Do I need to replace the underlayment during a re-roof?

Is New Underlayment Really Necessary for a Re-Roof?

Here’s the Straight Answer

When planning a re-roof, many homeowners ask us:
“Do I need to replace the underlayment, too?”

At L&L Roofing & Construction, our answer is simple:
Yes. Always.
Replacing the underlayment isn’t optional—it’s essential to protecting your home, your investment, and your roof’s future.

Here’s why.

FAQ: Do I need to replace the underlayment during a re-roof?

🧱 What Is Underlayment—and Why Does It Matter?

Underlayment is the layer that sits between your shingles and your wood roof deck. It acts as a second line of defense against:

• Wind-driven rain

• Leaks caused by damaged shingles

• Ice damming (yes, it happens even in parts of North Georgia)

• Moisture and condensation from attic heat

There are two common types:

• Felt paper (15-lb or 30-lb)

• Synthetic underlayment (what we use at L&L Roofing)

🚫 Why Reusing Old Underlayment Is a Bad Idea

Here’s the hard truth: If you don’t replace the underlayment, your new shingles are being laid over an aged, possibly compromised moisture barrier.

That can lead to:

• Leaks from hidden nail holes or tears

• Trapped moisture that causes rot

• Voided manufacturer warranties

• Shortened roof lifespan

We’ve seen it firsthand—shiny new shingles failing early because the layer underneath was too far gone.

✅ What We Do at L&L Roofing

When we do a re-roof, we remove everything down to the decking. Then we:

1. Inspect the roof deck for rot or softness

2. Replace any damaged plywood or OSB

3. Install high-performance synthetic underlayment

4. Follow with starter strips, shingles, and flashing

That’s the only way to make sure your new roof is fully protected from the inside out.

FAQs: Replacing Underlayment During a Shingle Re-Roof

Q: Can I skip the underlayment to save money?
A: We won’t recommend it. It’s a small part of the total cost, but it protects against thousands in future damage.

Q: What kind of underlayment do you use?
A: We use synthetic underlayment—it’s stronger, resists moisture better than felt, and provides better traction for installers.

Q: Will replacing the underlayment take longer?
A: Not significantly. It’s part of the normal re-roofing process and typically adds no extra time to your install.

Q: Does my warranty require new underlayment?
A: Yes. Most manufacturers (like Owens Corning and Malarkey) require it for full warranty coverage.

Do It Once, Do It Right

At L&L Roofing, we don’t believe in shortcuts—just solid craftsmanship that protects your home for the long haul.

Replacing the underlayment is one of the most important steps in the entire re-roof process. When we say we’re going to do it right, we mean it—even for the parts you’ll never see.

📞 Ready to re-roof your home with honesty and integrity?
Call L&L Roofing & Construction at (770) 874-0372 or book your free inspection at www.llroofs.com