How to Remove Moss and Algae From Your Roof Safely

Treating the two the same way, or reaching for a pressure washer, turns a cleaning question into a roof-damage problem. This guide separates algae from moss, explains soft-wash-only cleaning, and covers prevention with zinc or copper and algae-resistant shingles. For a maintenance assessment, call Clark Brothers Roofing at +1 470-613-9333.

Key points

Gloeocapsa magma shows up as dark streaks, worst on shaded, north-facing slopes that stay damp longest under Cobb's canopy. It spreads from roof to roof in a neighborhood, which is why whole streets streak at once. ARMA's position is that this discoloration does not damage the shingle or shorten its functional life; it is an appearance issue, and for many homeowners that appearance matters for curb appeal and resale. One caution: on a very old roof, heavy streaking can simply be a visible companion of age, so ask whether cleaning makes sense before paying for it.

Algae Streaks: Cosmetic, But Worth Understanding

Moss is a different problem. A moss mat holds moisture against the roof, and as it grows it lifts and curls shingle edges, breaking seals and opening paths for water. Freeze cycles then work the lifted edges further, and the mat's weight and root-like holdfasts degrade the surface. Moss signals chronic shade and moisture, common in Marietta's wooded lots. Unlike algae, moss should be removed promptly and the shade and debris conditions feeding it should be addressed, or it returns and compounds the damage each season.

The rule is absolute: never pressure-wash shingles. High-pressure water strips protective granules, forces water under courses, and can void careful diagnosis of the roof's condition, trading clean-looking shingles for a measurably older roof. Safe treatment is a soft wash: low-pressure application of a cleaning solution, dwell time, and a gentle rinse, following the solution maker's instructions and protecting landscaping. Moss should be treated and allowed to release, then removed gently, never scraped aggressively with stiff tools that tear granules and mat.

• Black algae streaks are cosmetic; moss is the growth that actually damages shingles
• Soft-wash only — pressure washing a shingle roof causes the damage you are trying to prevent
• Prevention is shade and debris control, metal strips, and algae-resistant shingles at replacement

Prevention works upstream of cleaning. Zinc or copper strips installed near the ridge release metal ions in rain that inhibit algae and moss growth down the slope. Keeping debris off the roof and trimming back shade-producing limbs reduces the damp conditions both organisms need. At replacement time, algae-resistant shingles use copper-containing granules to resist streaking by type, so discuss them as a category with your roofer. Note that prevention reduces growth; in deep-shade Cobb lots, some maintenance cleaning may still be needed over a roof's life.

The facts in this guide are drawn from the official and primary sources below, checked October 2026.

Moss: The One That Actually Damages Shingles

Still wondering? Call +1 470-613-9333 — we are open 24 hours.

Call +1 470-613-9333 any time — we are open 24 hours. You can also visit us at 1122 Powers Ferry Rd, Marietta, GA 30067, or find us on Google Maps.

1. Cause: Gloeocapsa magma feeding on shingle limestone filler
2. Worst on shaded, damp, north-facing slopes
3. ARMA: cosmetic discoloration, not functional damage
4. On aged roofs, weigh cleaning cost against remaining life

Roofing for Marietta homes and businesses — honest pricing, photographed inspections, and a crew based right here on Powers Ferry Road. Open 24 hours.

Soft-Wash Only: How Safe Cleaning Works

Services

Service areas

• Moss lifts shingle edges and breaks sealant bonds
• Mats hold moisture against the surface year-round

Contact

Clark Brothers Roofing

Prevention: Metals, Debris Control, and Shingle Choice

© 2026 Clark Brothers Roofing. All rights reserved.

1. Remove promptly, then correct shade and debris causes
2. Thick moss may reveal damaged shingles underneath
3. Never pressure-wash asphalt shingles, no exceptions
4. Soft-wash: low pressure, proper solution, gentle rinse
5. Protect plants and landscaping during treatment
6. No stiff scraping of moss or shingle surfaces

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Sources & Official Resources

Open 24 hours — 1122 Powers Ferry Rd, Marietta, GA 30067

Our site was rebuilt in October 2026 and some pages were merged. Try the services hub, the service areas hub, or the blog — or call +1 470-613-9333 and we will point you the right way.

• Zinc or copper strips near the ridge inhibit growth
• Debris removal and limb trimming cut moisture and shade
• Algae-resistant shingles are an option at replacement
• Deep-shade lots may still need periodic cleaning

A Marietta Roofer, Up Front About Everything

Helpful next steps

Clark Brothers Roofing is based at 1122 Powers Ferry Rd in Marietta, GA 30067, and this page is about how we work rather than a polished origin story. We inspect roofs carefully, photograph problems instead of describing them from the driveway, explain repair-versus-replace honestly, and put pricing in writing. If a roof has good years left, we will say so — even when a replacement would pay us more.

