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How to clean a roof

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3.8/5 - (13 votes)

There is only one way to clean your roof.  Of course, we have different levels of dirty roofs. Some may just be stained with mold, and others may have a ton of algae.

Cleaning just a moldy roof can be very easy. As we all know, mold can be killed in seconds with regular household bleach. However, household bleach is just not strong enough. Please see how to making roof cleaner

Now, many homeowners and contractors believe using a power washer is the answer. This is simply not true. For starters, using a power washer on your roof could very easily rip your shingles right off.

Below is the pictures of all the roof granules that came off after a so called roof cleaner used a power washer to clean a roof that I had to replace.


In short, when a new roof is installed there is something on the backside of the shingle called sealing strips. These strips heat up from the sun, yes even in the winter, and seal each shingle to the next. Thus preventing the shingle from lifting up in high winds. So, using a pressure washer would be the way to easy to separate that seal, allowing the water to get right under the shingle. Needless to say that shingle will fly right off your roof. Not to mention using a pressure washer you will remove most of the very important granular s (small stones) that make up a shingle.


The best way to clean a roof is to use a roof cleaning chemical and let it sit for awhile. With most good cleaners that’s all you need to do. Just spray it on and leave it. It will rinse off the next time it rains.

Here’s how I do it.

I mix up my cleaner in a bug sprayer container and spray it all over the roof. This can be done either while walking the roof or some hi-tech equipment I have – I can actually spray it from the ground without ever getting on the roof. But of course, if the roof is really bad I may have to walk the roof with a power washer, but set at very low pressure, about 400 psi about 12 inches away.

If you’re hiring a professional.

Always get references. Preferably from people who have had their roofs cleaned a month plus ago. This way, you will know if the contractor caused/created leaks in your house.

What do you use?

Roof Sparkle has the answers on how to clean a roof and clean it without damaging your roof. And the best part without using any pressure whatsoever. How they do not sell their product on the open market as of yet. Roof Sparkle comes in for the day and kills all that nasty stuff on your roof. Now, kills is the keyword here. Once the mold is dead it’s removed. Instead of just moving it around with a so-called power washer that their competition uses Roof Sparkle kills and simply rinses it off while also killing all the algae in the gutters.

Coming very soon. I’m almost done writing an Ebook on where to buy the chemical used and how to mix it and apply it. As well as on how to start your own roof cleaning business.

Read how to make it yourself.  The goods

Comments ( 14 )

  1. mr a having troble finding your info on using a chemical on your askmediy going to get my son from charlotte n .c to help me find info on newsletter it say it blocked will get it unblocked thank. al g

  2. Thanks for the great site Dominick! I’ve done a lot of research these past few weeks that I wish I’d known before I pressure washed my house and roof a couple months ago – this would have literally saved me days of work, decreased the damage to my roof and not to mention the mold/mildew/lichen that I blasted off my roof with the pressure washer was still alive and just landed all around the house as a wet relocation project to be tracked back inside the house by pets and people walking around the house. And I’m sorry if I’m being rude to some of the people posting but goodness people, read a few posts before asking the same question multiple times. 12-15% SH (liquid form, not from a a powder mix – easiest place to purchase is a local pool supply store), 1 gallon mixed with 2 gallons of water, or mixed 1:1 or 50/50 for heavier application for thick mold problems, and add ~4 ounces of a non-bleach soap like Dawn as a surfactant (to create a little suds to help thicken the SH mix to stick to the roof versus running off immediately). This 3 gallon mix will cover roughly 900 square feet, or a 30 ft width and 30 ft height. How much do you need? Do the rough math to figure the size of your roof. A rough guide would be a 2,000 Sq Ft home with average pitch probably has roughly 2500 Sq Ft of roof. Wet the plants and grass all around the areas being treated before and after application to help protect and clean the SH off the plants so the plants and grass receive minimal damage. I must have seen that question asked and answered at least 8 times already. Luckily Dominick is kind enough to keep answering each time.

    My question is what are the benefits/detriments of using SH as stated versus using a copper sulfate solution? I’ve seen people use copper to kill all kinds of root systems and mold and algae, but I’m curious why it isn’t used in place of SH since most of these molds have a root system as well? If you use SH first, is there any real benefit from using the copper sulfate after? I know the copper will sit on the roof after the water dries and prevent mold from growing again, but won’t it rinse off with rain in a matter of months and maybe only give you maybe one extra year of protection? I’d be happy to do that for my own home, but would it be worthwhile to do for a customer?

    I was also thinking about starting a small business and was curious what you could tell me about pricing jobs. And I wanted to share this link with you and see if you thought the product had merit for applying roofing and siding cleaning products like SH and copper sulfate? It appears to be a great product with lots of promise, but maybe not for this type of application? Using the pressurized storage tanks looks like it would work well, although you would probably have to adjust the screw to get the SH to water mixture down around the ratios you want and keep a steady air pressure. Even if this isn’t good for roofing applications, I have to salute the creator for his ingenuity.

    Thanks in advance for your time and for helping so many people Dominick!

  3. Is the cleaner safe on tile roofs?

  4. Dominick,
    hey man good post, roofs are looking good. I am getting into this business in pa and I was curious of your pump set up. do you use a suction type out of a 5 gallon jug or do you have a bigger tank with a pump on it? pics would be greatly appreciated, I am trying to be efficient as possible. thanks

  5. Hi. Noticed you said you use an air pump which will apply much quicker. A pump garden sprayer i would think would take to long as the mixture would dry to quick before getting it completely soaked and sprayed off in 5 minutes. Since I have no air pump is it possible to use a regular hose with with one of those garden bottle attachments with the dial settings. If so what setting would i use on the dial. Just a thought I had. Didn’t know if it could be done that way without purchasing an air pump which seems safer and more appropriate then the pump garden sprayer and having to walk all over the roof because they don’t really produce enough pressure to allow for the mix to flow downward fast enough. Thanks

  6. Considering a small business cleaning siding and roof tops. Curious to know the pump setup you are using. Most of the comments made speak of air pump. Am I to guess a diaphragm type. What pressure and volume size? You speak of 55 gallon tanks. Do you mean drums? You’re speaking of one 1-2 ratio covering 900 sq ft with pump up sprayer, does air pumping cover as much or less, just easier.

  7. Well I did it the way that I saw and read on this site, I have light spot here and there. NOT GOOD!
    Please help me fix, Thank you Mike
    PS I am a total Jack of all trades and a perfectionist at most!

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