Roof Maintenance, Moss and When to Request an Inspection

Begin with observations from a safe location

A maintenance check starts with noticing what has changed. From the ground, look for missing or displaced roofing, fallen pieces, accumulated leaves and growth on the surface. Binoculars or a photograph can help you record an area without walking on the roof. Note indoor stains or damp areas too, including when they first appeared and whether they change during rain.

GAF recommends ground level observation as a safer way for homeowners to recognize concerns that deserve professional assessment. Treat what you see as a reason to ask a question. A photograph does not establish the condition of every layer beneath the covering or the cause of a leak.

Distinguish moss from a change in roof color

Moss and algae are different. ARMA explains that dark streaking on asphalt shingles is often algae, while moss is plant growth that can hold moisture and affect shingle edges. The appearance and potential effects are not identical, so do not assume every dark area is moss or that every discoloration means the roof needs replacement.

Ask the roof assessor to identify the material and visible condition before discussing treatment. Include the location and any nearby debris or shade as observations about your property. A general description of the community's climate cannot establish what is happening on one roof.

A closer look at the roof in front of you.

Check the roof material before choosing a cleaning method

Cleaning methods need to follow the roofing manufacturer's guidance. ARMA advises against pressure washing asphalt shingles because it can damage the surface. Its guidance also cautions against abrasive scrubbing. A method used on another material should not automatically be applied to shingles, tile or a previously coated roof.

Ask whoever proposes treatment to identify the roof product, explain the method and account for access and protection of surrounding areas. Roof work belongs with people equipped for that access. A cleaner appearance is not proof that cracked components, loose flashing or concealed deterioration have been repaired.

Include drainage and roof details in maintenance

For a low slope roof, maintenance records should consider drainage, seams, penetrations, edges and equipment details as well as the main surface. GAF's commercial maintenance checklist separates observations and recommended actions so recurring conditions can be followed over time. A blocked drainage point and a damaged membrane connection are different findings and may require different work.

Use a dated record with recognizable locations. If equipment work occurs later, keep that information with the roof history. Ask how future access should be coordinated and which conditions require a repair proposal rather than routine attention. The maintenance plan should fit the installed system and its written requirements.

Request an inspection when a change needs explanation

New water indoors, missing roof material, changed flashing or a recurring problem after earlier work deserves a closer assessment. Explain the concern when booking so the inspection scope matches the question. Provide previous repair information and ask for findings that separate observations from recommendations.

Some areas or concealed layers may require additional access before the cause is understood. Ask what could be assessed during the visit, what remains uncertain and why any further investigation is proposed. Keep the assessment and subsequent work descriptions together so a future visit can distinguish a returning symptom from another roof issue.

Keep a simple record of the next steps

A useful maintenance file can be brief. It should allow you and the next person assessing the roof to recognize the same locations and understand what happened there. Set future check timing according to the roof system, observed condition and relevant maintenance instructions.

• Save dated photographs taken from safe locations and identify the roof area shown.
• Record the symptom, prior work and questions that remain unanswered.
• Request a written description of any proposed cleaning, maintenance or repair.
• Keep the final work record and applicable product instructions with the inspection notes.