Soft wash roof cleaning in Cumming & north Atlanta, GA
If your roof has dark streaks running down the shaded side, you are looking at algae, not worn-out shingles, and it does not come off with a garden hose. Alexus Pressure Washing has soft washed roofs across Cumming, Forsyth County, and the north metro Atlanta suburbs since 2014, and we do it the way the shingle makers actually recommend: low pressure paired with a cleaning solution that kills the growth at the root. No high-pressure wand, no granules blasted into your gutter, no voided warranty. A clean roof brings back the curb appeal those black streaks quietly drain away, and it matters even more before an appraisal, a sale, or an HOA notice. We are family-owned, licensed, and insured. Soft wash roof cleaning starts at $449 for a typical home. Call (470) 333-2525 for a free look at your roof.
What soft washing is, and why we never put high pressure on a roof
Soft washing cleans a roof with a cleaning solution and almost no pressure. The nozzle we use puts out water at about the force of a garden hose, well below the pressure a surface cleaner uses on a driveway. The algae, moss, and lichen come off because the solution kills them, not because water blasts them loose. That difference is the whole job. A pressure washer aimed at asphalt shingles does real harm. The top layer of a shingle is a bed of ceramic-coated granules, and those granules are what block UV and give the shingle its rated life. High pressure knocks them off by the handful. You can watch them wash into the gutter as a gritty black sludge, and every granule that leaves is roof life you paid for and will not get back. Pressure also lifts the shingle edges and drives water up under the courses where it does not belong, and it can break the tar seal that holds each row down against wind. On top of that, nearly every shingle manufacturer tells you in writing not to pressure wash the roof, and doing it anyway can void the warranty you are counting on. So we go the other way. We wet the roof and the landscaping below it, apply the cleaning solution, give it time to work, then rinse gently. No wand held six inches off the shingles. No granules in the gutter. The roof gets clean and stays intact.
Why north Atlanta roofs turn black: Gloeocapsa magma
The dark streaks running down the north side of so many Atlanta roofs are not dirt, and they are not the shingles wearing out. They are algae. The species is Gloeocapsa magma, a blue-green algae that spreads by airborne spores and settles on roofs all over the humid Southeast. It feeds on the limestone filler mixed into asphalt shingles. Manufacturers blend in crushed limestone, which is calcium carbonate, as a cheap filler and weight, and the algae eats it. As a colony grows it forms a dark protective sheath to shield itself from the sun, and that sheath is the black you see. The streaks run downward because rain carries spores down the slope, so the growth follows the water. It shows worst on the north-facing planes and the shaded sides, because those stay damp the longest after rain and morning dew. Once a roof is streaked, it gets worse on its own. The dark colony holds moisture and heat against the shingle, and a roof that stays wet longer grows more algae, which holds more moisture, and around it goes. Leave it for years and the same damp, shaded conditions let moss and lichen take hold in the valleys and along the edges. Moss is the one that actually damages a roof, because its roots work under the shingle edges and lift them. Killing the algae early, before moss and lichen join it, is far easier and cheaper than fighting all three later.
ARMA endorses soft washing, and it is safe for shingle, metal, and tile
The soft wash method is not something a pressure washing company invented to sell you a service. The Asphalt Roofing Manufacturers Association, known as ARMA, is the trade group for the shingle makers themselves, and it publishes guidance on exactly this. ARMA recommends removing roof algae with a low-pressure application of a diluted sodium hypochlorite and water solution, applied gently, with the plants below protected and rinsed. It specifically warns against high pressure. That is soft washing, described by the same industry that builds the shingles. The reason the method works across so many roof types is that the cleaning does not rely on force. A solution that kills algae kills it whether the surface underneath is asphalt shingle, standing-seam metal, concrete tile, clay tile, or cedar shake, so the same low-pressure approach adapts to each one with the mix and dwell time adjusted for the material. It also explains why soft washing outlasts a pressure rinse. When someone blasts a roof with a pressure washer, the top growth flies off and the roof looks clean for an afternoon, but the algae roots and the spores stay behind, so the streaks come back within a season or two. A soft wash kills the colony down to the root. Nothing is left alive to regrow from, so the roof stays clean for years instead of weeks, and you are not back up a ladder every spring chasing the same stain.
