Wear work gloves to protect yourself from direct contact with any mildew and the cleansing solution.
Combine 1/2 cup of ammonia with 1 gallon of hot water in a bucket. Dip a scrub brush in the bucket. Scrub the pavers to remove lichens, mildew and algae.
Rinse your scrub brush in a second bucket filled with only water. Apply more of the ammonia solution to the brush and continue to scrub the pavers.
Sprinkle sawdust over the paver surface to absorb the ammonia solution. Allow the sawdust to remain on the surface for 20 minutes. This is a more environmentally-friendly alternative than rinsing the ammonia solution into the grass or garden.
Sweep the sawdust off the pavers with a broom and dustpan. Discard the sawdust in the trash. Hose down the pavers to remove any sawdust remnants. Allow the pavers to dry.