If the water will not reach the peak of the roof from the ground you can spray while standing on a ladder.
How do you remove moss from a roof.
If you want to see quicker results consider sprayer an algae and moss killer like wet forget on the roof when you install the copper strips.
Liquid moss killers cover the roof more evenly than dry powders and they let you stay on the ground for the application.
Or clean the roof using a tsp and bleach mix.
It is only advisable to use a pressure washer because you no longer need to worry about the condition of the old roof.
After cleaning you ll also need to put some defensive measures into play to prevent roof moss from growing back.
Fortunately removing moss is a fairly simple task that you can perform on a seasonal or as needed basis to keep your roof weathertight and great looking.
Check out our article on how to remove black algae stains on roofs to find out more.
Whenever possible work with a second person who can hold the ladder and monitor you while you re on the roof.
Once you get on the roof tie one end of the rope around a secure structure on the roof such as a chimney.
Unfortunately you will have to get on the roof in order to treat the moss.
Your roofers will need to remove all the shingles on your old roof or they may need to remove the largest chunks of moss with a pressure washer and then apply the new roof.
You may also want to use a safety rope.