Best Roof Underlayment for Asphalt Shingles

Beneath your asphalt shingle roof lies a critical layer: the underlayment. This unsung hero provides waterproofing, protects against Arizona’s monsoon rains, and supports shingles during hail or high winds. Choosing the best roof underlayment for asphalt shingles is essential for a durable, leak-free roof in Phoenix’s extreme climate. In-Ex Designs Roofing has been installing top-tier underlayments for homes in Phoenix, Scottsdale, Maricopa, and the White Mountains for over 25 years. Whether you’re in Mesa facing heavy storms or Peoria enduring blistering heat, this guide covers the top underlayment options to safeguard your home. Call (602) 938-7575 for a free inspection today!

Why Underlayment Matters in Arizona

Underlayment acts as a secondary barrier against water infiltration, wind-driven rain, and hail, which are common in Arizona, per the National Oceanic and Atmospheric Administration. It supports asphalt shingles by providing a stable, waterproof base, preventing leaks that could damage your home’s interior in Chandler or Surprise. A quality underlayment also enhances shingle adhesion and extends roof life, reducing the likelihood of costly repairs or replacements.

Top Underlayments for Asphalt Shingles

Synthetic Underlayments

• Brands: GAF Deck-Armor, Owens Corning WeatherLock.
• Pros: Lightweight, tear-resistant, withstands Phoenix’s heat and monsoon winds up to 120 mph.
• Cons: Higher cost than traditional felt underlayments.
• Best For: Most asphalt shingle roofs in Scottsdale or Gilbert seeking long-term durability.

Synthetic underlayments are engineered for superior strength and waterproofing, making them ideal for Arizona’s extreme weather. They’re breathable, preventing moisture buildup under shingles.

Self-Adhered Underlayments

• Brands: GAF StormGuard, Tamko TW Metal and Tile.
• Pros: Exceptional waterproofing, sticks directly to the roof deck, perfect for low-slope roofs in Mesa or Maricopa.
• Cons: More expensive and requires skilled installation to avoid wrinkles.
• Best For: Monsoon-heavy areas like Casa Grande or low-slope roofs prone to pooling water.

Self-adhered underlayments create a seamless, watertight seal, ideal for protecting against Arizona’s heavy rains and wind-driven water.

Felt Underlayments

• Pros: Affordable, traditional option, easy to install, suits budget-conscious homeowners in Ahwatukee or Tempe.
• Cons: Less durable in extreme heat or prolonged UV exposure, prone to tearing in high winds.
• Best For: Newer roofs in milder climates with minimal storm risk.

Felt underlayments (e.g., #15 or #30 felt) are a cost-effective choice but require careful installation to avoid damage in Phoenix’s climate.

For shingle options that pair with underlayments, see our guide: Best Shingles for Roof.

Choosing the Right Underlayment

Selecting the best roof underlayment for asphalt shingles depends on your roof’s design and Arizona’s weather challenges:

• Shingle Type: Synthetic underlayments suit most asphalt shingles for their durability; self-adhered is best for low-slope roofs needing extra waterproofing.
• Roof Slope: Low-slope roofs in Mesa benefit from self-adhered underlayments; steeper roofs in Scottsdale can use synthetic or felt.
• Climate: Maricopa’s monsoons demand self-adhered for water resistance; Peoria’s heat favors synthetic for UV durability, per the National Roofing Contractors Association.
• Sealants: Underlayments work with sealants to create a leak-proof system.
• Budget: Felt is cheapest, but synthetic offers better long-term value. In-Ex Designs provides financing, like 12 months same-as-cash, to make premium options affordable.

How In-Ex Designs Installs Underlayments

Our expert process ensures your underlayment performs:

• Inspection: We assess roof deck condition and shingle compatibility.
• Preparation: We repair deck damage and clean the surface.
• Installation: We roll out underlayment, overlap seams, and secure with fasteners or adhesive, ensuring a tight seal.
• Quality Check: We verify alignment and waterproofing before shingle installation.

A Mesa customer said, “In-Ex Designs’ synthetic underlayment saved my home during last year’s monsoons—no leaks, even with heavy rain!”

Benefits of Quality Underlayments

• Waterproofing: Prevents leaks during Arizona’s storms, protecting interiors in Glendale.
• Durability: Synthetic underlayments resist tearing, extending roof life in Show Low.
• Insurance Support: Strong underlayments reduce damage, supporting claims for storm-related repairs.
• Energy Efficiency: By preventing moisture buildup, underlayments maintain insulation performance in Phoenix.

FAQs About Roof Underlayment for Asphalt Shingles

How long does underlayment last in Arizona?

Synthetic and self-adhered underlayments last 20–30 years, felt 10–15 years, depending on exposure.

Is synthetic underlayment worth the cost?

Yes, its durability and waterproofing make it ideal for Arizona’s climate, per NRCA.

Can underlayment prevent storm damage?

It reduces water infiltration during monsoons, protecting your Phoenix home.

Should I replace underlayment with shingles?

Yes, new underlayment ensures a watertight system, per In-Ex Designs’ standards.

Does underlayment affect insurance claims?

Quality underlayments can minimize damage, strengthening claims.

Don’t let Arizona’s weather compromise your asphalt shingle roof. In-Ex Designs Roofing offers expert underlayment installation, premium products, and financing to protect your home in Phoenix, Scottsdale, or beyond. Ready for a durable, leak-free roof? Call (602) 938-7575 or visit inexroofing.com for a free inspection and quote today!