How to remove moss from a garage roof?

[dennis thompson]

My garage roof has a lot of moss on one side of it, some of it in large 3-4" inch patches about 1/2"-1" thick. I just got an estimate to clean it for $500.
It seems they just spray the roof with a cleaning mixture and eventually the moss dies and blows off the roof.

I've watched some videos on you tube of just spraying it with a one-to-one water and heavy-duty bleach mixture from the ground or on a ladder against the side of the garage.
Has anyone tried this or have any other suggestions on how I might clean it without going up on the roof?
Thanks

[Jerome Stanek]

I did that to my shed and it did work.

[mike calabrese]

Can't help with suggestions without knowing how high your roof is one story ranch or high rise tower ?
Couple of tips
first get a hose connected pressure sprayer similar to one shown here . This one has brass components that will not hold up too long from the corrosion of the bleach but there have to be all plastic versions.
Water and bleach mixture. Also there are a smash of garden hose connected sprayers image also attached that are all plastic and large volume compacity.
Depending on your comfort on a ladder and the height of your roof you can hit the moss with water bleach spray from the ladder and neve get up onto the roof.

Additional research copper sulfate link details here https://www.google.com/search?client...UTF-8&oe=UTF-8
this will work better than the bleach / water mix and should be OK with metal sprayers.
calabrese55

Lastly the old time fix to this problem was to run some copper wire across your roof on the levels above the moss. Rain water hitting the wire will create a weak solution of copper sulfate and may prevent the moss from starting after you get it cleaned up from current situation.


https://www.amazon.com/Voodoo-Ride-V...43533813&psc=1

https://www.amazon.com/Pressure-Exte...a-814761982947

https://www.amazon.com/MEKOH-Adjusta...40860627&psc=1

https://www.amazon.com/SZSXHX-Cannon...88062201&psc=1

[Lee Schierer]

I had a similar moss problem on the roof of our house. I purchased some "Spray and Forget" roof cleaner from the local big box store. I sprayed the entire roof using my motorized tree sprayer.* Within a few days, the moss started turning brown and then pieces started blowing off the roof whenever the wind blew. Now my roof is clear except for an area that I couldn't reach with the spray from the ground. Be careful of the over spray because it will also kill plants on the ground.

* The plastic spray nozzle on small containers did not reach very far. They might be okay if you are walking around on the roof, but not from the ground.

[Zachary Hoyt]

You could use a snow rake to remove it mechanically from the ground. Then you wouldn't have to worry about killing other plants that you want to save. If you don't have a roof rake you can make one with a long pole and something to use for a head.

[Tom M King]

I have experience doing this, both on asphalt shingles on a rental house under very large Pin Oaks, and 42 year old Cedar Shakes on one side of the original part of our house also under very large Pin Oaks.

First, a few questions:

How steep and high is the roof? Are you comfortable walking on it? How good is your water pressure there?

I can tell you in details how to do it, and what to use. In the meantime, order or buy locally some of this. Don't get it in their hose end sprayer. Their sprayer is not very good, and might not last through one application. Just get the concentrate. Beware using it without discussing it first because it has a "soap" in it that makes it more effective, but slicker than grease if you end up walking on it. You Do Not want to have it under your feet on the roof.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

If they have that in a local store, also buy one of these while you're there. I use it on all the old museum houses I keep up, as well as the houses we own. Keep the sprayer after you use all the Windex.
https://www.youtube.com/watch?v=VhHSRngDFfk

[roger wiegand]

I used 20% household bleach plus a squirt of Dawn detergent as a wetting agent. I used my backpack sprayer from a ladder at the edge of the roof, since DW does not allow me to climb around on roofs any more. I was able to get to 90% of it. It took a few weeks to obviously die, but the runoff had no obvious ill effect.

I wore a "bunny suit" and full face respirator to avoid breathing it or getting the spray in my eyes or on my clothes.

[Paul F Franklin]

Most of the commercial sprays seem to work pretty well, although it may take a few weeks or months to see complete results. They all have warnings about potential eye damage so you have to use good PPE. And the runoff from most of them is harmful to fish and aquatic creatures, so you have to be careful to manage the runoff if you have a pond or stream nearby. Wetting down foundation plantings before using the sprays and then rinsing them afterwards will avoid damaging the plantings.

For long term prevention of shady areas after the moss is removed, you can have zinc or copper strips installed under a row of shingles near the top of the roof. a couple of inches of the strips are left exposed and as Mike mentioned above, rain washing over the strips and then down the roof prevents future growth. The strips tend to be more effective than a wire because of the increased surface area. Sometimes, in damp and really shady areas, installing a second row of the strips halfway down the roof is recommended.

[Jeff Clode]

I had a similar moss problem on the roof of our house. I purchased some "Spray and Forget" roof cleaner from the local big box store. I sprayed the entire roof using my motorized tree sprayer.* Within a few days, the moss started turning brown and then pieces started blowing off the roof whenever the wind blew. Now my roof is clear except for an area that I couldn't reach with the spray from the ground. Be careful of the over spray because it will also kill plants on the ground.

* The plastic spray nozzle on small containers did not reach very far. They might be okay if you are walking around on the roof, but not from the ground.

Another vote for “Wet and Forget” concentrate. I used successfully on my roof in prior house with a hose end sprayer which would reach about 30 ft. Didn’t seem to bother vegetation - tho I did rinse the plants that got doused. Spoke with a roofer about the moss and he wasn’t wild about folks using rakes, brooms, pressure washers on most roofing material

[Tom M King]

Wet and Forget works good on leaf stains, mildew, and if the Algae is just starting. It it grows into clumps of thick Moss, they need to be knocked off, and the Moss Off will kill what's left but won't penetrate all the way to the bottom of a thick clump enough to kill it. I have knocked the clumps off with a water hose, but some on these had gotten large enough that I kicked them loose with my foot. They bump right off of asphalt shingles.

I think if you can't walk on the roof, a lightweight wooden T would dislodge them.

I used to pressure wash our Cedar Shakes every five years or so, but after using that Moss Off on the rental house, I tried that on them a few weeks ago, and it's turned a light brown and is sluffing off, so if I use one of the concentrates, I believe I can eliminate the pressure washing.

Now that I have these roofs cleaned off, I'll start using Wet and Forget every year.

Moss Off doesn't need to be rinsed off either. You just wet the roof or deck with it. Just like Wet and Forget, the next rain takes care of it. It will make a deck as slick as Eel's ___ though.

[Myk Rian]

https://www.facebook.com/reel/111500...ibextid=Nif5oz

[Tom M King]

Yes, it's a lot easier if you can walk on the roof. I used a leaf blower first, and then kicked the clumps loose with my foot that were too strong to be dislodged with the air.

My shake roof is steeper than I want to walk on, so I just sprayed it and let the Moss Off work, but there were no thick chunks on it because I had just pressure washed it a few years ago.

[dennis thompson]

You could use a snow rake to remove it mechanically from the ground. Then you wouldn't have to worry about killing other plants that you want to save. If you don't have a roof rake you can make one with a long pole and something to use for a head.

Thanks everyone for the advice.
I had a roof rake which I hadn’t used in at least ten years. Last week as I was cleaning up my shop/garage I saw it and almost threw it out. Thanks Zachary, I never would have thought of using it for removing the moss. Well, today I used it to remove much of the moss on my garage roof, further proof that “ you never know when you might need it”
The roof is not too heavily pitched but i still don’t feel comfortable walking around the roof, as my wife keeps telling me, “ you’re 79 years old, don’t go on the roof” I guess I have to agree with her