Residential Exterior Cleaning
Soft Wash Roof Cleaning That Erases Black Streaks
Those black streaks aren't dirt — they're Gloeocapsa magma algae feeding on your shingles. We treat them at the source with a low-pressure soft wash.
What it is
Roof Washing, explained simply.
Pressure washing a roof tears off granules and voids most shingle warranties. Roof washing should always be a soft wash process: a careful application of cleaning solution that kills the algae, lichen, and moss responsible for staining, followed by a gentle rinse. Results are visible the same day and continue to improve as rain finishes the lift.
Is this service right for you?
- Homes with visible black streaks on the roof
- Roofs with green moss or crusty lichen patches
- Properties under tree cover or in shaded lots
- Sellers needing curb appeal before listing
Our Process
How we deliver a clean you can see.
- 1
Roof and gutter inspection
We check shingle condition, valleys, flashing, and gutters.
- 2
Landscaping protection
Plants and shrubs are pre-rinsed and shielded.
- 3
Low-pressure soft wash
A roof-safe cleaning solution is applied to kill algae and lichen at the root.
- 4
Gentle rinse and inspection
We rinse, then walk the property to confirm a clean, even result.
A closer look
Everything worth knowing.
Those black streaks running down your roof aren't dirt and they aren't shadow. They are a colony of Gloeocapsa magma — a hardy algae that feeds on the limestone filler in asphalt shingles. As it spreads, it traps heat, holds moisture against the shingle mat, and prematurely ages the entire roof. Pair it with lichen patches and green moss in shaded valleys and you have a roof that is failing years before it should.
Pressure washing a roof is one of the fastest ways to destroy it. The granules embedded in asphalt shingles are the roof's UV armor; blow them off and you've started a clock the manufacturer never warrantied. Every major shingle manufacturer — GAF, Owens Corning, CertainTeed — explicitly recommends a soft wash (low-pressure chemical) cleaning method.
Admiral's roof soft wash uses an ARMA-aligned cleaning approach: a roof-safe solution is applied at low pressure, the algae and lichen are killed at the cellular level, and a gentle rinse begins the lift. Over the next few rain cycles, the streaks continue to fade as the dead organic matter washes away.
DIY vs. Professional
When DIY makes sense — and when it doesn't.
The DIY reality
- Working from a ladder onto a wet, sloped roof is genuinely dangerous.
- Homeowner-grade bleach concentrations either underperform or burn landscaping below.
- Without surfactants, solution runs off before it can kill the algae — you treat the same roof twice.
What a pro brings
- We pre-wet and tarp landscaping below the drip line.
- Calibrated dilution kills algae in one pass without damaging shingles.
- Trained, insured technicians — your homeowner's policy is not the safety net.
Roof work is the single highest-risk DIY pressure-washing task. Hire it out — your roof, your shrubs, and your back will thank you.
Surfaces & materials
We tune the method to the material.
Asphalt shingles
The most common East TN roof. Soft wash only — pressure washing strips granules and voids warranties.
Metal roofing
Durable, but coatings can be damaged by aggressive scrubbing. Soft wash with the correct solution preserves the finish.
Tile and slate
Brittle and expensive to replace. We adjust pressure and access methods to avoid breakage.
Cedar shake
Requires a different solution profile to address mildew without raising the wood grain.
What we see go wrong
Common mistakes (and how we avoid them).
Pressure washing shingles
Strips granules, voids the manufacturer warranty, and shortens roof life by years.
Using straight bleach with no rinse
Burns gutters and landscaping below and leaves residue that re-stains within a season.
Ignoring lichen
Lichen embeds root-like structures into shingles. It must be killed chemically — scraping pulls granules with it.
Walking around in hard-soled shoes
Causes granule loss on hot days. We minimize foot traffic and use soft-soled, roof-specific footwear when needed.
What affects price
Honest pricing factors.
- Roof square footage and number of facets
- Pitch and accessibility
- Severity of algae, lichen, and moss
- Tree cover and amount of debris in valleys
- Add-ons: gutter cleaning, exterior gutter brightening, house wash bundle
When to book
Seasonality in East TN.
Roof washing is best done in mild, dry weather. We avoid washing immediately before heavy rain so solution has time to work. Spring and fall are ideal in East Tennessee; summer is fine with careful scheduling around storms.
Before we arrive
How to prepare.
- Trim back overhanging branches if possible — debris removal is easier and results last longer.
- Note any soft spots, leaks, or missing shingles so we can flag them.
- Move vehicles out of the driveway / drip zone.
- Close windows and skylights.
After we leave
What to expect.
- Expect immediate visual improvement, with continued fade-out over 2–6 weeks of normal weather.
- Algae will return — typical re-treatment cycle in East TN is 4–7 years depending on shade and humidity.
- Pair with annual gutter cleaning to keep valley debris from feeding new growth.
Why Admiral
The Admiral standard.
- ARMA-aligned soft wash method — safe for shingles and manufacturer warranties.
- Insured, with documented landscape-protection protocols.
- Local to East TN — we know which neighborhoods see the worst algae pressure.
Glossary
Terms worth knowing.
- ARMA
- The Asphalt Roofing Manufacturers Association — the trade body that publishes safe roof-cleaning standards.
- Lichen
- A composite organism of algae and fungus that anchors into shingles. Must be killed chemically; cannot be safely scrubbed off.
- Granule loss
- The shedding of the protective mineral coating on asphalt shingles, accelerated by high pressure and foot traffic.
Related Services
Often booked together.
House Washing
Gentle soft washing that lifts dirt, algae, and mildew off siding without damage.
Learn moreGutter Cleaning
Clear, free-flowing gutters — inside scoop-out plus exterior brightening.
Learn moreConcrete Cleaning
Sidewalks, patios, pool decks, and walkways restored to a clean, even finish.
Learn moreFAQ
Frequently Asked Questions
Roof washing is a soft-wash cleaning process that removes algae, lichen, moss, and the black streaks caused by Gloeocapsa magma — without high pressure on your shingles.
Yes. Soft washing is the method recommended by ARMA and major shingle manufacturers. It cleans with solution, not pressure, so granules stay put.
No. A pressure washer on a roof tears off granules and shortens shingle life. We apply a roof-safe cleaning solution and rinse gently.
Black streaks are a hardy algae called Gloeocapsa magma that feeds on the limestone filler in asphalt shingles. It thrives in humid East Tennessee weather.
Yes. Algae lifts immediately, and moss and lichen are killed at the root so they release as the next few rains rinse the roof.
Most roofs need a soft wash every 4–7 years. Heavily shaded roofs or those under tree cover may need it sooner.
Yes. Killing the algae and moss that feed on your shingles helps your roof reach its full expected service life.
Get a Free Quote
Ready to book roof washing?
Tell us what you need cleaned and we'll recommend the best service for your property.
Serving Knoxville, Lenoir City, Maryville, Oak Ridge, and surrounding East Tennessee communities.