Roof Cleaning Questions, Answered
Straight answers to the questions homeowners ask us most about roof cleaning, from a licensed roofing contractor that has cleaned more than 10,000 roofs across Rockland, Bergen, and Westchester since 1979. Have a question that is not here? Call (877) 492-9014.
Frequently Asked Questions
How often should you soft wash a roof?
For most homes in the tri-state area, every two to four years keeps algae and moss from taking hold. Heavily shaded or tree-surrounded roofs may need it more often; sunny, exposed roofs less. When you see the first faint black streaks, it is time to schedule.
Does roof cleaning damage shingles?
Professional soft washing does not — it uses low pressure and is manufacturer-recommended. High-pressure power washing can strip the protective granules and damage shingles, so it should never be used on an asphalt roof.
How long does a roof cleaning last?
A proper soft wash typically keeps a roof clean for several years, because it kills algae and moss at the root. A cheap power wash may look good for a season, but the growth usually returns within months.
Is soft washing safe for plants and pets?
Yes, when done carefully. The solutions are biodegradable, and a good crew pre-wets and rinses surrounding landscaping. Keep pets indoors during the job; once the roof is rinsed and the crew packs up, they are fine outside.
Will roof cleaning void my warranty?
Gentle, professional soft washing is warranty-safe and aligns with what shingle manufacturers recommend for algae removal. It is aggressive high-pressure washing that risks voiding a shingle warranty.
Do black streaks mean I need a new roof?
Usually not. Black streaks are surface algae (Gloeocapsa magma), not structural damage. A professional cleaning almost always restores the roof, and a licensed roofer can confirm it is otherwise sound.
What's the difference between soft washing and pressure washing?
Soft washing uses low pressure and a biodegradable solution to kill algae and moss at the root. Pressure washing uses high pressure that can damage shingles and only removes surface growth, so stains return faster.
Get an exact price for your roof
CALL TO ACTION: Get your free roof cleaning estimate. Call (877) 492-9014. Serving Rockland, Bergen, and Westchester.