Black Streaks & Roof Algae Removal
Those black streaks running down North Georgia roofs are not dirt and they are not stains. They are Gloeocapsa magma, a hardy algae that thrives in the humidity here and feeds on the limestone filler in asphalt shingles. Left alone it holds moisture against the roof surface and shortens shingle life.
- Soft wash only, never pressure wash
- Protects your shingle warranty
- Algae, moss and lichen
- We'll say if it isn't worth cleaning
- 5.0 on Google10 reviews
- 10, 25 & 50-yearworkmanship warranty tiers
- Limited lifetimeCertainTeed shingle warranty
- GAF Certified™residential roofing contractor
- ShingleMaster™CertainTeed credentialed
- Financingavailable on replacements
Soft wash, never pressure wash
This matters more than anything else on this page. A pressure washer will strip the protective granules straight off asphalt shingles, and those granules are what shield the mat from ultraviolet light. It looks clean and it has taken years off the roof. We soft wash, low pressure with a cleaning solution that kills the organism at the root, which is also what shingle manufacturers specify.
The part a pressure-washing company cannot tell you
Most roof cleaning in North Georgia is done by exterior-cleaning companies, not roofers. That distinction matters here, because pressure washing an asphalt roof can jeopardize the manufacturer's warranty, and the company holding the pressure washer is usually not the company who will be arguing that warranty claim with you later. We install CertainTeed systems and register that coverage on your behalf, so we have a direct stake in not voiding it. Ask anyone quoting you a roof clean whether they are willing to put in writing that their method complies with your shingle manufacturer's requirements.
Why Lake Lanier makes this worse here
Algae needs warmth, moisture and shade. North Georgia supplies all three, and proximity to Lake Lanier adds sustained humidity that keeps roof surfaces damp longer after rain and dew. Hall, Forsyth and Dawson counties wrap the lake, and the roofs we see with the heaviest streaking are consistently the shaded, north-facing slopes closest to water and under mature hardwood cover.
Algae, moss and lichen are different problems
Algae is the black streaking, and it is cosmetic before it is structural. Moss is worse: it holds water directly against the shingle and lifts edges as it grows, which lets water underneath. Lichen roots into the shingle surface and is the hardest to remove without damage. We identify which you have before deciding on the approach.
Why North Georgia roofs get it
Long humid summers, heavy tree cover and shaded north-facing slopes are close to ideal conditions. It usually shows first on the roof planes that get least sun. This is also why algae-resistant shingles are standard on our replacements, the copper granules in them suppress regrowth for years.
When cleaning is the wrong answer
If the shingles are already near end of life, cleaning a roof you will replace within a year or two is money better kept. We will tell you when that is the case rather than take the job.
Wondering what this costs? We publish our installed rates: $430 to $575 per roofing square, tear-off included, along with what moves a roof up or down inside that range.
from 10 reviews on Google
“Professional, attentive, installed the new roof and cleaned up like they had not even been there. On site manager explained what they were doing every step of the way. The job was done quickly and efficiently.”
“The team was friendly, professional, and took the time to answer all my questions. They showed up when they said they would and completed the job on schedule.”
Financing
Pay over time, not all at once.
Most people do not plan for a roof. We have partnered with Wisetack so the decision is about what your home needs, not about what is in your account this month.
0% APR available up to 24 months for eligible customers
Up to $65,000
Wisetack finances projects up to $65,000, which covers a complete replacement on essentially any home in our service area.
Terms from 3 to 120 months
APRs run from 0 to 35.9% depending on the amount and your credit. No hidden fees and no compounding interest.
Checking does not affect your credit
Prequalifying takes about a minute and runs a soft check, so you can see your real terms before deciding anything.
All financing is subject to credit approval. Your terms may vary. Payment options through Wisetack are provided by our lending partners. For example, a $5,500 purchase could cost $253.54 per month for 24 months, based on a 9.9% APR, or $1,833.33 per month for 3 months, based on a 0% APR. Offers range from 0 to 35.9% APR based on amount requested and creditworthiness. Not all merchants and lending partners participate in 0% interest programs. Terms range from 3 - 120 months and may vary based on merchant, lending partner, or transaction size. State interest rate caps may apply. No prepaid finance charges or participation fees. See additional terms at wisetack.com/faqs.
Roof Cleaning, common questions
What are the black streaks on my roof?
Algae, Gloeocapsa magma specifically. It is not dirt and it will not wash off in rain. It thrives in North Georgia's humidity and feeds on the limestone filler in asphalt shingles, which is why it is so common here and why it shows worst on shaded, north-facing slopes.
Can you pressure wash my roof?
We will not, and you should be cautious of anyone who offers to. Pressure washing strips the protective granules off asphalt shingles, the granules that shield the shingle mat from ultraviolet light. The roof looks clean and has lost years of service life. We soft wash, which is the method shingle manufacturers specify.
Will the algae come back?
Eventually, unless the conditions change. Soft washing kills the organism rather than just rinsing the surface, so regrowth is slow. Algae-resistant shingles, which we install as standard on replacements, contain copper granules that suppress it for years.
Does roof cleaning damage shingles?
Soft washing does not. Pressure washing absolutely does. The difference is entirely in the method and the pressure used, which is why we only do the former.
Where we do this work
Roof Cleaning across six North Georgia counties, from our office in Gainesville.
Other roofing services
- Roof ReplacementFull tear-off roof replacement across Hall, Forsyth, Gwinnett and North Georgia. CertainTeed systems with 10, 25 and 50-year workmanship warranties.
- Roof RepairRoof leak diagnosis and repair across North Georgia. We find the true source, show you the damage, and say honestly whether repair or replacement is right.
- Storm Damage & Insurance ClaimsHail and wind damage inspection, photo documentation and adjuster coordination for North Georgia homeowners. Free inspection, no obligation to file.
- Metal RoofingStanding-seam and exposed-fastener metal roof installation across North Georgia. Panel profile, gauge and fastening system named in your proposal.
- Roof InspectionFree roof inspections across North Georgia. Photo-documented report on condition, remaining life and any storm damage, whether or not you hire us.
- Gutters, Fascia & SoffitSeamless gutter installation, guards, fascia and soffit repair across North Georgia. Sized to your roof so water actually gets away from the house.
Soft wash only, the method that removes the algae without removing the granules.