Synthetic Roof Underlayment for Coastal Myrtle Beach Homes: Complete 2025 Guide
Shocking Industry Truth
If you're replacing or repairing a roof in coastal Myrtle Beach, there's one critical component beneath your shingles that determines whether your home survives the next Category 3 hurricane or suffers catastrophic water damage: roof underlayment. And while most contractors will recommend synthetic underlayment over traditional felt paper, not all synthetic products are created equal—especially in our harsh coastal environment.
Here's what's at stake: 65% of roofing contractors now choose synthetic underlayment for its superior strength (600% stronger than felt), better waterproofing, and longer UV exposure tolerance. But with 5+ major brands, varying wind ratings, and price differences of 40-60%, how do you know which synthetic underlayment is right for your coastal Myrtle Beach home?
This comprehensive guide cuts through the marketing hype to deliver honest, data-driven insights on synthetic roof underlayment for coastal homes. We'll compare top brands (GAF, Owens Corning, Sharkskin, Tyvek, Epilay), break down real costs for Myrtle Beach installations, explain hurricane wind ratings and South Carolina building codes, identify common problems and how to avoid them, and show you why choosing the right underlayment can save you $5,000-15,000 in premature roof replacement. As Myrtle Beach's only 5.0★ rated roofing contractor with 73 verified reviews, we're committed to educating homeowners so they can make informed decisions—whether they work with us or another qualified contractor.
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What Is Synthetic Roof Underlayment?
Roof underlayment is a water-resistant barrier installed directly on your roof deck (the plywood or OSB sheathing) before shingles, tiles, or metal roofing go on top. Think of it as your roof's "second line of defense" against water intrusion—if shingles blow off during a storm or develop leaks, the underlayment prevents rain from penetrating into your attic and damaging insulation, drywall, and structure.
Traditional Felt vs Synthetic: The Evolution
For over 100 years, roofing contractors used asphalt-saturated felt paper (often called "tar paper") as underlayment. Available in #15 felt (lighter) and #30 felt (heavier), felt paper served its purpose—but it has significant limitations, especially in coastal environments:
⚠️ Problems with Felt Underlayment in Coastal Myrtle Beach:
- Absorbs Water: Felt soaks up moisture like a sponge, causing it to wrinkle and lose protective quality
- Tears Easily: Felt rips during high winds and installation, creating water entry points
- Limited UV Exposure: Can only be exposed for a few days before breaking down (problem during hurricane season delays)
- Degrades in Heat: Coastal summer heat causes felt to "cook," leaching oils and becoming brittle
- Heavy & Cumbersome: Requires 14 rolls of #30 felt to cover a typical 2,700 sq ft home
Synthetic underlayment, developed in the 1990s and perfected over the last 15 years, is made from woven or spun polyethylene or polypropylene (plastic) polymers with a rubberized or fiberglass backing. Modern synthetic products address all the weaknesses of felt paper while providing superior protection for coastal homes.
How Synthetic Underlayment Works
Synthetic underlayment creates a waterproof barrier using advanced materials technology:
Water Resistance
Unlike felt (which absorbs water), synthetic underlayment repels water through a non-woven polymer structure. Water beads up and runs off instead of soaking in, maintaining the barrier's integrity even during multi-day rain events or if shingles fail.
Tear Strength
Woven polyethylene or polypropylene fibers create a fabric 600% stronger than #30 felt paper. This means synthetic underlayment can withstand foot traffic during installation, resist tearing from tree branches, and hold up under high coastal winds without ripping.
UV Resistance
Special UV inhibitors allow synthetic underlayment to remain exposed for 30-180 days (depending on product) without degrading. This is critical in Myrtle Beach, where hurricane season can delay roofing projects for weeks.
Temperature Stability
Synthetic materials don't "cook" in summer heat or become brittle in winter cold. They maintain flexibility and adhesion across temperature ranges of -40°F to 240°F, ensuring year-round protection.
