What Makes Underlayment an Important Roofing Component?

If you’ve been looking up roofing options or are reviewing a roof replacement estimate, you’ve probably seen the term “underlayment” a few times. In today’s post, the roofing contractors at Easton Roofing discuss what makes this underlayment an important roofing component.

What Is Roofing Underlayment?

The roofing underlayment is a layer of material that’s installed between the roof deck and the outer roofing material. It serves as a barrier that protects the roof against moisture infiltration in case the outer roofing layer is pierced, punctured or otherwise damaged.

On standard roofing systems, sheets of underlayment are placed on the decking and adhered in place with specially-designed fasteners. A moisture-resistant tape is applied over seams and breaks in the roof to create a virtually unbroken barrier. In some roofing systems, a separate, self-adhering membrane called a leak barrier is installed at the valleys and the roof’s edge to protect them from wind-driven rain.

Types of Roofing Underlayment

There are three main types of underlayment to choose from:

• Felt. Traditional underlayment is made from sheets of paper soaked in asphalt (also known as bitumen), which gives it a felt-like texture. In fact, it’s not uncommon for people to use the term “felt” for any type of underlayment. Some roofers still offer felts because of its relatively lower cost, and because it adds rigidity to the roof.

• Rubberized asphalt. While it’s functionally the same as traditional felts, rubberized asphalt doesn’t require a substrate like paper — they’re sheets of asphalt mixed with rubber. Instead of fasteners, they’re attached to the decking using adhesive.

• Synthetic. If you’ve had your roof built in the last 10 to 15 years, chances are it has synthetic underlayment. They’re durable and flexible, which makes them less at risk of being torn as the roof expands and contracts from the heat. Most synthetic underlayment can also wick moisture, which helps reduce the risks of moisture damage, should it find its way onto the decking.

Which Underlayment Is Right for You?

In most cases, your choice of roofing decides which type of underlayment is going to be used. This is especially true with complete roofing systems from manufacturers like CertainTeed®, as all components are designed to work together. If the property owner takes a more customized approach, then the roofer will offer recommendations — felts for additional impact resistance, or perhaps rubberized asphalt if the installation timeline is longer than what’s typical.

Find out which underlayment and other roofing products are right for you. Give Easton Roofing a call at (913) 257-5426, or fill out our contact form to schedule a free consultation. We serve Kansas City, MO, and surrounding communities.