Moss growing on damp, shaded areas of tarmac is easy to remove with just a few household items and some elbow grease. You need bleach, liquid detergent, a stiff broom, a scrub brush, a scraper, a bucket and a garden hose with sprayer.
Clean the area
Before attacking the moss, use the stiff broom to sweep all debris and dirt from the tarmac. Cover any nearby plants with plastic bags to protect them.
Soak the moss with cleaning solution
In a large bucket, mix 1 gallon of water, 1 cup of household bleach and 1 cup of laundry or dish detergent. Stir it well, and then apply the mixture over the moss you want to eradicate. Allow it to sit 5 minutes to be sure it kills the moss.
Spray and scrub the area
Use a strong spray of water to clear the dead moss off the tarmac. Use a bristle brush and scraper to remove stubborn patches of moss, and rinse the area with a strong spray of water again.
Prevent new moss from growing
The bleach retards moss growth for up to a year. To impede the growth of new moss, prune back nearby plants so direct sunlight shines on the tarmac. Because moss needs abundant moisture to grow, try to avoid wetting the tarmac with lawn sprinklers or while hand watering nearby plants.