Roof Cleaning Advice from Home Advisor

Asphalt Cleaning Solutions

“Because asphalt shingles are the most popular type of roofing material, there is no shortage of advice and DIY internet recipes for cleaning them. The most popular recipe includes chlorine bleach, water, and trisodium phosphate (TSP). However, there are several dangers associated with this combination, including the fact that bleach only kills the surface layer of mold and algae, opening it to regrowth. Furthermore, it poisons the vegetation underneath the roof and corrodes metal fastenings. Another common product, sodium hydroxide (lye), is safer for plants but toxic to humans and similarly corrosive.”

So what gives? First I’ve heard that SH “…only kills the surface layer of mold and algae, opening it to regrowth.” Is this an effort to drive the DIY’s to safer, more expensive proprietary products sold in big box stores?

Bleach is your friend and what ARA recommends. But I don’t clean roofs so it’s moot to me :slight_smile:

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That is true i wash roofs with calcium hypocrite. It also will not kill plants.

Chlorine destroys metal. That much is true.

I’d imagine on a roof, the metal wouldn’t be exposed anyway.

I’m like IBS though - I don’t do roofs!

Regrowth is just apart of the mother nature, and i call it job security.

Of course algae, and mildew are going to regrow on the roof, the house, the driveway and everything outside. Just like too much water can kill plants.

I’ve not seen anyone on this site or in a soft wash demo video suggest that their SH house or roof wash mix was only killing the “top part” of moss or algae, and for a total or complete kill, they used a “silver bullet” ingredient. If there is something better than 12.5% SH TSP, Borax, and a surfectant for algae, mold, lichen and moss, I don’t know what it is. But I have to wonder about the knowledge level or motives of the authors of these articles.

HA also says that an average housewash in my area should be $153 and window cleaning should be $89.



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Sorry I got a chuckle out of that.

Oh and HA can fall off a cliff.


IBS you shouldnt make your secret accounts so obvious. Off duty fireman. :stuck_out_tongue_winking_eye:

It’s no secret. My info is in my profile. I’ve posted my name, number and address here countless times.

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I was just joking around because you guys both have the same business name. On a completely unrelated note, I miss Buzzlightyear. Lol

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Not sure if what he is saying about SH is true of not but it makes sense.

That’s AC lol. He could sell ice to Eskimos


What he says about the blooms opening up causing the black color sounds plausible. Further research needed. Or maybe we can just ask @CaCO3Girl

I couldn’t help thinking throughout the video, “Dang, that’s a lot of solution. And very little dwell time. Also, he must be breathing in an awful lot of splash-back, standing so close.”

Downstreaming that house would be faster and safer (for one’s health, since you can stand further back, and would likely use a more diluted mix).

SH with a good surfactant is definitely the solution of choice. But a 12v pump is the wrong application method. IMHO :smirk:

But a 12v has to be the answer because all the vendors are selling $5k aluminum slide in skids with $1k proportioners mated to disposable $100 pumps. Couple that with miracle grow watered down and relabeled and lots of other usless chems and a softwash franchise fee and it has to be the greatest thing since pump up sprayers we’re invented. A fool and his money are easily parted when greedy vendors and snake oil salesmen are involved. Just my opinion.


Bloom opens? :rofl::rofl::rofl:

Nope! It’s called shocking the crud out of a living thing and it curls up and dies. If it was just blooms opening it would go back to green if you rinsed it right?

SH kills what it touches on hard surfaces. There will always be spores that will regrow. The additive they spoke up is likely a quat that stays there so it doesn’t regrow for awhile.

We all know that spore + moisture + shaded area equals mold and mildew. The spores are in the air, nothing can be done about them.

Does that answer the questions?

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Can you point us to a good quat to use? Seems interesting… or point me in a direction of something I could look at and pick or choose if it’s a good fit?

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I agree but pat clark the guy whos filming runs a 1.5 million dollar business doing it so im not hoing to say ones better than the other. He started out with him and his wife sleeping in their car outside of conventions to this so i think that is awsome. Hes also a honest good hearted guy that looks out for his employees and works hard along side of them. Hes A1 in my book even if he is hoseing houses with a 12v :wink: lol

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As far as that other guy lol. Hes seems like the definition of a snake oil sales man and sounds like it too​:joy::joy::joy: but it does sound good when he says it. Haha

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Thats what we wanted to hesr all along. It just took all this to get you hear lol