Asked on Jul 20, 2012

cleaning concrete

Ger LeahyBarb M.Candi


I power washed some concrete that has never been washed before and now it looks worse than it did before I washed it. Mildew is running rampent . What happened? I power washed it.
9 answers
  • When you say it looks worse. is it just streaky or has the surface of the cement become damaged from the power washer. When cleaning cement you must be very careful when using a power washer. The water can deteriorate the surface quite quickly. You must use a wide spray pattern, keep the wand several inches away from the surface and keep it moving all the time. Can you describe what happened or what it looks like. Better yet post a photo.

  • KMS Woodworks
    on Jul 20, 2012

    By washing it you introduced a ton of new moisture that may have not been present might have some luck knocking the mildew down with a bleach or oxygen based cleaner.

  • Pat S
    on Jul 20, 2012

    I found putting straight pool chlorine in a hose container thingy attached to the hose and hosed down and a scrub brush worked the best... after trying all the other products out there. My north side is the worse.

  • Jeanette S
    on Jul 21, 2012

    To me concrete always looks nasty no mater how hard you work to keep it clean! Our trees are always droping leaves and debris on it that stain and that adds to the ugly look. I wish we could afford pavers, but it is out of the question!

  • Pat S
    on Jul 22, 2012

    I'm hoping one of these days to paint it! Can't look any worse.

  • Barb M.
    on Jul 22, 2012

    Thank you to everyone who answered my question.

  • Candi
    on Jul 22, 2012

    Tide with bleach powder laundry detergent.. we made a paste and scrubbed it with a broom then rinsed with pressure washer...our cement was bright white again!!

  • Barb M.
    on Jul 27, 2012

    Thanks Candi for your advice Barb

  • Ger Leahy
    on May 12, 2015

    WE have a thing called Sodium Hypochlorite it says mix 20 to 1 we mix 10 to one dangerous stuff do the path with that pure white in 2 weeks keep away from PVC door and windows use rarely it will eat the concrete

Your comment...