Synthetic vs Felt Underlayment: Coastal Comparison
While felt underlayment is still allowed by South Carolina Building Code, most Myrtle Beach contractors (65%+) now recommend synthetic for coastal installations. Here's an honest comparison:
| Factor | Synthetic Underlayment | Felt Underlayment (#30) |
|---|---|---|
| Material Cost | $7-10 per sq (100 sq ft) $700-1,000 for 3,000 sq ft home |
$5 per sq $500 for 3,000 sq ft home |
| Tear Strength | 600% stronger than felt Resists ripping during installation & storms |
Tears easily during high winds, installation, tree branch contact |
| Water Resistance | Repels water - water beads and runs off Maintains barrier integrity when wet |
Absorbs water like a sponge Wrinkles when wet, loses protective quality |
| UV Exposure Tolerance | 30-180 days depending on product Critical for hurricane season delays |
Few days to 2 weeks Breaks down quickly in sun |
| Weight/Coverage | 3 rolls cover 2,700 sq ft Lighter, easier to handle |
14 rolls cover 2,700 sq ft Heavy, cumbersome |
| Temperature Stability | Remains flexible -40°F to 240°F No oil leaching in heat |
Leaches oils in high heat Cracks in cold weather |
| Installation Time | Faster (fewer rolls, lighter) Can walk on safely |
Slower (more rolls, heavier) More labor intensive |
| Hurricane/Wind Performance | Excellent - superior fastener retention Resists blow-off in high winds |
Poor - tears easily in high winds Loses adhesion when wet |
| Lifespan Under Shingles | 30-40+ years (matches shingle lifespan) | 15-20 years (may degrade before shingles) |
| Best For | Coastal homes, hurricane zones, long-term value | Budget projects, inland areas, temporary structures |
💡 WeatherShield Recommendation for Coastal Myrtle Beach:
We recommend synthetic underlayment for 95% of coastal installations. The additional $200-500 in material cost is justified by superior hurricane protection, longer lifespan, and peace of mind during storm season.
Felt may be appropriate only for: Budget-conscious projects on outbuildings/sheds, temporary structures with <10 year expected life, or DIY projects where labor cost savings matter more than performance.
Top 5 Synthetic Underlayment Brands for Coastal Homes
Not all synthetic underlayment is created equal. Here are the top 5 brands we recommend for Myrtle Beach coastal homes, ranked by overall performance in our harsh coastal environment:
#1 GAF - FeltBuster & Deck-Armor
Best OverallWhy We Love It: GAF is North America's largest roofing manufacturer, and their synthetic underlayment line represents the gold standard for coastal installations. FeltBuster (standard) and Deck-Armor (premium) both offer exceptional hurricane protection.
Key Specs:
- UV Exposure: Up to 180 days (Deck-Armor)
- Tear Strength: 12x stronger than #30 felt
- Waterproofing: 100% waterproof polypropylene
- Wind Rating: High wind resistance, excellent fastener retention
Coastal Performance:
- ✅ Resists salt air corrosion
- ✅ UV-stable for hurricane season delays
- ✅ Slip-resistant surface for safety
- ✅ Compatible with all GAF shingle systems
Cost: $8-10 per square (100 sq ft) | Best For: Asphalt shingle roofs, high-wind coastal areas, premium protection
#2 Owens Corning - ProArmor & RhinoRoof U20
Best ValueWhy We Love It: Owens Corning offers excellent synthetic underlayment at a competitive price point. RhinoRoof U20 provides 12x the strength of felt, while ProArmor is their lighter, more affordable option.
Key Specs:
- UV Exposure: Up to 6 months
- Tear Strength: 12x stronger than #30 felt
- Waterproofing: Water-resistant synthetic
- Weight: Lightweight for easy handling
Coastal Performance:
- ✅ Long UV exposure tolerance
- ✅ Good wind uplift resistance
- ✅ Thin profile (fits tight spaces)
- ✅ Excellent value for performance
Cost: $7-9 per square | Best For: Budget-conscious homeowners who don't want to sacrifice quality, asphalt shingle installations
#3 Sharkskin - Ultra SA
Best PremiumWhy We Love It: Sharkskin Ultra SA is a peel-and-stick (self-adhering) underlayment that offers maximum protection for extreme weather. While more expensive, it creates a fully sealed waterproof barrier—no fastener penetrations.
