Synthetic Underlayment for Shingle Roofing: A Better Barrier for Your Home

At L&L Roofing & Construction, we believe in doing the right thing—even when no one is watching. And when it comes to protecting your home, synthetic underlayment is a right step forward.

If you're getting a new shingle roof in Gainesville, GA, or surrounding areas like Buford, Dawsonville, or Flowery Branch, here's why we recommend synthetic underlayment over traditional felt.

What Is Underlayment?

Underlayment is the moisture barrier that sits between your roof deck (wood sheathing) and your shingles. It acts as your roof's second line of defense against wind-driven rain, ice dams, and leaks.

There are two main types:

• Felt (aka tar paper) – an older, asphalt-saturated paper.

• Synthetic underlayment – made from durable plastics like polypropylene or polyethylene.

Why Synthetic Underlayment Wins

1. Stronger and Longer-Lasting

Synthetic products are tougher and more tear-resistant than felt. That means better protection during installation—and in Gainesville’s summer storms.

2. Lightweight and Safer to Work On

Synthetic rolls are lighter, easier to carry up a ladder, and less likely to wrinkle or buckle. They also provide better traction for roofers, making installs safer and cleaner.

3. Better Moisture Resistance

Unlike felt, synthetic underlayment doesn’t absorb water. It repels it. So even if your shingles take a few days to install, the underlayment won’t break down or mold underneath.

4. UV Resistance

Some synthetic brands hold up to 90 days of sun exposure without degrading. That gives peace of mind if a project gets delayed—especially after a big hailstorm.

5. Code Compliance & Warranty Friendly

Many leading shingle manufacturers require synthetic underlayment to honor their full product warranties. It also meets or exceeds Georgia Residential Building Code requirements.

When We Recommend Synthetic Underlayment

We install synthetic underlayment on every shingle roof replacement—especially when:

• You’re filing a roof insurance claim after storm or hail damage.

• Your home has low-slope areas prone to water backup.

• You want longer-lasting weather protection without revisiting your roof anytime soon.

Real-World Experience: What Homeowners Say

“Luke and his crew found rotted wood under my shingles—something the adjuster missed. They replaced the decking, laid down synthetic underlayment, and gave me a leak-free roof. Couldn’t be happier.”
— Kim Opager, Gainesville, GA

FAQs About Synthetic Underlayment

Is synthetic underlayment required by code in Georgia?
While not always required, many building inspectors and shingle manufacturers strongly prefer it. It often aligns with best practices and helps pass final inspections.

How long does synthetic underlayment last?
It can protect your roof deck for weeks or even months before shingles go on. Once covered, it plays a quiet but critical role for 20+ years.

Can I still use felt to save money?
Felt is cheaper upfront, but synthetic is more cost-effective long-term. It better protects your decking and reduces the risk of repairs.

Does synthetic underlayment need a slip sheet under metal panels?
Yes—when used under metal, some synthetics may require a slip sheet to prevent sticking and tearing from thermal movement.

Honest Roofing Advice. No Shortcuts.

We’ve seen roofs fail early because the wrong materials were used—or installed in a rush. That’s not how we do things.

L&L Roofing & Construction is here to protect your home with:

• Faith-driven service

• Certified shingle installation

• Quality materials like synthetic underlayment

• Straightforward, trustworthy guidance

Let’s get your roof done right.

📞 Call us at (770) 874-0372 to schedule a free inspection or request an estimate.