Commercial Roof & Soft Washing
Commercial Roof Cleaning & Soft Washing in Knoxville, TN
Low-pressure soft washing that lifts black streaks, moss, and algae off commercial roofs and facades — protecting the roof's lifespan instead of shortening it.
Those black streaks are Gloeocapsa magma, an algae that feeds on roofing and spreads across shaded, moisture-holding surfaces. High pressure would strip it — and the roof's granules or coating along with it. We use a low-pressure soft wash with targeted solutions that kill the growth at the source and slow its return, without damaging the surface or surrounding finishes.
We clean shingle, metal, and low-slope commercial roofs, and we extend the same soft-wash approach to facades where organic growth has taken hold. Roof type and access are assessed first so the method fits the building.
Typical maintenance plan cadence
Soft-wash roof treatments typically hold for one to three years. Shaded, north-facing slopes and tree-heavy sites tend to need attention sooner — we build that into the maintenance calendar.
Serving commercial property across Knox, Anderson & Blount counties — built for property managers, HOAs, NNN tenants & storefronts.
Popular service areas: Knoxville, Farragut, Hardin Valley, Powell, Oak Ridge, and Maryville.
What we treat
- Shingle roofs (low-pressure soft wash)
- Metal & standing-seam roofs
- Low-slope & flat membrane roofs (debris + treatment)
- Black streak (Gloeocapsa magma) removal
- Moss, algae & lichen treatment
- Facade soft washing for organic growth
The Work
Roof & Soft Washing in the field
In depth
What to know before you book
Soft wash vs. pressure wash for roofs
This is the single most important thing to understand before anyone touches your roof: a roof should never be pressure washed. The high-pressure stream that's right for a concrete sidewalk is exactly wrong for roofing. On an asphalt shingle it blasts off the mineral granules that protect the shingle from UV and give it its rated lifespan — granules that don't grow back — leaving the roof to age years faster than it should. It can force water up under the shingles, loosen seals, and on almost every manufacturer's terms it voids the warranty. The damage often doesn't show for a season or two, which is why homeowners don't realize a cut-rate roof wash cost them years of roof life until it's too late.
Soft washing does the opposite. It uses low pressure — closer to a garden hose than a pressure washer — paired with professional-grade cleaning solutions that actually kill the algae, moss, and lichen at the root rather than just knocking the visible layer off. Because the growth is killed instead of scraped away, the roof comes clean without a single granule lost, and it stays clean far longer than a plain rinse ever would. It is the method roofing manufacturers themselves specify for asphalt shingles, and it is the only method we use on a roof.
What the black streaks and moss actually are
Those dark streaks running down a roof aren't dirt, soot, or normal aging — they're a living organism. The culprit is Gloeocapsa magma, a blue-green algae that feeds on the limestone filler in asphalt shingles and spreads as a dark stain across the broad, moisture-holding faces of a roof. East Tennessee is close to ideal for it: our long humid summers, frequent rain, and heavy tree shade keep roofs damp exactly the way the algae likes. It usually shows up first on the north-facing and shaded slopes that dry out slowest.
Moss is the algae's heavier cousin. Where algae stains, moss grows in thick green clumps that hold water against the shingles like a sponge, lifting and curling the edges and working its way underneath — and lichen digs in with root-like structures that cling even harder. None of it is only cosmetic. By trapping moisture and heat and eating away at the shingle surface, the growth genuinely shortens a roof's life, which is why leaving it up is more than an appearance problem.
What our roof service includes
Every job starts with a look at the roof — the material, the pitch, the extent of the growth, and the access — so the treatment and the plan fit the building rather than a one-size approach. From there we apply a low-pressure soft wash with solutions matched to what's growing and to the surface underneath, working carefully around the landscaping, and we treat the growth at the source so it's slow to return instead of back in a few months.
We clean the full range of roof types: asphalt shingle, metal and standing-seam, tile, and the low-slope or flat membrane systems common on commercial buildings, each with the appropriate method and pressure. Because we're already up on the roofline, roof cleaning pairs naturally with gutter cleaning and service — the same algae and debris that streak a roof end up washing down into the gutters, so clearing both in one visit gets the entire top of the building handled at once. Many clients book the two together and keep them on the same schedule.
Commercial vs. residential roof cleaning
Commercial roof cleaning is our specialty, and commercial roofs come with their own considerations. An office building, retail center, medical facility, or HOA community may mean large low-slope membrane roofs, multiple buildings on one property, work that has to happen around tenants and customers, and a property manager or board that needs a certificate of insurance on file and documentation of the work. We handle roofs as a scheduled part of a property's exterior care, carry general liability and workers' compensation, and provide the COI and completion records those clients need.
Residential roof cleaning is a single home and a simpler arrangement — no route, no COI packet, just a homeowner who wants the streaks gone and the roof protected. The soft-wash method, the low pressure, and the care taken around the roof and the plantings are identical; only the scale and the paperwork change. Whether it's a warehouse membrane or a two-story shingle roof over a family, the growth comes off the same safe way.
