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Moss on roof

Discussion in 'Power Washing' started by REDH, Mar 31, 2008.

  1. REDH

    REDH LawnSite Member
    Messages: 9

    Hey guys, home owner here. I had a tree cut down that was to close to the house and since it over hanged the roof, it caused moss to grow only in that area. What do ya'll recommend to get rid of it? Is there something I can spray on it?

    Thanks for any info,

    FCPWLLC LawnSite Senior Member
    Messages: 352

    Bleach... :)
  3. Marcos

    Marcos LawnSite Gold Member
    Messages: 3,720

    Clorox bleach, diluted down to about a 1:12 ratio with water, will work just fine.
    But it's not exactly the most environmentally-friendly, nor the safest product (as far as potential exposure to the applicator) to use.
    One wrong move, or weird gust of wind (if you're not wearing goggles) and you'll likely end up in the emergency room.

    The product I use for the number of mold jobs I do every summer is "M1 Roof Cleaner Concentrate", and the local Sherwin-Williams special orders it for me, for pick-up at their local store ( to save me the UPS freight).
    But you can also order it online direct from S.W. if you want.

    I have also used what they generally keep on their shelf- "M1 House Wash Concentrate"- but I didn't like it near as much.

    Both of these products need to have "common sense" precautions in terms of safety too, but they're much less dangerous than bleach !!!

    FCPWLLC LawnSite Senior Member
    Messages: 352

    ARMA recommended method for cleaning Shingles... http://www.asphaltroofing.org/pdf/tb_217.pdf

    GAF(Shingle Maufacturers recommendation to clean shingles)... http://www.gaf.com/Content/Documents/22710.pdf

    We actually use a stronger solution than clorox and don't have the issues that you hear about from folks that sell another chem. The other chems do work but not fast enough or without the prsence of using a pressure washer. Bleack require NO Pressure to rinse. We use a garden hose and often time don't even get on the roof.

    FTC also frowns on ANY advertising of "Environmentally Friendly" methods/products without fact to back it. So if you seek a pro in your area to do the cleaning, be wary of false claims of "safe for environment" Most often those claims are just to play on folks emotions to environmentally concious. There isn't much in this world that doesn't have an affect on the planet. If bleach was so bad, it wouldn't be sold at the grocery and folks wouln't use it to clean thier clothes. It is about the process in which it used. You don't let your teenage son do the Laundry because you know he will ruin the load. Same goes for hiring the hack with a truck with 4 different tires and a few bottles of bleach in the truck bed. It is about the manner in which the bleach is handled and steps taken to minimize risk of damage.

    Be careful when hiring a "contractor"
  5. Marcos

    Marcos LawnSite Gold Member
    Messages: 3,720

    Manufacturers and independent scientists agree that household bleach does pose a significant threat to the environment although use of chlorine by paper mills and plastics manufacturers has wrought significant damage to the Earth's animals, ozone layer, water and air.

    How can the same element be so benign in some instances and so damaging in others? This Jekyll-and-Hyde story revolves around chlorine's peculiar nature. Chlorine does not appear in the environment in raw form; it is born when a salt molecule is split with electricity. The greenish gas that results from the split can introduce the molecules of one element to the molecules of another without becoming part of die resulting compound. Chlorine's amazing joining ability is why it is used in the production of some 15,000 commercial compounds sold in die United States, including pesticides, pharmaceuticals and plastics. About 34 percent of America's chlorine goes into plastics and 10 percent into pulp and paper, says Bonnie Rice, a campaigner in Greenpeace's Chicago office. Only 4 percent is used in drinking water and disinfection, and usage in the cleaning of laundry and countertops isn't even big enough to track.

    Concern over chlorine usually emanates from widespread publicity about the 1 1,000 or so compounds that result when chlorine reacts with substances that contain carbon, creating what are known as organochlorines, or chlorinated organics. Environmentalists say organochlorines are persistent, toxic, damaging to the ozone layer and sometimes carcinogenic, using DDT and dioxin as examples. Dioxin is best known for its presence in Agent Orange, a chemical defoliant used during the Vietnam War. Both chemical manufacturers and paper manufacturers say the threat posed by organochlorines is overestimated.