Key Specs:
- UV Exposure: Up to 6 months
- Installation: Self-adhering (peel & stick)
- Waterproofing: Fully sealed, no fastener holes
- Tear Strength: Extremely durable
Coastal Performance:
- ✅ Ultimate wind-driven rain protection
- ✅ Seals around nails automatically
- ✅ No blow-off risk (adheres to deck)
- ✅ Perfect for oceanfront homes
Cost: $12-15 per square | Best For: Oceanfront properties, extreme weather areas, metal & tile roofs, maximum protection
#4 Tyvek (DuPont) - CommercialWrap
Best for MetalWhy We Love It: Tyvek is famous for house wrap, and their roof underlayment brings the same breathable, waterproof technology to roofing. Excellent choice for metal roofs where breathability prevents condensation.
Key Specs:
- UV Exposure: Up to 4 months
- Breathability: Allows moisture vapor to escape
- Waterproofing: 100% waterproof, fully breathable
- Tear Strength: Excellent durability
Coastal Performance:
- ✅ Prevents condensation under metal roofs
- ✅ UV-stable for extended exposure
- ✅ Lightweight and easy to install
- ✅ Reduces mold/mildew in humid climates
Cost: $8-11 per square | Best For: Metal roofing, tile roofing, applications where breathability is critical
#5 Epilay - Protectite Line
Best UV RatingWhy We Love It: Epilay offers four different grades of synthetic underlayment, with some products offering up to 1 year of UV resistance—the longest in the industry. Excellent for projects with extended timelines.
Key Specs:
- UV Exposure: Up to 12 months (Protectite Platinum)
- Tear Strength: High-strength polypropylene
- Waterproofing: Superior water resistance
- Options: 4 grades for different budgets
Coastal Performance:
- ✅ Industry-leading UV resistance
- ✅ Perfect for hurricane season delays
- ✅ Multiple grades for any budget
- ✅ Excellent tear resistance
Cost: $7-12 per square (varies by grade) | Best For: Projects with uncertain timelines, hurricane season installations, maximum UV protection
🏆 WeatherShield's Top Pick for Myrtle Beach:
For most coastal Myrtle Beach homes, we recommend GAF Deck-Armor (premium) or Owens Corning RhinoRoof U20 (best value). Both offer excellent hurricane protection, long UV exposure tolerance, and proven performance in our coastal environment. For oceanfront properties or maximum protection, upgrade to Sharkskin Ultra SA self-adhering underlayment.
Hurricane Ratings & Wind Performance Requirements
In coastal Myrtle Beach, your roof underlayment isn't just about keeping water out—it's about surviving Category 2-3 hurricanes with sustained winds of 96-129 MPH and gusts up to 140 MPH. Here's what you need to know about wind ratings and South Carolina building codes:
South Carolina Building Code Requirements
📋 SC Building Code for Roof Underlayment:
South Carolina has adopted the International Residential Code (IRC) with state-specific amendments. For roof underlayment, materials must conform to these ASTM standards:
- ASTM D226: Standard for asphalt-saturated organic felt (traditional felt paper)
- ASTM D4869: Standard for asphalt-saturated inorganic felt
- ASTM D6757: Standard for underlayment used in steep-slope roofing (synthetic underlayment)
- ASTM D1970: Standard for self-adhering polymer-modified bitumen (peel & stick ice/water shield)
All underlayment products must bear a label indicating compliance with the applicable ASTM standard designation.
Wind Uplift Ratings Explained
Wind uplift is the force that tries to "suck" your roof off during high winds. Coastal homes face significantly higher uplift forces than inland properties. Here are the key ratings:
| Rating | Wind Speed Resistance | Recommended For |
|---|---|---|
| UL 580 Class 15 | 60 MPH winds | Inland areas, low wind zones |
| UL 580 Class 30 | 75 MPH winds | Moderate wind zones |
| UL 580 Class 60 | 100 MPH winds | High wind zones, coastal areas 1+ mile inland |
| UL 580 Class 90 | 120 MPH winds | Myrtle Beach coastal homes (MINIMUM) |
| FM 1-90 or FM 1-105 | 135-157 MPH winds | Oceanfront properties, maximum protection |
⚠️ Critical Wind Uplift Factors for Coastal Homes:
- Fastener Type & Spacing: Synthetic underlayment must be fastened with plastic cap nails or staples with proper spacing (6-12" depending on wind zone)
- Roof Slope: Steeper roofs experience higher uplift forces; slope affects fastener requirements
- Roof Edges: Perimeter edges and corners require enhanced fastening (2-3x more fasteners)
- Building Height: Taller structures experience higher wind speeds; homes >35 feet may need upgraded systems
- Distance from Ocean: Homes within 1 mile of the coast face extreme wind uplift; oceanfront properties need maximum ratings
Insurance Requirements & Wind Mitigation
Many coastal homeowners insurance policies require hurricane-rated roofing systems—and proper synthetic underlayment is part of that system. Here's what you should know:
Insurance Benefits
- Premium Discounts: Hurricane-rated underlayment can qualify for 10-20% premium reductions
- Wind Mitigation Credit: Proper documentation of UL 580 Class 90+ systems reduces rates
- Claims Approval: Certified systems improve claim approval rates after storms
- Replacement Requirements: Some policies mandate synthetic over felt for claim payouts
Required Documentation
- Product Labels: Keep labels showing ASTM D6757 compliance
- Wind Rating Certificate: Request UL 580/FM certification from contractor
- Installation Photos: Document proper fastening patterns
- Contractor Affidavit: Written statement of code compliance
Pro Tip: When replacing your roof, ask your contractor to provide a wind mitigation inspection form. Submitting this to your insurance company can save you hundreds per year in premiums—often enough to cover the cost of upgrading to premium synthetic underlayment within 2-3 years.
