I have moss growing on my roof how can I get rid of the moss?

use Wet and Forget

We have cleaned our concrete patio that was covered in moss and whatever else with a pressure washer. Next we sprayed Wet it and Forget It on half of the patio. The next spring we could not believe how well that product works at keeping the moss and stains off. There was a definite line where we ran out of product. The bottle says that you can use on the stains and it will remove them but we did not try that. We cleaned the area first.

My friends all love the Wet and Forget for their Roofs

Here's a link that may help. https://www.thisoldhouse.com/ask-toh/getting-algae-and-moss-roof

Zinc strips placed on the roof ridge (if your house has one) will kill off the existing moss and keep it off (that could take some time), or you could spread a moss killer on the roof (check which product to use with your local store that sells moss killer). You might need to sweep the dead moss off with a stiff broom. A lot depends on the composition of the roofing, how old it is, and in what shape, slope of the roof etc. etc. Whatever you do, be careful that you don't get too vigorous and end up with roof leaks, or fall off the roof because the moss is very slippery. If you choose to use a power washer be certain to keep it low pressure. Roofs can be delicate and costly if you do the wrong thing to them.

There are products made for this problem. Google.

The black mold-like stains and streaks that appear on roofs, particularly light-colored asphalt shingles, is actually a blue-green algae (Gloeocapsa magma). Commonly found in climates with warm, humid summers, it does no damage to the roofing, but it certainly does looks bad.

The less expensive solution is to spray wash the roof with a 50 percent mix of water and bleach to get rid of the algae. (No pressure washers, please. They're likely to damage the shingles.) Just be sure to wet your foundation plantings first, and rinse everything in clean water when you're done. Plants don't like bleach, and wetting them with plain water first protects them. You can also cover them with tarps or plastic sheeting, which will protect the soil around your plants as well. Make sure that you create a wide radius around your home to be safe.

Allow the solution to soak into the shingles for at least 15 minutes. If they are severely molded, you may want to give it a little longer. Next, rinse the shingles thoroughly with a garden hose at low pressure. Start from the top shingle and rinse downward to prevent water seepage.

To keep the algae from coming back, insert 6-inch-wide strips of zinc or copper under the row of shingling closest to the roof peak, leaving an inch or two of the lower edge exposed to the weather. That way whenever it rains, some of the metal molecules will wash down the roof and kill any algae trying to regain a foothold on your shingles.

You can probably see this same principle working on roofs in your neighborhood. Look for chimneys with copper flashing; the areas directly below the flashing will be free of any algae stains.

The strips also work on roofs suffering from moss buildup. Just scrub it off first with a brush, then bleach as above.

try to reduce the humidity and you need to think about rain runoff if you don't have it