Installing a metal roof over existing shingles is a practical way to upgrade your home’s protection without a full tear-off, but it introduces unique challenges. Moisture control, durability, and ease of installation become critical, as the right underlayment acts as a vital barrier against leaks and weather damage.
This guide reviews the best underlayment options for metal roofs over shingles, focusing on waterproofing, installation flexibility, and compatibility. Whether you’re a homeowner tackling a DIY project or a contractor seeking reliable materials, you’ll find clear comparisons and practical advice to help you make a confident choice.
Our Top 9 Best Underlayment For Metal Roof Over Shingles Picks
Whether you’re buying your first Underlayment For Metal Roof Over Shingles or replacing an old one, we compared trusted options to help you make an informed choice.
1. SIPA 100 GSM Synthetic Waterproof Roof Underlayment
When installing a metal roof over shingles, preventing water intrusion and ensuring long-term protection is essential. This synthetic underlayment provides a robust waterproof barrier, making it a reliable choice for both new installations and repairs.
SIPA’s 100 GSM underlayment stands out for its broad compatibility and resilience, suitable for both commercial and residential rooftops. It’s ideal for homeowners and contractors who need flexibility in scheduling, thanks to its strong UV resistance and wide application range.
- Waterproof synthetic membrane: Shields roof decking from moisture before and during metal roof installation.
- UV resistance up to 60 days: Allows for flexible installation timelines without compromising protection.
- Meets ASTM standards: Ensures compliance with industry benchmarks for safety and durability.
Compared to traditional felt, SIPA’s synthetic design prioritizes weather resistance and ease of handling. While it offers excellent coverage and adaptability, it does require proper fastening tools for secure installation.
- Strong water resistance
- Long UV exposure window
- Compatible with metal and shingle roofs
- Covers large areas efficiently
- Meets key ASTM standards
- Requires specific fasteners
- No stated fire rating
2. Tyvek Protec 200 Roof Underlayment 4' x 250'
Roofing projects often face delays, making prolonged weather protection a real concern. This underlayment offers up to six months of exposure, giving installers peace of mind during unpredictable schedules.
Tyvek Protec 200 is designed for those who value both durability and code compliance. Its Class A fire rating and long warranty make it a dependable choice for residential and light commercial projects where extended exposure may occur.
- Six months weather protection: Maintains integrity even with project delays.
- Class A fire rating: Meets high safety standards for roofing materials.
- 50-year limited warranty: Provides long-term assurance for buyers.
Unlike basic synthetics, Tyvek Protec 200 prioritizes exposure resistance and safety certifications. The tradeoff is a slightly heavier roll, which may require more effort during handling.
- Long exposure tolerance
- Fire-rated for safety
- Comprehensive warranty
- Approved for code compliance
- Large coverage per roll
- Heavier roll weight
- Higher initial cost
3. Garden Armor ArmorLay 25 Synthetic Roof Underlayment
Slippery surfaces can be a hazard when working on metal roofs, especially over existing shingles. This underlayment addresses that issue with a slip-resistant bottom and textured fabric, making it safer for installers on steep slopes.
ArmorLay 25 is a practical pick for both professionals and DIYers who need extra traction during installation. It’s also water-resistant and resists warping, providing reliable performance in various weather conditions.
- Slip-resistant polymer backing: Enhances safety on steep or wet surfaces.
- 60-day UV exposure: Offers flexibility for project timelines.
- ASTM D4869 and D226 compliant: Meets recognized performance standards.
Compared to felt or smoother synthetics, ArmorLay 25 prioritizes installer safety and walkability. The main compromise is that it may not offer the same fire rating as some premium options.
- Excellent walkability
- Water-resistant design
- Resists buckling and warping
- Good UV exposure window
- Meets ASTM standards
- No fire rating listed
- Limited to 60-day UV exposure
4. INTERWRAP Roof Underlayment 48in x 250ft
For those seeking straightforward, broad coverage under metal roofing, this underlayment provides a no-frills solution. It’s designed to cover large areas efficiently, making it suitable for bigger residential or commercial projects.
INTERWRAP’s UDL25 is best for users who prioritize ease of installation and need to cover significant roof space quickly. It’s a practical choice for contractors and property owners looking for reliable, uncomplicated protection.
- Large 48-inch width: Reduces seams and speeds up installation.
- 250-foot roll length: Covers up to 1,000 square feet per roll.
- Simple synthetic construction: Focuses on basic waterproofing and coverage.
