What Is The Best Underlayment For Your Roof?

There is much discussion and debate about which roofing material is the best. Some people prefer the cost and durability of metal roofs, while others favor the good looks and longevity of clay tile. Meanwhile, underlayment largely goes unnoticed and underappreciated. In this article, we will discuss underlayment and its importance in serving as your roof’s last line of defense.

What is underlayment?

Underlayment is a protective barrier installed between the roof deck and the roofing material (e.g., shingle, shake, metal, clay tile). Its primary function is to protect your home from the elements if your roofing material is ever damaged.

In order to serve its purpose properly, the underlayment must be waterproof (or at least water-resistant), lightweight, resistant to tearing or heat/cold damage, and relatively simple to install. There are three main types of underlayment to choose from.

Underlayment types

The three primary types of underlayment are asphalt felt, synthetic, and rubberized asphalt.

Asphalt felt

Asphalt-saturated felt is the most common type of underlayment and is sometimes referred to as tar paper or felt paper. It comes in several different weights depending on the amount of protection you need.

Price and availability are the two main advantages of asphalt felt. While it provides good protection, asphalt felt is not the best-performing underlayment available. However, recent inflation and supply chain problems have reminded roofers and homeowners that availability and price are powerful advantages.

The primary disadvantage of asphalt felt is the potential for damage due to water absorption. The underlayments discussed below perform better when it comes to water resistance, primarily because asphalt felt can wrinkle or buckle over time due to water damage.


Synthetic underlayment is typically made of polyethylene or polypropylene. In recent years, it has enjoyed increasing popularity because it is lighter, more durable, and more water resistant than asphalt felt.

Synthetic underlayment’s advantages revolve around durability and longevity. It does not tear easily and tends to avoid the wrinkling and buckling problems observed with asphalt felt.

The cons list for synthetic underlayment is relatively short – it has a higher upfront cost and requires more expertise to install correctly.

Rubberized asphalt

Rubberized asphalt underlayment is made of a mix of asphalt and rubber polymers. It usually comes with a peel-and-stick backing, which simplifies installation.

Rubberized asphalt is one of the best underlayment options on the market today. Unlike some of the options discussed above, it is indeed waterproof. That is why it is often used in areas that are prone to water damage, even when a different underlayment is used on the remainder of the roof.

Quality products tend to be more expensive; the same is true of rubberized asphalt underlayment. It is the most expensive of the options discussed in this article. It is also the heaviest, which can make installation a bit more cumbersome.

We know the importance of good underlayment

Our team is comprised of expert roofers who have installed thousands of roofs across the country. We understand that your roof protects your family and your most important investment. That’s why we are serious about installing the best-performing underlayments available. Contact us today to discuss underlayment options and to start planning your new roof.