Register Now


Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Add question

You must login to ask a question.

How to Make the Roof Cleaner used in the Video

3.5/5 - (303 votes)
Cleaning A roof

A little background on how I started Roof Sparkle. A company that’s making cleaning products asked me if I could make a video for some of their cleaning products. Now I won’t go into details on who they are but they had a roof cleaner that involved the use of a power washer. A big red flag in my eyes. Being a contractor for years, I knew right off the bat that was a big no-no.

So the next question I asked myself what’s that black stuff on the roof. Well, it’s mold. And what kills mold, bleach right. Well, as true as that is bleach is only made up of 5-6% Sodium Hypocrite. And that’s great for your whites and around the house but not on your roof.

For the roof, you will need something a lot more powerful. Some of you may know it as pool shock. This is made up of 12% by weight “Sodium Hypochlorite”. But because it’s as thin as the water it will run right off the roof and not really have the time (five minutes) to do its job. So we have to thicken up a bit. The best way, add some liquid dish soap to the mix to help the SH stick to the roof for more than one second. You can go into any pool supply and ask for a gallon of shock, for about $4.00 per gallon. This is just a heavy-duty version of household bleach. And no Walmart does not sell this or the big box stores. This method will remove algae from a roof.

Now, of course, we buy it from the manufacturer and by the truckloads at a time.

Applying It

When we started we used a regular bug sprayer. Use a three gallon pump sprayer, use one gallon of SH and two gallons of water (H2O) add about 4 oz. of liquid dish soap and spray from the roof top working your way down.


  • clean your roof when it’s super hot out in the baking sun. It will kill the SH and dry before it’s clean.
  • Don’t touch the SH with bare hands. Wear gloves and eye protection.
  • Don’t spray your roof down first with water to cool it off.
Dirt Roof
Dirty Roof
Clean Roof
Clean Roof

Roof Cleaning Products The I Recommend

Comments ( 173 )

  1. My situation was complicated by having a slate roof I couldn’t walk on. I climbed a ladder to the eaves and used a $15 WalMart SuperSoaker filled with 10% pool shock and the algae was gone
    immediately. Yeah I know…it’s a bit hinky but if anyone can figure out a better way I’d love to hear it.

  2. This comment is edited.

    Thanks for the great info!

  3. Will spraying a solution of hydrogen peroxide/water,before or after, neutralize the affects of the sh/water for the plants and shrubs around the house?

    kind of wanting this to be foolproof with some customers, thx

  4. 2.2 gallons of normal 6% bleach mixed with 0.8 gallons of water will give you 42,000 ppm.
    That’s with the realization that 6.00% sodium hypochlorite is used, and this is equivalent to 5.80% available chlorine. Available chlorine is the amount of chlorine available for sterilization (or moss killing, in this case).

  5. I ran the calculation and it comes to 38,100 ppm both ways.

    But maybe you’re doing something different.

  6. This comment is edited.

    Okay, I have a bit of Chemistry in my CV.

    You’re asking us to take a gallon of 12% concentrate Sodium Hypochlorite and mix it with 2 gallons of water. That results in a 4% concentrate sodium hypochlorite. And you have 3 gallons to work with.

    I know, I know, you keep saying it’s based on weight, but we are talking volume of fluid here, regardless. And this calculation is correct.

    Normal bleach is 6% sodium hypochlorite. Mixing 2 gallons with 1 gallon of water results in a concentration of 4%. Precisely the same as above, with 3 gallons to work with. This calculation is also correct.

    Sorry, but there is no getting around this. There is no need to do it your way. Your way is fine, and probably better for you as you’re dealing with smaller volumes of potentially dangerous liquid getting hauled all over town, but for those of us with a few gallons of bleach in the basement, that is good enough.

    The only reason to do it your way, for the homeowner, would be if the higher concentrate bleach was less than double the cost of normal bleach. Also there is the hassle of finding and going to a place that sold the higher concentration stuff instead of just picking it up at Costco or wherever people normal go for groceries (no extra trouble at all).

    Now then, if you were needing to use the bleach undiluted, or diluted to a strength higher than 6%, you’d be out of luck with normal bleach and have to do it your way. But that’s just not the case in this case.

    Also, on another topic, one of the posters below mentioned that the label on a liquid soap he was considering using said never to mix with bleach. NEVER try to second guess warnings like that. It means that whatever chemical is in that particular soap reacts with bleach and releases chlorine gas, very dangerous and potentially fatal (in a very nasty way).

  7. For clarification, here’s what I found at lowes:

    (if you click to zoom in on the bottle’s picture, you’ll see at bottom left it lists “Sodium Hypochlorite” at 10%)

  8. Sorry, but I don’t think this was clearly asked before; I’m having trouble finding exactly 12 or 12.5% Sodium Hypochlorite (even in my local pool shop). However, I have found 10% options. Would that work?

  9. Do you rinse the roof after applying? if so how long after?

  10. I used the 3 gal. Solution on my roof. 100%improvement. I still have “black areas” I just did it yesterday. Should I go back and respray those dark areas? Also, I mix d sprayer on my deck and now I have bleach spots. Is there a home remedy for cleaning my deck? It is free treated wood.


Leave a reply