Gallons of housewash solution per house?

hello everyone, I’ve been lurking on this forum for a few weeks soaking up info. I am trying to start my own power washing business here in Arizona, right now I’m trying to get a rough estimate of my costs of doing business so that I can factor everything into my pricing. Basically my question is, how many gallons of house wash solution(SH mix) do you use on the average (2500 sq ft) house? If I’m running a 50/50 SH to water mix, will 5 gallons of bleach be enough (more than enough?) to do the house?

10 gallons of my mix will last me approx 2 house roughly 2500 Sq ft.

This is down streamed from my truck at 8gpm.



Awesome thank you! I’ll be working with 5.5 GPM so I’m assuming 10 gallons of mix would last me for a little bit more square feet right? a lot of houses in my area are stucco and in the 4-5k sq ft range. Thanks for the input, happy new years,and I hope you have a great spring season!

Smaller machines tend to draw at a faster rate- so you could blow through more mix if you’re not careful.

In general, it should take about the same amount of solution to properly clean a house, regardless of the machine you’re using. The exact amount will vary depending on level of algae/mildew growth and the substrate (type of siding/surface being cleaned).

With the higher draw rate of the 5.5, soaping really shouldn’t take much longer than if you were using an 8gpm.

Where a larger machine really pays you back is when it’s time to rinse.


nice, good to know. majority of the houses here in AZ are stucco, do those usually take more solution in your experience? thanks for the response!

I have no idea. Not much stucco in these parts. I would suggest using the search feature. I seem to recall some people needing a stronger mix than what they could achieve with a DSI. I think xjet or a 12v chem pump were recommended alternatives.

Typically here on east coast where we have more mold, will take a stronger mix to do stucco, but in AZ you’ve probably never even seen mold on a house, so you’re just mainly washing dirt and dust.
Could probably get by with 1 gal SH per 5gal but may want to use a little more of a good soap


Is it necessary to use chemicals? I mean it seems if you choose the right pressure washer and apply the suitable pressure the machine works well and there is no need for chemicals?

Pressure isn’t necessary on houses and can cause damage. Houses are usually always soft washed with little to no pressure and the chemicals do all the work. Pressure washing is more for flat work like driveways, etc.


Yes, let the chemicals do the work and the PW do the rinsing.

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So I live in Idaho and would like to add soft washing houses to my jobs. I do window cleaning primarily however I know I can sell a lot of soft washing to my previous customers. We don’t get a lot of mold here since it’s pretty much considered a desert climate so I think I would have a similar situation as Arizona, I think it would be mostly dirt that I will be washing off. My friend is giving me his Honda pressure washer which is a 3500 psi and 3.9 gallons per minute, will this be enough to downstream? Also is just a regular house wash mix of bleach sufficient for dirt or is there other things that are better used for dusty and dirty climate?

That will be fine for DS. If that side of your business grows, at some point may want a larger machine mainly for rinsing and doing flatwork. Just speeds up the process, doesn’t make it any better. Just remember you’ll spend 1/3 of your time soaping and 2/3 rinsing.

Bleach isn’t the answer to everything. I mean you don’t use bleach every time you wash your hands do you? See my response up above. Talk to some professionals in your area and see what mixes they’re using.


Hi Dean, I got started with a 3.5 gpm machine. Worked pretty well for the occasional house washes I was doing. It would soap up just fine, but was a little slow to rinse.

I eventually upgraded to a pressure pro 5.5 @ 2500 last year. What a difference! Depending on the engine and condition of the machine you’ve inherited, you might consider getting a 5.5 gpm pump, either belt or gear drive (gear drive would be simplest - direct bolt-on replacement), and upgrading the machine. PSI will be reduced, but you don’t need pressure for house washing.

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thanks for the tips @Racer and @Infinity. I have done a couple house washes before with my little 2800 2.3 gpm honda with just water for a couple people. It actually turned out looking really good since i pre brushed for webs and stuff and i was only rinsing dirt off for the most part. I plan to upgrade in the future however i don’t plan to get a buffer tank just yet so i am trying to not go past 4 gpm for now. Right now i only offer that service to customers with houses that i feel comfortable doing until I have a little more experience. Not to steal the thread but is there a safe choice surface cleaner to use with the size machine i will be getting?

Rough rule of thumb is 4" of surface cleaner for each gpm. That said my 4 gpm would push my 20" whisper wash just fine. So I’d say stay 20" or less, you may need to adjust your walking speed. I’m a whisper wash fan but there are some that are less expensive that will work fine.

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We don’t use cleaning solution, only water. We find people in our market are very environmentally conscientious and don’t want us washing cleaning solution down the storm drain. In fact, plain water works very well.

Pro-Long Roof Care

Lol. That is funny.

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So you just spray water on the roof and all the moss and mildew come running off? Please post video.

Believe it or not they use high pressure air lines to blow off the moss, and shingles, from the roof lol. Guess it is tree hugger friendly. Absolutely destroys the integrity of the roof but I guess the gimmick works or they wouldn’t be in business. Lot’s of these guys in state of Washington but not many other places. Plenty of videos on youtube of it.

So here’s what I use for my soft wash business in NJ. I use a battery powered backpack sprayer (that I attached to a hand truck) that holds 4.5 gallons. It has as an accessory, a 14ft wand extension attached to a 50ft. line. This allows me to get most two story houses done from the ground. I use both a fan sprayer and adjustable nozzle (that come with the sprayer) for my attachments. I believe this way uses far less product than all others. Instead of dousing homes with cleaner, I regulate the amount that gets sprayed on via a dial that regulates the amount sprayed on and spray on only as much as is absolutely needed. For a two story house (approx. 3000 sq.ft.) I only use 2-3 gallons of bleach. I also use a product called Jomax which is available at Lowe’s. I bring my own hoses but hook up to the homeowners water. It works great and all my customers are extremely satisfied and my business is growing like crazy. It may take a little longer to get it done but expenses are very low doing it this way.

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