Natural Properties
The most important characteristics of Western Red Cedar are: its outstanding dimensional stability, fine texture, pattern of growth, and freedom from pitch and resin. These characteristics contribute to its exceptional ability to accept and retain many different types of finishes.

Paint strippers will also remove oil-based stains and latex stains. Most are supplied as ready-to-use liquids. After use, residual strippers should be thoroughly rinsed from the wood surface before any other coating is applied.

Dimensional Stability
Is the resistance of wood to swelling and shrinkage when it gains or loses moisture. Light, low-density woods such as Western Red Cedar shrink less than higher density woods. Its' excellent dimensional stability is an important factor responsible forthe longer life of paints on Western Red Cedar in comparison to other woods.

Texture
Refers to the smoothness of the wood surface after sawing, planing or sanding and depends on the size of the wood's cells. Paint performs better on smooth, finer textured, wood species than on coarse textured species. Western Red Cedar has smaller wood cells and a finer texture than most other conifers or softwoods.

Pattern of growth
Refers to the alternating bands of light-colored, low density, springwood and dark-colored, higher density, summerwood. Together, these two bands constitute one year of tree growth. Paint performs better over the lower density spring wood which Western Red Cedar has a greater percentage of than most other conifer species.

Pitch or resin
May interfere with the bonding or penetration of a finish can be found in most softwoods but are absent in Western Red Cedar.

Manufacturing Characteristics Surface Texture
Western Red Cedar products are available with a smooth (planed) or a textured (sawn or rough sanded) surface. As a rule, textured surfaces provide the best mechanical adhesion of the finish to the wood; for smooth surfaced Western Red Cedar, a two coat paint system is preferred.

Moisture Content
Finishing wood that is wet (above 20% moisture content) may increase the risk of coating failure. It is best to finish Western Red Cedar when its moisture content has stabilized at the level that will prevail during the service life of the product. In North America this level is approximately 12% moisture content. The best product choice is Western Red Cedar that is kiln dried at the time of manufacture.

Construction Practices
Construction practices have a significant influence on the performance of cedar and the finish over it. Care should be taken from the time the Western Red Cedar is delivered to the job site through to its installation and finishing. The moisture ontent of the wood (both prior to and during its service life), exposure to sunlight and surface contaminants (dirt) are important factors affecting the performance of each finish.

While it is not within the scope of this publication to describe in detail the many construction techniques necessary to maximize performance, the following brief checklist is helpful:

. Use stainless steel, hot-dipped galvanized or aluminum fasteners.
. Install flashing over all openings and above skirt and band boards.
. Provide adequate overhangs at eaves and gables.
. Install drip caps over windows and door frames.
. Allow at least 6 inches of clearance between the bottoms of siding and trim boards and the ground line.
. Allow at least 2 inches of clearance between the bottoms of the siding and trim boards and roofing materials.
. Install vapor barriers on the warm side of walls to minimize condensation within walls.
. Vent high humidity areas such as kitchens, laundries and bathrooms.
. Vent attics and crawlspaces.
. Keep cedar protected from the elements on the job site.
. Acclimatize Western Red Cedar to local humidity conditions before installing

Apply primer or stain to all six sides, including surfaces exposed after they are field-cut, before installing. Note that the end grain may require 2 coats to fully protect it.

Installing siding over a rain screen greatly decreases the chance that the backs of the siding will get wet and remain wet. This ensures that any water that penetrates the wall assembly will drain down and away from the walls. Rain screens also minimize moisture imbalances within the siding, thus reducing the potential for cupping and extractive bleeding. As a result, coating performance is markedly improved.