How to Clean Roof Shingles the Right Way (from Expert Roofers)

“Did You Know? A well-maintained roof can last up to 50% longer than a neglected one.”
When it comes to preserving the lifespan of your home’s most critical asset, regular maintenance is key. Yet, many homeowners overlook the importance of cleaning their roof shingles—a task that, when done correctly, can protect your home from costly damage and extend the life of your roof by decades.

But here’s the catch: improper cleaning methods can do more harm than good, potentially leading to expensive repairs or even a complete roof replacement.

In this guide, we’ll walk you through the right way to clean your roof shingles, helping you avoid common pitfalls and ensuring your roof remains in top condition. Whether you’re dealing with algae, moss, or just general grime, these expert tips will equip you with the knowledge to keep your roof looking great and functioning at its best.

Table of Contents

Firstly, can you clean shingles?

While it is technically possible to clean shingles using the methods outlined below, we typically don’t recommend you clean them since you can easily damage them.

If you’re at the stage of your shingles needing a clean, the roof is either nearing the end of its lifespan anyway, or the material quality wasn’t up to par in the first place.

So, what can you do?

Well, this is where you should consider replacing your roof, especially if you’re likely going to be in the same home for a decent amount of time.

If you’re in Wisconsin, get in touch with our team here at Prairie Exteriors for a quote on shingle replacement.

How to clean roof shingles step by step

Before starting the cleaning process, it’s important to know the type of shingles you have. Asphalt shingle roofs, for instance, are delicate and can be damaged by aggressive cleaning. Once you’ve identified your shingle type, you can proceed with the cleaning.

To clean your roof shingles, you can use a mixture of bleach and water. This solution is effective in removing moss and algae formations. Alternatively, you can use a mixture of equal parts water and sodium hypochlorite to scrub away algae. If you need a stronger solution, use two parts sodium hypochlorite to one part water.

Remember to rinse the roof thoroughly after cleaning to prevent any residue from damaging the shingles.

Cleaning roof shingles while on the roof requires careful attention to detail and safety precautions as a priority:

1. Safety first

Before you even think about climbing onto your roof, prioritize safety. Roof work can be hazardous, especially if the surface is wet or steep.

Harness: Always wear a safety harness that is securely anchored to a stable point on the roof. This will prevent falls in case you slip.
Non-slip Shoes: Invest in good-quality, non-slip shoes designed for roofing work. These will provide a better grip and reduce the likelihood of slipping.
Sturdy Ladder: Use a sturdy, extension ladder that reaches at least 3 feet above the roof edge. Secure the ladder at the base and at the top to prevent movement. Consider using a ladder stabilizer for added safety.
Weather Conditions: Choose a clear, dry day for roof cleaning. Avoid working in wet or windy conditions, as they increase the risk of slipping. Early morning or late afternoon, when the sun is not at its peak, are ideal times.

2. Remove debris

Before applying any cleaning solution, remove all loose debris from the roof. Debris like leaves, twigs, and dirt can trap moisture, leading to moss and algae growth.

Tools: Use a leaf blower for large, loose debris. For smaller, more stubborn debris, a soft-bristle brush is ideal.
Technique: Begin at the roof’s peak and work your way down, gently sweeping or blowing debris off the roof. Be careful not to scrape or press too hard on the shingles, as this can dislodge the protective granules.
Gutters: Don’t forget to clear the gutters while you’re up there. Clogged gutters can lead to water buildup, which can seep under the shingles and cause damage.

Be gentle to avoid damaging the shingles when doing this!

3. Moss and algae treatment

Once the loose debris is clear from the roof, If it has visible moss, algae, or lichen, it’s crucial to treat these before they cause long-term damage, apply an appropriate roof cleaner following the manufacturer’s instructions.

Choose a Cleaner: Select a roof cleaner specifically designed to remove moss and algae. Sodium hypochlorite-based cleaners are effective but require careful handling.
Application: Pour the cleaner into a pump sprayer for easy application. Starting at the top of the roof, spray the cleaner evenly over the affected areas. Be sure to follow the manufacturer’s instructions regarding dilution and application.
Wait Time: Allow the cleaner to sit for the recommended time, typically 15 to 20 minutes. This gives the solution time to break down the moss and algae, making it easier to remove.

Allow it to sit for the recommended time to loosen growth.

