A cleaning contractor cannot reliably follow product-specific guidance if the roof's material and finish are unknown. Aggressive treatment may remove visible contamination while creating another concern. Identification should come before selecting the cleaning method.
What to do next
Provide the roof's product and warranty records. Ask for the proposed method and any limitations. Where the condition appears to involve deterioration rather than ordinary dirt, obtain an assessment before authorizing cosmetic cleaning.
Related Perkins guidance
Contact Perkins Roofing to discuss your roof and the appropriate next step.