Rust-like concrete stains appearing

Hello folks!

I am new to the business and community. I’ve been using my surface cleaner on my driveway to get to know my equipment. I didn’t have any growth of organic, mainly just dirt here in AZ but I used bleach still just to get a bit more familiar with using it and to see if it made any different. I didn’t have any staining like this before, but it seems to have appeared today. I don’t think it’s rust though… does anyone recognize this or can they diagnose it? I want to make sure this doesn’t happen to customers. I don’t know if it was there before but dirt covered it and now it’s appeared after drying, or if I did something wrong… any feedback or experience shared here would be greatly appreciated.

Welcome to the board.

Couple things, what was your method of surface cleaning, what pressure was used and what are your equipment stats.

There is a group on Facebook, Front 9 that strictly deals with non-organic stains. His company has four chemicals that handle stains such as yours. Some people on here aren’t fond of them but I’ve witnessed very good results.

3500 PSI - 4.7 GPM Landa pressure washer. I washed it this weekend with that, though I didn’t get the wand very close. Maybe a foot away. It was mostly a rinse.

Previous to that, a couple weeks ago I surface cleaned it with a 3500 PSI-2.6GPM pressure washer and a ridge washer surface cleaner from Amazon. I’ve been seeing this result on all surfaces and I’m starting to wonder if it’s some kind of etching? I didn’t realize initially that you only need 2500-2900 PSI to surface clean.

Bleach was applied via a pump bottle at about 2-3% and sat for about 5min.

Thank you! I’ll look up that page!

My .02, you stripped it (removed the cream) on some of the broom finished surface. Too much pressure.
No big deal, it is yours, I did it to mine experimenting too. I didn’t get that pink stuff, but might be your concrete.

Here is my take and other may or may not agree

If you had a milky white/grey runoff, you saw your top going down your drive. I never saw it on mine, the runoff was soo black coming off from the equipment being run over it all the time.

Thank you! I was thinking it had to be something like that… because the surface is very clean lol. I’m not familiar with this cream. Is it something that I can reapply or is this permanent damage? I just got a new surface cleaner for my 4.7gpm and will make sure to get some 3gpm nozzles to drop that PSI down significantly.

2 things

  1. Wait for some other people’s feedback on here. I’m not saying I nailed it, but I am pretty sure that is what happened.

  2. Your choices are, to put it simply, up to you. You took the cream off, you really can’t put it back on. I don’t know what you do or don’t know about concrete, so I won’t go into the construction of it. You could paint it, stain it, put an overlay on it, or rip it up and repour that section. What you pick is up to you, but with vehicle and heavy foot traffic and your local hotter temps, I don’t know if anything would last. Since I don’t live in your neck of the woods, I won’t make a recommendation on a covering. My understanding is that some places in AZ get 110 degree weather for days to weeks on end and that could affect your choices.

Learn how to read a nozzle sizing chart before doing anything. There is no 3gpm nozzles, and if there was, that’s going the wrong way. You will want either a couple 2.5 or 3 size nozzles to get you around 2500-3000 psi max.

Looking at the pics, I’d guess as well you stripped the cream off and it’s permanently damaged. How old was the concrete?

Yes, 3.0 orifice is what I meant, not gpm. My apologies. I have 2.5s on the way and will order some 3.0s as well.

I’m not sure how old the concrete was since we bought the house a year ago, but given the quality of it compared to other homes around d I would say it was done in the last few years.

The general rule of thumb on this forum seems to be if it is 2 years old or less - don’t use pressure. It can still be cleaned, just not with pressure and not as quickly in some cases. as nickski said, you have to know the nozzle chart if you are going to be in this business.

There are other PW on this forum from that area (AZ). Hit them up, they may be of better assistance to you than someone in the north. My season is over. Got a couple of iffy days now, then 25 low-35 degree high days this week. Putting tarps over rig today.

Thank you both so much! I can definitely see where the cream way taken off and the concrete is much rougher now. Terrible lesson to learn but I’m glad it was on my own home. Still not sure what the pink is… it looks terrible.

I appreciate your experience! Thank you for sharing it here.

0 degree surface cleaner nozzles exist… and do that if improperly attended to. Or properly attended to!
Eagle wash bro!