Roof cleaning decision guides
Clean if you have moss, which holds water against shingles and can lift their edges. Cleaning for black streaking alone is a cosmetic decision - ARMA identifies it as algae producing a pigmented sheath, not structural damage. If the roof is close to replacement anyway, cleaning it is usually money better saved.
Work it in three questions. What is growing? Moss is worth removing. Algae streaking is cosmetic and mainly worth removing if appearance matters to you - before a sale, for example. Lichen sits between the two and is the hardest to remove cleanly.
How old is the roof? Get an honest read on remaining life first. If a roofer tells you three to five years left, a $255-$1,190 clean (Today's Homeowner's typical range) buys you appearance for a fraction of that. Weigh it accordingly.
Will it come back? Yes. ARMA states results are only temporary and discoloration will likely recur. So the honest question is not "will this fix it" but "is it worth this every two to three years?" Today's Homeowner's guidance is every 2-3 years for most homes and annually in humid or tree-covered locations. Multiply the cost by that frequency before deciding.
One decision that is not close: if you do clean, buy soft washing. ARMA's position is that a pressure washer should never be used on an asphalt shingle roof, so saving money by choosing high pressure means accepting granule loss and likely premature roof failure. Choose to clean or not to clean; do not choose to clean badly.
Choosing roof cleaning between the options
The judgement calls that decide the bill, before anyone quotes you.
- Identify the growth before you buy a service Moss, algae, and lichen are different problems with different urgency. Photograph the roof and ask the contractor to name what they see.
- Get remaining roof life from a roofer, not a cleaner A cleaning company has no incentive to tell you the roof needs replacing. That question belongs to someone not quoting you for a wash.
- Multiply the cost by the frequency At $255-$1,190 every 2-3 years, cleaning is a recurring expense. Compare that against branch trimming or algae-resistant shingles at your next re-roof.
- Treat curb appeal as a legitimate reason Cleaning for a sale or because the streaks bother you is a perfectly good reason. Just know you are buying appearance, not roof protection.
- Never trade method for price The cheap quote is usually cheap because of the method. On asphalt shingles that trade is not worth making.
All roof cleaning decision guides
Repair vs Maintain Roof Cleaning
When to Call a Pro for Roof Cleaning
DIY vs Professional Roof Cleaning
Where these figures come from
Sources last checked
- ARMA - Algae & Moss Prevention and Cleaning for Asphalt Roofing Systems · retrieved 2026-07-25
- Today's Homeowner - How Much Does Roof Cleaning Cost? (2026) · retrieved 2026-07-25
- EcoWatch - Roof Cleaning Costs (2026): Professional vs DIY · retrieved 2026-07-25
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