Delivering Durable, High-Quality Roofing Services in Denver, CO

What Is Roofing Felt For

November 30, 2025

2 min read

dilshadakram

Roofing felt is a material placed under your roof shingles to protect your home from water damage. It acts like a waterproof barrier between the shingles and the wood underneath. Roofing felt stops leaks, helps shingles last longer, and keeps rain from getting into your attic. Most homes use roofing felt because it is cheap and works well. Without it, water would seep into your home and cause big problems like mold and rot.

Why Do Roofs Need Felt?

Roofing felt protects the wooden frame of your roof. When rain falls, water can slip under loose shingles or get blown up by wind. The felt catches this water and guides it down and off your roof.

Felt also gives your shingles something to stick to. This keeps them in place during storms. According to RubyHome, the average roof replacement cost is $9,526, and using good felt during installation helps prevent leaks that could cost much more in repairs.

Related articles:

Types of Roofing Felt

There are two main types: tar paper and synthetic felt. Tar paper is the older type and costs less. Synthetic felt is newer and lasts longer.

Tar paper is made with asphalt and fiberglass. Synthetic felt is made from plastic and polymers. Both work, but synthetic felt can last up to 30 years, while tar paper lasts about 15 to 20 years. According to industry data, asphalt shingles, which rest on felt, last between 20 and 30 years on average.

When Do You Replace Roofing Felt?

You replace roofing felt when you replace your roof. The old felt gets pulled off and new felt goes down first.

If you see water stains on your ceiling or wet spots in your attic, your felt may have failed. According to industry data, 33% of homeowners have roofs replaced due to leaking, which often means the felt underneath has worn out. You may also need to replace felt if you see mold, rotting wood, or daylight coming through.

How Much Does Roofing Felt Cost?

Roofing felt is affordable. According to RubyHome, roof installation costs range from $4 to $40 per square foot, and felt is a small part of that cost.

Felt TypeCost per Square FootLifespan
Tar Paper$0.30, $0.6015, 20 years
Synthetic Felt$0.50, $1.0025, 30 years

Most roofers include felt in their estimate when they give you a price for a new roof. According to industry data, 85% of roofing industry revenue comes from replacement of existing roofs, and nearly all of these projects include new felt underlayment.

Related articles:

Work with a professional professional roofer to protect your property with quality roofing solutions.