Installation Best Practices for Coastal Homes
Even the best synthetic underlayment will fail if installed incorrectly. Here's what proper coastal installation looks like (and red flags that indicate shoddy work):
Proper Installation Steps
Step 1: Roof Deck Preparation
- Clean Deck: Remove all debris, old nails, and protruding fasteners
- Repair Damage: Replace any damaged or rotted plywood/OSB sheathing
- Dry Conditions: Install only when deck is completely dry (moisture traps underneath cause mold)
- Drip Edge First: Install metal drip edge before underlayment at eaves
Step 2: Underlayment Application
- Start at Bottom: Begin at eaves and work upward toward ridge (water flows down)
- Proper Overlap: Minimum 6" side lap, 4" end lap (follow manufacturer specs)
- No Stretching: Lay flat without pulling tight—stretching causes tears and wrinkles
- Smooth Application: Eliminate wrinkles and bubbles as you go
Step 3: Fastening for Wind Resistance
- Proper Fasteners: Plastic cap nails or staples with 1" minimum caps
- Coastal Spacing: 6-12" spacing in field, 3-6" at edges/corners (per wind zone)
- Nail Pattern: Stagger fasteners, avoid straight lines (creates tear lines)
- Penetration: Drive flush—not overdriven (tears material) or underdriven (wind uplift risk)
Step 4: Valley & Penetration Details
- Valley Reinforcement: Use ice & water shield or double-layer synthetic in valleys
- Chimney Flashing: Extend underlayment 6-12" up vertical surfaces
- Pipe Boots: Seal around all penetrations with compatible sealant
- Ridge Vents: Proper underlayment termination at ridge for ventilation
Step 5: Ice & Water Shield Application
- Eaves Protection: Install ice & water shield on first 3-6 feet of roof at eaves
- Valleys: Full valley coverage with ice & water shield
- Penetrations: Seal around chimneys, pipes, skylights
- Low-Slope Areas: Any roof slope <4:12 requires enhanced waterproofing
🚨 Red Flags: Signs of Poor Installation
If you see any of these during installation, stop work and address with your contractor:
- ❌ Wrinkles & Bubbles: Indicates improper application or wet deck
- ❌ Stretched Material: Creates weak points that tear in high winds
- ❌ Insufficient Overlap: <6" side lap or <4" end lap creates leak paths
- ❌ Wrong Fasteners: Regular nails (not cap nails) blow through in winds
- ❌ Wide Fastener Spacing: >12" spacing allows wind uplift
- ❌ No Drip Edge: Undermines waterproofing at eaves
- ❌ Exposed Edges: Underlayment edges not secured blow off in winds
Safety Considerations: Slippery When Wet
One of the biggest concerns with synthetic underlayment is that it becomes extremely slippery when wet—a serious safety hazard for roofers working on steep slopes. Here's how reputable contractors mitigate this risk:
⚠️ Safety Protocols for Coastal Installations:
- Weather Monitoring: Delay installation if rain is forecast within 2-3 hours
- Slip-Resistant Products: Some synthetics have textured surfaces for traction (GAF Deck-Armor, RhinoRoof U20)
- Safety Equipment: Roofers must wear proper footwear and use fall protection (harnesses, roof jacks)
- Staged Installation: Complete sections and cover with shingles before moving to next area
- Walkways: Use plywood walkways or roof pads on steep slopes
Homeowner Tip: If you see roofers working on wet synthetic underlayment on a steep roof without safety equipment, that's an OSHA violation and a sign of an unsafe contractor. Ask them to wait until conditions are safe.
