All about Cedar Shake & Shingle Roofs

In order to truly understand your roof, it is helpful to understand what kind of material is keeping you dry. There are various media for roofing including asphalt or fibreglass laminate, metal, clay tile and several types of materials made from recycled rubbers and plastics that are very common.

This website is concerned about cedar roofs only.

In the Greater Vancouver area, cedar is the only roofing material that is of natural source. It is the only wood material approved for roofing.

There are many types of cedar shakes and shingles though. The type of shake your roof is composed of will be a major factor in determining how long your roof will last.

A general rule of thumb states that the thicker the shake the longer it will last. This is also true if the shake is handsplit rather than tapersawn. If the shake is pressure treated at the mill, the shake can last upwards of 50% longer than untreated.

Cedar Shakes and Shingles

• Cedar shingles are more expensive compared to most Asphalt Shingles and slightly more expensive than a properly installed Concrete Tile but less than most Clay Tile.
• Cedar shingles are one of the most difficult roofing materials to install correctly.
• Cedar shakes are fairly easy to cut valleys and around roof protrusions using a circular saw.
• Cedar shakes require a great deal of craftsmanship to install correctly.  A beginning roofer can be taught to install Cedar Shakes and Shingles properly with supervision in about a year or so but it takes years of experience to be a craftsman at it.
• Cedar shakes are a 2 or 3 ply roofing system if Cedar Shakes (depending on weather exposure) and a 3 ply roofing system if Cedar Shingles, meaning that when drilling a hole anywhere through the exposed surface area of the shingle there are one or two layers below that the drill would have to go through before reaching the underlayment.
• have little chance of leaking in the field because of their multiple plies.
• can easily be walked on without damaging the roof.
• are fairly easy to repair.
• should last 20 to 25 years or more depending on the quality of the installation and the wood.  In some areas like Colorado can last 40 or more years.
• can be installed as a Class A Fire Rated roof system at additional costs and somewhat less life expectancy.
• are more resistant to damage from hail than most other types of Steep-Roofing materials.
• are more resistant to wind blow off than most other types of Steep-Roofing materials.  If installed properly can withstand 160 mph plus winds.
• can be easily installed on small areas and on difficult cut up architectural areas.
• will resist snow sliding off better than most other roofing materials because of the surface adhesion they provide.
• are medium in weight, from about 2 pounds per square foot to just over 3 pounds per square foot depending on how wet they are.
• fade naturally to a grey brown.
• are easily matched.  A replaced area or shingle will at first stand out but within a year or so completely blend in.
• come in only one color and shade unless you paint them, which is not recommended.
• can be installed in all temperatures from near 0 to 120 degrees or more.
• are very slippery when wet.  Are very dangerous to walk on when wet.

The Does & Don'ts of Cedar Roof Restoration

According to the Cedar Shake & Shingle Bureau

Topical Treatment Products

It is not within the mandate of the Cedar Bureau to recommend brand names of topical roof treatment products. Consult with your local professionals for product information regarding cleaning and preserving cedar in your area. The Cedar Bureau does however, recommend the following:

Do use a topical treatment that:

• Offers a MSDS (Material Safety Data Sheet) that lists the ingredients and the safety precautions.
• Is labeled as a cedar roof treatment product or has a letter from the manufacturer stating that treating cedar roofs is an appropriate use for this product.
• Is a water repellant, UV inhibitor, and/or EPA registered wood preservative
• Has a manufacturer’s performance guarantee

Do NOT Use a topical treatment that:

• Makes outrageous claims (such as a 10 year warranty)
• Makes fire retardant claims
• Is a sealant, waterproofer or plasticizer
• Contains unfortified linseed oil, diesel fuel or crank case oil

The Cedar Bureau is aware of numerous bleaching and cleaning agents. Consumers are advised to heed the preceding topical treatment precautions before allowing such products to be applied to a cedar roof.

Cedar Roof Power Washing

This is the most controversial issue in the care and maintenance industry. It is a fact that pressure washing by inexperienced people will cause significant damage to any material. Some debris can be easily removed with garden hose pressure.

