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.
DON’T
- 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.
Comments ( 173 )
How do you keep the bleach from hurting the plants, grass or leave obvious streaks on surfaces below?
Is it best to clean the roof then in the AM or PM, after the sun goes down sometimes the roof remains hot for well into the night.
Thank you so much
How large of an area will a 3gal batch of cleaner cover?
When we go out to clean a roof there is always two guys on a job. One is the guy on the roof spraying / cleaning the roof and the other ones job is to spray everything and anything that could get over sprayed with the roof cleaner.
So, you would wet down all plants and then rinse them again once you’re done cleaning the roof. We clean roofs all day long. But once in a while it just gets way to hot. At that point you really can’t walk on the roof anyway without damaging it because it’s way to soft. Hope this helps… Dominick
I have a very steep and dangerous multi roofed home in the Puget sound area. Walking on most of my roof is impossible because there no anchors. Your moss killer sounds like what I need as I am starting to get a carpet on the north and west sides. I have a pressure washer that has a small tank on it that could deliver the stuff onto the roof. I just wanted your opinion on putting it on that way. will that work with the really wide attachment. Thank you for your help. Leroy
Over time that would or could work. But you could be adding to much water to the mix at that point. However the SH would end up eating your power washer. The best wat is to stand on the gutters edge for a pump up system. Something like what Roof Sparkle uses. Unfortunately that info I can not give out just yet. And needless to say it’s not cheap. And the over spray you would get from a power washer would be way to intense.
I am having trouble locating the 12% sodium hypochlorite. Is there a site online I can order it from? Keep find calcium hypochlorite anywhere from 48 to 90%. Thanks.
Go to a pool store and buy liquid pool shock.
This might be a silly question, but if you are diluting the 1 gallon of pool shock that is 12% SH with 2 gallons of water, doesn’t that reduce the % of SH to 3%? Which is less than bleach that is 5-6% SH?
One would think so. However this is a very common mistake. You are thinking outside the box. It’s very important that you mix it the way I stated. This is by weight. not by volume like baking a cake.
Any danger of this mix discoloring a dark shingled roof?
Absolutely not. Safe on all asphalt roofs. It’s actually the only approved method by the roofing manufactures of America
Was curious to know if using dishwasher dish soap would be better so you don’t have so many suds?
Sure you can. But don’t use any with bleach in it.
My question is when you rinse off the roof, Does the gutter runoff from the shock hurt the lawn (I’m guessing it doesn’t as long as it isn’t 95 degrees out)?
Appreciate you explaining this process to fix a problem many of us have! Thanks, George
NO, the SH will kill plants, grass and anything in it’s way. Rinsing good is very important. We wet down all the plants, clean the roof and rinse the plant and grass again.
Do you rinse the solution off and how long do you wait?
You can. For the most part we don’t. However if your roof comes clean in under five minutes then it’s to strong. So then yes you would rinse it. Five minutes is a good number to go by and then you don’t need to rinse it.
hi can you email me the name of the liquid pool shock brand name please and a bottle of that is already mix with water. do i have to add more water ….and i want to know for 10 gallons of water i will have to put 5 gallons of liquid shock for pool and thats gonna work to clean the black mold and the algae on a roof
There is no brand name. It’s SH aprox 12 % Just follow how I show you.
hi dominick if we buy the sodium hypoclorite liquid do we have to mix that with water ….what i exactly need for 10 gallons of water if i use liquid sodium hypochlorite
You must only use liquid. For free I’m only showing here how to mix three gallons at a time.