Roof Soft Washing in Northwest Arkansas
Those black streaks running down your roof aren't dirt — they're a living algae called Gloeocapsa magma, and it's feeding on your shingles. Specifically, it eats the limestone filler inside asphalt shingles, which means the streaks are quietly shortening your roof's life while making your house look older than it is.
Southern Exterior removes roof algae the only way it should be done: soft washing. We apply a low-pressure detergent treatment that kills the algae, moss, and lichen at the root. No pressure washer ever touches your shingles. Every roof is quoted flat and free up front, based on its size and how heavy the growth is.
We soft wash roofs across all of Northwest Arkansas — Bentonville, Rogers, Bella Vista, Fayetteville, Springdale, Cave Springs, and beyond. Fully insured, locally owned, 5.0 stars on Google.
- Fully Insured
- Locally Owned
- 5-Star Rated
What Causes Black Streaks on NWA Roofs
Gloeocapsa magma is an airborne algae that thrives in humid climates, and Northwest Arkansas summers are exactly the environment it loves. Spores land on your roof, take hold on the shaded slopes first — usually north-facing — and spread. The black color is the algae's protective outer coating, which is why the streaks darken and widen over time.
The algae isn't just ugly. It feeds on the crushed limestone that manufacturers mix into asphalt shingles, slowly degrading them. It also holds moisture against the roof surface and darkens the roof, which raises attic temperatures in summer. Moss and lichen, which often follow, are worse — their root structures physically lift shingle edges and pry granules loose.
Our Roof Soft Washing Process
We start with an inspection from the ground and the ladder line, checking shingle condition and noting anything fragile. We protect landscaping below the roofline with a thorough pre-soak, and we keep a dedicated crew member on plant duty during application on heavily landscaped homes.
Then we apply a soft wash solution across the roof at low pressure — the application is closer to a heavy mist than a spray. The solution kills algae, moss, and lichen on contact and keeps working after we leave. Black streaks typically vanish immediately or within days as the dead algae rinses away in the next rains. Moss and lichen die off and release over the following weeks rather than being ripped out, which is exactly what you want — pulling live moss tears shingles.
We finish by rinsing gutters, walkways, and landscaping. Your roof gets clean without a single granule blasted off.
Why You Should Never Pressure Wash a Roof
Asphalt shingles are coated in mineral granules that provide UV protection and fire resistance. High-pressure water strips those granules off by the pound. You can literally find them piled in the gutters after someone pressure washes a roof. Once the granules are gone, the asphalt underneath bakes in the sun and the shingles fail years early.
High pressure can also drive water under shingles and into the decking, break shingle seals, and void manufacturer warranties — most shingle makers explicitly recommend low-pressure chemical cleaning and warn against pressure washing. Soft washing is the method endorsed by the Asphalt Roofing Manufacturers Association, and it's the only method we use.
Clean Roof, Longer Roof Life, Better Curb Appeal
A roof replacement in NWA runs well into five figures. Killing the algae that degrades your shingles is one of the cheapest forms of roof maintenance there is, and it buys you time. Many customers soft wash their roof when the streaks first appear and then again every three to five years as needed.
It also matters for resale and insurance. A streaked, mossy roof photographs terribly on a listing and can raise flags during inspections even when the shingles are structurally fine. A clean roof reads as a maintained home — because it is one.
What Customers Say
“Best pressure washing job I've ever received! Will definitely use Southern again 10/10 recommend”
“Very impressed how professional the service was, and due to the weather some times had to change, but yet the communication was spot on. Highly recommend!”
“Great service and extremely respectful young gentlemen.”
Frequently Asked Questions
How much does roof cleaning cost?
It depends on the size of the roof and the severity of the algae, moss, or lichen we're treating. Send us your address and we can measure the roof from satellite imagery and quote it flat and free, usually the same day.
Will soft washing damage my shingles?
No. Soft washing uses application pressure similar to rainfall — the detergent does all the work. It's the method shingle manufacturers themselves recommend. What damages shingles is pressure washing, which strips protective granules, and the algae itself if you leave it.
How long until the black streaks are gone?
Most streaking disappears during the treatment or within a few days. Heavy accumulation, moss, and lichen die immediately but release gradually over several weeks of weather. That gradual release is intentional — it protects the shingles.
How long does a roof cleaning last?
Typically three to five years before streaks start returning, depending on shade and tree cover. That's far longer than a house wash lasts, because the treatment keeps working on the roof surface after application.
Is it safe for my gutters, plants, and pets?
Yes. We pre-soak and post-rinse all landscaping, rinse the gutters, and ask that pets stay indoors during the work. Aluminum and vinyl gutters are unaffected by the solution when handled properly, which is our job.
Do you walk on the roof?
Only when necessary. Most roofs can be treated from ladders and roof edges, which is safer for both the crew and your shingles. Steep or delicate roofs are treated entirely without foot traffic.
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