We are also up front about the trade itself. Georgia does not license roofers, prices in this market vary wildly, and storm season brings out-of-town crews who disappear. Our answer is simple: local address, published phone number +1 470-613-9333, open 24 hours, and business licence and insurance certificates available on request for every customer who asks. That approach shapes everything on this page: how we inspect, how we price, and how we handle the paperwork Georgia homeowners actually need.

• Phone+1 470-613-9333
• Address1122 Powers Ferry Rd, Marietta, GA 30067
• HoursOpen 24 hours, seven days a week
• 1122 Powers Ferry Rd, Marietta, GA 30067

Every job starts with a real inspection: shingles, flashing, valleys, vents, decking where accessible, and the attic side when a leak is involved. You get photos and a plain-language explanation of what is failing, what is cosmetic, and what can wait. Then you get options — repair, maintenance or replacement — each priced separately, so you can choose the scope instead of being sold the largest one by default.

Contact Clark Brothers Roofing

Many roofing websites imply a state licence that does not exist. Georgia does not license roofers; roofing is a traditional specialty trade under O.C.G.A. 43-41-17. We will not dress that up. What we can show you is our business licence and current insurance certificates, on request, before you sign anything. Ask any roofer you interview for the same documents — a legitimate local company will hand them over without hesitation.

• Open 24 hours
• Marietta, GA
• Written scope & pricing
• Photographed inspectionsYou see the roof before you decide
• Published October 2026 pricingRanges in writing, by measured roof area
• Open 24 hoursBased at 1122 Powers Ferry Rd, Marietta

That page has moved

As of October 2026, our published ranges are architectural shingle at $4.50–$7.00 per square foot installed, typical replacements at $12,000–$22,000, and most repairs at $300–$1,500. Quotes are calculated from measured roof area, not living area, and include tear-off, underlayment, drip edge and ventilation checks. If a permit applies to your parcel in the City of Marietta or unincorporated Cobb, we confirm that before quoting rather than adding it later.

Our base at 1122 Powers Ferry Rd puts us minutes from East Cobb, the Marietta Square, Franklin Gateway and the I-75 and I-285 corridors. We work on the housing stock we know: Marietta homes with a median year built around 1984, Cobb homes around 1989, layered shingle roofs, aging flashing and heavy tree cover. Local means accountable — you know where to find us after the job, not just during it.

• Photo-documented inspections
• Repair and replacement priced separately
• No work sold that the roof does not need
• Written scope before work starts

Clark Brothers Roofing is a roofing contractor based in Marietta, Georgia. We work from 1122 Powers Ferry Rd — our mailing address, our base, and where our crews roll out from. Mailing address: Clark Brothers Roofing, 1122 Powers Ferry Rd, Marietta, GA 30067. Call us at +1 470-613-9333 — we are open 24 hours, including for emergency roof work.

About Clark Brothers Roofing

How We Work, Step by Step

We inspect, repair, and replace roofs across Marietta and Cobb County: roof replacement, roof repair, roof inspections, emergency and storm damage work, leak detection, metal and shingle roofing, flat and commercial systems, gutters, and maintenance. Every job starts with photographs and a written scope.

Honest About Licensing in Georgia

Georgia does not issue a state roofing licence — roofing is a traditional specialty trade under Georgia law, so treat any roofer who implies a state roofing licence with suspicion. What you can verify about us: our local business licence and current insurance certificates, available on request before you sign; a written, photographed scope before any work; and published pricing that carries the date it was set. Verify any Georgia contractor the same way, using the official sources below.

Honest About Pricing, Too

Call +1 470-613-9333 for a photographed inspection and a written scope. Clark Brothers Roofing is based at 1122 Powers Ferry Rd, Marietta, GA 30067 and open 24 hours.

Rooted on Powers Ferry Road

Open 24 hours · 1122 Powers Ferry Rd, Marietta, GA 30067

Who We Are

A tree limb through the roof or water pouring through a light fixture turns a home into a triage problem. The first hour matters, but almost everything useful in that hour happens inside the house, not on the roof. Wet roofs are fall hazards, damaged decking can give way, and electrical hazards hide in wet ceilings.

What We Do

By Clark Brothers RoofingPublished October 22, 2026Updated October 22, 2026