Understanding Moss, Algae & Lichen on Your Roof
Biological growth on roofs is one of the most common maintenance issues homeowners face, particularly in the Pacific Northwest, Northeast, Southeast, and any region with moderate to high humidity. While often dismissed as purely cosmetic, moss and algae growth can significantly reduce the lifespan of asphalt shingle roofs and lead to costly damage if left untreated for years.
Understanding the difference between the three main types of biological roof growth is the first step toward effective treatment. Each organism behaves differently, causes different levels of damage, and requires different removal methods.
Algae (Gloeocapsa magma)
Algae is the most common form of biological roof growth in the United States. It appears as dark black, dark green, or blue-green streaks that run down the roof surface following the path of water flow. The dark coloration is actually the algae's protective outer coating, not the algae itself. Algae feeds on the limestone filler used in asphalt shingles, which is why it is so prevalent on modern roofing.
Damage level: Low to moderate. Algae does not physically lift or damage shingles, but it darkens the roof surface (increasing heat absorption by 15-25%), reduces curb appeal, and can lower property value. Left untreated for many years, algae colonies can trap moisture that contributes to premature granule loss.
Moss (Bryophyta)
Moss is the thick, green, spongy plant growth that forms raised clumps on roof surfaces. Unlike algae, moss has root-like structures called rhizoids that physically attach to and work underneath shingle surfaces. Moss thrives in shaded areas with persistent moisture -- north-facing roof slopes, areas under tree canopy, and valleys where debris collects are the most common locations.
Damage level:High. Moss is the most damaging biological growth. Its rhizoids pry up shingle edges, creating gaps where water infiltrates. Moss acts like a sponge, holding moisture against the roof surface 24 hours a day -- even during dry weather. This constant moisture contact accelerates shingle degradation, promotes wood rot in the roof deck, and can lead to leaks that damage the attic and interior. Untreated moss can shorten a roof's life by 5-10 years.
Lichen (Symbiotic Algae-Fungus Organism)
Lichen appears as light gray, white, yellow, or pale green crusty patches on the roof surface. It is actually a composite organism -- a partnership between algae and fungus growing together. Lichen is extremely hardy, drought-resistant, and very difficult to remove compared to moss or algae. It bonds tightly to shingle surfaces and often takes granules with it when scrubbed off.
Damage level: Moderate to high. Lichen is difficult to remove without damaging shingles, and its tight bond means physical removal often strips the protective granule layer. Chemical treatment followed by allowing the lichen to weather away naturally over 2-3 months is usually the safest removal approach for roofs with lichen.
What Causes Moss & Algae to Grow on Your Roof?
Biological growth does not occur randomly. Specific environmental conditions create the perfect habitat for moss and algae, and understanding these conditions is essential for both treatment and long-term prevention. If you address only the growth without addressing the underlying causes, regrowth is virtually guaranteed within 8-12 months.
Shade and Reduced Sunlight
Overhanging trees and north-facing roof slopes receive less direct sunlight, keeping the roof surface cool and damp -- ideal conditions for moss. Roofs with heavy tree canopy coverage can retain moisture for hours longer than sun-exposed roofs, creating a persistent damp environment.
Humidity and Moisture
Regions with annual humidity above 60% (Pacific Northwest, Southeast, coastal New England) see dramatically higher rates of roof biological growth. Morning dew, frequent fog, and rainfall that keeps roof surfaces damp provide the constant moisture these organisms need.
Debris Accumulation
Fallen leaves, pine needles, and twigs that collect in roof valleys, behind chimneys, and in gutters trap moisture against the roof surface. This organic debris also provides nutrients that feed moss growth. Regular debris removal is one of the most effective prevention measures.
Poor Ventilation
Inadequate attic ventilation allows warm, moist air to condense on the underside of the roof deck, keeping it damp. This moisture migrates through the sheathing and creates conditions that promote growth from both above and below. Proper soffit-to-ridge ventilation helps keep the roof surface dryer.
Limestone-Filler Shingles
Modern asphalt shingles use limestone as a filler material to reduce manufacturing cost. Unfortunately, algae feeds on limestone. Older shingles made before widespread limestone use rarely developed algae problems. This is why algae-resistant (AR) shingles with copper granules were developed.
Proximity to Water Sources
Homes near lakes, rivers, ponds, or wetlands experience higher ambient humidity and more persistent morning dew. These locations often see biological growth develop 2-3 times faster than homes in drier inland locations. Extra vigilance and preventive measures are recommended.
