Rinsing roofs

So I have a big roof cleaning job tomorrow. i just bought a roof pump kit from Pressuretek. As of now I’m planning on applying SH with the pump then rinsing with my pressure washer.

My questions are:Do any of you carry your rinse water on site and rinse with a pump? I could definitely see this being more efficient.

2nd: If I’m using the tap to supply water to my PW can I also have someone else rinsing. Or should I reserve all the water pressure for the PW? I do have a belt driven PW but don’t have it plumbed to a tank yet.

Thanks in advance for any help.

I would not show up at the job until you did some more learning. Rinse or don’t rinse is a long boring debate but never rinse with a pressure washer.

@Innocentbystander I’ve read that a lot of people rinse with a pressure washer. Just with low pressure nozzles. My job is scheduled for the morning so that doesn’t help much. I could rinse with a garden hose…but obviously that’s not ideal. Do you have any helpful advise? I’m going to rinse because we don’t get much rain in my area. I have the proper tools to apply the chems. There’s almost no greenery at the roof line. What do you suggest I learn? If you wouldn’t mind, maybe you could educate me.

I would suggest not rinsing. But there goes that long debate. I would also suggest not doing roofs but that is a personal decision i made to be able to sleep better at night. You would not believe how some contractors tell customers the black streaks increase the electricity bill, destroy shingles, are a health hazard and other nonsense. So, in answer to your question; if you are determined to rinse use a garden hose. You may being using low pressure tips but the homeowner and neighbors will only see a guy on a roof with a pressure washer running.


Sorry if you didn’t find my first advice helpful. The second advice is the same as the first with more verbosity to make it easier to swallow.

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Hi. Thanks for getting back to me. I hope I didn’t come off as an ass in the my first response, totally not my intention. I appreciate your input regardless of its content, I was just hoping for something a little more specific. I have made the decision to expand into roof because it’s a HUGE market where I’m at and there’s very little competition…ie: huge money maker. I’m pretty sure I can competently handle what’s involved so I really don’t see any reason not to. I didn’t tell the customer any of those things, but I do believe that home owners should maintain their property including their roof. Around here most roof cleaning i do will be the first time the roofs EVER been cleaned, sometimes in 20-30+ years. I don’t even offer roof cleaning. But after getting the request from a long time commercial client to do her home (roof, siding, deck, and full int/ ext window cleaning) I decided to go for it, it’s the perfect opportunity to have the equipment pay for itself.

Why do you suggest I don’t do roofs? What makes a garden hose better than a PW with low pressure nozzles I bought them from Bob at Pressuretek). I also have an x jet that I can roof disconnect from the bucket and use just as a low pressure adjustable nozzle. From what I now a garden hose is probably the worst thing I could use to rinse besides a bucket of water… why do you suggest a garden hose?

Seeing as how you don’t offer roof cleaning, do you actually know what you’re talking about? Again, i don’t mean to be rude but I can’t help but read a condescending tone in your posts with no real helpful advise.

Anyone else have any input? I’m very open minded/ willing to learn and would like to do things as efficient as possible. I do have an extra 55 gal barrel I could use as a buffer tank for when I’m rinsing, I’m just curious if that’s how other people do things.

I washed roofs for about 15 years but quit about 5 years ago. I didn’t offer it exclusively but we did about 800 to a 1000 over the years. I personally didn’t rinse. The part of about not using a pressure washer to rinse is a perception thing to bystanders and potential new customers. They don’t know what a low pressure nozzle is. All the see is a pressure washer and someone on the roof “blasting” away. How many gpms is your pressure washer? Most faucets put out at least 5 gpm. Lot less pressure than a low pressure nozzle and probably as much volume as your machine if you don’t currently use a tank. Again, my advise is don’t do roofs, if you do do roofs don’t rinse, if you rinse don’t use a pressure washer. Either way it’s not my roof so it doesn’t matter. I’ve had black streaks on my house since I bought it in 1998.

That is cute. You could not find a finer senior adviser than our very own @Innocentbystander[quote=“Innocentbystander, post:2, topic:6840, full:true”]
I would not show up at the job until you did some more learning. Rinse or don’t rinse is a long boring debate but never rinse with a pressure washer.

Do follow his counsel, take notes, and you will become a better contractor because of it.

I’ll repeat his advice for you here. ~I would not show up at the job until you did some more learning. Rinse or don’t rinse is a long boring debate but never rinse with a pressure washer.~

The man nailed it in the first response.

If you’re talking about rinsing the plants, etc with your PW, that may be a different story…I just tried that a couple of weeks ago as an experiment and I LOVED it! But, for reasons already mentioned by @Innocentbystander I would never be seen with my PW on the roof. (PS, I don’t rinse unless it insanely heavy moss, and then it’s a once-over, “what comes off, comes off, what stays will come off shortly” rinse)

@Tim4 I wasn’t trying to be cute. I asked a pretty legitimate question. @Innocentbystander said he didn’t clean roofs. Naturally I could assume that he might not be a good resource. I don’t go around giving people advice on roof cleaning because I wouldn’t know what I was talking about. I wasn’t trying to be a dick. I’m not sure why you you feel the need to be rude. I’ve studied these forums religiously and am making a serious effort to learn. If there’s something I should know before I showed up to the job then that’s why i posted in the first place. I did take his advice on not using the pressure washer, however not showing up to the job after buying all the equipment/ chems and telling the client I would be there was definitely not an option. I’m no expert by any means but i understand the process involved with cleaning a roof and purchased the necessary equipment to do the cleaning. I just needed some help/ advice on what the best method of rinsing is. I understand many don’t rinse but I live in San Diego and it doesn’t rain much here.

