Moss and black streaks are different observations
The Asphalt Roofing Manufacturers Association distinguishes moss from algae. Its guidance explains that moss can affect asphalt-shingle performance, including lifting or curling at shingle edges. Dark staining alone does not establish the same condition. Describe what you can see from a safe ground-level view, without climbing onto the roof or pulling at the growth to identify it.
Read the separate guide to black roof streaksPut the roof's condition ahead of an appearance goal
GAF's homeowner moss guide recommends contacting a roofing professional rather than going onto the roof yourself. When requesting help, report leaks, recent storm damage, prior repairs and any visibly displaced shingles. If there is a known roof defect, ask an appropriate roofer to assess it before treating the request as routine cleaning. A wash cannot establish that a roof is watertight.
Find the shingle brand or installation records if available.
Say approximately how old the roof is and whether sections differ in age.
Include a wide photo of the roof plane and the clearest ground-level detail you can obtain.
Mention the leak or repair history even if the main concern is appearance.
Ask for an asphalt-shingle-specific method
ARMA warns against pressure washing asphalt-shingle roofs because of granule loss. GAF's moss article also cautions against forceful washing and leaves removal decisions to a roofing professional. Ask how the proposed approach follows the guidance for your actual shingles and their condition. A method for a concrete walkway, metal roof or tile roof does not establish suitability here.
See surfaces that need special careAgree on treatment and follow-up expectations
ARMA notes that treated moss can loosen over time. Ask the contractor what should change on the visit, what may remain visible afterward and when to request a follow-up assessment. Avoid judging success by a promise that every patch will disappear immediately. The timing and next step should reflect the roof and the chosen method, not a universal deadline.
Ask how the condition and extent of growth affect the proposed work.
Confirm whether a later inspection or additional treatment is included or separate.
Ask what observations should prompt a roofing assessment instead of more cleaning.
Keep dated ground-level photos for the agreed follow-up.
Discuss shade, drainage and the area below the roof
GAF identifies shade and moisture as conditions that encourage moss. Show the assessor overhanging branches, drainage concerns and planting areas below the roof. Ask who should handle any tree or drainage work separately. Naming these conditions helps plan the visit; it does not mean the cleaning company will alter trees, repair gutters or prevent all future growth.
Send a roof-specific request to JC
For a home in Sparta, Hopatcong or Newton, include the town, roof material and the visible growth in your request. Ask JC to confirm whether the condition is within the roof-cleaning scope or needs a roofer first. Keep house washing or driveway work as separate items so the estimate describes what will actually be assessed and cleaned.
Ask about a roof-cleaning assessmentRelated questions
Is roof moss the same as black streaking?
No. ARMA distinguishes moss from algae staining. Describe raised growth and dark streaks separately, then let the assessor identify the condition and appropriate next step.
Should I remove a patch of moss before sending photos?
Leave the area as it is and photograph it from the ground. Do not climb onto the roof or scrape a patch just to prepare an estimate. Share the roof history and ask what assessment is needed.
Will every moss patch disappear on the cleaning day?
Do not assume an immediate uniform result. Ask what the selected treatment is expected to do, what may remain visible and when the contractor recommends a follow-up. Avoid a universal timeline.
Can roof cleaning repair lifted shingles or a leak?
No. Treat visible displacement and known leaks as roofing concerns. Ask an appropriate roofer to assess the defect, and confirm whether cleaning should wait until that issue is addressed.
Sources and care instructions
Check the instructions for your exact material and product before choosing a cleaning method.