Discoloration on concrete


Jul 5, 2015
Central NJ
This happened the first year I had a cover on. I've pressure washed, scrubbed with a cleaner for patio, I get very little change. Any ideas how to fix this? It's literally the outline of the cover. 109061


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
We see that a lot on the forum. I believe the exposed concrete (darker) is dirty -- but not sure you can clean it well enough to make it match.


In The Industry
Jul 20, 2017
Windsor, Ontario. Canada
What did you try and wash, the bright or the dark as Marty asked ? I see this every year as the dirt builds up over the winter due to no rain. I pressure wash and it brings it back to match the clean area that was under the cover. You will need a lot of pressure and have the wand set to only an 1" wide spray and be very close to the surface, slow going and will take many hours. I am experimenting with a sealer this year to see if the "clean up" time can be reduced.


Gold Supporter
Silver Supporter
Jul 8, 2013
Columbus, Ohio
Be careful with a pressure washer on concrete. The jet tips can etch the concrete. A 40 degree tip is suggested for cleaning. I'll be cleaning mine this weekend with a new cleaner. I'll let you know if that helps.