Why Forsyth and North Fulton roofs streak first, and what a clean roof is worth
Algae needs moisture and shade, and the north metro Atlanta suburbs hand it both. Forsyth County, north Fulton, and the towns up the GA-400 corridor grew up inside the tree line. Subdivisions in Cumming, Alpharetta, Milton, and Johns Creek were carved out of oak and pine woods, and most homes still sit under a heavy canopy that keeps the roof shaded through the day. Add Georgia humidity and the afternoon storms that soak everything all summer, and a shaded roof here can stay damp most of the week. That is why a house on a wooded lot streaks years before an identical house across the street that sits in full sun. It is also why whole new subdivisions streak at once. When every roof went on the same year, the algae reaches all of them on the same schedule, and a street of matching black-streaked roofs is a common sight in the newer north-metro neighborhoods. A streaked roof costs you in ways past the look, too. Buyers read a black-streaked roof as a worn-out roof, and more than one seller has watched an offer soften because the house photographed like it needed a new roof when the shingles had years left. Inspectors and appraisers note heavy algae and moss. Plenty of north-metro HOAs treat a streaked roof as a maintenance issue and mail a notice about it, the same way they do for a dirty driveway. A soft wash answers all three at once, which is why owners often book it before listing, ahead of an appraisal, or the week an HOA letter shows up. If you want the siding to match the fresh roof, our house washing service handles the walls on the same visit.
What roof soft washing costs in Cumming and north Atlanta
Roof soft washing is priced up front, not guessed at on the day. A soft wash roof cleaning runs $449 for a typical home, and that covers the full roof: wetting down and protecting the landscaping below, applying the algaecide solution, the dwell time it takes to kill the colony, and a gentle rinse. Very large roofs, steep multi-story rooflines, or a roof buried under years of moss and lichen get quoted after we look, because those take more solution and more time, and we would rather hand you the real number than a low one that changes at the end. The best value is bundling, since the crew is already at your house with the gear set up. Pairing the roof with a house wash, priced by square footage from $249 for a smaller home up to $599 for a large one, cleans the roof and the siding on one trip for less than two separate visits. Adding gutter whitening at the same time lifts the dark oxidation streaks off the gutters so the whole top of the house matches. You can see every rate on the full price list, build your own number in about a minute with the instant estimate tool, and read what really moves a wash price in our 2026 Atlanta pressure washing cost guide. We are based in Cumming and cover Forsyth County and the north metro Atlanta suburbs up and down GA-400, and the estimate is always free. The number we quote is the number you pay.
How much does roof cleaning cost in Atlanta?
Soft wash roof cleaning runs $449 for a typical home, which covers protecting the landscaping, applying the algaecide solution, the dwell time it takes to kill the algae, and a gentle rinse. Very large, steep, or heavily mossed roofs get quoted after we see them. Bundling the roof with a house wash, priced from $249 to $599 by square footage, or with gutter whitening is the cheapest way to do it, since we are already on site with the equipment set up.
Is soft washing safe for asphalt shingles?
Yes. Soft washing uses low pressure, close to a garden hose, and lets the cleaning solution do the work instead of force. The Asphalt Roofing Manufacturers Association recommends exactly this method for roof algae and warns against high pressure. It is pressure washing that damages shingles, stripping off the protective granules and often voiding the manufacturer warranty. A soft wash leaves the granules where they belong and kills the algae at the root.
Why is my roof streaked black?
The black streaks are a blue-green algae called Gloeocapsa magma. It spreads by airborne spores and feeds on the limestone filler in asphalt shingles, then forms a dark sheath to protect itself from the sun, which is the black you see. Rain washes the spores down the slope, so the streaks run downward and show up worst on the shaded, north-facing planes that stay damp the longest. It is very common on wooded lots in Forsyth County and north Atlanta.
Will roof cleaning damage my roof?
Not the way we do it. The damage people worry about comes from pressure washing, which blasts off the granules that protect the shingles and can lift the edges and break the wind seal. Soft washing uses almost no pressure and a solution that kills the algae at the root. We wet and protect the plants below first, then rinse gently, so nothing gets forced up under the shingles and no granules end up in the gutter.
How long does a roof soft wash last?
Longer than a pressure rinse, because the algae is killed at the root instead of knocked loose on top. In our experience a soft-washed roof stays clean for a few years before streaks start to return, though a roof under heavy oak or pine canopy that stays shaded and damp will need it sooner than one in full sun. It is not permanent. Zinc or copper strips fitted near the ridge can slow regrowth on roofs that streak fast.
Is there roof cleaning near me in Cumming?
Yes. Alexus Pressure Washing is based in Cumming, GA and soft washes roofs across Forsyth County and the north metro Atlanta suburbs along GA-400, including Alpharetta, Milton, Johns Creek, Suwanee, and Buford. We are family-owned, licensed, and insured, and part of the AlexUS Service family. Call (470) 333-2525 or email Alexusbestcompany@gmail.com for a free look at your roof.
Get Your Free Roof Soft Washing Estimate
Tired of the black streaks running down your roof? Call (470) 333-2525 or email Alexusbestcompany@gmail.com for a free look. Family-owned in Cumming since 2014, licensed and insured, using the ARMA-recommended soft wash that kills roof algae at the root instead of blasting your shingles.