Cost Breakdown for Myrtle Beach Homeowners
Let's talk real numbers. Here's what synthetic underlayment costs in the Myrtle Beach market as of 2025:
Material Costs by Brand
| Brand & Product | Price per Square | 2,500 sq ft Home | 3,000 sq ft Home |
|---|---|---|---|
| Felt #30 (baseline) | $5/sq | $400-500 | $500-600 |
| Owens Corning ProArmor | $7/sq | $560-700 | $700-840 |
| GAF FeltBuster | $8/sq | $640-800 | $800-960 |
| Owens Corning RhinoRoof U20 | $9/sq | $720-900 | $900-1,080 |
| GAF Deck-Armor | $10/sq | $800-1,000 | $1,000-1,200 |
| Tyvek CommercialWrap | $10/sq | $800-1,000 | $1,000-1,200 |
| Sharkskin Ultra SA (peel & stick) | $14/sq | $1,120-1,400 | $1,400-1,680 |
*Prices are for materials only. Total project cost includes labor, ice & water shield, drip edge, and other components. Prices as of November 2025 and subject to change.
Total Project Cost (Material + Labor)
In Myrtle Beach, professional installation of synthetic underlayment as part of a complete roof replacement typically costs:
2,500 sq ft Home
- Standard Synthetic: $800-1,200 total
(materials + labor + ice & water shield) - Premium Synthetic: $1,200-1,800 total
- Peel & Stick: $1,800-2,400 total
3,000 sq ft Home
- Standard Synthetic: $1,000-1,500 total
(materials + labor + ice & water shield) - Premium Synthetic: $1,500-2,200 total
- Peel & Stick: $2,200-3,000 total
Cost vs Value: Is Synthetic Worth It?
The $200-1,000 premium for synthetic over felt may seem expensive upfront, but here's the long-term value analysis:
💰 ROI on Synthetic Underlayment:
Scenario: 3,000 sq ft Coastal Home
- • Felt underlayment: $600 (materials + labor)
- • Synthetic underlayment: $1,200 (materials + labor)
- • Upfront Premium: $600
Value Over 20-Year Shingle Lifespan:
- ✅ Hurricane Protection: Synthetic's superior wind resistance prevents $5,000-15,000 in storm damage repairs (1 avoided leak pays for upgrade)
- ✅ Longer Lifespan: Synthetic lasts 30-40 years (vs 15-20 for felt), meaning no mid-life underlayment failure requiring early roof replacement
- ✅ Insurance Savings: Wind mitigation discounts save $100-300/year = $2,000-6,000 over 20 years
- ✅ Resale Value: Hurricane-rated roofing system adds $3,000-8,000 to home value
- ✅ Peace of Mind: No worrying about underlayment failure during hurricane season (priceless)
Total Value: $10,000-29,000 over 20 years
ROI: 17x to 48x return on $600 investment
🏆 WeatherShield's Recommendation:
For coastal Myrtle Beach homes, synthetic underlayment is a no-brainer investment. The $200-1,000 upfront premium is recovered within 2-5 years through insurance savings alone—and the hurricane protection and peace of mind make it one of the best ROI upgrades you can make during a roof replacement.
Our advice: Don't cheap out on underlayment. It's the foundation of your entire roofing system and the most cost-effective way to protect your home from catastrophic water damage.
Common Problems with Synthetic Underlayment & How to Avoid Them
While synthetic underlayment is superior to felt in most ways, it's not perfect. Here are the 5 most common problems homeowners experience—and how to prevent them:
Problem #1: UV Degradation During Extended Exposure
The Issue: Even UV-rated synthetic underlayment breaks down if left exposed too long. In Myrtle Beach, hurricane season can delay roofing projects for weeks—and if your underlayment exceeds its UV rating, the surface layer deteriorates, becoming brittle and losing water resistance.
