Does Bleach damage asphalt shingle?

Will Bleach Damage Asphalt Shingles? (Read before cleaning your roof)

If you’ve ever thought about cleaning your roof, you’ve probably considered using bleach or some other kind of harsh chemical. Depending on the stain, or mold/lichen, that’s grown on your roof- just pressure washing isn’t going to be enough to totally remove the filth.

With that being said, it’s important to understand how such a powerful chemical like bleach can damage your roof if not applied properly.

So the main question you might have before you go up to clean your roof is, “Will bleach damage asphalt shingles?”

If you don’t have time to read the entire article- or just need a quick answer to your question, then here’s your answer.

Also, if you’re located in South Florida, and you’re interested in roof cleaning services, reach out to us for a totally free, digital estimate.

Straight To The Point: 

If applied with an appropriate water-bleach ratio, then bleach will definitely not damage your asphalt shingles.

How to clean asphalt shingles:

  1. Softwash the roof with water very quickly to moisten up the roof, get the debris and dirt going, and open up the asphalt to cleaning
  2. Spray a solution of 50% Bleach and 50% Water all over the roof. By the time you’re done spraying down the roof, you can start soft washing immediately, this doesn’t take long for the bleach to work.
  3. Softwash the roof shingles and work down the dirt and debris. Power washing can dislodge shingles, or compromise your roof. Stick to soft wash for shingles.
  4. (Repeat step 2 & 3 as needed until all debris, mold, algae, or whatever you have on your roof is gone.

However, applying straight bleach to your roof and then pressure washing, is a terrible idea- and can cause serious discoloration, shingle damage, and even structural damage to your roof.

*Note* This guide uses laundry bleach, not professional level 10% (or greater) Sodium Hypochlorite. In other words, this 50-50 mix is way too strong if you’re using pool bleach or something much more potent.

There are a variety of methods for cleaning different roof materials, but let’s look at the most popular material and how to clean asphalt shingles.

Can Bleach be Used to Clean Roof Shingles?

will bleach damage asphalt shingles?
Example of pressure cleaning with bleach

Roof shingles could become grimy and discolored with time. Algae, mold, fungus, lichen, and dust are frequently drawn to shingles.

Roof shingles could be cleaned efficiently using bleach, and even the worst stains can be removed. Keeping roof shingles cleaned would not only help improve the appearance of your house, but it would also preserve the shingles from algae and fungus damages.

Of course, before you decide what chemicals to use- you want to know, “will bleach damage asphalt shingles?”

So, to answer the question a bit more comprehensively than I did earlier- bleach is extremely effective at removing all filth and preventing any additional growth, at least for some time after the washing. It’s even recommended for removing complex growths like lichen, moss, and fungus!

Roof specialists recommend a chemical-to-water mix of 50:50 when cleaning roof shingles. If the mixtures exceed the above ratio, then asphalt may discolor or even shingles may premature breakdown.

Or, in short, bleach will definitely not damage your roof- and it’s actually recommended for most use cases.

Only chlorine bleach or TSP chemicals with phosphorus mixtures can drying out shingle roofs, which can reduce the lifetime of the roof due to the components bending in response to it. Chlorine, as well as various roof cleaners available, can include toxic compounds such as lye, that cannot simply damage the atmosphere and slowly eat at your guttering but can also destroy your grasses and plant.

What is the Best Way to Clean Asphalt Shingles?

Many asphalt shingle roofing cleansing techniques necessitate the use of a detergent, which is especially important when fighting with algae spots and other aesthetic difficulties.

Most of the time, a combination of bleach and pressure cleaning will be more than enough to totally clean a roof. However, if you have any kind of complicated stain or algae growth, you may want to specifically research your case and find what additional measures will be necessary.

Whatever you choose, avoid using random harsh chemicals (not including bleach) as they may deliberately reduce the lifetime of your tiles. Use a solution that is not only designed to eliminate mosses and mildew spots and is labeled as suitable for use on asphalt shingle roofs.

