Dark Roof Streaks Are Not Just Ruining the Look of Your Roof!
Those dark streaks running down your roof aren’t just an eyesore — they’re living organisms actively feeding on your shingles. Gloeocapsa Magma, a cyanobacteria, causes the black staining you see on roofs across Roanoke and Smith Mountain Lake. Left untreated, it traps moisture and accelerates the breakdown of your asphalt shingles, shaving years off their lifespan and potentially voiding your manufacturer’s warranty.
At Guardian Exterior Services, we’ve spent over a decade restoring properties and we’ve seen firsthand what roof neglect costs homeowners — often tens of thousands of dollars in premature replacement. Our Roof Wash process uses a low-pressure soft wash system and specially formulated cleaning solutions to safely eliminate the root cause, not just the symptom.
What Is Soft Wash Roof Cleaning?
Soft washing uses a low-pressure application — similar to a garden hose — combined with professional-grade biodegradable cleaning solutions. Unlike pressure washing, which can crack or loosen shingles, soft washing treats the biological growth at its source, delivering results that last 3–5 years rather than weeks.
The ARMA (Asphalt Roofing Manufacturers Association) specifically recommends low-pressure chemical cleaning for asphalt shingle roofs. High-pressure washing can strip granules, void warranties, and cause leaks. Guardian follows ARMA standards on every job.
Benefits of Our Roof Wash Process
✅ Extends Roof Life Algae and moss hold moisture against your shingles 24/7. Removing biological growth is one of the most cost-effective maintenance steps you can take — extending roof life by years and avoiding a $10,000–$20,000+ replacement.
✅ Safe for All Roof Types Our low-pressure process is safe for asphalt shingles, metal roofing, tile, cedar shake, and slate. No blasting. No cracking. No warranty concerns.
✅ Environmentally Responsible We use biodegradable cleaning agents and take special care on Smith Mountain Lake and Roanoke area properties to prevent chemical runoff into the lake. We pre-soak surrounding vegetation and follow all responsible application protocols.
✅ Results That Last Our chemical soft wash treatment kills biological growth at the root. Most roofs remain clean for 3–5 years after a single treatment — not just weeks like a simple rinse.
✅ Backed by Real Experience Guardian isn’t a seasonal cleaning crew. With over a decade of property restoration experience and 100+ projects, we understand what protects homes long-term — and what damages them. That context shapes every service we provide.
Is Your Roof Ready for a New Look and an Extended Life?
You may need a professional roof washing if you notice:
- ⚠️ Dark black or gray streaks running down the roof slope
- ⚠️ Green or dark moss patches — especially on north-facing sections
- ⚠️ Orange or white lichen growth (lichen is the hardest to remove and causes the most damage)
- ⚠️ A general darkening or discoloration compared to when the roof was new
- ⚠️ Your roof is 3+ years old and has never been professionally cleaned
🚫 Don’t wait until the damage is done. The restoration work we’ve seen from years of deferred roof maintenance is preventable with a $300–$600 investment in professional cleaning.
Frequently Asked Questions
What Are Those Black Streaks on My Roof?
Those streaks are caused by Gloeocapsa Magma, a type of cyanobacteria that feeds on the limestone filler in asphalt shingles. It spreads by spores, holds moisture, and accelerates shingle degradation over time. Soft washing eliminates it at the root.
How much does roof washing cost in Roanoke, VA?
Most residential roof cleanings range from $300 to $600, depending on roof size, pitch, and level of biological growth. We provide free, no-obligation quotes for every property and offer package discounts.
Will soft washing damage my shingles?
No. Soft washing is the ARMA-recommended method for cleaning asphalt shingle roofs. High-pressure washing is what damages shingles — stripping granules, loosening edges, and voiding manufacturer warranties.
How long does roof washing take?
Most residential roofs take 2–4 hours from setup to completion. Roofs with heavy lichen growth may require additional time or a follow-up treatment.
How long will my roof stay clean?
Our soft wash treatment typically keeps roofs clean for 3–5 years. Heavily wooded areas or north-facing roofs may see regrowth sooner.
Is the cleaning solution safe for my plants and pets?
Yes. We use biodegradable solutions and protect your landscaping by wetting plants before and after treatment. We take this especially seriously on Smith Mountain Lake properties.
More Frequently Asked Questions