quality sufficient for most applications
  • Factory flitches: sawable into shorter pieces, 80% fault-free, suitable for garden furniture, for example
  • Tight Knotty: wood with an unlimited number of healthy knots, f.ex. for deckings
  • Standard and Better: Slightly lower quality, but excellent for pergolas, bearers for terraces and various constructions


Western Red Cedar dries easily, particularly small cross sections. At a thickness of 30 mm, for example, it is advisable to first allow the wood to dry for two months on stickers in the open air before drying artificially. Thicker wood requires a specific drying process. Drying for a long period on stickers and then drying naturally prevents collapse and internal splitting.


Western Red Cedar is easy to work, both mechanically and manually. The dust may irritate. The early wood is soft. Using sharp tools and a moderate pressure on the working surface avoids compression, especially when planing and milling. Otherwise, the wood can exhibit a ribbed, irregular surface. Moreover, the wood is fairly brittle and risks crumbling at the edges. Make sure the blades and chisels (of machines) are clean and without burrs.


Western Red Cedar splits easily. Nevertheless, it can easily be nailed. The substances in the wood do react with metals such as iron and brass, which can cause corrosion. You should therefore use stainless steel.

Finishing and treating

There is no problem with painting or staining if the wood has been properly dried. Applying a coat of finishing paint or a transparent coating is also easy. Western Red Cedar is often left untreated for exterior applications. The wood then has a silky gloss and naturally turns grey, giving a beautiful silvery surface. North-facing wood risks flecks and algae growth. In areas with a lot of air pollution, the wood also darkens quickly.  The surface of the wood is soft and vulnerable.

  • Wall cladding
  • Shingles and shakes
  • Eaves
  • Window frames
  • Pergolas
  • Terraces
  • Conservatories
  • Light constructions
Professional information

Western Red Cedar 


Average density*

370 kg/m³

Radial shrinkage

60 to 30% r.a.h.**



90 to 60% r.a.h.**


Tangential shrinkage

60 to 30% r.a.h.**



90 to 60% r.a.h.**



60 to 30% r.a.h..**



90 to 60% r.a.h.**


Flexural strength

54 N/mm²

Modulus of the elasticity

8000 N/mm²

Compressive strength (parallel with the fibers)

34 N/mm²

Shear strength

5,6 N/mm²

Hardness - Radial

3040 N

Hardness - Surface

1470 N

* at wood moisture content of 15 per cent / ** relative atmospheric humidity


Commercial information


45 mm

52 mm

65 mm

105 mm

155 mm


105/155/205/255/305 mm

90 mm

155/205/255/305 mm

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