What Is Felt Paper in Roofing? A Deep Dive Into Its Importance, Benefits & Installation

When it comes to roofing materials, most homeowners focus on the outermost layer — shingles, tiles, or metal panels. But beneath the surface lies an unsung hero that plays a critical role in protecting your home: felt paper.

Also known as roofing underlayment, felt paper is a key component of your roofing system, yet many homeowners are unaware of its existence or purpose. In this comprehensive guide, we’ll walk you through everything you need to know about felt paper — what it is, why it matters, how it compares to synthetic alternatives, and what to expect during installation.

If you’re planning a roof replacement or repair, or simply want to be an informed homeowner, keep reading.

What Is Felt Paper in Roofing?

Felt paper is a type of underlayment that is installed directly on your roof deck, beneath the shingles. It’s made from natural or synthetic materials that are saturated with asphalt to provide water resistance and durability.

Roofing felt is commonly referred to as:

Roofing tar paper
Felt underlayment
Asphalt-saturated felt
15 lb or 30 lb felt

Felt paper comes in rolls and is applied in overlapping layers before the top roofing material is installed.

Why Is Felt Paper Important?

Felt paper provides a crucial secondary layer of protection for your home. Here’s why it’s indispensable:

1. Water Barrier

Shingles are your first line of defense, but they’re not waterproof. Felt paper offers a secondary moisture barrier to help prevent leaks caused by wind-driven rain or ice dams.

2. Protects During Construction

Before shingles are installed, the felt paper protects the roof deck from rain or snow, especially if your roof replacement spans multiple days.

3. Improves Fire Resistance

Felt underlayment contributes to a Class A fire rating when used with certain roofing systems.

4. Adds Durability

It adds an extra layer of resilience against environmental wear and tear, such as heavy storms, wind uplift, or debris.

5. Smooth Surface for Shingles

It creates a smooth, even surface for shingles to adhere to, reducing the risk of unevenness or bumps.

Types of Roofing Felt Paper

There are two main types of felt paper commonly used in residential roofing:

🧰 15-Pound Felt (15 lb)

Lightweight and easier to handle
Less durable than 30 lb
Typically used in residential roofing under asphalt shingles
More affordable

🧰 30-Pound Felt (30 lb)

Thicker, heavier, and more tear-resistant
Provides better durability and water resistance
Ideal for high-pitched roofs or areas with severe weather

Felt Paper vs. Synthetic Underlayment

In recent years, synthetic roofing underlayment has gained popularity. So how does felt stack up against its modern counterpart?

Feature	Felt Paper	Synthetic Underlayment
Cost	Less expensive	More expensive
Weight	Heavier	Lightweight
Durability	Moderate	High
Water Resistance	Good	Excellent
UV Resistance	Limited	Excellent
Walkability	Slippery when wet	Usually textured for grip

While synthetic underlayment is gaining traction, many roofing contractors still trust traditional felt for its affordability and proven performance — especially in Ohio, Texas, and North Carolina, where weather conditions vary.

Roofing Systems That Use Felt Paper

Felt paper is compatible with most residential roofing systems, including:

Asphalt shingles
Wood shakes
Clay or concrete tiles
Metal roofs (with special layering)

At S&K Construction And Remodeling LLC, we evaluate each roof’s slope, size, and location to determine the best underlayment type for your needs.

How Felt Paper Is Installed

Here’s a breakdown of the felt paper installation process:

1. Roof Deck Inspection

We inspect and repair any rotted or damaged plywood decking to ensure a solid base.

2. Drip Edge Installation

Metal drip edge is installed at the eaves to direct water off the roof and prevent rot.

3. Rolling Out the Felt Paper

Felt paper is unrolled in horizontal rows starting from the eaves upward, overlapping each layer by at least 2 inches.

4. Fastening

Roofing nails or staples secure the felt to the deck, with care taken to avoid creating tears or punctures.

5. Flashing & Valleys

Flashing and waterproof barriers are applied to valleys, chimneys, vents, and other vulnerable areas.

6. Shingle Installation

Once the felt paper is in place, the shingles are installed over it.

Signs Your Underlayment May Be Failing

Since felt paper is under your shingles, damage isn’t always easy to spot. However, there are symptoms you can look for:

Persistent roof leaks
Mildew or mold in the attic
Ceiling water stains
Curling shingles or frequent blow-offs
Bubbling or soft spots on your roof deck

If you see any of these signs, call a professional roofer for a free inspection.

Is Felt Paper Required by Code?

Yes. Most building codes, including those in Ohio, Texas, and North Carolina, require a roofing underlayment like felt paper or synthetic to meet fire safety and weatherproofing regulations. Insurance companies may also require it to validate claims.

Roof Felt Paper FAQs

❓ How long does roofing felt last?

Standard felt underlayment lasts 15-20 years under shingles, but exposure to direct sunlight can degrade it quickly if left uncovered.

❓ Can I install new felt over old felt?

It’s not recommended. Old felt may trap moisture and compromise the integrity of the new roofing system. A full tear-off is best.

❓ Is felt paper waterproof?

It is water-resistant, not fully waterproof. It provides temporary moisture protection but should be covered by shingles or tiles.

Why Homeowners Trust S&K Construction And Remodeling LLC

When it comes to roofing underlayment and repairs, S&K Construction And Remodeling LLC is your local expert in Ohio, North Carolina, and Texas. Here’s why clients choose us:

✅ Owens Corning Preferred Contractor
✅ Top-rated on Google & Facebook
✅ Affordable financing plans
✅ Lifetime product warranties
✅ Quick emergency service

Whether you’re in Youngstown, Charlotte, Temple, or nearby areas, we’ve got your roofing needs covered.

Real Customer Review

“We had a roof leak during a storm, and S&K Construction handled everything — from tear-off to felt paper and shingle replacement. Super professional and fast!”
— Tom R., Temple TX

Financing Options Available

Roofing underlayment problems can’t wait, and we understand not everyone is ready for a big expense. That’s why we offer easy financing, including:

Low monthly payments
0% interest for qualified buyers
No down payment
Quick approvals

Apply in minutes and protect your home today.

Service Areas

We proudly install and repair felt paper and full roofing systems in:

🏠 Texas

Temple
Belton
Killeen
Waco
Harker Heights

Request a Free Roofing Inspection Today

Don’t wait until a small roofing issue becomes a major disaster. Whether you’re due for a full replacement or suspect your underlayment may be compromised, we’re here to help.

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If you’re considering a roof replacement, roof repair, or just want to understand your roofing system better, don’t hesitate to contact our friendly team. Your roof deserves quality from the ground up — and it starts with the right underlayment.

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Felt Paper in Roofing