Soft Washing with 4gpm 4000 psi machine

I purchased a Pressure Washing business from my father in law about 6 months ago. All of our machines are 4gpm 4000 psi. He has been doing it for 20 years and taught me what some call the old school way. (Downstream SH and rinse with high pressure) I’ve read a few forums on this page and it looks like with the right tips I can possibly use the soft wash method with the machines we have. Can anyone please elaborate on this and let me know if this is possible? And if so what exactly I’ll need to perform this. Also wanting to get into roof cleaning and wondering the set up I would need to perform this witj with the same machine if possible. Any insight will be greatly appreciated.

Downstream SH, then pull the line out of the chem tank and also rinse with low pressure. Use the search function (little magnifying glass on top right) and all will be revealed.


Thanks. Since I’ve wrote this post I’ve realized that magnifying glass is a great tool to answer pretty much any question I could ask. I’ve Learned that you don’t have to have to purchase a soft wash system to soft wash a house.


I use the very same set up. I feel its nice to have the machine i do because I can soft wash the houses and then use pressure when I need to for surface work, brick, etc. Like the best of both worlds when using the right tips and tools.


Do you mind sharing what tips you use for soft washing? Also soft wash mix
and dwell time?

Sure ill take a pic or two tonight or tomorrow. Honestly the guys at the pressure washing place helped me make decisions but my cousin was already doing iton the side from his landscaping business so he kind of led me to what I would need.

Colby, Please keep reading and using the magnifying glass. You’re asking questions that have been answered a thousand times. You’ve only spent 3 hours reading in the forum.


That’s right. Regretted making the post once I realized how much information this forum had on the exact questions I was asking. Just figured since someone replied I would pick their brain for any added knowledge.



Purchase this
The orifice size will reduce your pressure. I pretty much do every job with this and a 45 degree tip.


Hi Colby

I also “softwash” with my 4gpm pressure cleaner. It’s all in the tips - I have a full set (0, 15, 25 & 40 deg) of #40, #50 & #60 nozzles, and usually use the #40’s.

Most of my houses are painted timber covered in dust, oxidation, road grime & mould which the “softwash” won’t fully remove, so I get out the brush for the worst sections & those where people can touch easily.

I apply the “bleach” at between 0.5 & 1.0% - you will need to test your d/s system to calculate your batch mix ratio.

Roof cleaning (and other surfaces that need a stronger mix) will need a dedicated pump (eg. 12v etc)



I’m thinking about going ahead and upgrading to the 8gpm 3500 psi pump. Everything I’ve read and found online this set up will cost $3000-3500. I searched to see if anybody on this forum had any advice of building there own and haven’t found anything. I’ve always built my own 4gpm machines and planned on doing the same with the 8gpm. I can get a 8gpm 3600 psi general pump for $699 and a 22hp predator motor for $699(we use predator motors on all our machines have great luck and harbor freight will take them back no questions ask with the two year warranty). That’s $1400 add in say another $300 for pulleys, belt, unloader etc. and that puts me at $1700 for a brand new 8gpm. Is there a reason more people don’t do this? What’s your thoughts?

I’m a big believer in doing what you’re good at. I’m good at cleaning. I could build one, but the aggravation and time it would take me to build one, I can make up in cleaning in a day or two and I’ve got known and proven reliability. But that’s just me, each to their own.


Understand. I just wanted to make sure that building my own didn’t have drawbacks as if the manufacture did something that I couldn’t do.

Same here…I can build one as it is not rocket science…I just don’t want to.

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@Racer @JimLuke I use the same engines, coils, generators and pumps on all my skids. When something gets well worn or has any issues I just simply swap parts with used rebuilt backups and sometimes new . I have multiples of every item that’s used in my rigs so when I want to build a new machine or make a repair I just start grabbing parts from my personal store and it’s just a simple remove and reinstall. I guess what I’m trying to say is if you need a engine because of a catastrophic failure or it’s just severely worn are you going out and buying an all new rig? Same with the pump and all the other major parts that can and will fail. Well so you keep backup items, well there you go, now you have all the parts needed to build your own in an evening rather than having someone putting it together who may do shoddy work, build it with thin ass plate steel that will crack to save $2.33, install janky China ball valves and couplers that won’t freely turn or leak, use light pattern brass that will crack if you look at it mean, use worm drive hose clamps that rust when they could have used stainless band clamps. I could go on for hours and miles. I’d like to see him figure out exactly what he wants and put it together better than anyone else would for him so he can turn around to pay himself with the money he saved and buy more parts but then again that’s me and I’m a lifer lol

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You can and should but I wouldn’t run the clone lol I’m a die hard Vanguard fanboy though

But see, that’s your thing and you’re obviously very good at it based on your posts. If something happened to my pump, I wouldn’t even take the cover off to look at it. I’d replace it and send it somewhere to get fixed. But that’s what makes the world go around. Somethings I like tinkering with, some I don’t.

I agree with you and will do the same…replace components as needed.

The post that Racer and I were commenting on was talking about building the unit from scratch. I have no interest in that…and when I bought my unit…I made sure the skid was substantial and that its failure was not likely, even after years of use, so that replacing components would be the only issue that I would face.

Having a hard time finding any knowledge on how to match up the correct pulleys and belts for the pump I plan to purchase. Should vendor supply these items with pump or is that something I have to purchase on my own?