Why Do Roofs Need Roof Underlayment?

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Most homeowners don’t think about all the components that make up the roof of their home, but there’s a lot going on underneath your shingles.


The shingles are the outermost layer of your roof (the roof tiles) and they help protect you from the sun’s rays, rain, wind, and snow. However, there’s another layer of protection between the roof deck and the shingles: roof underlayment, which plays an essential role in protecting your home from water damage.



roofer laying down underlayment


What Is Roof Underlayment, and Why Is It Important?


Roofing underlayment is a barrier material that’s installed directly onto the wooden boards of your roof known as the roof deck.


This layer of your roofing system is typically made of asphalt saturated felt or modern synthetic materials. It covers your entire roof deck, acting as a secondary moisture barrier between the roof deck and shingles to help prevent wind-driven rain from infiltrating your home through the roof.


It also safeguards your shingles from tear-away due to high winds, and protects your roof deck from damage caused by ice dams. Underlayment exists to protect the deck so that if moisture does get past the primary roofing material, the underlayment can stop it from damaging the deck. While it is an additional cost, it will also save money by preventing water damage to the wood beneath.


Basically, it helps keep your home dry and patched up. It’s just one of many layers of material that provide your home with the best protection possible against the elements.



What Are the Different Types of Roof Underlayment?


There are three main types of roof underlayment used on roof decks:


  1. Asphalt-Saturated Felt
  2. Non-Bitumen Synthetic Underlayment (also known as “synthetic underlayment”).
  3. Rubberized Asphalt Underlayment

Asphalt-saturated felt and synthetic underlayment are water-resistant. Rubberized asphalt underlayment is waterproof; either way, they’re a secondary layer of added protection that helps keep water during heavy rain events out of your home.



Do I Have to Get An Underlayment?


Technically speaking, no, roofing underlayment isn’t 100% necessary for an asphalt shingle roof— at least not in areas with unregulated building codes.


A lot of issues will beset your roof over time. Without underlayment, rain and snow will soak into the roof deck and create issues like mold, rot, leaks and more to the roofing structure. Storms and high winds will also break down your shingle defense. Ultimately, these repairs are significantly more costly in the long run.


In any case, most homeowners are required by local building code to include roofing underlayment and roof covering. Additionally, some shingle manufacturers require an underlayment as part of their warranty.


laying down underlayment


What’s the Condition of My Roof Underlayment?


If you’re wondering about the state of your current roofing system, get it inspected as soon as possible. Leaks and water infiltration quickly lead to rot and degradation. Better to change out a few shingles than replace a whole portion of roof deck.


Phoenix Exteriors offers free roof inspections with licensed roofing professionals. We carry GAF Roofing WindProven™ Limited Warranty Shingles—the industry’s first wind warranty with no maximum wind speed limitation— for maximum roofing protection.


If you need a licensed professional to inspect your roof, contact Phoenix Exteriors today and schedule a free inspection!









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