How Do I Choose a Roof Cleaning Pump?

Here is an article I wrote for eClean Magazine on the pros and cons of different types of pumps.

So you want to be a roof cleaner? Great!
You’ve researched demographics, vehicles, marketing, and what kind of mix you are going to use. Now the big question: how are you going to get the stuff up on the roof? Because you not only have to get it up there, you need to keep it up there. Too much flow and you risk nuking your client’s expensive landscaping. Not enough applied and you don’t kill the stains and you can’t bill the client.
So, you need to get enough of your mix on the roof to do the job and make sure it’s evenly applied with minimal runoff. The good news is that as opposed to even five years ago, there are lots of options for your roof-cleaning pump. The bad news is that there are seemingly endless options for roof cleaning pumps and systems and it is easy to become overwhelmed when trying to decide among them.
What do you need to look for? Which type of pump or system is right for you?
Most guys who have been cleaning roofs for more than the last few years started out with a small 12 volt pump and a very rudimentary system. There weren’t any commercially made systems so they used their ingenuity to figure out a way to get their roof cleaning mix from the ground onto the client’s roof.
These small pumps were not built to handle the corrosive effects of roof-cleaning mix and did not have the power to shoot very far. Roofs had to be walked and the mix was typically much stronger than what is used today because of the very low volume put out by these setups. Just a little missed overspray on someone’s plants or deck had the potential for disaster.
As pump design progressed, things got easier for roof cleaners. The introduction of the Delevan 5850, five gallon per minute pump allowed longer hose runs, bigger hose, and longer shots for those difficult to reach spots on unwalkable roofs. These pumps were designed to spray agricultural chemicals and used Viton valves and Santoprene diaphragms for chemical resistance.
Probably the most commonly used 12v pump these days is the Delevan Fatboy. It produces up to 7 gpm at 60 psi and has a field-replaceable relay. It is necessary with all 12v pumps to use spray tips with an adequate orifice size so the pump won’t continuously cycle on and off and overheat, but the use of an accumulator tank can mitigate excessive cycling and allow the use of smaller orifice tips without damaging the pump.
The next step up is the air diaphragm pump. These pumps are powered by a separate air compressor. They produce more volume than 12-volt pumps and are considered to be more durable. Another notable feature is that air-operated diaphragm pumps can use very small orifice tips without damaging the pump. Many high-volume roof-cleaning companies use air-operated pumps for multiple roofs, five or six days a week and never rinse them out. The downsides are that they are more expensive than electric pumps and you also need to purchase a separate air compressor. If the air compressor won’t start, you’re not cleaning!
The last type of pump we will consider is the gas engine-driven pump, like the John Blue or Udor Zeta. These are by far the most expensive option but also produce the highest psi and spray volume. This setup is often used for large commercial jobs where thousands of square feet a day are being cleaned.
Scott “Squirtgun” Karvonen of Karvonen’s Pro Clean in Tifton, Georgia, swears by his John Blue setup for roof cleaning: “It has been the most reliable system I’ve used,” Karvonen said. “I like the fact that I’m not limited to short hose runs when cleaning and there are no priming issues like we used to have with the 12v pumps. You can climb on a roof and start spraying without worrying about priming it on the ground and whether you will lose prime as you climb. We often shoot up to 40 feet for difficult shots, but most of our cleaning is done with a 40 orifice fan tip. It is extremely fast and efficient and the small gas engine hardly burns any fuel at all.”
One who has run the gamut of roof-cleaning pumps is Don Phelps of All Seasons Exteriors, a roof cleaning company based in Orlando, Fla. He has offered labor-for-learning and online tutoring for countless contractors over the last few years. The man who is dubbed “The Roof Cleaning Guru” by fellow contractors and the one to bring the “Phelps Wand” to the roof cleaning masses toldeClean Magazine, “I started out pressure washing but kept getting requests for roof cleaning. My first roof-cleaning job was a 1400 square foot ranch that took me five hours with a pump up sprayer. I knew there had to be a better way!”
He used a roller pump setup for a while but that proved unreliable. “Since the roller pump wasn’t rated for roof cleaning mix, it kept freezing up and trying to meld together. I had to remember to pull the cord on the engine often to keep it from seizing up. When we went on vacation, the housesitter’s instructions were, ‘Water the plants, take care of the dogs, and remember to pull the cord on my roof cleaning rig a couple of times a day!’” he joked.
He then went to the small 12v pumps, but as he started landing very large multi-story commercial jobs these small pumps couldn’t keep up. That’s when he began using gas engine-driven pumps.
“Gas-driven pumps are great for larger commercial jobs. They put out more pressure, shoot farther, and are much more productive on the big roofs, especially for the difficult shots. That being said, I feel that the best all-around choice for the average contractor is the 12-volt once you balance cost versus return. We use the John Blues for the big jobs, but 90 percent of the time we use Delevan Fatboy pumps and just regard them as disposable. The biggest hassle is making sure that the batteries stay charged but for average residential and small commercial. We just have them on quick connects and if one stops working we slap in another one and keep cleaning. I get between 75 to100 roofs out of each one.”
No matter what you decide is the best fit for you or if you have to try a few different kinds of pumps and setups one thing is for certain: You have lots of options and it’s a great time to be a roof cleaner!
Thad Eckhoff is the owner of Apex Services Window Cleaning and Pressure Washing Company, and the co-founder of Pressure Washing Resource Association (PWRA). The PWRA provides practical, proven resources and marketing/sales helps for member companies. To learn more, visit