    This debate is one of the most volatile environmental arguments of this century, and it may well follow us into the next. Among the players is the Washington, D.C.-based International Joint Commission (IJC), an advisory agency founded in 1909 by the U.S. and Canadian governments to assess problems and progress in the Great Lakes region. Since 1992, the commission has advised both countries to set a timetable for "sunsetting," or phasing out the use of chlorine, especially in industrial situations. This recommendation is based on an IJC report that assessed numerous worldwide studies conducted on the effects of organochlorines, says Frank Bevacquah, a public information officer at the IJC. "The bibliography is 60 pages long in six-point type," he says of the 1994 report, tided "The 6th Biennial Report on Great Lakes Water Quality." Among IJC'S findings is a chart summarizing endocrine damage in wildlife, including the failure to hatch in birds, fish and turtles. A new report is due in late winter 1996.

    Meanwhile, the staff of the U.S. Environmental Protection Agency (EPA) has amassed a similar scientific review of dioxin where it assessed research conducted by more than 100 independent scientists; the resulting 2,000-page 1994 draft report concludes that low levels of dioxin may suppress the human immune system and adversely affect the reproductive system. Now undergoing review by the Scientific Advisory Board, a panel of EPA advisors, the draft is so controversial that the EPA staff is reluctant to talk on record, and rumors about the board's impending assessment circulate regularly.

    Greenpeace has taken aim at organochlorines with a comprehensive campaign, and chlorine trade associations--first Chlorine Institute and later the Chlorine Chemistry Council (CCC)--have returned fire. The Washington, D.C.-based Chlorine Institute maintains in press releases that connections between chlorinated chemicals and human health are unsubstantiated and that readers of Greenpeace's report on organochlorines should "bear in mind who issued [the] report." More recently, the Washington, D.C.-based CCC assembled a group of independent scientists to review the same studies that IJC, EPA and Greenpeace cited; the resulting interpretations directly contradict those found in the other reports. For instance, the CCC's expert panel concluded that recent modifications to pulp mills have decreased concentrations of chlorinated dioxins in the environment by a hundredfold and that current levels "would not be expected to cause adverse effects in fish or piscivorous wildlife." Environmentalists aren't impressed with the findings. Peter de Fur, Ph.D., senior scientist at the Washington, D.C.-based Environmental Defense Fund, says, "The Chlorine Chemistry Council has as much credibility as a cockroach around here."

    With all this fighting it's no wonder that two years ago, Clorox Inc., the nation's leading household bleach manufacturer, started to distance itself with an ad campaign announcing that household bleach is environmentally safe. "We're trying to explain the difference," says Jim McCabe, senior environmental scientist at Clorox's technical center in Pleasanton, Calif "There are all different types of bleaches and all different uses."

    From everything we could gather, what Clorox says is true. "Greenpeace is not concerned about [household usage of bleach]," says Rice. "Household and swimming pool [usage] are very small."

    Small volume isn't the only reason scientists are unconcerned about household bleach. Conditions in your laundry room are vastly different from conditions in a paper-bleaching plant, and as a result the household bleach behaves differently. "I am not aware of chlorine in washing machines causing significant hazards," says Vern Snoeyink, Ph.D., a professor of environmental engineering at the University of Illinois at Urbana-Champaign. "We're not aware of any significant problems with the bleach used in laundry, even at some of the bigger facilities," says the IJC's Bevaquah. "It's just not a problem."

    Why isn't it a problem? Scientists say that at least two major conditions are necessary to produce a long-chain organochlorine like dioxin, and they aren't present in a household situation. To produce dioxin, the chlorine must have a low pH, and it must have a precursor (a set of carboncontaining molecules) to react with. The pH of household bleach is too high, says de Fur, and there are few, if any precursors available in the average load of dirty socks. In contrast, a paper-bleaching plant is packed with carbon-containing substances, and has a low pH. "I suppose you could throw a bunch of sawdust in the laundry," speculates McCabe, "but even then you still could'nt make dioxin."

    Your final concern probably stems from wondering what happens when the bleach goes down your drain. According to the Clorox ad campaign, household bleach breaks down to "little more than salt and water" after use. In addition to salt and water, Clorox's studies show that between 3 percent and 5 percent of the bleach's original chlorinated compound is still intact after use. In a septic system, this compound could kill all the good microbes hat compost the waste and make the septic system work-but since there's so little chlorine, the microbes will prevail, according to Snoeyink. Finally, there exists a small chance that some of the chlorine will encounter ammonia and become monochloramine, chlorine, which could be dangerous to wildlife if it is directly discharged into the environment, says Snoeyink. However, Clorox says it has not been able to measure monochloramine, and Snoeyink notes that water-treatment plants typically remove monochloramine before discharge anyway.

