How to safely remove moss from shingled roof?

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This week I noticed that my 12 year old roof has bright green moss on the shingles. This roof faces north/east and we have had two very wet summers in SW Michigan. I called our building contractor and he recommended bleach but I am not going in that direction.
I'm looking for a non-toxic solution that will not harm the shingles, cement porch, siding or landscaping. We are an organic homestead here that eats our food and drinks our water and use no bleach.
I've researched and find a number of non-toxic roof washing materials for moss (Like Roof Wash) so I think I am set there. But how to SAFELY remove the existing moss? I read about pressure washers (which we do not have though could rent) but I also read about not using a pressure washer when you are not used to using one due to potential damage.
My son who lives in wet Portland Oregon, land of the rain, said he was successful in getting up on his roof and scraping off the moss with a paint scraper. My IT type husband (not the skilled contractor type) wants to use a stiff, metal scrub but I am worried about him damaging the shingles...
Any other ideas/suggestions?
  14 answers
  • Janet Pizaro Janet Pizaro on Oct 09, 2015
    There is a product called wet and forget that is suppose to be non toxic.I think it is available at your local hardware store. After researching the cleaning process it states definately do not power wash the shingles as it will do damage. Good Luck

  • Janie Emmert Janie Emmert on Oct 09, 2015
    We had a heavy moss growth on our 30 year old roof. My husband sprayed with Wet and Forget that he purchased from Home Depot for around $35. It hooks up to the hose and is very easy to use. It isn't an instant fix, but within 3 weeks, most of the moss had dried up. My son in law got on the roof and swept it off for us. It says to retreat in 3 months. Good luck!

  • Charlene Charlene on Oct 09, 2015
    I hate to say this but it seems to me the only way is to use a toxic weed killer. If you want to try song natural you can try salt, the only down side is that is that you have to keep it off any plants or areas that you plan to plant in salt free. NOTHING will grow on salted ground, this I found out the hard way. You can also try VINEGAR, it works by balancing the ph and this should eventually kill the moss. You could also advertise for someone to pick it off you would be surprised at the crafter will actually come do it, we use it in crafting projects.

  • William C Ross William C Ross on Oct 10, 2015
    In my experience which is limited i have found that tile roofs and moss seem to love each other and when you try to seperate them you can have major problems. My advice is to get a experienced person to take a look first before going for it.

  • Duv310660 Duv310660 on Oct 10, 2015
    Moss needs a very specific environment to flourish - I know this because my husband is a botanist and I have been working to get moss to grow between my pavers a.k.a. 'green grout'. The biggest factor is sunshine. Even on the North side, if you have any shading trees, prune (or get an arborist to prune for you) to allow for more sun and air circulation to hit your roof. If this doesn't apply to you, the next step is to try to interrupt the moisture flow to the moss with a mixture of something a bit alkaline with water following a dry spell. Then borrow a roof rake - moss does not usually attach to anything firmly, and a good period of heavy growth followed by a moisture purge should allow easy clump-removal. On the other hand, if your roof normally doesn't have moss, it is pretty reasonable to expect it to return to this stasis once you get beyond the current period of wet!

  • Barbara Marshment Barbara Marshment on Oct 10, 2015
    Is there a downside to just letting it grow? Sounds pretty -- and a natural green roof!

  • Renee Owen Renee Owen on Oct 10, 2015
    Our home owners insurance required us to remove the moss growing on our cedar shingles roof. For what reason I am still baffled. :-/ . We used a Clorox rinse but then had to scrape it off. What a job!!!!!! Found that metal spatulas worked like a charm!! Like the ones you flip burgers with. Paint scrapers were too narrow and too thick. It's been four years and none has grown back.

  • Susan Susan on Oct 10, 2015
    Oh, don't destroy the moss. There are lots of people willing to pay $25 for a square foot of moss. I know people who have hand carried it home on a plane. A notice on a local online selling site or a local garden supply co. should bring people running. It would in the South.,

  • Jrh274669 Jrh274669 on Oct 10, 2015
    Jan, Port Angeles, WA We get rain every day, and had the same problem on our roof. The locals told us to use dry laundry soap and sprinkle it on the roof. Leave it there and when it rains, the soap will melt down on the roof and kill the moss. I purchased three large boxes for our house and garage, and my husband climbed on the roof and sprinkled the soap from the peak down the bottom edges. It worked quite well. If you try to scrape the moss, you will damage the roof tiles or asphalt shingle. Moss is a plant, and it grows and attaches itself to the roof and also concrete sidewalks and steps. Good Luck

  • Jrh274669 Jrh274669 on Oct 10, 2015
    Jan, Port Angeles, WA Washington state has rain every day, and the roof on our house and garage had moss growing on it. We found out from the locals that you buy the cheapest dry laundry soap and climb up on the roof and sprinkle it from the peak of the roof down to the bottom edges by the gutters. Just use a scoop and sprinkle a light coating of dry soap everywhere. I purchased three large boxes of dry soap for our house and garage. Leave it up there and when you get rain, the rain dampens the soap and thus kills the moss. We used it and it was a success. Laundry soap is safe and you should not worry about yard animals around it. We found out if you try to scrape this moss, it does damage the roof. Moss is a plant and it grows into the roof tiles, or shingles and even on the concrete sidewalks around the house.

  • Recycler Recycler on Oct 10, 2015
    did I miss something? Are they cedar? or asphalt? If asphalt, our roofer said to leave it alone since it does no harm If cedar, listen to the insurance companies because it would leave the roof wet all of the time....not good.

  • Recycler Recycler on Oct 10, 2015
    I would still leave it...I think it does look cool on asphalt because it makes it look more like a natural cedar. The less you are on the roof the better, since walking would do more harm than the moss, says our roofer who has been great at keeping up our roof so that we don't have leaks. Ours is green in that direction as well, and sometimes if it dries up a bit , some falls off....I try to cultivate it elsewhere. Moss is a great plant

  • NAN from PDX NAN from PDX on Oct 11, 2015
    I also live in Portland, OR......used a 3gal garden sprayer ..mix 1cup of liquid Tide (non bleach) in and fill with water...on a dry, sunny day...spray the pesky moss...saturate it good...by the following year...after the rainy season has passed...go back and sweep the loose dead moss with a stiff broom...bye, bye moss....that was over 5yrs ago...no moss back since, so it has a residual effect, I'm guessin'...lol

  • Sharon Sharon on Sep 17, 2021

    Here in the Pacific Northwest rain belt, we put Moss Out on our roofs twice a year - spring and fall. You can sprinkle it on from a large can if you are able to walk your roof. or buy the liquid in the hose attachment bottle and spray it down.