Note: This is cleaning/treatment/restoration only. We do not offer roof repair services.
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How to Clean Your Asphalt Shingle Roof without Damaging the Shingles

how to clean roof without damaging shingles


Asphalt shingle roofs are a popular choice for homeowners due to their affordability and durability. However, over time, they can become covered in dirt, debris, algae, and moss, which can not only be unsightly but can also damage the shingles. Cleaning your roof shingle is an essential part of maintaining its longevity and appearance. Here is a guide on how to clean asphalt shingles without causing any damage.

Why Clean Your Roof Shingle?

Your roof is the first line of defense against harsh weather conditions such as wind, rain, snow, and ice. If it is not maintained properly, it can lead to costly repairs, leaks, and even structural damage. Regular cleaning can prevent any damage to your roof and keep it looking new. That’s the reason why roof cleaning is necessary.

Materials You Will Need

  • Garden hose
  • Soft bristle brush
  • Roof cleaner
  • Safety gear (gloves, goggles, and slip-resistant shoes)

Avoid Using Chlorine Bleach

While chlorine bleach is an effective cleaning agent, it can damage your shingles. It can cause the granules on the shingles to come off, reducing their lifespan. Moreover, bleach can also discolor the shingles, leaving behind unsightly streaks. Therefore, it is best to avoid using bleach when cleaning your roof.

Use a Roof Cleaner

Using a roof cleaner is the best way to clean your roof without damaging the shingles. Roof cleaners are designed specifically for cleaning roofs and are safe to use on asphalt shingles. They are available in both spray-on and hose-on formulas. A roof cleaner will help remove any dirt, algae, and moss that has accumulated on the shingles.

Rinse Thoroughly

After applying the roof cleaner, it is important to rinse your roof thoroughly. Use a garden hose to rinse off any dirt or debris that has been dislodged by the cleaner. Make sure to rinse the roof from the top down to prevent any water from getting under the shingles.

Avoid Using a Pressure Washer

Using a pressure washer to clean your roof shingle can be tempting, but it can also cause damage. The high-pressure water can dislodge the granules on the shingles, reducing their lifespan. Moreover, it can also force water under the shingles, causing leaks and other damage. Therefore, it is best to avoid using a pressure washer when cleaning your roof.

Use a Soft Bristle Brush

A soft bristle brush is an excellent tool for removing any remaining dirt, algae, or moss from your roof. Gently scrub the shingles with the brush, using a back-and-forth motion. Make sure not to apply too much pressure, as this can damage the shingles.

Beware of Black Streaks

If you notice black streaks on your roof, it could be a sign of algae growth. Algae can feed on the limestone filler in your shingles, causing them to deteriorate. To remove black streaks, use a roof cleaner specifically designed to kill algae.

Prevent Algae and Moss Growth

Preventing algae and moss growth is key to maintaining the longevity of your roof. Trim any overhanging branches or trees that may provide shade and allow moisture to accumulate on the roof. You can also install zinc or copper strips on the roof ridge to prevent algae and moss growth.

When to Hire a Professional Roof Cleaning Service

If your roof is heavily covered in dirt, debris, algae, or moss, or if it has not been cleaned in several years, it may be best to hire a professional roof cleaning service. They have the necessary tools and expertise to clean your roof thoroughly without causing any damage.

In conclusion, cleaning your asphalt shingle roof is an essential part of maintaining its longevity and appearance. With the right tools and techniques, you can clean your roof shingle without causing any damage. Avoid using bleach and pressure washers, and instead, use a roof cleaner and soft bristle brush. Rinse thoroughly and prevent algae and moss growth to keep your roof looking new.

Regular cleaning can also help you identify any issues with your roof shingle early on. If you notice any missing or damaged shingles or any signs of leaks, it is important to address them immediately to prevent further damage.

In addition to cleaning your roof shingle, you should also have it inspected by a professional at least once a year. They can identify any potential issues with your roof and recommend necessary repairs. By following these tips, you can clean your roof shingle without causing any damage and keep it looking new for years to come. Regular maintenance and cleaning can also help you avoid costly repairs and prolong the lifespan of your roof.

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

Meet Bruce

50 Years of Experience &
Over 2,000 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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