4. Soft washing

Soft washing is a safer alternative to pressure washing, especially for delicate roof shingles. Using a pressure washer in the lowest setting or a garden hose with a gentle nozzle, rinse the shingles.

Pressure Washer Settings: If you must use a pressure washer, set it to the lowest pressure setting. However, a garden hose with a gentle nozzle is often sufficient and safer.
Washing Technique: Begin rinsing from the top of the roof and move downward. This method prevents water from being forced under the shingles, which could lead to leaks. Use smooth, sweeping motions to wash away the loosened moss and algae.
Avoid High Pressure: High-pressure washing can strip shingles of their protective granules, drastically shortening the lifespan of your roof. Keep the pressure low to protect the shingles.

Avoid high-pressure washing to prevent shingle damage.

5. Manual cleaning

At this stage, you’ll likely have removed the majority of the “dirt”, but for stubborn spots, gently scrub the shingles with a soft-bristle brush or broom.

Be cautious not to apply too much pressure, as you can dislodge granules from the shingles.

6. Repeat if necessary

If the shingles are still not clean, repeat the soft washing and manual cleaning process until you achieve the desired results.

You may also want to use more aggressive cleaning methods for stubborn algae and mold stains.

7. Final rinse and inspection

Finish by giving the roof a thorough rinse with clean water.

Carefully inspect the shingles for any damage and ensure all cleaning solution residue is removed.

8. Preventative maintenance

To reduce the frequency of future cleanings and extend the life of your roof, consider these preventative measures:

Zinc or Copper Strips: Install zinc or copper strips along the roof ridge. Rainwater running over these metals will inhibit the growth of moss and algae.
Regular Inspections: Schedule regular roof inspections, especially after severe weather, to catch and address issues early.
Trim Overhanging Branches: Trees that hang over your roof can drop leaves and debris, creating a damp environment that promotes moss growth. Keep branches trimmed back to allow more sunlight to reach the roof, reducing moisture buildup

Regular maintenance can keep the roof in its pristine condition and extend the life of your shingles.

If you’ve been through the steps above and need help from a Wisconsin shingle roofing company, contact us for a no-obligation quote for your roofing project.

Additional reading: how to repair roof shingles

Shingle roof cleaning by type

While the above steps work as a generic cleaning process, there are some specifics you need to know about for the type of roof material you have.

Naturally, you should still wear the relevant safety gear as the above steps, but also be sure to wear PPE for cleaning products.

Cleaning asphalt shingles

For asphalt shingles, consider a cleaning solution of 1 part bleach and 3 parts water, which will be highly effective against mold and algae growth.

Pour or spray the water-bleach solution directly onto the algae-affected areas of the roof surface. Be cautious not to oversaturate.
Allow the solution to sit for 15 to 20 minutes before rinsing.
Afterward, use a hose to rinse the treated areas thoroughly.
Depending on your chosen chemical, you may need to rinse your roof one more time.
Make sure you rinse your plants after cleaning.

Additional reading: GAF vs Owens Corning shingles

How to clean shingles made of wood

To effectively clean a wooden roof, gentle handling is crucial.

Use bleach and water mixture, with options including 5 percent sodium/calcium hypochlorite chlorine bleach or oxygen bleach with sodium percarbonate.

For best results, commercial oxygen bleach is recommended. Always start with the least concentrated solution to prevent harm to your shingles’ wood fibers.

Clean the shingles with a sponge, soft bristle brush, or sprayer
After 15 minutes, rinse off the solution, keeping the water aimed downward to avoid seeping beneath the shingles and compromising your wooden roof’s integrity.
Allow 2-4 days for drying in fair weather.
Let the wood age naturally until the next cleaning in five to seven years, preserving the shingles’ lifespan.

Cleaning a shingle roof made from slate & clay

When tackling algae on different roof types, tailor your approach to the specific material:

Clay: Mix 1 part vinegar with 4 parts water. Apply the solution to algae growth, gently scrub with a brush, and rinse using a hose.
Slate: Prepare a solution with 1 tablespoon of dish soap and 2 cups of water. Pour it over the algae, scrub with a brush, and rinse thoroughly with a hose.

Cleaning shingles made of metal

Honesty, a low-pressure garden hose will suffice for most dirt and debris on a metal roof.

Stubborn spots can be cleaned with mild detergent, but you can also step it up and use a diluted laundry bleach to tackle mold and algae without damaging the metallic surface.

