Looking for soft washing for asphalt shingle roofs in District of Columbia? We look at the surface first, choose the right method and pressure for it, and give you a price before any work starts. On asphalt shingle roofs, the method we use is soft wash (no pressure).
Method and pressure
Cleaning solution: A diluted sodium hypochlorite solution with surfactant; plants below are pre-wet and rinsed.
What to know about cleaning asphalt shingle roofs
The black streaks on many asphalt roofs are a type of algae, often Gloeocapsa magma, that feeds on the limestone filler in shingles. It is killed with a soft wash solution, not blasted off. The Asphalt Roofing Manufacturers Association advises against pressure washing shingles because it strips the granules that protect them.
Avoid: Pressure washing, which strips granules and shortens the roof's life, and walking on wet, slick shingles.
How often: Every 3-5 years, or when streaks return.
When to book soft washing for asphalt shingle roofs
- Green, black or gray film on siding, especially on the north side
- Black streaks running down the roof
- Moss or lichen on shingles or tile
- A musty smell around shaded walls
- Pressure washing would damage the surface
Why it gets dirty
- Algae, mold and mildew that grow in shade and humidity
- Roof algae that feeds on the limestone filler in shingles
- Pollen and dust that give growth something to hold on to
- Sprinklers and gutters that keep walls damp
What you can do yourself
- Trim back branches and shrubs that touch the house so walls can dry
- Keep gutters clear so water doesn't overflow down the siding
- Spot-clean small areas with a soft brush and mild detergent
- Aim sprinklers away from the house
Not sure what you're looking at? The free stain identifier and safe pressure guide explain each stain and surface.
What can go wrong with DIY pressure washing
- Using too strong a mix, which can burn plants and fade surfaces
- Using too weak a mix, which leaves growth alive and it returns quickly
- Climbing ladders with a spray wand and chemicals
- Mistaking soft washing for 'pressure washing on low'
Our process for soft washing for asphalt shingle roofs
- Identify the surfaces and the type of growth
- Pre-wet plants, cover sensitive fixtures and close windows
- Apply a solution mixed for the surface and let it dwell
- Rinse at low pressure from the top down
- Rinse plants again and check every side with you
Soft Washing for Asphalt Shingle Roofs cost in District of Columbia
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 asphalt shingle roofs
Local soft washing for asphalt shingle roofs for District of Columbia
Humid summers in District of Columbia grow green algae and black mildew on the shaded sides of homes, especially on vinyl and painted wood. A soft wash kills the growth rather than just knocking it off, so the siding stays clean longer.
We cover 52 cities and towns across District of Columbia. Find soft washing for asphalt shingle roofs in your city:
- Washington
- Downtown DC
- Columbia Heights
- Mount Pleasant
- Central 14th Street / Spring Road
- Northwest One
- Foggy Bottom
- Mount Vernon Triangle
- H Street NE
- Pleasant Plains
- NoMa
- Petworth
Soft Washing for Asphalt Shingle Roofs: frequently asked questions
How much does soft washing for asphalt shingle roofs cost in District of Columbia?
Soft Washing for Asphalt Shingle Roofs typically costs $300-$800 for a typical single-family home exterior, 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 soft washing for asphalt shingle roofs?
For asphalt shingle roofs: no pressure washing; the solution is applied at very low pressure and rinsed gently. What we avoid: pressure washing, which strips granules and shortens the roof's life, and walking on wet, slick shingles. The cleaning solution does most of the work, followed by a gentle rinse.
Is soft washing for asphalt shingle 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 soft washing for asphalt shingle roofs?
Every 3-5 years, or when streaks return. 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.