Well this is really good post you made.It was really good to know the way you are operating.The pump you are using are must reliable and good to get perfect work from them.Even my company also using there apparatus.Well your method is too good of working as it help me to change my operations.

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Nice job on the article Thad.

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Great info regarding 12v pumps from Bob at Pressure Tek:


Great info. Good for the guys who are on the fence about adding the service. I just started roof cleaning this season & love it. Looking forward to next season.

Awesone article Thad…

Great article, you really hit all the different pros and cons for each type of pump.

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All we do is roof cleaning, mainly cedar shakes and the fat boy 12v pumps works great for our needs. Just make sure you rinse it out at the end of the day.


good looking setup! what are the 3 tanks set up for? I’m trying to get something like this myself I’m trying to figure it all out.

Josh Rouse
Carolina Clean

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[QUOTE=josh2726;19119]good looking setup! what are the 3 tanks set up for? I’m trying to get something like this myself I’m trying to figure it all out.

Josh Rouse
Carolina Clean

I have three tanks one for chemicals, one for cleaning mix and the small one was for pump rinsing at the end of the day.
I got rid of the small tank and have another way to rinse now. I have everything plumbed with three way cutoff valves.

Once I have more posts here I’ll send picture.

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I know this is an old post but I am trying to get 10 posts in as a new member. I bought the THE FATBOY BANDIT ROOF CLEANING SYSTEM from Bob at Pressure Tek. I tried it out one time before storing it till spring. What a great system!

It is a good system.

Yeah that is a great beginning roof cleaning system… Just rinse that bad boy out and it will make you bank over the next 2 years!! The main benefit that I like in that system is the no noise!

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Great article, especially for the roof cleaning newbies like me.


I’m glad it helped.

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I think that Fatboy System look like a nice little affordable setup. I have a couple questions.

Is it possible to do roof cleaning without a ladder working from the ground using this equipment?

Someone mentioned that they considered the pump disposable after 75-100 roofs, is the pump the only thing that needs to be replaced at that point? For a $250.00 pump that is not a bad expense of $2.50-$3.50 per roof.

What is the going rate to charge for roof cleaning?

I would like to add roof cleaning at some point, but did not realize how affordable a setup is.

You ask some good questions. I personally use the Fatboy pump and I do a lot of cedar or mostly cedar roofs which requires more pump use per cleaning than say an asphalt roof. I have done about 175 roofs with my present pump. The key is to flush or rise out the pump at the end of the day.

I do not see how you could possible clean all roofs without at least a ladder. I personally do not get on a roof and clean all mine from a ladder. there will be times you need to get behind dormers etc. which has to be done from a ladder.

Roof cleaning cost is all subjective on location and roof type. Also how good your marketing is and how well you sell your service or can. Personally I have no set service cost, I take into account the roof, infestations, location etc. and quote a price. I believe you will find the
pricing is all over the chart. I can assure what I get here in Iowa you wouldn’t get half that in Florida.

I buy my fatboys online and have built my own pump system. PWMall-7870-101E-Delavan FB 2 Diaphragm Pump 12V, 60PSI, 7.0GPM, DEM

You could also consider a pump in the box from Bob @ pressure tek.

Good luck


One point of clarification (to the new guys). The “accumulator tank” that Thad refers to in his article is a bit like an expansion tank. It basically moderates pressure fluctuations in your system so the pump does not cycle on an off. The repeated “cycling” of a pump (turning on and off) can cause it to overheat and also damage the pressure switch.

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Great thread, it will help with my soon to be made purchase.

Question for Sullivanroofcleaning…or for anyone… are yall flowing your chemicals such as SH straight through the FatBoy or are you down streaming?

Charlie w/ Nozzlemen’s Pressure Washing