DIY Moss & Algae Removal Methods
For light to moderate algae staining and thin moss growth, DIY removal is feasible for homeowners comfortable working on a roof safely. However, there are critical safety and technique considerations that can mean the difference between effective cleaning and expensive shingle damage.
Safety Warning
Roof work is inherently dangerous. Wet, mossy roof surfaces are extremely slippery. Falls from residential roofs are a leading cause of homeowner injury. If your roof has a steep pitch (above 6:12), is two stories or higher, or you are not comfortable with heights and ladder work, hire a professional. No cosmetic roof cleaning is worth a fall injury. Always use proper footwear, a safety harness, and have a spotter present.
Method 1: Bleach Solution (Best for Algae)
Mix: 50% water, 50% household bleach (sodium hypochlorite). This is the method recommended by the Asphalt Roofing Manufacturers Association (ARMA).
Process: Pre-wet foundation plantings with clean water to protect them. Apply the bleach solution with a garden sprayer (not a pressure washer), working from the ridge down. Let it sit for 15-20 minutes. Rinse with a garden hose at normal pressure, working from top to bottom. Rinse plantings below the roof edge thoroughly with clean water.
Cost: $30-$80 in supplies. Effectiveness: Excellent for algae streaks, moderate for thin moss, poor for thick moss or lichen.
Method 2: Oxygen Bleach (Plant-Safe Alternative)
Mix: Oxygen bleach powder (sodium percarbonate) dissolved in water per manufacturer directions. Brands like OxiClean, Stain Solver, or dedicated roof cleaners use this active ingredient.
Process: Apply with a garden sprayer, let sit for 20-30 minutes (longer than chlorine bleach -- oxygen bleach works more slowly). Gently agitate thick growth with a soft-bristle brush. Rinse with a garden hose. Oxygen bleach is safe for plants, so no tarping or pre-wetting is needed.
Cost: $40-$100 in supplies. Effectiveness: Good for algae and light moss. Less effective than chlorine bleach on heavy staining but much safer for landscaping and the environment.
Method 3: Commercial Roof Cleaners
Products:Wet & Forget, Spray & Forget, Mold Armor, Jomax, and similar products are designed specifically for roof cleaning. Most use quaternary ammonium compounds or sodium hypochlorite as the active ingredient.
Process: Varies by product. Some are spray-and-walk-away formulas that work over weeks through natural rain exposure. Others require active application, dwell time, and rinsing. Read the product label carefully for your specific shingle type.
Cost: $20-$50 per application. Effectiveness:Good for algae and light moss. The “spray and forget” products are the safest DIY option since you apply from the ground or a ladder without actually walking on the roof.
Never Do This
- ✗ Never pressure wash asphalt shingles (destroys granules, voids warranty)
- ✗ Never scrape moss upward against shingle edges (lifts and damages shingles)
- ✗ Never use undiluted bleach (excessive concentration damages shingle adhesive)
- ✗ Never clean a roof in direct sunlight (solution evaporates before it can work)
- ✗ Never walk on a wet, mossy roof without proper safety equipment
Professional Roof Cleaning Costs (2026)
Professional roof cleaning is recommended for homes with heavy moss growth, steep or multi-story roofs, or homeowners who prefer not to do the work themselves. Professional services use commercial-grade solutions, soft-wash equipment rated at safe pressures for roofing, and have the experience to clean without damaging shingles.
| Service Type | Cost Range | What's Included |
|---|---|---|
| Algae Treatment (soft wash only) | $200-$500 | Chemical application, low-pressure rinse, gutter flush |
| Moss Removal (soft wash + manual) | $400-$800 | Manual moss removal, chemical treatment, rinse, debris cleanup |
| Heavy Moss + Debris Removal | $800-$1,500 | Extensive scraping, chemical treatment, valley/gutter cleanup, preventive treatment |
| Zinc Strip Installation | $200-$600 | Zinc strips along ridge line and mid-roof breaks, fastened under shingle edge |
| Annual Maintenance Plan | $200-$400/yr | Annual inspection, preventive chemical application, spot treatment of new growth |
| Full Roof Clean + Prevention Package | $600-$1,200 | Complete cleaning, zinc strip install, gutter cleaning, first-year maintenance included |
Costs vary by roof size, pitch, accessibility, and severity of growth. Multi-story homes and steep roofs (above 8:12 pitch) typically cost 25-40% more due to additional safety equipment and labor time. Get multiple quotes and verify that the contractor uses soft-wash methods only -- any company that proposes pressure washing asphalt shingles should be avoided.