For Knoxville homeowners
If you own a home anywhere around Knoxville — Farragut, Powell, Hardin Valley, Maryville, or out toward Oak Ridge — those black streaks on your roof are the region's climate at work, and they're worth taking seriously. A soft-wash roof cleaning does two things at once for a homeowner. It restores the roof's appearance, erasing the dark staining that can make an otherwise well-kept house look tired and drag down its curb appeal. And it protects the investment underneath: by killing the algae, moss, and lichen that eat at the shingles and trap moisture, it helps the roof reach the lifespan you paid for instead of aging out early.
Because we soft wash rather than pressure wash, it's genuinely safe for the shingles — no lost granules, no voided warranty, no water driven up underneath. Most homes do well with a cleaning every few years, sooner for shaded, north-facing, or tree-heavy roofs where the growth comes back faster. We'll take a look, tell you honestly whether your roof needs it yet, and treat it with the same care we bring to a commercial building.
High pressure is the fastest way to shorten a roof's life. Soft washing does the opposite: it removes the organic growth that degrades roofing while protecting shingles, coatings, and everything below the roofline.
- Low-pressure methods protect roofing and many warranties
- Treats the growth at the source to slow regrowth
- Roof type and access assessed before any work
- Pairs with facade and gutter service on one schedule
FAQ
Roof & Soft Washing questions
Is soft washing safe for the roof?
Yes. Soft washing uses low pressure and targeted solutions rather than high-pressure blasting, so it removes streaks and growth while protecting shingles, coatings, and the roof's lifespan — and stays within most roofing warranties.
What causes the black streaks on a roof?
It's Gloeocapsa magma, a hardy algae that thrives in shade and humidity. Soft washing removes it and treats the surface so it's slower to come back than it would be after a simple rinse.
Can you clean flat or membrane commercial roofs?
Yes — we handle debris removal and appropriate treatment for low-slope and membrane roofs. We assess the roof type and access first so the approach matches the system.
How long does a roof cleaning last?
Typically one to three years, depending on shade, tree cover, and exposure. We can schedule recurring treatment so growth never gets a foothold.
Will roof cleaning void my shingle warranty?
No. We soft wash at low pressure following ARMA (Asphalt Roofing Manufacturers Association) guidance — the method shingle manufacturers specify — so the algae and streaks come off without damaging the granules or voiding your roof's warranty.
How much does roof cleaning cost in Knoxville?
It depends on the roof size and pitch, the material (shingle, metal, or flat/membrane), how heavy the algae and streaking are, and access. We give a flat quote after looking at the roof, with no charge for the assessment.
Do you carry insurance and provide a COI?
Yes. Roof work is exactly what property managers screen vendors for — we carry general liability and workers' compensation and provide a certificate of insurance (COI) naming your company or property as additional insured.
Do you clean residential roofs, or only commercial?
Both. Commercial roofs — office buildings, retail centers, medical facilities, and HOA communities — are our specialty, but homeowners are genuinely welcome, and we soft wash a single-family home to the same standard. The low-pressure method, the algae- and moss-killing treatment, and the care taken around your shingles and landscaping are identical; for a house it's usually a one-time cleaning or an every-few-years rhythm rather than a recurring commercial schedule.
Will roof cleaning damage my plants or landscaping?
We take real care to protect them. A soft wash uses cleaning solutions to kill the algae and moss, so before and during the work we account for the beds, shrubs, and plantings below the roofline — pre-wetting and rinsing greenery and controlling runoff so the landscaping is looked after. It's one of the reasons the job is done by a crew that does this for a living rather than sprayed on and walked away from. If you have specific plantings you're worried about, point them out before we start and we'll plan around them.
Can you get rid of moss and green growth, or just the black streaks?
Both. The black streaks are algae and the raised green clumps are moss — often with some lichen mixed in — and a soft wash treats all of them. The solutions kill the growth at the root so the moss dies off and releases its grip rather than being scraped away, because scraping or pressure-blasting moss off a shingle roof does real damage. Thick, established moss can take longer to fully weather off after treatment than a light algae stain does, and heavily shaded, north-facing roofs are the most prone to it here in East Tennessee. We'll tell you what to expect once we look at the roof.
Get a Quote
Request roof & soft washing for your property
Tell us about the property and we'll put together a maintenance plan or one-time quote. Commercial is our specialty; homeowners are welcome too.
5.0 on Google · 18 reviews
Related services
Often handled together
Commercial Pressure Washing
Facades, lots, sidewalks, dumpster pads, and loading docks — commercial scale, built for the size of the job.
Learn more →Gutter Cleaning & Service
Clear, free-flowing gutters for commercial and multi-building properties — one-time or on a seasonal maintenance plan cycle.
Learn more →Solar Panel Cleaning
Keep commercial arrays producing at the output you paid for, on a scheduled cycle.
Learn more →
Ready to set your exterior maintenance schedule?
Lock in your schedule once. We handle the rest — across Knox, Anderson, and Blount counties.