Streaked my Concrete with Pressure Washer!

#1
Have had our new pool for only two years now. I used a pressure washer last fall to clean the dirt from our concrete, which by the way was unsealed, and now it appears that I have ruined it.

The concrete itself is in tact and seemingly strong, but everywhere I used the pressure washer I apparently took the top surface off the concrete. In essence, when I thought I was diligently "washing" the concrete little did I know that it was actually the concrete surface itself that I was removing.

The "washed" concrete portion now appears to be grayish in color compared to the relatively untouched section that is still white in color.

Needless to say, I am extremely upset as this was a major project for our family that we spent considerable money on. Unfortunately, I am not made of money and I am at a real loss on how to remedy our situation.

Any possible help would be greatly appreciated!!!
 
#2
I am going to go out on a limb and say that you left the mark of Zoro, or wands marks in the concrete. What size tip did you use? I hope it was not the 0°. If you were only using water I am sure you did not ruin the concrete. Try using a 15° tip and take your time making sure to over lap each pass so that you do not leave wand marks or use a turbo tip which and be purchased for around $50.00. A turbo tip is a rotating 0° stream of water that will clean concrete quickly and efficiently.
 
#3
Any other remedies needed?

Correct me if I'm wrong, but is what you are saying that if I go over what I did with more of a fanned spray that it should flatten out the area that looks gray and then it will look white again?

You are correct ... even in the spots where I was just spraying loose debri, the good part, you can see the circular lines or how you describe "Marks of Zoro" where I sprayed. Obviously I was using the wrong tip. I was just using water however.

The problem I have is that I did a very thorough job on the rest of the area and it literally looks gray compared to the part around the perimeter of the pool or the "good part".

Is there any other thing that has to be done besides rewashing using more of a fanned spray? ... possible cleaning or bleaching to remedy this part ... Or does the color just appear gray because I made uneven grooves in the concrete from using to fine of a spray?


I've been told that I can do the same exact thing on the rest of the concrete to match what was done, but then we have an entire streaky gray mess instead of partial. Doesn't seem to make too much sense to me.

I appreciate any more help that you might be able to offer!
 
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#5
If you were using a turbo tip(I don't like cause I can feel the particles of concrete hitting me when I use it to clean) or a zero degree tip then you most likely damaged the concrete beyond reasonable repair. Mostly a aesthetical problem but that top surface also protects the concrete to an extent. If you used a wide fan and probably a homeowner unit(2700psi or less) and it still damaged the surface than you made have some substandard concrete. Concrete usually ranges from 3000psi to 4000psi, pools are probably 4000 psi but I am not sure. I would get a core sample taken and compressive tests done to determine if its bad concrete. Another culprit could be that the pool contractor floated the concrete too much after pouring it. This causes the surface of the concrete to have a higher water/content ratio which greatly reduces its compressive strength. Its uncanny how many contractors do that, messing up the slabe without even knowing or caring.
 
#6
May I suggest that you have an experienced pressure wash contractor in your area come and take a look? If the surface can be evened-out, then you would not want to be the one doing it. No offense, but it sounds like its time to call in a pro.

Another possibility is that the concrete can be chemically cleaned. Sometimes, the area outside of the cover will turn color and can be brought back. Don't give up yet, it may be salvageable. Sorry I don't know anyone in Buffalo.
 
#7
Thanks for the responses ...

I hope they don't stop. I'd like to think that our problem is fixable to a certain degree. Not sure how to post pictures ... but maybe I'll give it a try.

It scares me thinking that our problem might be more than just aesthetic. Believe me, the looks are enough of a problem at this point.

To me, the concrete structurally looks okay. Then again, who am I to tell.
 
#8
When the top surface of concrete is floated and troweled it creates a dense surface layer of concrete that protects the slab. Once that surface is removed, it allows more moisture into the slab than normal, when this moisture freezes it will begin to "spall" at the surface. So... water will go in the spots that you f'd up and spread out under the surface, when it freezes it will "pop" the surface layer up and poof there goes your beautiful pool.
 
#9
If you have difficulty posting pictures, you can email to me and I'll post for you. There are a couple of contractors in the NY area that visit this bbs - maybe one will see your post and help you out. Without close up photos though, it is difficult to determine if you've removed the cream coat or not.

Celeste
 

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