Signs of UV Degradation:
- Surface becomes chalky or powdery
- Material becomes brittle, cracks when walked on
- Color fades significantly
- Water no longer beads (absorption increases)
How to Avoid:
- ✅ Choose products with longer UV ratings (Epilay Protectite: 12 months, GAF Deck-Armor: 180 days)
- ✅ Schedule installation outside hurricane season (Oct-May)
- ✅ Complete shingling within manufacturer's UV window
- ✅ Cover with tarps if delays exceed UV rating
Problem #2: Moisture Trapping & Condensation
The Issue: Synthetic underlayment is a vapor barrier, which means it can trap moisture if your attic lacks proper ventilation. In humid coastal Myrtle Beach, trapped moisture leads to mold growth, wood rot, and deteriorated insulation.
Signs of Moisture Issues:
- Mold/mildew on attic sheathing
- Water stains on underside of underlayment
- Musty odor in attic
- Insulation appears damp or compressed
How to Avoid:
- ✅ Ensure adequate attic ventilation (1 sq ft per 150 sq ft attic space)
- ✅ Use breathable synthetic (Tyvek) for metal/tile roofs
- ✅ Install ridge vents + soffit vents for airflow
- ✅ Verify insulation doesn't block soffit vents
Problem #3: Improper Installation (Overstretching, Wrong Fasteners)
The Issue: Contractors unfamiliar with synthetic underlayment often make critical mistakes: overstretching the material (causing tears), using wrong fasteners (staples vs plastic cap nails), or improper spacing. These installation errors create weak points that fail during high winds.
Signs of Poor Installation:
- Wrinkles, bubbles, or stretched areas
- Tears near fasteners or seams
- Fasteners >12" apart in field
- Regular nails instead of cap nails
How to Avoid:
- ✅ Hire experienced contractor (ask: "How many synthetic installs?")
- ✅ Verify they follow manufacturer specs
- ✅ Inspect before shingling (check fastener spacing)
- ✅ Require photos of fastening pattern
Problem #4: Slippery Surface Safety Hazards
The Issue: Synthetic underlayment becomes extremely slippery when wet—more so than felt paper. This creates serious fall risks for roofers, especially on steep slopes. OSHA reports that falls are the leading cause of construction deaths, and wet synthetic underlayment is a contributing factor.
Red Flags:
- Roofers working in rain or dew
- No fall protection on steep slopes
- Walking on wet underlayment >6:12 pitch
- No roof jacks or walkways
How to Avoid:
- ✅ Delay work if rain forecast
- ✅ Use slip-resistant products (GAF, RhinoRoof)
- ✅ Require fall protection equipment
- ✅ Install roof jacks on steep slopes
Problem #5: Temperature-Related Cracking or Adhesion Loss
The Issue: Low-quality synthetic underlayment can crack in extreme cold or lose adhesion in extreme heat. While less common with major brands, budget products may use inferior polymers that don't handle temperature swings well.
Signs of Quality Issues:
- Cracking in cold weather
- Adhesive failure on peel & stick products
- Material becomes brittle
- Delamination of layers
How to Avoid:
- ✅ Use major brands (GAF, Owens Corning, Sharkskin)
- ✅ Verify temperature rating (-40°F to 240°F)
- ✅ Avoid off-brand "bargain" products
- ✅ Check manufacturer warranty terms
✅ WeatherShield's Problem Prevention Protocol:
We prevent all 5 common problems through:
- Premium Products Only: We use GAF Deck-Armor (180-day UV) or Owens Corning RhinoRoof (6-month UV) to handle hurricane season delays
- Proper Installation Training: Our crews follow manufacturer specs exactly—proper overlap, correct fasteners, appropriate spacing
- Ventilation Check: We inspect attic ventilation and recommend upgrades if needed to prevent moisture trapping
- Safety First: Strict no-work-in-rain policy, fall protection equipment, and slip-resistant products on steep slopes
- Documentation: Photos of fastening patterns, product labels, and installation process for your records and insurance
How Long Can Synthetic Underlayment Be Exposed?
This is one of the most important questions for coastal Myrtle Beach homeowners: If a hurricane delays my roofing project, will my underlayment survive?
The answer depends on the product—and understanding UV ratings can save you thousands in premature roof failure.
