Note: This is cleaning/treatment/restoration only. We do not offer roof repair services.
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How to Maintain a Cedar Shake Roof in 2022

How to Maintain a Cedar Shake Roof in 2021


Bruce's Quick Guide on How to Maintain a Cedar Shake Roof

A cedar shake roof will decay if it is infested with algae, moss, mold, lichen, and fungi.

Here’s how to maintain a cedar shake roof to keep it in good shape.

A roof installed with cedar shakes is designed to last and given the proper care and maintenance, it will last a long time, even if the cedar shakes look old and weathered they can be saved.

Roofs installed with cedar or redwood shakes have been used for generations and are one of the oldest roofing materials. Originally, the shingles and shakes were spread atop spaced lathing strips to keep the shakes dry. As a result, roofing made of cedar or redwood would persist for many generations.

This is because cedar and redwood shakes do not decompose on their own. Moisture is required, as well as some type of infestation (moss, mildew, lichen, mold, or fungi). As a result, the only way to get the most out of a cedar/redwood roof or siding is to maintain it and have it cleaned regularly.

The installation of cedar/redwood roofs that were installed in the last 30 years has changed.

The usage of a lath construction is no longer common; instead, they are now erected on decking with an underlayment, or roof felt.

Although the felt acts as a good water barrier, the shakes are often unable to breathe or dry properly due to insufficient spacing between the felt and the shakes. As a result, the shakes retain moisture, allowing infestations to thrive. There is supposed to be a layer of cedar breather between the felt and shakes.

Walk on a Cedar Shake Roof
How to Maintain a Cedar Shake Roof
How Long Does a Cedar Shake Roof Last?

If regular roof maintenance and cleaning are not performed, the shakes will lose their integrity over time, resulting in interior water damage and premature roof replacement.

Many cedar/redwoods shake roof owners are unaware that they must maintain their roof for it to reach its natural life span of 40 to 60 years. A homeowner will usually see green moss or mold, lichen, or the dark brown to black hue of fungi after a 10-year period of not cleaning.

Cleaning is essential for a cedar shake roof’s longevity.

Many homeowners feel that a new roof is required at this time, while in truth, a thorough cleaning will typically cure the problem. The pests and moisture are removed from the wood roof once it has been thoroughly cleaned, allowing the shakes to breathe and keep dry once more. A decent cleaning should last between seven to 10 years on average.

Staining and sealing a cedar/redwood roof is good for aesthetic appearance but provides no practical value to the roof’s long-term preservation. Sealing cedar/redwood roofs is never a good idea since it prevents the shakes from accessing the air, they require to stay dry. Cedar shakes need to be able to breathe.

In addition to cleaning, make sure there is no debris in the valleys and that there are no overhanging trees overhanging the roof, which will produce dampness and shade. Also, any missing shakes that would expose the felt should be replaced, as UV rays might cause felt degeneration.

A cedar or redwood roof can survive for decades if properly maintained.

Cedar Shake Roof Cleaning in Des Moines Iowa
Cedar Shake Roof before & after cleaning

Meet Bruce

50 Years of Experience &
Over 1,500 Shake Roofs Cleaned

Bruce Sullivan has over 50 years of experience in maintaining, cleaning, and restoring cedar shake roofs. Making him one of the top authorities on cedar shake roofs in the US.

Watch the Cedar Shakes Cleaning Process in Action in this video

Play Video about Roof Cleaning How to Remove Moss, Lichen, Fungi from a Cedar Roof Sullivan Roof


What can I say? Bruce and Keith provided an exceptional service, and they are really nice guys too. Found out at the last minute they were in Minneapolis, and they fit me in for a cedar shake roof cleaning the next evening after their regular job was done. Even cleaned up my gutters, small fence, and small deck at no charge. The place looks outstanding! Highly recommended.

Mike Richards

I highly recommend this business. Due to the work performed we are going to get another 10-14 years out of our cedar shake roof. We were told by some roofing companies that the roof should be replaced in 2 years. I lucked out and found Sullivan Roof Cleaning while researching companies that perform this service, and was pleased to learn that the company does work outside of Iowa. If you need your cedar shakes cleaned, go with Sullivan Roof Cleaning.

Eric Oelrich, 
St Cloud, MN

Bruce did a great job cleaning the whole exterior of my house. The roof has new life! It looks practically brand new. All the mold and moss on the roof, on the gutters, under the eaves, completely gone. He exceeded all our expectations. When he tells you what he can do for your house, you can believe and trust him. Great guy, great service.

Stuart Malone
Kansas City, MO


Cedar shakes are organic. Though a resilient material. Being organic they need to be maintained. Over time, like any organic material that are subjected to weather elements, they reach a stage of deterioration. Like UV exposure, moisture and seasonal changes. Which results in moss, mold, mildew, lichen and brown rot fungi. These infestations need to be removed to further preserve the integrity of the cedar shake.
The proper way to clean a cedar shake roof is from a ladder. By spraying a special formulated solution onto the shakes and then rinsed with a garden hose pressure. Best done by a professional cedar shake roof cleaner. Not DIY recommended.
No. Pressure washer will require walking on the shakes, which will harm them, and even at its lowest setting will also damage the shakes.
On average, cedar shakes should be cleaned every 10 ten years. Subjective to the grade of the shakes and the amount of surrounding tree cover.
Avoiding walking on a cedar shake roof, other than for repairs.
Never seal a cedar shake roof. Cedar shakes need to breathe. They expand and contract in rain conditions. Seal will shorten the lifespan, to the point of premature replacement.
Staining has no real preserve value and can also harm the integrity of shakes, as stated, they need to be able to breathe. Also, if the shakes are not properly cleaned staining can seal the deteriorating infestation within the shakes.
Depending on the grade of the shakes and installation, and if maintained properly, 40 to 60 years.


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