Long-Term Prevention Strategies
The most cost-effective approach to biological roof growth is prevention. Once you have cleaned your roof, implementing these strategies will dramatically reduce regrowth and extend the interval between professional cleanings from 1-2 years to 3-5 years or longer.
1. Trim Overhanging Branches
The single most impactful prevention step. Trim tree branches back at least 6-10 feet from the roof surface to increase sunlight exposure and air circulation. This reduces moisture retention time after rain and dew by 40-60%. Professional tree trimming costs $200-$800 depending on the number and size of trees. This also reduces leaf and needle debris that feeds moss growth. Many arborists will combine this with gutter cleaning for a bundled price.
2. Install Zinc or Copper Strips
Metal strips installed along the ridge line and at mid-roof breaks create a passive prevention system that works every time it rains. Rainwater flowing over the metal carries microscopic metal particles down the roof surface, creating an inhospitable environment for moss and algae. Zinc strips ($1-$3 per linear foot installed) last 15-20 years. Copper strips ($3-$5 per linear foot) last 25-30 years and are slightly more effective. For a typical home, expect $200-$600 for zinc or $400-$1,000 for copper installation.
3. Keep Gutters and Valleys Clean
Clogged gutters cause water to back up under the roof edge, creating a perpetually damp zone where moss thrives. Clean gutters at least twice a year (spring and fall) and consider gutter guards if your property has heavy tree cover. Similarly, clear debris from roof valleys, behind dormers, and around chimneys -- these areas trap moisture and organic material that feeds biological growth. Gutter cleaning costs $100-$300 per visit, or $200-$1,000 for gutter guard installation.
4. Improve Attic Ventilation
Proper attic ventilation (balanced soffit intake and ridge exhaust) keeps the roof deck dryer from the underside, reducing moisture available for biological growth. The standard is 1 square foot of net free vent area per 150 square feet of attic floor space (or 1:300 with a vapor barrier). Many older homes have inadequate ventilation. Adding soffit vents, a ridge vent, or improving existing ventilation costs $300-$1,500 and provides benefits beyond moss prevention, including reduced energy costs and extended shingle life. See our roof ventilation cost guide for detailed pricing.
5. Choose AR (Algae-Resistant) Shingles at Replacement
When your roof is eventually replaced, specify algae-resistant shingles. AR shingles contain copper granules mixed into the surface layer that continuously inhibit algae growth. Most major manufacturers (GAF, CertainTeed, Owens Corning) offer AR options in their standard product lines at a modest premium of $200-$500 over non-AR equivalents for a full roof. AR shingles typically carry a 10-15 year algae protection warranty. This is the most effective long-term prevention for algae-prone regions.
When to Hire a Professional vs. DIY
While DIY moss removal is feasible in some situations, there are clear scenarios where hiring a professional roof cleaning service is the safer, more cost-effective choice. Understanding the threshold between a manageable DIY project and one that requires professional equipment and expertise can save you money and prevent accidental roof damage.
| Factor | DIY Appropriate | Hire a Professional |
|---|---|---|
| Roof Pitch | Low to moderate (below 6:12 pitch) | Steep pitch (above 6:12) or any multi-story roof |
| Growth Severity | Light algae streaks or thin moss patches | Thick, embedded moss covering large areas or lichen |
| Roof Age | Under 10 years old with good shingle condition | Over 15 years old with unknown shingle condition |
| Roof Complexity | Simple gable or hip roof, few obstacles | Multiple valleys, dormers, skylights, or chimneys |
| Physical Comfort | Comfortable on ladders and roof surfaces | Any discomfort with heights or physical limitations |
| Coverage Area | Small sections (under 500 sqft of growth) | Widespread growth covering most of the roof surface |
When hiring a professional, look for companies that specialize in roof cleaning rather than general pressure washing services. A qualified roof cleaning professional should use soft-wash methods exclusively (never pressure washing on asphalt shingles), carry liability insurance and workers' compensation, and be willing to provide references from previous roof cleaning jobs. Ask whether their process includes a pre-cleaning roof inspection to identify damage before they begin, as this protects both parties.
