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vinyl siding cleaning help please

Discussion in 'Power Washing' started by petroskie, Jul 21, 2011.

  1. petroskie

    petroskie LawnSite Senior Member
    Messages: 251

    Just bought my first home and noticed in areas theres mildew or small mold spores on the siding, Ive used several different vinyl siding cleaning chemicals that you spray on then hose off and shocker non of them work, mother inlaw said to use bleach but cause it worked on her house but i dont wanna kill my grass and plants and im sure its not good for the house period, can anybody point me in the right direction?
  2. JCinNJ

    JCinNJ LawnSite Member
    Messages: 159

    it sounds like what you are dealing with is "shotgun fungus" aka "artillery fungus". depending on how long it has been on the siding it may not come off without leaving a shadow behind. Try the bleach, keep plants wet and soak the ground with water before treating the siding and you wont have any problems with plants dieing. Bleach will not hurt vinyl siding.
  3. petroskie

    petroskie LawnSite Senior Member
    Messages: 251

    ok thanks, My thought is to load up my joke of a pressure washer with bleach in the soap tank and wet the siding, then spray with bleach and let sit for 5min or so the spray off. would this be a good method or should i skip the wetting of the siding and just spray bleach?
  4. JCinNJ

    JCinNJ LawnSite Member
    Messages: 159

    if your using store bought bleach, 4:1 (4 water, 1 bleach) and apply with a brush. You can bump your mix up to straight bleach if the weaker solutions dont work. If that does not work you need to learn to live with it or replace the siding.

    I googled this a few years ago and did not find any good info. I tell my customers (during the estimate) that the majority of the time, it will not come off.
  5. RussellB

    RussellB LawnSite Fanatic
    Messages: 8,185

    Use outdoor bleach. I spray my house down with water then use my pump sprayer to spray a 50/50 mixture (water/outdoor bleach). For heavy areas you'll need a brush to loosen it up then rinse with water.
  6. sdm111

    sdm111 LawnSite Member
    Messages: 12

    Great site just joined anyway, been installing siding for 13yrs. use a pump up sprayer with 100% bleach, don't wash it off just leave it. Make sure you spray it good or it'll leave streaks.
  7. petroskie

    petroskie LawnSite Senior Member
    Messages: 251

    i did some siding today and i did straight bleach and i let it site for 5min and it all just washes off, but you say it will come back? most of it is on the north side of the house, kinda like moss on a tree
  8. JCinNJ

    JCinNJ LawnSite Member
    Messages: 159

    You got the algae off, great to hear!! It will always come off with the proper mix.

    How about the little black dots (small mold spores you described), that is the shotgun fungus I was talking about, did that come off?
  9. petroskie

    petroskie LawnSite Senior Member
    Messages: 251

    in some areas it came off right away but the heavy areas knocked most of it off but if you look hard enough you can see that it was there and the bleach did get it off. I would have scrubbed it but i didt have a brush since were not moved in yet, it there a way to get the rest of it off or did it stain the siding?
  10. Torque454

    Torque454 LawnSite Member
    Messages: 24

    Ordinary bleach wont work very good through the power washer (it dilutes it too much) but you don't need to use it full strength. Yes the mold will come back, but thats just because it grows, like everything else.

    It wont come back from the dead or anything like that.

    Id mix about 3:1 (3 parts water 1 part bleach - as in 1/3rd bleach 2/3 water to each gallon of mixture) and put it in a pump up garden sprayer and spray the house with that. If the mixture turns yellow but doesn't disappear on the siding, add more bleach. Then rinse off.

    If you do it right, you dont even need a power washer most of the time. An ordinary garden hose will work to rinse the stuff away. The power washer comes in handy for spider webs, bird droppings, etc. The tougher stuff like that. But if all you've got is mold mildew and algae, bleach water in a pump up sprayer and a garden hose is all you really need.

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