Illustration for Roof Flagged for Moss by Your Insurer

This is not a rare mix-up. California’s insurance department said in March 2025 that it had investigated numerous complaints. In them, flawed aerial imagery led to wrongful cancellations or nonrenewals. Your case may turn out differently, but regulators in several states point to the same steps.

This is general information, not insurance advice. Your policy and your state’s insurance department have the final word.

Algae streaks and moss differ

The asphalt roofing manufacturers’ trade group describes algae as brown to black discoloration that can look uniform or streaky. It says algae can be mistaken for soot, dirt, moss or tree droppings. A low-resolution photo can’t sort those out.

Regulators draw the line in the same place:

  • Streaks and discoloration. Connecticut’s department says cosmetic conditions such as natural discoloration and streaking don’t support nonrenewal. Pennsylvania’s says aerial images showing only discoloration or streaking shouldn’t be the sole evidence for canceling or nonrenewing.
  • Moss buildup. That one can count. Connecticut’s 2026 consumer advisory lists “excessive debris, including moss buildup” among the roof conditions insurers review. Massachusetts says a roof with a significant amount of moss can be a reason an insurer declines to keep insuring a home.

So black streaks are usually something to contest. Thick moss is something to fix.

What to do, in order

Step Why it helps Who says so
Read the notice for the specific reason and the date coverage ends Insurers must state why; CT requires 60 days’ notice and MA 45 CT and MA insurance regulators
Ask the insurer for specific details about the roof issue You can’t answer a vague claim Connecticut Insurance Department
Get a licensed roofer’s or contractor’s written report Connecticut named such a report as one acceptable check on aerial images Connecticut Insurance Department
Fix confirmed problems and send receipts or a signed contract Insurers may review new documents; a signed contract may help if work runs late CT and MA insurance regulators
Ask whether a temporary extension is available while work is underway Repairs and cleaning can take longer than the notice period Connecticut Insurance Department
Shop for other coverage now One insurer’s decision doesn’t bind another CT and MA insurance regulators

Notice periods and rules differ in other states, so check yours.

When a soft wash answers the notice

If the roofer confirms moss or heavy growth, cleaning is the fix. The roofing trade group says a bleach-and-water solution can lighten algae. It says the effect is temporary. It also says never to use a pressure washer or brush on asphalt shingles. Our guide to whether roof cleaning is worth it covers the method shingle makers describe.

Two timing points matter here. First, book early. Connecticut has encouraged insurers to give more notice, because scheduling roofers and repairs inside 60 days is hard. Second, dead moss can take weeks to fall off after a wash, as our roof soft wash results guide explains. Don’t count on the roof looking clean in a new photo. Send the invoice and the roofer’s report instead.

For typical roof cleaning prices, see our pressure washing cost guide. Use our questions to ask a house washing company before you hire anyone.

Watch for “your roof was flagged” mailers

In November 2025, Massachusetts regulators warned about mailers sent to Rhode Island residents by a third party. The mailers claimed homes were “flagged” for roof age or condition. They pointed people to inspections and contractors. The Division said these were not from any insurer. A real nonrenewal notice comes from your insurer or agent. Don’t authorize costly repairs based only on unsolicited marketing.

If the insurer won’t budge

Pennsylvania’s department reminds insurers that “the mere suspicion or question that something has changed is not cause for nonrenewal.” It also says homeowners need notice and a chance to fix a hazard that may not be obvious to them.

California’s department takes consumer calls on its hotline at 800-927-4357. Wherever you live, the NAIC lists every state’s insurance department and how to file a complaint.

This is a different situation from an insurance claim. Filing a claim after a fire? See our guide to wildfire smoke and ash on your house instead. Aerial work is also covered in drone washing for tall buildings and domes.

Here’s how we check our sources.

Sources

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