    Even though household bleach itself does not damage the environment, some consumers may still decide to forgo it. Making and transporting chlorine, which is toxic, are both dangerous processes. Greenpeace reports that despite tight controls, organochlorines are occasionally produced during chlorine manufacture, and Clorox, which buys the chlorine to make its bleach, readily admits that a serious transport accident in the late 1970s caused a total overhaul of its handling systems. But Mary Ellen Waghorm, president of Greenhome, a Chicago-based catalog of ecological products for household use, says you will have trouble finding an acceptable substitute for chlorine bleach. "I use lemon juice and put whatever it is in the sun," she says. "But that's not always practical, and it's not always effective."

    Environmental activists hope consumers will take on a more global approach. Read the summary reports and understand where the big discharges of organochlorines are occurring. If you're worried about the potential health and environmental hazards associated with chlorine, then take a stand against the major creators of organochlorines; paper bleaching, plastics manufacture and pesticides.

  6. Marcos

    Marcos LawnSite Gold Member
    Messages: 3,720

    All that debate aside...

    Using dilute bleach all day does nothing but give a person a headache ! :cry:

    And I don't know what you're talking about...I've never had to use a power washer after applying M1 Roof Cleaner !

    (REDH, power washers are a definitely a no-no on asphalt shingles!)

    Just apply M1... and the mold 'fades' over a few days or maybe a week, then it gradually washes away with the rain within the next 1 to 2 rainfalls.
  7. yard_smart

    yard_smart LawnSite Senior Member
    Messages: 590

    So you spend fifty dollars to buy a kit to do it yourself instead of hiring Michael or Me or another Pro to clean it. . . okay so you save 300 bucks but what happens if you mess your roof up our insurance will cover that will yours? what happens if you fall of your out of work not us! The point is some things need to be left to the attention of a qualified professional. Like Roof Cleaning and Power Washing!
  8. Marcos

    Marcos LawnSite Gold Member
    Messages: 3,720

    I'm no "rookie" here, yard_smart !

    I've been rock climbing and rappelling for 25 years....since I was a teenager; so I'm no stranger to heights, nor am I afraid of them.

    And I'm fully insured, and equipped to do the work.

    I've incorporated roof mold cleaning into part of my business offerings since late 2002...largely because of the lull in lawn care and landscaping during the "dog days" of mid and late summer.
    And I've never had to even advertise to get enough work in this area.
    I've always had more than enough to keep me busy; just from referrals from past clients.

    FCPWLLC LawnSite Senior Member
    Messages: 352

    So, you don't rinse? I HAVE to rinse and the roof HAS to be clean when I leave. I can't see trying to collect my check and telling customer that the roof will be clean in a week.

    If you do rinse, do you use just a garden hose? If it requires being on roof and getting up close and personal with rinsing, then it won't fit my business model due to profit eating Workers comp for time spent on that roof. Most roofs we clean are done in 45 minutes to 1 hour.

    Where do you get the M1? I am always open minded enough to try different things. But I gotta tell you, if it takes too long or requires more labor than needed, I will can it in favor of the more profitable method. That is why I am in Business.

    Marcos, open dialouge like this is good. It helps show that our industry isn't full of uneducated hacks. Thanks for not hiding under a bush and speaking up about your method. It gives the original poster a choice. For all we know, he could be allergic to bleach and need to know his other options.
  10. Marcos

    Marcos LawnSite Gold Member
    Messages: 3,720

    I don't rinse M1 off, because, from the customer's perspective on the ground in front of their house looking at their roof, the mold begins to fade dramatically in just a couple of days...like I said.

    I know what you're saying about (some) customer's "immediate expectations", though.

    But what you do may be somewhat different that what I do; in that I do alot of work for repeat customers around town...people that I've done lawn care, landscaping, seeding, etc through the years....and I know their NEIGHBORS, and so on...
    I think I'm more diverse in my work than you, over time, by design, or by fate, (who really knows? :confused:)

    You may be more streamlined into cleaning and washing..and your rep hangs more heavily on perfection in that arena.
    That's OK too.

    And honestly, I tell them right up front what they're going to see...before I even start...so there's no misunderstandings.
    As a matter of fact, I once got a letter from one retired couple who thanked me for my prompt service, and said they enjoyed watching the mold fade away from their roof ! :laugh:

    As I said previously, I have Sherwin-Williams special order M1 Roof Cleaner for me by the case, then I pick it up from their store locally.
    (I could order it from the net, but then I'd have to pay shipping.)

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