How to clean roof shingles from the ground: what you need to differently

Clear loose debris and clean gutters using a broom or roof brush — you might need an extension handle for the broom to reach the top of your roof and a step ladder for the gutters. Avoid using a blower, as it may blow debris into vents and attic spaces.
Use a garden hose with a spray nozzle to reach and rinse the shingles effectively.
Mix your cleaning product as per the guidance above and apply to your roof using use a pump and spray canister.
Rinse off the cleaning product and repeat as needed.

So, what’s the best way to clean roof shingles?

The best way to clean roof shingles depends on the type of roof materials you have, but for the most part, you’ll want to be on the roof to do the cleaning.

It’s just a much more effective and efficient way to get the cleaning done. Just note that there are obviously more dangers involved from being at a greater height, so safety first, always!

In terms of a process, it really depends on the size of your roof and what your shingles are made of.

If you’re in Wisconsin and aren’t confident about cleaning your roof and would like a quote for a replacement, get in touch with us so we can discuss your project in more detail!

Roof shingle cleaning: do’s and don’ts

Whether you’re dealing with asphalt, wood, clay, or metal shingles, following these principles is crucial:

Do’s:

Prioritize safety with proper gear and equipment, especially when working at heights.
Clean your shingle roof periodically to prevent algae and debris buildup.
Select an appropriate solution based on your roof material.
Follow the manufacturer’s guidelines, regardless of your choice for cleaning.
Begin with the least aggressive cleaning approach and escalate as needed.
Always test cleaning solutions on a small, inconspicuous area of the roof first.
Apply solutions and rinse from the top of the roof downwards to prevent water from seeping beneath the shingles.
If your roof is steep or you’re uncomfortable with the process, consult experts and hire a professional.

Don’ts:

Avoid power washing, as it can damage shingles and compromise your roof’s integrity.
Don’t oversaturate the roof, as this can lead to water infiltration and damage.
Stay away from harsh chemicals that may harm the shingles or the environment.
Don’t wait too long between cleanings, as this can lead to severe algae or moss growth.
Always rinse thoroughly to prevent any residue.
Don’t assume one-size-fits-all. Remember, different roof materials require tailored cleaning approaches.

Need an alternative to shingle cleaning? Get in touch with us

If you’re concerned about the potential damage and cost associated with shingle cleaning, we recommend an alternative approach. Consider shingle replacement as a more effective and long-lasting solution.

Prairie Exteriors specializes in expert shingle replacement services. Get in touch with us today if you’re in Wisconsin to explore the best options for your roofing needs.

Conclusion on cleaning roof shingles

Even though we don’t recommend the cleaning approach, with the right care and attention, there’s a chance you won’t damage your shingles.

Yet, we so-often see homeowners investing in all the gear and cleaning products to end up needing to replace their shingles anyway, which is a more costly process compared to just replacing them in the first place, especially since you can replace shingles in batches.

If you’re determined to do the cleaning yourself:

Be safe at all times
Test the cleaning product first
Be very gentle and careful
Ensure you properly rinse the chemical off the roof, other parts of your home and plants

FAQs on how to clean a shingle roof

Will bleach damage roof shingles?

Bleach can potentially damage roof shingles if used in excessive concentrations or left on for extended periods. It’s crucial to follow manufacturer recommendations and industry best practices to avoid harming shingles during cleaning. Also test the bleach mixture on a small patch before covering the entire roof.

Can I clean my roof myself?

Yes, you can clean your roof yourself, but it requires safety precautions and the right equipment. It’s advisable for relatively small tasks. However, for complex or steep roofs, or if you’re uncomfortable with the process, consider professional help to ensure safety and effectiveness.

Can you brush a shingle roof?

Yes, you can brush a shingle roof, but you should do it gently to avoid damaging the shingles. Use a soft-bristled brush to remove loose debris or algae and clean the roof, ensuring minimal abrasion to maintain the shingles’ longevity and appearance.

Is it OK to wash shingles with soap?

It is generally not recommended to wash shingles with soap. Using soap can leave a residue that may trap dirt and affect the shingles’ appearance and performance. Instead, opt for appropriate roof cleaning solutions and follow manufacturer guidelines for best results.

Is it OK to pressure wash a shingle roof?

Pressure washing a shingle roof is generally not recommended. High-pressure washing can damage your roof shingles, dislodge granules, and potentially lead to water infiltration beneath the shingles. A safer alternative is using a garden hose with a sprayer attachment for gentle, effective cleaning.