The Importance of the Roofing Underlayment

The Importance of the Roofing Underlayment

For many homeowners, the roof is just what they see: the shingles, gutters and maybe the flashing strips. Most are unaware that there’s more to the roof than what’s on the surface. The roofing underlayment is a hidden yet integral part of the roof that plays a key role in the overall health and stability of the entire structure.

In this post, we discuss what the roofing underlayment does and why it’s so important.

The Underlayment

The underlayment is a water-resistant or waterproof barrier material that, as its name suggests, is installed under all the other roofing materials. Its main role is to serve as an additional layer of protection from the weather, especially water damage. Think of it as the final barrier that a leak must overcome after it has gone through everything else.

The roofing underlayment comes in three types: asphalt saturated, non-bitumen synthetic underlayment and rubberized asphalt underlayment.


Asphalt-saturated felt used to be the quintessential underlayment until about 15 years ago when synthetic materials became commonplace. Despite this, it’s still a reliable underlayment as it’s flexible and water-resistant. It’s also readily available, making it the most affordable kind.

Non-Bitumen Synthetic

Non-bitumen synthetic is the most common type of underlayment and what your prospective roofer, including us, would recommend. It’s essentially the direct upgrade to asphalt-saturated, but with better water resistance. It’s also designed for full application on the entire roof, making it a cost-effective choice for most homeowners.

Rubberized Asphalt

Finally, the rubberized asphalt is the premium underlayment type that essentially boasts all the benefits of the two other underlayments and more. Unlike the first two mentioned here, it’s completely waterproof thanks to its higher percentage of asphalt and rubber polymer.

What’s unique about this underlayment is that it has a sticky back with a protective membrane. This special backing creates a “natural” waterproof seal between it and the roof deck. The only disadvantage of this underlayment is that it’s more expensive.

Not all underlayments are made the same way, and some are more appropriate for certain homes than others. As your trusted local roofing contractor, we’ll help you pick the right underlayment for your home for maximum roof protection and efficiency. Call us today at (651) 968-8888 to learn more about our services. We offer complete roofing services in St. Paul and Minneapolis.

Copyright 2023 © Krech Exteriors. All Rights Reserved

Book Appointment

    [gravityform id="1" title="true"]