Cedar

Cedar shake roofs have many positive qualities. When installed properly, they are
extremely wind resistant. They have twice the insulating value of standard asphalt
shingles. Hail does not easily damage cedar shakes. When treated with certain chemicals,
cedar shakes can be made fire resistant.
Cedar shake roofs, have a certain amount of prestige as a roofing material. This is why
many of the other roofing product companies manufacture materials that simulate real
cedar shakes. The texture, color, and appearance of a cedar shake roof very appealing.
However, this beauty comes with a price. Cedar shake roofs do require a certain amount of
maintenance to maximize their useful life. The enemies of cedar shakes, as you might
expect, are water and sunlight.
Many people know that cedar contains high amounts of natural chemicals which help
preserve the wood. These chemicals are called extractives. They dissolve easily in water.
In certain conditions, rainfall can leach these chemicals from the cedar shakes in less than
10 years.
Ultraviolet light (UV) from the sun actually causes the surface cells of the cedar to break
down. This microscopic refuse is washed away with each rainfall. UV rays also cause very
tiny cracks to develop which allows water to drive deeper into the shakes. This simply
accelerates the process of dissolving the extractive chemicals.
The key to maintaining a cedar shake roof is to help it dry. What I mean is that after a
rainfall, a cedar roof needs to dry out as rapidly as possible. The shakes must be free of
moss, fungus, debris (twigs, pine needles, leaves, etc.), or any other thing that can trap and
hold moisture. Overhanging tree branches must be sufficiently high so as to provide good
air circulation above the roof.
Chemical preservatives are available which can be applied to cedar shakes. These
preservatives when applied to clean, dry cedar shakes can dramatically add years of life to
a cedar roof. Most of these chemicals can be applied with a hand held sprayer. Professionals
who treat cedar roofs for a living have pressurized machines that allow them to do large
roof areas efficiently in a short amount of time. When selecting a coating for a wood roof,
make sure the product is appropriate for cedar roofs. Never use a waterproofing, sealant or
other coating that creates a film or otherwise encapsulates the wood. Wood roofing needs to
breath, therefore, penetrating oil finishes are best for cedar shake and shingle roofs. An
airless sprayer is the preferred method of application.
If you decide to clean and treat your roof yourself, you need to exercise extreme caution.
You need to protect yourself from the dangers of falling. You need to protect your roof from
the dangers of cleaning. Cedar shake roofs that are damp, covered with moss, or any object
can be extremely slippery. I once stepped on some moss on a low pitched cedar roof and
ended up at the bottom before I knew it. Serious and fatal injuries are a big threat.
The use of mechanical power washing equipment used in untrained hands can seriously
damage your shakes. Cedar is a soft wood. Cedar that is covered with damp moss is even
softer. A low pressure power washer is recommended so the cedar does not get damaged.
A great cleaner for cedar shake roofs is oxygen bleach. This non-toxic cleaner is a powder
you mix with water. It will not harm the cedar roofing or anything else it contacts. You
must saturate the shakes for about 10 to 15 minutes with the solution making sure it does
not evaporate. Lightly scrub the shingles with a push broom and rinse with a garden hose.
The shakes will look brand new!
How long a cedar shake or shingle roof lasts depends on a variety of factors, including the
quality of the wood used, the quality of the installation, environmental conditions and
whether or not the roof is maintained. Cedar shakes and shingles may also be pressure-
impregnated with preservatives for use in areas with high humidity. Pressure-
impregnated fire-retardant treated products are often installed in California.
“The reason shake roofs deteriorate is because natural oils are washed and baked out of the
wood by rain and the sun’s UV rays,”
In between treatments, it is important that roofs be kept clear of debris. “Debris, such as
leaves, pine needles, etc., holds moisture, providing ideal conditions for moss, mold and
mildew. Seasonal removal of debris will help keep the shakes in sound condition.

Below Is Before and After pictures of a Cedar Roof in Easton Pennsylvania which was
restored by: Dutt Roofing Solutions

Before