Generally, you’re going to want to dilute your chemicals cleaners with an appropriate amount of water. Put all of the materials into a pump-style garden spraying and thoroughly mix them together. Once you’re done, climb up on your rooftop (taking care mostly against a collapse and the reality that you’re dealing with toxins) and completely spray down your rooftop. After you’ve washed out your whole rooftop with the mentioned mixture, let it sit for around 15 minutes.

Then, using an ordinary gardening sprayer, wash down the roof to completely eliminate the mixture. If any trouble spots exist, return to the roof with a brush and wipe clean each tile separately. But be careful not to use too much force, or you might create harm that has long-term implications both indoors and outside your house.

Can You Put Bleach On Shingles?

If you dilute the bleach, then yes- you can apply bleach on shingles. What you don’t want to do is apply bleach directly without dilution.

Also be careful if you’re using stronger Sodium Hypochlorite mixtures, especially those above 10% concentration, as those are much stronger and will need to be diluted down more than regular laundry bleach.

Another thing to be mindful of is the runoff from the roof down to nearby plants, pools, or animals. You’re going to want someone constantly hosing down the nearby areas- especially if you have plants. Otherwise, you’re going to risk that the plants get damaged or even just die altogether. No matter how diluted the bleach is, it can still damage any living creature.

Will Bleach Discolor Shingles?

No, bleach will not cause discoloration in your shingles, or asphalt shingles.

Especially not if you apply bleach with the 50-50 mixture that we recommended above, then you’re definitely not going to deal with any discoloration.

Generally, the only thing elements that can cause shingle discoloration is just general wear-and-tear from getting absolutely blasted by the heat of the sun over the years. Also, certain kinds of algae and moss can cause discoloration, which is even more motivation to get your roof cleaned routinely.

To eliminate risk, hire a professional

Hire professional roof cleaning services if your roof is inaccessible. They’ll have had the appropriate tools and will safeguard your landscaping by not having to walk on the rooftop to clean it.

To summarize, roof cleaning can help you save money by extending the lifetime of your roof because moss is now eating away at the lime in shingles or the covering on your metal roof, causing them to become fragile after degradation.

Roof Cleaning may remove the microalgae at the spore’s layer, and a professional roof cleaning will last for a minimum of 3 years before you need someone to come back out and pressure clean the roof again.

If you are looking for roof cleaning in Miami, give us a call at (305) 796-2443, and we’d be more than happy to give you a totally free, digital estimate.

Most of the time, our team is ready for a same-day, or next day appointment for most roof sizes.

Get A Free Pressure Cleaning Estimate

If you’re interested in a free, comprehensive roof inspection for any kind of bacterial growth, call (305) 796-2443 today! (Serving All Of South Florida)

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6 responses to “Will Bleach Damage Asphalt Shingles? (Read before cleaning your roof)”

    • Good point! Definitely with household bleach, if you’re using 10% sodium hypochlorite, it’s going to be much much less bleach. Not 100% sure on the specific amount, but I can’t imagine it being more than 15-85 bleach to water ratio in that case.

    • Chlorine 12.5% kills roofs…its called Softwash… but call is Publix “bleach” @ 1%… that is the scam. Its NOT Bleach…but Chlorine 25x STRONGER – Corrosive!!!
      Roof Manufacturers Assoc say 0.5% the rinsed off. Nope they leave 12.5% chlorine on the roof to dry and RUST the hell out of metal, fasteners and nails.
      Rinsed off your entire yard will be dead. Softwash reduces service life, creates leaks

    • Will 6% percent house hold bleach damage my shingles with mixing the bleach 1 gallon bleach and 1gallon water. And 6oz detergent.

  1. I came across your blog while searching for information about using bleach on asphalt shingles. Your blog was very informative and easy to understand. I appreciate the time you took to provide such helpful insights. Thank you for sharing your knowledge. I look forward to reading more of your blogs in the future!

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