Before accepting a quote to clean an asphalt-shingle roof, ask the company to describe its method in writing. A promise to make the roof look new is less useful than a clear explanation of the equipment, products and precautions it will use. This focused review complements a broader roof maintenance plan.
Confirm the material and proposed method
The Asphalt Roofing Manufacturers Association's algae-discoloration bulletin warns against power washing or using brushes and brooms to remove algae from asphalt roofing. Abrasion can loosen granules, and high-pressure washing can damage the roof. ARMA also directs owners to the shingle manufacturer for cleaning recommendations.
Ask the cleaner to identify the roof material before recommending a process. Request the product names and the manufacturer's guidance they are following. Do not treat a marketing term such as soft washing as a complete specification; have the company explain what it means for this job.
Discuss protection around the house
ARMA notes that cleaning solutions can affect surrounding landscaping and other building surfaces, and that treatment can make the roof slippery. It encourages professional cleaning. Ask the contractor how it will protect those areas and manage access during the work.
Walk around the property together from ground level. Point out delicate planting, outdoor furniture, painted surfaces and any areas of concern. Agree on what you should move beforehand and what the cleaning company will protect. Keep those responsibilities with the quote.
Set realistic expectations
According to ARMA, algae discoloration may return after cleaning. Ask which stains the proposed treatment is intended to address, what result is expected and what follow-up is included. Cleaning is not a substitute for assessing damaged shingles or investigating an active leak.
Take dated ground-level photographs before work and ask the contractor to document any existing defects it identifies. Afterwards, compare the agreed scope with the completed work and keep the invoice, product details and maintenance advice together. This gives you a record of what was done without relying only on before-and-after advertising photographs.
