Here is 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 )
I have 2 honda cold water rigs with on board detergent tanks. What is the setup your using in this application? I’d to provide this service to my customers in MA. Thanks for the video, it was awesome!
All air pumps. No metal at all. The SH will kill metal in one day.
Could the roof cleaner be use for molded and stained concrete driveways?
It can to a degree.
Regarding the dilution factor (your recommended solution): “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.”
If you dilute the solution per the above, then the concentration of the SH will be reduced 3X, yielding a hypochlorite concentration of about 4%, which is less than regular bleach and it won’t be effective against roof moss. Am I missing something?
What do you want the final solution SH concentration level to be?
It’s very easy to misunderstand this. You are referring to is volume. But what I’m doing here and how it’s done in this world is by “Weight” not volume.
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).
You’re looking at this like you’re baking a cake. And that would be wrong. What you’re doing is making 42,000 parts per million.
Hello Dominic first of all great site and thanks for all the help. Second I am having trouble finding a 3 gallon pump sprayer and if I do find one it is either bigger or expensive so I was going to get a 2 gallon one if that would work. Any idea how much shock and water and dish soap to use to get the mixture right. I got the 12.5 shock from pool place I have the The dish soap and water but I don’t know ratios go the 2 gallon pump sp5rsyer. I figured I would run it by you see what you thought or if you had another idea
It really depends on how bad the roof is. If it’s really bad you could do 50/50 But no. The smallest I know is 1/3
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
I am want to start a buisness in roof washing concrete and vinyl sideing. I saw your reply about 500$ for your help. I am very interested in what info u would give me?
I would give you all the info you need to know to start your own roof cleaning business.
I have a composite deck at the base of my roof area I’ll be treating. The deck also has mold from it being on the north side. Will this solution be okay on the decking material? It’s like a trex deck but not that brand. Actually, forgot the name. duh! Can I try it on my front small wood deck to clean off the black from years of it sitting? Normally power washing would be done on it. I’m selling my home and the realtor gave me things to do to prepare it for a buyer. The poconos in PA is woodsey and while it’s beautiful, it’s also requires maintenance. Thanks Dom.
Hi, sorry for the delay. Your question came in as spam for whatever reason..
The SH wont harm the deck but clean it very well. I’ve used it with a big mop before and it came out great. But then again, that was for me. The Poconos ?. Heck we’re not that far apart at all. I’m there almost every weekend.
Will this work in the cold weather? My husband and I are going to settlement on a summer home in northern PA in December and we can’t get homeowners with all the moss on the roof. We have to agree to get rid of it ASAP after settlement. We plan on a new roof in spring anyway.
How old is the question or how old is the roof? The roof is at least 18 years old. The question is current. We will not be able to work on the roof until settlment that is in early December this year 2013.
It will, but how old is the question. The cold does degrade the SH.
I apologize that I hadn’t seen the actual mix stated in the big blue box – lol. That says to use one gallon of SH and two gallons of water (H2O) add about 4 oz. of liquid dish soap spraying from the roof top working down. In your reply you mention that “a cup is plenty on the above mix” which I’m assuming is the mix stated in the big blue box. So to 1 gallon of SH + 2 gallons of water, do I add 4 oz or 1 cup of liquid dish soap? Also, might you have any idea how much SH I would need for a U shaped ranch that is around 2,100 square feet?
It really depends on how bad it is. You’ll soon find out once you start lol. Perhaps about 12 gallon mix. The steeper the roof the more soap you’ll want, like I said, it’s not for cleaning but rather to hold the SH there longer.