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 )
BTW stick with straight sodium hypochlorite and avoid the calcium formulations. They leave a white residue.
I finally found the SH 12.5, but I’m TERRIFIED to get on the roof! So I thought I would get a hose-end sprayer? Now I cannot figure the calculations to keep the mixture ratio correct? The biggest I could find was a 36 oz. any ideas on how to do this, or not possible?
It’s really not, sorry.
You mention mixing the sodium hypocrite with some liquid dish soap to thicken it up a bit. Do you have a recommendation regarding what dish soap and are you referring to regular dishwashing liquid or dishwasher gel? Also, what is the mixture ratio of sodium hypocrite to dish soap?
Just use a dish soap without any bleach in it. The soap is only to help aid the SH to stick on the roof a little longer, that’s all. A cup is plenty on the above mix
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.
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.
Dear Admin,
Firstly, thank you so much for still answering questions to this old thread. Very much appreciated. And I got a lot of info about protecting plants and other considerations as well.
My question is regarding the same question posed by Garbonzo and some others regarding using household bleach ~6 – 8% SH instead of the pool shock which is 12.5%. I guess some pool bleaches also use Calcium hypochlorite instead of SH (= sodium hypochlorite = NaOCl), but we’re only concerned with SH.
I see that you mention that it is by weight. So 12.5% w/v (weight/volume) pool shock will be the equivalent of 12.5 g NaOCl / 100 mL of water. So 12.5 g of SH was dissolved in water, and more water was added until the entire solution totaled 100 mL. Household bleach will be 6% = 6 g / 100mL of water. Then the rest fits what Garbonzo was saying, wouldn’t it?
12.5 g NaOCl / 100 mL of water = 500 g / 4 L of water (assume 4 L ~ 1 gallon)
Add 2 more gallons to dilute (~8 L), which gives 500 g / 12 L (3gallons),
500g / 12,000 mL = 4.1667 g / 100 mL which is 4.1666% w/v (weight/volume)
which is less than the 6% w/v of household bleach.
Or, are you’re saying that it’s (w/w) weight / weight?
12.5% w/w = 12.5 g SH / 100 g water. But 100 mL of water weighs exactly 100 g, so the rest is exactly the same.
We could also look at density, but it gets kind of stupid. The density of 12.5% w/v SH solution in water is ~1.2 g/mL , so a little denser than water at 1.0 g/mL. The density of 6% SH is 1.1 g/mL. There might be varying amounts of NaOH, NaCl, etc, but it’s only a little bit of the product so let’s focus solely on SH. But not really much difference between 1.1 and 1.2.
I read in some pool forums, where pool owners will use regular bleach because it’s cheaper for the same amount of Chlorine, but admit that it’s much bulkier and heavier and pain in the butt, so prefer the more concentrated formulation. Also, I guess Calcium hypochlorite or whatever pool product has some additive or something that releases the chlorine slower, so that it’s not all gone by the next day. I assume that for a pro like you who has to lug lot of liquid volume around, it would make more sense to carry a more concentrated form of chlorine, then just add water at the site.
Of course, the simplest thing for me to do would be to just try it and see. If it shows visible improvement in ~10 minutes, it works. If it doesn’t, it doesn’t.
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Anyways, I also noted that you were using a 3 gallon sprayer when you first started. I was looking at chlorine safe sprayers (I guess because they use Viton gaskets). So thank you for all your info, and your valuable insight is giving me the courage to try it DIY style.
Thank you,
Always my pleasure.Thank you so much for your very long and nice post.
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.
Thank you Dominick, what i meant was can you send me a link so I can purchase the machine used in the video. Not trying to bother you sir, just amazed at the results. Here in MA there are so many homes that look like this!
It’s been a few years and I don’t have those links anymore. And it’s not a machine per say. It’s a series of hoses, pumps, tanks and a gas power air compressor to power the air pump. It’s a few bucks for sure. What do you plan on doing with it? Just a roof here and there? or do you plan on doing many?
Thank you for your videos are very helpful! 🙌🏻
Thank you so much.
Want to make rood cleaner I see 1 gal to 2 gallons water. I’d like to run this though a downstream chemical injector as my roof is way to tall and steep to get on it. Do you know what the ratio should be?
Same, just add a bit more soap so it will hang there longer