Roof Mix


Whats the most effective roof mix?

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Roof cleaning solution

There is no universal mix. It depends on a variety of factors. Climate, SH availability(fresh 12.5% vs stale 10% home depot crap), What type of contaminant on roof. The info for basic roof mixes are posted dozens and dozens of times on several forums.
Search and read, then ask.


Ive read and there are many theories. I was hoping to get a more recent consensus. My local pw guy just gave me a lecture on how bad chlorine was and not to use it. Sorry for the inconvenience.

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what exactly did he say was so bad about it?
Bleach ( chlorine bleach - SH) is recommended by the ARMA and by the USDA for the cleaning of both asphalt shingle roofs and also cedar shake roofs…

and as long as your not mixing it with other crazy cleaners… and rinsing appropriately it breaks down to into salt in the soil or water…


He said… using too much will start curling shingles. His mix is more detergent, mildew buster then chlorine.

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Not immediate but over time.

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What state are you in? If you use a 60% water to 40% SH and add some dish soap (or commercial grade surfactant) you’ll be fine. I experimented with different strengths of SH. I have one place that says their SH is at least 11.5-12.5% any day of of the week and one place that has a 10.5% label on their silo… Honestly they both do a fine job. Even at 10% a 50/50 mix would put you at the strength of store bought bleach. But I’m not an expert by any means and that’s why I come here :cool: If you spray a shingle roof, leave it up there, and do t get rain for 2 month then I’m sure it would/could dry out the shingles. Spray it, let it sit for 20-30 mins and hose it off and you’ll be fine.


Thanks for the advise. I needed it.

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so whats your sh to water ratio? Using 13%sh from pool store

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I use either 12% or 10.5% depending on what shop I get my SH from. Either way I do a 40% SH to 60% water. Give or take to make room for your surfactant. But that’s just me… Some might do a 30/70 mix.


Your local PW guy doesn’t know what he is talking about. Tell him that you would never use chlorine to clean a roof. You use SH; there is a difference. If he doesn’t know, tell him to look it up and read.


And please take careful notes so you can share his response with the rest of us…We could all use a good laugh.

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I do not do roofs myself at the present time, but have talked to several roofing contractors on
the " curling shingles " issue discussed in this thread. They assure me the shingles are curling up
due to poor air circulation in the attic (too hot) or shingles at end of their expected life. Often
they say it is a combination of both. Hope this helps.:slight_smile:

Bill Sullivan
Bill’s Window Cleaning.


Mike (Mizzle)

I like your 60/40 mix idea. How much dish soap do you decide to put in and what kind? Also what do you think your coverage is Per gallon for this mixture?

How does this work on roofs covered moderately with moss. I will be working on a steep roof and will be using a fatboy system for the application. I would prefer not having to walk the roof. Here is a picture of what I’m talking about.



I’m not too sure how it will do with the moss. I’m in FL and mostly deal with mold build up. The times I have sprayed it on fences with moss it worked pretty good. Sometimes if I’m spraying a guttered house and the roof really funky I’ll do a 50/50 mix. Just make sure you bag the gutters. As for the soap I’ll get any CONCENTRATED dish soap. Typically this is Ajax and I’ll dump 2 big containers per 50 gallons. If it’s running too much just add more soap. As far as coverage per gallon that all depends on the roof. On a standard shingle roof here I can do a 2000 sq ft house with 50 gallons of mix easy. If it’s something like scratch tile then it will take like 100 gallons for me. Barrel tiles tend to take more mix also because everything rolls off the tops of the tiles and channels itself in the valleys of the tiles. Flat/smooth tiles you’ll get more out of mix… Just show up with a little extra supplies Jude incase you need them. When I first started spraying roofs I treated them all equal and learned quickly that wasn’t a good idea lol. Luckily one of the big dogs here in town has been very good to me and showed me some tricks to the trade. If you get the chance look at my YouTube video. I was using the fatboy in that. Mix was 60/40 with 2 bottles of Ajax dish soap. I did that roof with 35 gallons of mix. Feel free to pm me anytime.


Oh… And don’t over apply. Spray a little bit, let it run, spray another spot, let it run, and then pick up where it stops moving. If you need to touch up then you could always spray more. It’s better than wasting your mix. You’ll see in my video how I start from the top and the soap do its thing.


what is the link to your youtube video? Also, how much do you pay per gallon for you SH? I see your on your avatar image, you are on a fire engine. Are you a F/F by chance?


The reason I asked is that the price I have been finding is about $11-16 per gallon. Does that seem right?


Yes I’m a firefighter/paramedic and PC most days I’m off shift. I get 10-12% SH for approx $1.30… Give or take a few I forget the actual rate. I just fill up and pay anymore lol. Those rates you said are CRAZYYYY high. You’d be better off buying Clorox and use that at $4 a gallon if that’s the rates by you.