Roof cleaning and moss removal runs $300 to $1,050 — an average of $675 for a 1,500-square-foot home — at $0.20 to $0.70 per square foot, with moss removal included in most basic cleanings, per This Old House.
There is no single whole-roof total for a cleaning; the price tracks roof size, growth severity, and the add-ons a homeowner selects.
What Does Roof Cleaning and Moss Removal Cost in NJ?
Roof cleaning costs $300 to $1,050, an average of $675 for a 1,500-square-foot home, at $0.20 to $0.70 per square foot, per This Old House. Moss removal is included in most basic cleanings at that same per-square-foot rate, so a moss job and a streak job on the same roof generally price the same way, per This Old House.
A moss-prevention treatment after the cleaning adds $150 to $250, per This Old House. The treatment slows regrowth on an existing roof, which matters because proper maintenance extends asphalt-shingle service life by roughly 25 to 30%, per ARMA, so the prevention cost offsets earlier wear.
Zinc applied as strips or powder costs $0.05 to $0.15 per square foot, per This Old House, but only at a roof replacement. ARMA does not recommend adding zinc or copper strips to an existing roof, because the strips require exposed nails that cause leaks over time or break the sealant bond, so this line item belongs to a re-roof, not a cleaning.
Why Does the Price Vary Across a Roof?
Roof size, growth severity, and slope exposure move the cost within the $300 to $1,050 range, per This Old House. North-facing and shaded slopes hold moisture and grow moss faster, per CSSB and NRCA guidance, so a roof with heavy moss along those slopes that requires hand removal before the wash sits at the higher end of the range.
The cleaning method also separates a sound price from a damaging one. Pressure-washing an asphalt shingle roof costs less in the moment but causes granule loss and premature failure of the roof system, per ARMA, so the cheaper pass shortens the roof's life. A low-pressure chemical wash — the ARMA 50:50 laundry-strength chlorine-bleach-and-water mix, a 15-to-20-minute dwell, and a low-pressure rinse — kills the growth at the root by chemical action and protects the granules, per ARMA.
Granule loss exceeding roughly 30% of the surface marks a roof beyond cleaning, per GAF and InterNACHI. A pre-cleaning assessment that finds sandy grit in the gutters and bare patches across the field redirects the spend from a cleaning toward a replacement, which is why an honest estimate rates the roof-covering condition before quoting a cleaning.
How Do You Get an Accurate Roof Cleaning Quote?
An accurate quote comes from a written, itemized estimate after an on-site assessment, not a phone number given sight-unseen. The estimate names the cleaning method, identifies the growth as moss, Gloeocapsa magma algae, or lichen, and rates the roof-covering condition, so the price reflects the actual roof rather than a square-footage guess.
A commercial low-slope cleaning prices on the membrane and drainage, not on shingle square footage. EPDM lasts 15 to 25 years, TPO 7 to 20 years, and modified bitumen 20 years, per the InterNACHI life-expectancy chart, and biological growth that holds moisture against the membrane accelerates that deterioration, so the estimate accounts for clearing drains during the rinse rather than ponding cleaning solution on the membrane.
A roof cleaning is a small per-job cost rather than a whole-roof project total: $300 to $1,050 for a typical home, with optional prevention adding $150 to $250, per This Old House. A written estimate that follows an on-site assessment, names the low-pressure chemical method, and rates the roof condition keeps the price honest and the granules intact.