Request itemized quotes from at least three companies. A quality quote should specify the cleaning method (soft wash, manual removal, or both), the chemicals being used, whether preventive treatment is included, and a description of any damage found during the pre-cleaning inspection. Avoid companies that quote by phone without seeing the roof -- effective pricing requires an in-person assessment of the growth severity, roof size, and accessibility. For tips on evaluating contractors, see our guide to choosing a roofing contractor.
How Moss & Algae Affect Home Value and Insurance
The impact of biological roof growth extends beyond aesthetics and structural concerns. Moss and algae can directly affect your home's market value, insurance premiums, and your ability to sell when the time comes. Understanding these financial implications helps frame roof cleaning and prevention as an investment rather than an expense.
Curb Appeal and Appraisal Impact
A visibly mossy or algae-stained roof is one of the first things potential buyers and appraisers notice. Real estate professionals estimate that a roof with significant biological growth can reduce perceived home value by 3-8%, as buyers assume the roof is nearing end-of-life or has underlying damage. In a competitive market, a mossy roof may cause qualified buyers to skip your listing entirely. Conversely, a professionally cleaned roof with visible zinc strips signals proactive maintenance and can support a higher asking price. For a $400,000 home, the difference between a mossy roof and a clean one could represent $12,000-$32,000 in perceived value.
Home Inspection Red Flags
During a home sale, the buyer's inspector will flag significant moss growth as a deficiency. Inspectors are trained to note biological growth as an indicator of potential moisture problems, and their reports often recommend a dedicated roof inspection when moss is present. This can lead to buyer requests for a roof cleaning credit, a professional roof inspection (at your expense as the seller), or price reduction negotiations. Having your roof cleaned before listing eliminates this inspection issue entirely and removes a negotiation point from the table.
Insurance Considerations
Some insurance companies are tightening coverage requirements related to roof condition. In states like Florida and Texas, insurers are increasingly sending drone or satellite imagery assessors to evaluate roof condition before renewal. Visible biological growth can trigger a request for a professional roof inspection, a coverage surcharge, or in extreme cases, a non-renewal notice. While most standard policies cover damage from storms and accidental events, they specifically exclude damage from deferred maintenance -- and untreated moss growth falls squarely into the “deferred maintenance” category. Keeping your roof clean helps maintain your insurability. For more on roof insurance, see our state-by-state roof insurance guide.
Moss & Algae Susceptibility by Roofing Material
Not all roofing materials are equally vulnerable to biological growth. Your roofing material significantly impacts how quickly moss and algae develop, how much damage they cause, and what removal methods are safe. Here is how common roofing materials compare.
| Material | Susceptibility | Damage Risk | Safe Removal Method |
|---|---|---|---|
| Asphalt Shingles (Standard) | High | High -- moss lifts shingle edges, algae feeds on limestone filler | Soft wash only, bleach solution, no pressure washing |
| Asphalt Shingles (AR) | Low | Low -- copper granules inhibit algae for 10-15 years | Soft wash if needed, typically self-cleaning |
| Metal Roofing | Very Low | Minimal -- smooth surface discourages attachment | Garden hose rinse, mild detergent for stains |
| Cedar Shake | Very High | Very high -- wood retains moisture, moss accelerates rot | Professional soft wash recommended, avoid bleach (damages wood fiber) |
| Clay or Concrete Tile | Moderate | Moderate -- porous surface holds moisture but tiles are durable | Low-pressure wash acceptable, chemical treatment effective |
| Slate | Moderate | Low -- slate is non-porous, but moss grows in gaps between tiles | Gentle brush and chemical treatment, never pressure wash |
If you are dealing with persistent moss problems and your roof is nearing replacement age, upgrading to a moss-resistant material can eliminate the ongoing maintenance cycle entirely. Metal roofing, in particular, is virtually immune to biological growth due to its smooth, non-porous surface and natural runoff characteristics. See our metal roofing cost guide for current pricing.
For homes that will keep asphalt shingles, the upgrade to AR (algae-resistant) shingles at replacement time is one of the most cost-effective investments available. The $200-$500 premium over standard shingles saves $500-$1,500 in cleaning costs every 2-3 years for the first 10-15 years of the roof's life. Every major manufacturer now offers AR options -- look for the “algae resistant” or “StainGuard” designation in product specifications.
Best Time of Year to Clean Your Roof
Timing your roof cleaning correctly can improve the effectiveness of treatment, reduce the risk of regrowth, and make the job safer. The optimal window depends on your region and the type of biological growth you are dealing with.