UV Exposure Ratings by Brand
| Product | UV Exposure Rating | Best For |
|---|---|---|
| Felt #30 (baseline) | Few days to 2 weeks | Fast projects, immediate shingling |
| Owens Corning ProArmor | 30 days | Standard projects, short timelines |
| GAF FeltBuster | 30 days | Standard projects, short timelines |
| Tyvek CommercialWrap | 120 days (4 months) | Longer projects, metal/tile roofs |
| GAF Deck-Armor | 180 days (6 months) | Hurricane season installations |
| Owens Corning RhinoRoof U20 | 180 days (6 months) | Hurricane season installations |
| Sharkskin Ultra SA | 180 days (6 months) | Premium protection, extended timelines |
| Epilay Protectite Platinum | 365 days (1 year) | Maximum UV protection |
Hurricane Season Considerations
🌀 Hurricane Season Reality Check:
Atlantic hurricane season runs June 1 - November 30, with peak activity in August-September. If your roof replacement starts in July:
- Best Case: Project completes in 1-2 weeks, underlayment exposed <30 days → 30-day UV rating sufficient
- Typical Case: Hurricane threat causes 2-4 week delay, underlayment exposed 45-60 days → Need 180-day UV rating
- Worst Case: Multiple storms delay project 6-8 weeks, underlayment exposed 60-90 days → Need 180-day minimum, 365-day ideal
WeatherShield Rule: During hurricane season (June-Nov), we only install synthetic underlayment with 180+ day UV ratings. The $100-200 premium for extended UV protection is cheap insurance against underlayment failure during storm delays.
What Happens When UV Exposure is Exceeded?
If synthetic underlayment remains exposed beyond its UV rating, you'll see:
Week 1-2 After UV Limit
- Surface becomes slightly chalky
- Color begins to fade
- Material still functions normally
- Action: Complete shingling ASAP
Week 3-6 After UV Limit
- Surface becomes powdery/brittle
- Cracks appear when walked on
- Water resistance begins to fail
- Action: Cover with tarps or replace underlayment
2+ Months After UV Limit
- Severe degradation, tears easily
- Water soaks through
- No longer protective
- Action: Must replace underlayment before shingling
Within UV Rating
- Material remains flexible
- Water resistance intact
- No degradation or cracking
- Action: Complete project as normal
💡 Pro Tip: Document Exposure Duration
If your roofing project experiences delays, document the timeline:
- 📅 Date underlayment installed
- 📅 Date shingles completed (or project paused)
- 📸 Photos showing underlayment condition
- 📄 Product label showing UV rating
This documentation is critical if you need to file an insurance claim or if the contractor tries to shingle over degraded underlayment (which voids manufacturer warranties and creates leak risks).
The Cost Comparison: Maintenance vs. Neglect
Without Maintenance
- Roof lifespan: 12-15 years
- Insurance claims often denied
- Emergency repairs cost 3x more
- Property value decreases by 5-10%
- Warranty becomes void
- Total 20-year cost: $35,000+
With Regular Maintenance
- Roof lifespan: 25-30+ years
- Insurance claims approved
- Prevent costly emergencies
- Property value protected
- Full warranty coverage maintained
- Total 20-year cost: $8,000-10,000
Don't Wait Until It's Too Late
Every day you delay costs you money. Get your FREE professional roof inspection today and discover exactly what condition your roof is in.
Emergency? Call our 24/7 hotline: (843) 877-5539
Frequently Asked Questions
About the Author
David Karimi
Lead Roofing Specialist & Coastal Systems Expert
David Karimi is WeatherShield Roofing's Lead Roofing Specialist with over 12 years of experience protecting coastal Myrtle Beach homes. As a certified roofing contractor specializing in hurricane-rated systems, David has installed synthetic underlayment on hundreds of coastal properties and understands the unique challenges of salt air, high winds, and intense UV exposure that affect Myrtle Beach roofs.
The Bottom Line: Your Roof, Your Choice
Every day you wait is another day closer to that emergency call no homeowner wants to make. The statistics are clear: 80% of roofs fail prematurely, and 61% of homeowners can't afford the emergency repairs that follow.
What You Get with Weather Shield Roofing:
Don't Wait Until It's Too Late
Join thousands of smart Myrtle Beach homeowners who protect their investment with regular maintenance.
Emergency? Call our 24/7 hotline: (843) 877-5539
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