Some contractors do power washing to clean cedar roofs, while others do not. If power washing is used, the roof should receive a topical treatment to restore the roof.

The Cedar Bureau recommends having a professional assess each job on an individual basis to determine if power washing is appropriate or not. Care and maintenance professionals know the proper procedures, which include factoring in:

• Age, condition and environment of roof Gallons sprayed per minute
• Distance spray nozzle is held from roof Pressure per square inch and others…
• Fan tip size

The Beauty of Cedar

Another good thing about cedar is that it is possible to replace and repair parts of the roof, without worrying that your replacement shakes or shingles are significantly different in composition from your original shakes or shingles. Over the hundreds of years that cedar has been used, the product has remained unchanged…it’s still cedar. As cedar advances to its mature stage, it is natural to expect some pieces to require replacement. Individual repairs are possible, and with prompt attention, proactive repairs can extend the life of your wise Certi-label cedar investment.

Copied verbatim from the New Roof construction Manual issued by the Cedar Shake & Shingle Bureau January 2006
Contact address: #2-701 Horne Street Mission BC V2V 7A2
Website: www.cedarbureau.org Telephone: 604-820-7700

Environmental considerations

• Think Green

• Keep the cedar roof you have

• Repair your cedar roof

• Maintain your cedar roof

• Green Roofing at its best

Two major factors that impact what to do with your roof or, in fact anything in your life, these days.

They are the cost (value) of the decision and the environmental impact on our lives by making the decision. The bottom line is always going to come down to the dollar impact unless we are truly wealthy and altruistic in our beliefs. Most of us are not at that point in our lives. We want the best value for our investment no matter which way we decide to go with fixing our roofing concerns.

Getting past the dollar concerns, we believe it is essential that we give consideration to the environment in the decision making process.

We all know that eventually the roof on our home is going to have to be changed. But doesn't it make sense to keep the roof intact for as long as feasibly possible?

There is a belief amongst some people that a cedar roof should be left alone until it is either rotten and falling or or until some salesman comes along and convinces the owner that the roof has too go.

Too often, in our estimation, cedar roofs are replaced that are still good or may have lasted longer if it had been looked after.

Creating and managing a consistent repair program is key to the longevity of your roof. While repairs alone will not extend the life of the roof directly, it does extend the servicibility of the roof. It will extend the roof by stopping rot from spreading unnecessarily.

Environmentally, repairing your cedar roof is worthwhile because over the long term, it reduces the amount of garbage going to the dump.

Cleaning and treating your roof with Timber Pro UV Roof Treatment is also a good environmental consideration. This product is designed to feed nutrients back into the cells of the shakes and to protect the shakes from the ravages of the sun. To my knowledge, it is the only product that actually extends the life of the cedar roof available in the Lower Mainland.

Other products generally are solvent, acrylic or silicone based. They smother the roof causing the natural respiration to be inhibited or even eliminated. Respiration is absolutely necessary for the longevity of the roof. It is much like applying a suntan lotion or moisturizer to your own skin. You need to apply something that supports your skin's ability to breathe, otherwise difficulties will ensue.

Timber Pro UV is recognized by The LEEDS green building program as well as the GVRD Buildsmart program.

Environmentally speaking doing the full program of repairs and treatment is of great value because it keeps you in your roof for an additional 5-7 years over the repairs only scenario. That is about 1/2 more of life for the roof.

Maintaining your roof keeps the material on your roof, on your roof longer. That reduces the amount of garbage in the land fill and lets you keep your cedar roof for much longer. It reduces the number of cedar trees that need to be cut down and reduces our dependency on oil by reducing the need for more asphalt/fibreglass shakes to be manufactured.

We believe it is a win-win situation for all of us and you get to have a beautiful roof as a bonus.




If you would like to know more about cedar shakes, please have a look at the powerpoint presentation on this page.

If you do not have powerpoint on your computer, you can get valuable information from the Cedar Shake and Shingle Bureau's website www.cedarbureau.org.