Best Months
Late Spring (May-June) or Early Fall (September-October)
These windows offer moderate temperatures (chemical solutions work best between 50-80 degrees Fahrenheit), lower UV intensity (solutions do not evaporate as quickly), and enough remaining warm-weather days for the treatment to fully take effect before winter. Late spring cleaning addresses growth that developed over the wet winter months. Fall cleaning removes growth before winter moisture locks it in.
Avoid These Times
Mid-Summer Heat or Freezing Winter Months
Hot summer days (above 85 degrees) cause cleaning solutions to evaporate before they can penetrate and kill the organisms. Cleaning in freezing temperatures is dangerous (ice on ladders and roof surfaces) and chemicals may not activate properly below 40 degrees. Rainy weeks should also be avoided -- clean on a dry, overcast day with no rain forecast for 24-48 hours to let the treatment work.
For homeowners on an annual maintenance plan, the ideal schedule is a single professional cleaning in late spring with a follow-up preventive treatment application in early fall. This two-touch approach keeps growth under control through both the wet and dry seasons and is more effective than a single annual treatment. Schedule your cleaning as part of your overall annual roof maintenance routine.
Regional Moss & Algae Risk by Climate Zone
Biological roof growth varies dramatically by region. Understanding your area's risk level helps you determine how aggressively to pursue prevention and how often to schedule maintenance.
High Risk: Pacific Northwest (WA, OR)
The Pacific Northwest has the highest moss pressure in the US due to persistent rainfall, cool temperatures, heavy tree canopy, and long overcast periods. Most homes in Portland, Seattle, and surrounding areas will develop visible moss within 3-5 years of roof installation if no preventive measures are taken. Annual or biannual professional maintenance is recommended. Zinc strips are considered essential, not optional, in this region.
High Risk: Southeast (FL, GA, SC, NC, AL, MS, LA)
The Southeast's combination of heat and humidity creates ideal conditions for algae growth specifically. Black algae streaks (Gloeocapsa magma) are ubiquitous on non-AR shingle roofs in this region, often appearing within 2-3 years. Moss is less common due to the heat, but algae treatment is a near-universal maintenance need. AR shingles are strongly recommended for any new roof installation in the Southeast.
Moderate Risk: Northeast (ME, NH, VT, MA, CT, RI, NY, NJ, PA)
The Northeast sees both moss and algae growth, with moss more prevalent on shaded, north-facing slopes and algae common on south- and west-facing exposures. The seasonal cycle means growth is most active from spring through fall. Homes in heavily wooded lots may develop significant moss within 5-8 years. Prevention measures and inspection during the annual roof maintenance checklist are important in this region.
Low Risk: Arid West & Southwest (AZ, NM, NV, UT, CO, West TX)
Dry, arid climates rarely support biological roof growth. Homes in Phoenix, Las Vegas, Albuquerque, and similar locations almost never develop moss or algae issues. The primary roof maintenance concerns in these regions are UV degradation and thermal cycling, not biological growth. If you live in an arid climate and see biological growth on your roof, investigate for unusual moisture sources (irrigation overspray, HVAC condensate, plumbing leaks).
When Moss & Algae Signal Deeper Roof Problems
While biological growth is often a surface-level maintenance issue, in some cases it indicates or has caused more serious underlying damage. Knowing when to investigate further can prevent a $500 cleaning job from becoming a $15,000 roof replacement.
Shingles That Lift or Crumble During Cleaning
If shingles break, crumble, or lift easily when moss is removed, the shingles have been compromised by the prolonged moisture exposure. This indicates the shingles are at or near end-of-life and cleaning alone will not restore them to functional condition. A professional roof inspection is warranted to determine how much of the roof surface is affected and whether spot repair or full replacement is appropriate.
Soft or Spongy Roof Deck
If the roof deck feels soft, spongy, or gives when walked on in areas with heavy moss growth, water has penetrated through the shingles and is rotting the plywood or OSB sheathing beneath. This requires not just moss removal but roof deck replacement in the affected areas ($40-$80 per sheet of plywood installed). Left unaddressed, rotten decking can lead to structural sagging and potential failure.