Compared to feature-rich alternatives, this product prioritizes simplicity and area coverage. However, it lacks detailed exposure or fire resistance information, so it may not suit projects with specific code requirements.
- Covers large areas fast
- Easy to handle rolls
- Straightforward installation
- Suitable for big projects
- No detailed specs listed
- No fire or UV rating provided
5. Tyvek Protec 160 Roof Underlayment 4' x 250'
Not all roofing jobs require heavy-duty underlayment. For lighter projects or where ease of handling is key, this synthetic option delivers reliable protection without added bulk.
Tyvek Protec 160 is ideal for homeowners and contractors looking for a balance between performance and manageability. Its lighter weight makes it easier to transport and install, especially on smaller roofs.
- Lightweight synthetic design: Eases handling and reduces fatigue during installation.
- Standard 4' x 250' roll: Provides ample coverage for most residential roofs.
- Tyvek brand reliability: Trusted for consistent quality in roofing materials.
Compared to thicker or more feature-rich underlayments, this product prioritizes simplicity and ease of use. The tradeoff is fewer advanced features or certifications.
- Easy to carry and install
- Covers standard roof sizes
- Trusted brand
- Good for DIY projects
- Limited advanced features
- No detailed exposure specs
6. INTERWRAP Roof Underlayment Pro-Grade UDL30
Professional-grade projects demand materials that can withstand demanding conditions. This underlayment is engineered for durability, making it a solid choice for contractors and those seeking long-lasting performance.
INTERWRAP Pro-Grade UDL30 is best for users who want a more robust underlayment for metal roofs over shingles, especially in areas with challenging weather. It’s designed to deliver consistent protection over time.
- Pro-grade synthetic material: Built for enhanced durability and longevity.
- Wide 48-inch roll: Reduces seams for a cleaner installation.
- Suitable for demanding projects: Intended for professional use and tough environments.
Compared to lighter-duty options, this product prioritizes strength and durability. However, it may be more than what’s needed for smaller or simpler jobs.
- Professional-grade construction
- Long-lasting material
- Wide roll for fewer seams
- Good for harsh climates
- Potentially overbuilt for small jobs
- No detailed exposure or fire specs
7. Gueevin Peel and Self Stick Roofing Membrane
Targeted repairs and quick fixes are sometimes all that’s needed, especially for leaks or vulnerable seams. This peel-and-stick membrane is designed for easy application, making it a go-to for DIYers and emergency repairs.
Gueevin’s butyl rubber membrane is flexible and solvent-free, adapting to thermal expansion and contraction. It’s best for homeowners or maintenance teams needing a simple, effective solution for sealing leaks on metal roofs and other surfaces.
- Peel-and-stick installation: No special tools required for quick application.
- Flexible butyl rubber: Adapts to movement and surface changes for lasting adhesion.
- Covers up to 96 sq ft per roll: Suitable for patching seams, flashing, and leak-prone areas.
Compared to full-roll underlayments, this product prioritizes ease of use and targeted repairs. The tradeoff is limited coverage, making it less suitable for full-roof applications.
- Simple DIY application
- Strong adhesion
- Flexible material
- Good for small repairs
- No toxic fumes
- Limited coverage per roll
- Not for full-roof use
8. JevLoN Asphalt Roof Shingles Repair Tape
Persistent leaks and cracks can undermine a metal roof’s effectiveness, especially over aging shingles. This repair tape provides a long-lasting, weather-resistant seal for problem areas.
JevLoN’s self-adhesive tape is made from polymer-modified asphalt and thickened aluminum foil, offering strong adhesion and heat insulation. It’s ideal for those needing a versatile, cut-to-size solution for sealing leaks, flashing, or joints.
- Self-adhesive asphalt and foil: Fills cracks and gaps for a durable, watertight seal.
- Weather and fire resistant: Suitable for varied climates and conditions.
- Easy to cut and install: Customizable for different repair needs.
Compared to liquid sealants or standard tapes, this product prioritizes longevity and versatility. The main limitation is that it’s best suited for repairs rather than full underlayment coverage.
- Long-lasting seal
- Heat and weather resistant
- Customizable sizing
- Multi-surface compatibility
- No heating device needed
- Not for full-roof use
- Requires clean surface for adhesion
9. ZIP System Peel and Stick Underlayment
Areas prone to ice dams or wind-driven rain require extra protection at vulnerable points. This peel-and-stick underlayment is engineered to seal around nails and protect eaves, valleys, or entire roofs from water intrusion.
