Weird stains on concrete

A few years ago I hot pressure washed my neighbors driveway and back then it came clean except for there was splotchy Areas with lighter and darker parts. I’m back here looking at it again now that I’ve got more experience but I am puzzled by what is causing the different colors. Pics attached.

I think the pics need to be reloaded.


Thanks man, it’s fixed!

If that is completely dry, that’s some bad looking concrete.

It looks like there’s a sealer on it and it’s wearing away.

But some concrete just looks like that. I had some SH left at the end of last season and decided to clean my sidewalk. What was underneath the dirt and algae still didn’t look that great cleaned up.

1 Like

Looks like part of sealer was stripped