Active Leaks or Attic Moisture
Check the attic beneath heavily moss-covered areas for signs of water intrusion: water stains on rafters, mold or mildew on sheathing, damp insulation, or daylight visible through the roof deck. Any of these findings indicate that the moss has caused or is allowing water penetration that goes beyond a surface cleaning issue. Address both the leak source and the moss to prevent continued damage.
Granule Loss Exposing Black Substrate
When moss removal reveals large bare areas where the protective granule layer has been completely worn away, exposing the dark asphalt substrate beneath, those shingles have lost their UV and weather protection. These bare areas will deteriorate rapidly even after moss removal. If granule loss is widespread, the roof is approaching or past the point where cleaning provides meaningful life extension -- replacement should be planned. Check your gutters for excessive granule accumulation (a sign of advanced wear) during your annual roof maintenance.
Cost-Benefit: Cleaning vs. Replacement
The decision between cleaning a mossy roof and replacing it depends on the roof's age, the extent of damage underneath the growth, and the cost comparison. Here is a practical framework.
Clean When...
- ✓ Roof is under 15 years old with 10+ years of life remaining
- ✓ Shingles are intact under the moss -- no crumbling or lifting
- ✓ Roof deck is solid (no soft spots when walked on)
- ✓ No active leaks or attic moisture issues
- ✓ Growth is primarily algae or thin moss (not deep, embedded lichen)
- ✓ Cleaning cost ($250-$1,500) is well under 10% of replacement cost
Replace When...
- ✗ Roof is 20+ years old and approaching end-of-life regardless
- ✗ Shingles crumble, lift, or break during cleaning attempts
- ✗ Roof deck has soft spots indicating rot underneath
- ✗ Multiple leaks have developed in heavily mossy areas
- ✗ Widespread granule loss reveals bare asphalt substrate
- ✗ Cleaning plus needed repairs exceeds 40% of replacement cost
When replacement is the right path, you can get an instant satellite-measured quote through RoofVista to see exact replacement costs for your roof. This helps you compare the economics of repeated cleaning ($500-$1,500 every 1-3 years) versus a one-time replacement with AR shingles that resist biological growth for 10-15 years from installation. See our metal roof vs. shingles comparison if you are considering a material upgrade -- metal roofs are virtually immune to moss and algae growth.
Common Moss & Algae Myths Debunked
Misinformation about roof moss and algae treatment is widespread online, leading homeowners to use damaging methods or ignore growth until it is too late. Here are the most common myths and the facts behind them.
Myth: “Moss is just cosmetic and does not hurt anything.”
Fact:Moss is structurally damaging. Its rhizoids (root structures) physically lift shingle tabs, creating entry points for water. A thick moss layer acts as a sponge, keeping your roof surface wet around the clock even in dry weather. This constant moisture exposure degrades the asphalt base layer, loosens granules, and can rot the plywood decking underneath. Left untreated for 5+ years, moss can shorten a roof's lifespan by a third.
Myth: “Pressure washing is the fastest, most effective way to clean a roof.”
Fact: Pressure washing is the single worst thing you can do to an asphalt shingle roof. High-pressure water (typically 1,500-3,000 PSI from consumer pressure washers) strips the protective granule layer from shingles in seconds, leaving the asphalt substrate exposed to UV radiation. This causes more damage than years of moss growth. It also voids virtually every manufacturer warranty. Always use low-pressure soft washing (under 100 PSI at the nozzle) with appropriate chemical solutions.
Myth: “I can scrape moss off with a shovel or stiff brush.”
Fact: Aggressive mechanical removal tears shingle tabs, breaks the adhesive seal strip between courses, and removes granules along with the moss. If you must physically remove thick moss clumps, use a soft-bristle push broom and always brush downslope (in the direction shingles overlap) to avoid prying up edges. Apply a chemical treatment first to loosen the moss, wait 15-20 minutes, then gently sweep. Never scrape upward against the shingle grain.
Myth: “Moss on my roof means I need a new roof immediately.”
Fact: The presence of moss alone does not mean replacement is necessary. Many roofs with surface-level moss have years of functional life remaining once the moss is properly removed and prevention measures are put in place. The key factors that determine whether cleaning or replacement is the right choice are the condition of the shingles under the moss, the age of the roof, and whether the roof deck shows signs of water damage. A professional inspection after cleaning gives you the most accurate assessment. See our signs you need a new roof guide for the full checklist.
Moss & Algae Roof Removal: Frequently Asked Questions
Frequently Asked Questions
Everything you need to know about getting your roof replaced with RoofVista
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