What is the best roof moss remover?

Step 1: kill before you remove

Live moss is anchored by root-like strands that grip the granules. Pulling it off while it is alive tears granules out with it. A roof-labeled treatment applied on a dry day kills it, and within a week or two it turns brown or orange and lets go far more easily.

Step 2: remove it gently

• Work from the top of the slope down, the direction the shingles overlap, and never push up under the edges.
• Use a long-handled soft-bristle brush, or a plastic putty knife for clumps along shingle edges.
• A low-pressure garden hose rinse is fine; a pressure washer is not.
• Clear the loosened debris out of gutters and downspouts when you finish.

Or let the rain do it

Leave-on treatments are designed so dead moss weathers away over weeks or months of rain. It is slower, but it keeps everyone off the roof, which is the safest choice on anything steeper than a gentle pitch.

Safety first

Moss and treatment residue make shingles slick. Steep roofs are dangerous without fall protection, and a slide off a two-story eave is a serious fall. If you cannot reach the moss from a ladder at the edge, hire it out.

Check what the moss was hiding

Once it is gone, look for lifted shingle edges, bare spots without granules, or cracked tabs. Those areas may need repair before the next heavy rain. Keep moss from coming back by trimming trees for sun and airflow. More in moss and lichen on roofs and our Georgia roof maintenance checklist.