Anyways… The job went great yesterday. Everything came clean with the first application except for some heavy algae that was growing in a few spots (this house was built in the 70’s and the roof has never been cleaned). After rinsing I reapplied my roof mix to the algae, gave it a quick scrub and let it sit. We just happened to get a heavy storm rain early this morning and when I stopped by to check in with the client earlier today the roof was perfectly clean. She was very happy and I’ve got a job doing a neighbors house next week.

I ended up bringing two 55 gal barrels and used one for the roof mix and one for straight tap water. I rinsed with my roof pump. It worked great but was slow. Credit to @Innocentbystander a garden hose probably would have worked better:grin: but instead I had my technician use the hose to rinse plants, siding, etc… I would love to know how other people that DO rinse go about doing so.

@Atlas1 Hey, thanks for chiming in. I ended up just rinsing plants with a garden hose but I’ll definitely consider the PW next time. How do you/ what do you use to rinse?

If you search “rinsing roofs” not much pops up. And what does is mostly just a debate about whether or not to rinse, or people saying not to rinse. But there’s not much info on how to rinse/ what equipment to use. I’m thinking your basic water pump would work. For those with experience/ knowledge in this particular aspect maybe this would be a good place to post it.

No harm no foul from me. Glad it worked for you. In all honesty the last thing you want is rain right after doing a roof. Let the stuff dry and evaporate as long as it can before it hits the grass and vegetation. That is the reason myself and most others don’t rinse the roof. Bag the gutters. Wet everything. Buy cheap 5 dollar sprinklers and hook up before you leave. Tell homeowner they are his and to turn them off before he goes to bed.


There are some other forums where you can find more on the rinse/don’t rinse debate. (TGS, PTState, etc) I researched heavily, and was part of the “don’t rinse” school from job one. I live in an area where we usually get heavy rain every afternoon in the summer, so the Creator already has 96% of my rinsing taken care of.

If I do need to rinse heavy moss I just use garden hose, but that will change when I get my AODD setup next season, which will be used for chem AND rinse. (I will be starting with a 15 GPM pump). A lot of guys who rinse regularly will get an electric booster pump to supplement the garden hose pressure.

I agree completely! One thing I forgot to mention in my last post…We ALWAYS schedule our roof cleanings as the first job of the day, and we NEVER schedule one for the afternoon…All scheduled roof cleanings have a “gonna-reschedule-if-it-even-looks like-it-might-rain-too-soon” clause built in that the customer is informed of from the get-go.

(Is that some kind of hyphen use record?)

I dont always rinse.

But when I do I use the Pure Water from my WFP

Because minerals.

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You clearly aren’t educated on the topic you’re discussing. First, the energy bills will go up in the summer due to the fact the algea has removed the granules. The granules reflect sunlight which in return keeps the attic cooler. Secondly, those black streaks will eventually turn into lichens and moss which will also destroy a roof. I would ask you to research the subject and educate yourself just a bit more. Also, I have insurance companies pay me to clean roofs. I doubt an insurance company would pay out on something bogus. Well wishes and continued success my friend

Xtreme Cleanz
Birmingham Alabama

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Lol. You must be a roof cleaner. Do what you have to feed your family. I’m just saying be honest. There is zero evidence that promotes energy savings. None. Reflecting energy? Nice. Insurance companies are swayed by the lobbyist same as EPA and other entities. Do you think we would be forced to reclaim of if it wasn’t for Robert and other vendors trying to make a buck? Educate yourself and keep washing roofs. There is a market for it. Just be honest with the customers. Scare tactics and lies is no way make a dollar. At least for me.

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Actually insurance companies pay because they promote a algea resistant shingle. As far as lying to my customers I don’t call them or make them do anything against their will. I think where we differ is with the stage of the algea growth. In the beginning “black streaks” won’t hurt anything. Most of my customers have them cleaned for more of an ascetic issue than functional anyways. But, over time those streaks will turn into something which will destroy the roof. At the end of the day you believe what you want and ill do the same. Have a merry Christmas brother

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Fair enough. I have some properties in Hoover so I’ll call you in May when we come into town to wash.

Sounds good buddy

I would love to know which insurance companies “pay” for roof cleaning. I have contacted State Farm, Allstate, Farm Bureau, and an independent agent all of which said “No” - “Nada” - “Never Heard of it!” According to them roof cleaning is considered maintenance and is not coverable by insurance. They did acknowledge that a dirty roof draws scrutiny from their auditors and underwriters but none have ever heard of a policy being canceled due to a dirty roof.