Black spots

Discussion in 'Pressure Washing' started by super mck, Jan 27, 2016.

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  1. super mck

    super mck Active Member
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    how do you guys get rid of the black spots on slabs etc .I mean after pressure washing them.
     
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  2. Eviestevie

    Eviestevie Grand Master
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    Done one today
    The spots you refer to are lichens
    Depending how long they have been left it can be impossible to move
    I attack them by power washing the entire area with a turbo nosel this certainly fades them
    I then go over the area with a turbo and steam 155degrees
    Then I spot clean with sodium hypochlorite
    Sometimes it is impossible to remove every last trace but the overall effect is good
     
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