Post Treating Concrete

Hey guys, I’m researching how to get better at concrete and I’m seeing alot of people talking about post treating their concrete drives. Is this simply applying more mix to the drive after you’ve washed it to kill any mildew left over? And from my research, it seems you just let the post treat mix dry up on the concrete? Just wanted to verify that I’m viewing this correctly


Yep helps get out spots the Pressure washer was not able to also when it dries the concrete is a little brighter . Know your going to do it before and afterwards let’s you get away with using less pressure on the concrete which means less chance of taking off the cream coat


Thank you. This is really helpful info and why I love this forum. That’s something I’ve battled on the concrete jobs I’ve done so far, having a few mildew spots that seem to require way too much pressure to fully come off. But I have not been post treating…

Newb question. Are you post treating with surfactant in your mix?

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Yes there is always surfactant in my mix


Keep in mind if you pre treat or post treat with strong mix like roof mix there is always to potential to burn the grass along the edge of the concrete. Some customers will not care others will loose there mind

Any time there is standing water, whether post treating a driveway or even spray ox on a deck after cleaning, you need some surfactant in there for the chem to penetrate. Otherwise your “success ratio” goes way down and you could be wasting chemical.


I always leave 12in on each side of the drive as a safe zone so I don’t burn grass. When you go back days later you can’t really tell those areas didn’t get hit with the post treatment.


How often do you go that strong on the post mix? Ive noticed a 2% hw mix doing wonders on the concrete here in Illinois. But again ive just applied, dwelled, and rinsed. Nothing post yet

It’s really an ass needed kinda thing. Mainly because it has potential to cause damage to sod . But I do rince every driveway with housewash I just leave my injector on . Apply using DS then wash then I rince with the DS . It’s not strong enough to brown the grass and it help the driveways get clean after you leave. Plus it saves a trip back to the truck to switch the injector off

Haha ya I burned the edges of a customers lawn for the first time two weeks ago. Customer was not happy, sent me a picture of what the lawn fertilizing company said about what happened (that it was chem burn).

I drove by today and it was hardly noticeable, I guess my Roof mix was hotter than I expected. I normally just downstream as my post treatment but his driveway was bad. Even a 30% Roof mix is solid for post treatment but I think my Roof mix that day was closer to 50/50.

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Some customers will get upset that’s why it’s an as needed thing. Either way it will come back quickly especially this time of year

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I’ve only been PW’ing four years and developed some repeat accounts. Please reply with product brands and vendor sources of post mix. I used to sell Amway and did okay with their commercial products. Maybe Zep, Amsoil, Shaklee or Watkins Products have this chemical for concrete. I am bidding a large concrete parking lot and all concrete around a large bank. I hope to get the job and would be proud to have it look first class work.

You just post treat with Sodium Hypochlorite.

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Did a drive way with a surface cleaner and post treated with a light sh. This concrete hadn’t been cleaned in years and the previous guy used a wand and damaged the surface. The damaged areas looked different than those not damaged and I was wondering if there is a method to have all areas look the same.

You really need to post some pictures to get an accurate answer. If I had to guess the guy with the wand probably removed the cream from the concrete in certain areas. That’s just a guess though and have no way to know for sure without seeing it. There are a number of different reasons why one area might look different than another.

You can always damage the rest of it so that it looks the same. :grinning:


It’s most likely not damaged, it’s just zebra striped. When you do this on a driveway over time the bits that haven’t been cleaned properly will obviously look darker as it ages out in the elements at the same rate as the parts that were hit with a few thousand psi.

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Next time you see ‘damage’ like that, tell the customer right away so you’re not blamed for it.

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If I were to use a backpack sprayer for post treatment, what would be a good mix for that?
I see people saying they use HW mix, but is the HW being directly applied or DS?