Cedar Shake Roof Stain Versus Seal Sparrow Exteriors Specializing in roof repair and

Cedar Shake Roof Stain Versus Seal Sparrow Exteriors Specializing in roof repair and

Cedar Shake Roof Stain Versus Seal

Posted by Sparrow on May 3, 2013

We recently received a phone call from an Atlanta resident with a Cedar Shake roof who had a question concerning staining and maintenance.  Several of his neighbors have had their Cedar roofs sealed and he wanted an expert’s opinion. While the percentage of Cedar roofs in Atlanta is low when compared to asphalt shingles, we still have thousands of Cedar roofs throughout the Greater Atlanta area. Sparrow Exteriors is an expert in specialty roofing like Cedar, Slate, Stone-Coated Metal, Synthetic Polymers, Clay & Concrete Tile, etc.

While a Cedar roof provides a beautiful and rustic look to any home, it does require a little more maintenance than others. Given the high cost of a specialty roof like Shake, it is critical that it receives routine maintenance to extend its lifespan. For this reason we recommend annual inspections beginning around year 8. This way missing, broken, curling and otherwise damaged shakes can be repaired before compromising the roof system’s integrity.

There is quite a bit of confusion in staining versus sealing due in no small part to contractors who use the words interchangeably.  This means a simple Google search can be misleading. However, the Cedar Shake & Shingle Bureau advises against sealing and promotes staining. What your contractor should use is non-drying oil (WoodRich Timber Oil. Ready Seal. Wood Defender a parafinnic, non curing oil). While clear “stains” are available, without stain pigments shakes will stay or turn gray. This is a matter of personal preference. Do you like the look of fresh cedar, or the rustic weathered gray?

When it comes to cleaning, staining and sealing, here’s what you need to know…

Take this opportunity to repair the roof if routine maintenance has not been previously performed. Then move on to cleaning the shake and finally staining it.

Powerwashing is the most controversial issue in the care and maintenance industry. It’s a fact that high pressure cleaning by the inexperienced will cause significant damage to any material, including Cedar Shake. Most debris can easily be removed with basic garden hose level water pressure.

Some contractors powerwash to clean roofs, while others do not. If powerwashing is to be used, the roof should receive a topical treatment to restore the roof afterwards.

Sparrow Exteriors bases our use of powerwashing on the individual roof and its condition. We do not believe in a one size fits all approach to specialty roofing! The CSSB (Cedar Shake & Shingle Bureau) recommends having a professional assess each job on an individual basis and we couldn’t agree more! A professional should consider the following factors to determine if powerwashing is appropriate or not:

• Age, condition and environment of roof

• Gallons sprayed per minute

• Fan tip size

• Distance spray nozzle is held from roof

• Pressure per inch and others…

First a word of caution: Pressure-impregnated (pressure treated) and fire-retardant cedar shake products should not receive after market roof treatments without written permission from the manufacturer of such products.


• Offer a MSDS (Material Safety Data Sheet that lists  product ingredients and 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 of this product.

Cedar Shake Roof Stain Versus Seal Sparrow Exteriors Specializing in roof repair and

• Is a water repellent, UV inhibitor, and/or EPA registered  wood preservative.

• Has a manufacturers performance guarantee


• Makes outrageous claims (such as a 10-year effectiveness).

• Makes fire-retardant claims.

• Is a sealant, waterproofer or plasticizer.

• Contains unfortified linseed oil, diesel fuel or crank case oil.

There are numerous bleaching and cleaning agents on the market and being promoted by various contractors. Many claim to be effective on moss/mildew removal or accelerating cedars change to the weathered gray color. It is in your best interests to heed these precautions before allowing such products to be applied to a cedar roof.

For example:  While many contractors in Atlanta use and promote Thompson’s WaterSeal. a simple call to the manufacturer reveals this product should not be used on Pressure Treated Cedar Shake roofs. Additionally, should your cedar roof be untreated they anticipate the coating only lasting roughly 18 months.

For more information, we recommend consulting the Cedar Shake & Shingle Bureau .

Leave a Reply