Moss on your roof isn't just an ugly problem; it's also a dangerous one. Whether you like the way it looks or not, moss will greatly reduce a roof's lifespan. Moss can lift up shingles, exposing the roof to moisture, which allows rot to form. Remove moss from your roof as soon as you see it, and don't let it become a much bigger problem in the future.
Step 1 - Dress Accordingly
Put on slip-resistant shoes or special shoe grips before going up on your roof. This is very important because wearing the right footwear is the most important step you can take in keeping yourself safe. You'll also want to wear old clothes that can get messy, put on protective gloves and slip into a pair of safety glasses. This will protect you from flying moss particles and potential chemical fumes.
Step 2 - Climb
Place an extension ladder on level ground near a low part of your roof, and climb up. Unfortunately, you will have to get on the roof in order to treat the moss. Whenever possible, work with a second person who can hold the ladder and monitor you while you're on the roof. You may also want to use a safety rope. Once you get on the roof, tie one end of the rope around a secure structure on the roof, such as a chimney. The other end of the rope will go around your waist and around your chest to protect you in case you fall.
When you’re on your roof, work slowly and step carefully. Losing your focus for even one moment can lead to a physically damaging accident. Never forget where you are, and stay aware of where you place your feet at all times.
Step 3 - Spray
Use a garden hose to spray water directly onto your mossy areas. Go with the slope of the roof, always spraying water downward toward the ground instead of going against the shingles. If you spray upward, you run the risk of loosening shingles and causing more damage than the moss.
Don't use a pressure washer or an extremely strong hose attachment for this process. High-powered water will loosen shingles and soon you'll be doing even more extensive roof repairs.
Step 4 - Clean
As you wet down the moss-infected area of the roof, use a soft-bristle brush to gently scrub moss away. Work in downward motions, again avoiding upward motion that may lift or loosen shingles. Scrub softly and don’t apply too much pressure. Work in very small sections of the roof at a time. It's better to go slow and be careful than to attempt to rush through this process and cause your roof more harm than good.
Step 5 - Add Soap
If simple water isn't removing the moss entirely, step up your game and add some soap. Make sure you use a gentle solution by mixing one cup of liquid soap with two gallons of water. Apply this soapy solution to the roof and then scrub those stubborn spots.
If the soap still isn't strong enough, put it aside and add two cups of distilled white vinegar to two gallons of water instead. Scrub at the moss with this mixture until the moss is gone. Apply cleaning solution only after the roof and moss are thoroughly wet.
If you're going to use one of these solutions to remove moss, climb down from the roof and cover any landscaping that's in the line of fire with a plastic tarp. Hedges and other decorative landscaping directly under the roof line that could be splashed with vinegar or soap must be covered, as they may become damaged.
Step 6 - Prepare for the Future
After you remove moss from the roof, you're not going to want to do it again. Make sure sunlight is getting to your roof by trimming tree branches that keep the roof shadowed, and clean off any debris like leaves or branches when they appear. Next, add strips of copper or zinc, or zinc-coated metal flashing around the edges of your roof, below the ridge caps. When water flows past the zinc, it will release particles that actually prevent the growth of moss. This process can be fairly labor-intensive, but it will protect your roof from moss growth in the future.