From the free quote to the final rinse, roof cleaning for metal roofs in Rockville, MD follows a simple process: inspect, protect, clean, rinse and check. On metal roofs, the method we use is soft wash.
How we clean it
Cleaning solution: A mild detergent or soft wash solution suitable for painted metal.
What to know about cleaning metal roofs
Painted metal roofs collect dirt, mildew and oxidation chalk. A soft wash cleans them without damaging the coating, and rinsing off salt film matters on coastal homes.
Avoid: High pressure at the seams and fasteners, and abrasive or strongly acidic cleaners that dull the paint.
How often: Every 2-4 years.
Signs you need roof cleaning for metal roofs
- Black or dark streaks running down the roof
- Green moss or lichen spots, often on the north side
- Roof looks older than it is
- Moss lifting the edges of shingles
- A home inspector or insurer has noted roof growth
Why it gets dirty
- Roof algae (often Gloeocapsa magma) spread by wind
- Shade from trees and the north-facing side staying damp
- Debris piles in valleys that hold moisture
- Moss and lichen that root into the roof surface
What you can do yourself
- Keep valleys and gutters clear of leaves and pine needles
- Trim branches to let in sun and air
- Consider zinc or copper strips near the ridge to slow regrowth
- Look from the ground with binoculars instead of climbing on the roof
Not sure what you're looking at? The free stain identifier and safe pressure guide explain each stain and surface.
Why more pressure isn’t better
- Pressure washing strips granules and can void a shingle warranty
- Falls from a slippery, wet roof
- Chemical runoff that burns plants below
- Water forced under shingles and flashing
Our process for roof cleaning for metal roofs
- Check the roof type, pitch and condition from the ground and ladder
- Pre-wet and protect plants and cover sensitive areas
- Apply a soft wash solution suited to the roofing material
- Let it work, then rinse gently or let rain finish the job as recommended
- Rinse gutters, downspouts and plants and check the results
How much does roof cleaning for metal roofs cost?
What moves the price:
- Size: square footage of siding, roof or flatwork
- Condition: heavy growth, old stains and peeling finishes take longer
- Access: number of stories, roof pitch, slopes and how close we can park
- Add-ons: sealing, gutter brightening and other services done in the same trip
These are typical U.S. ranges, not a quote. You get an exact price before any work starts. For a quick estimate, try the pressure washing cost calculator.
Other services for metal roofs
Roof Cleaning for Metal Roofs in Rockville, MD
Black algae streaks are common on asphalt roofs in Maryland, particularly on north-facing slopes and under trees. Soft washing removes them without stripping the granules that protect the shingles.
Near the coast, salt air leaves a film on siding, windows, screens and railings that dulls finishes and speeds up corrosion on metal. Regular rinsing and washing help protect them.
Crews serve all of Rockville (ZIP codes 20847, 20848, 20849, 20850, 20851 and more), plus Derwood (2.3 mi), North Bethesda (3.3 mi), Aspen Hill (4.3 mi) and Rossmoor (4.6 mi). Call (555) 010-0000 for a free quote in Rockville.
Roof Cleaning for Metal Roofs: frequently asked questions
How much does roof cleaning for metal roofs cost in Rockville, MD?
Roof Cleaning for Metal Roofs typically costs $400-$1,000 for a typical single-story or two-story home, and usually takes 2-4 hours. The exact price depends on the size and condition, and you get it before any work starts. Call (555) 010-0000 for a free quote.
Do you use high pressure for roof cleaning for metal roofs?
For metal roofs: soft wash, typically under 500 PSI. What we avoid: high pressure at the seams and fasteners, and abrasive or strongly acidic cleaners that dull the paint. The cleaning solution does most of the work, followed by a gentle rinse.
Is roof cleaning for metal roofs safe for my plants and pets?
We pre-wet plants and lawns, keep cleaning solutions diluted to what the surface needs, and rinse landscaping again when we finish. Keep pets and children inside until surfaces are rinsed and dry.
How often should I schedule roof cleaning for metal roofs?
Every 2-4 years. Shade, nearby trees, humidity and heavy traffic mean more frequent cleaning; sunny, dry spots can go longer. Our free cleaning frequency tool gives a recommendation for your climate.
What if it rains on the day?
Light rain doesn't stop most washing, but heavy rain, high wind, lightning and freezing temperatures do. If the weather isn't right, we reschedule at no charge. Our work is backed by a satisfaction guarantee.