How to remove moss from house roof

a power washer co. gave me quote for roof that included a solution that gets rid of and helps prevent mold. Best way to prevent is to trim all trees that hang over roof

To keep moss from growing on the roof, Install zinc or copper strips at the top of the roof ridges. String copper wire across the roof in intervals using nails or screws on the side of the roof (Do not hammer the nails or place the screws through the asphalt shingles.

To remove moss:

https://www.bobvila.com/articles/how-to-remove-moss-from-roof/#.WYeBr_krLGg

The most effective method of cleaning algae and moss from a roof is with a 50:50 mix of laundry strength liquid chlorine bleach and water. Apply with a sprayer and allow the solution to dwell on the roof surface for 15 to 20 minutes, and then rinse thoroughly with low pressure water.

https://www.thespruce.com/remove-moss-from-roofs-4136874

Around here in Oregon where moss is the state flower, we use Lilly Miller Moss Out annually on our roofs. You can buy it in the sprinkle can if you can get up there. I buy the liquid that fastens to the hose, and spray it on. Kills it, it drys up and blows or washes off. I do mine in spring after the rains, and then in fall in prep for winter.

Use wet and forget safe for all surfaces

You need to make sure you know what kind of moss you have so you can purchase the right kind of chemical. Make sure the chemical does not contain any bleach, acid or chlorine or it will dry out your roof. Mix the chemical in a spray bottle and then spray carefully. Once you've let it set long enough to kill off the moss, it is time to wash. Same spray method with water, but do not power wash, because it could knock off the granules.