ZIP System’s rubberized asphalt membrane is best for users needing a high-performance barrier in critical roof zones. Its slip-resistant surface aids installation, and it meets code requirements for ice barriers.
- Self-adhered rubberized asphalt: Seals tightly around fasteners to prevent leaks.
- Slip-resistant surface: Improves safety and ease of application.
- High temperature tolerance: Withstands up to 260°F for demanding environments.
Compared to standard underlayments, this product prioritizes targeted leak protection and code compliance. The tradeoff is that it’s typically used in specific areas rather than as a full-roof solution.
- Excellent for vulnerable areas
- Strong nail-sealing ability
- High temperature resistance
- Meets code for ice barriers
- Not intended for full coverage
- Requires careful surface prep
Buying Guide: How to Choose the Best Underlayment for Metal Roof Over Shingles
Choosing the right underlayment for a metal roof over shingles is a technical decision that impacts your roof’s longevity and performance. Buyers must weigh waterproofing, exposure tolerance, installation method, and compatibility with both metal and shingle substrates. Many assume all underlayments are similar, but differences in material, application, and coverage can significantly affect results.
- Synthetic rolls vs. peel-and-stick membranes: Synthetic rolls offer broad coverage and are ideal for full-roof applications, while peel-and-stick membranes and tapes are best for targeted repairs or vulnerable areas.
- Waterproofing and UV resistance: Not all products provide the same level of moisture protection or resistance to sunlight during installation delays.
- Fire and code ratings: Some underlayments meet strict fire or code requirements, which may be necessary in certain regions or for insurance purposes.
- Ease of installation: Lightweight or slip-resistant options can make installation safer and faster, especially on steep slopes or for DIY users.
- Coverage area: Full rolls are suited for large projects, while tapes and membranes are intended for patching or sealing specific problem spots.
- Common misunderstanding: Many buyers overlook the importance of matching underlayment type to both the roof design and local climate conditions.
Choosing Between Full-Roll Underlayments and Repair Tapes
The main decision is whether you need a full underlayment for the entire roof or a product for targeted repairs. Full-roll synthetics are best for new installations or re-roofing, while tapes and membranes excel at sealing leaks, seams, or flashing.
- Full rolls: Provide consistent moisture and weather protection across the entire roof.
- Repair tapes/membranes: Offer quick, effective fixes for leaks or vulnerable areas without the need for full-roof coverage.
Understanding Exposure and UV Resistance
Installation delays or phased projects may expose underlayment to sunlight for extended periods. Products with higher UV resistance can withstand these conditions without degrading, giving you more flexibility in scheduling.
- 60 days or more UV resistance: Ideal for projects where weather or logistics may delay final roof installation.
- Shorter exposure ratings: Require faster completion to avoid material breakdown.
Fire Ratings and Code Compliance
Some regions or insurance policies require underlayments with specific fire or code ratings. Products like Tyvek Protec 200 offer Class A fire ratings and code approvals, which can be essential for compliance and peace of mind.
- Check local requirements: Ensure your chosen underlayment meets any necessary codes or fire safety standards.
Installation and Handling Considerations
Ease of installation varies by product. Lightweight synthetics are easier to handle, while slip-resistant surfaces improve safety, especially on steep roofs. Peel-and-stick membranes simplify repairs but may require careful surface preparation.
- Lightweight rolls: Easier for one person to carry and install.
- Slip-resistant backing: Reduces risk of slips during installation.
- Peel-and-stick: Great for quick fixes but less suited for full-roof coverage.
Final Buying Advice
Selecting the right underlayment depends on your project’s size, local climate, and specific needs. Avoid overbuying heavy-duty materials for small repairs, or underbuying patch products for full-roof jobs.
- Match product type to project scope—use full rolls for new roofs, tapes for repairs.
- Consider climate and exposure—choose higher UV or fire ratings if needed.
- Prioritize safety and ease of use—especially for DIY or steep slope installations.
- Check code and warranty requirements—some projects require specific certifications.
- Don’t overlook surface prep—proper installation ensures long-term performance.
FAQ For Underlayment For Metal Roof Over Shingles
1. Do I need to remove old shingles before installing metal roof underlayment?
2. What is the difference between synthetic and peel-and-stick underlayment?
3. How important is UV resistance for underlayment?
4. Can I use repair tape as a full underlayment?
5. What tools are needed to install synthetic underlayment?
6. Are all underlayments fire-rated?
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