Nobody wants to deal with roof leaks, so as you have a new roof installed, be sure a roof underlayment is included. Your roofing underlayment acts as a barrier to safeguard your home and roof deck from costly moisture intrusion and the impact of heavy precipitation. This waterproof or water-resistant material goes directly on your roof deck and under any other roofing materials that are installed, such as asphalt shingles or metal roofing.
Read on to learn the benefits of a roof underlayment and various types on the market you have to choose from.
5 Benefits of a Roofing Underlayment
Several layers of materials make up your roofing system. Your underlayment is a vital part of the elements that work together to keep roof leaks at bay. It is sandwiched between your roof shingles and your decking. Here is why it is important to include it in your next roof replacement:
1. Safeguard Your Home Against Moisture Intrusion
When heavy snow or rain showers combine with high winds, water can become trapped under your asphalt shingles. Your roof underlayment keeps the moisture from coming into contact with your roof deck so your home won’t experience the harmful effects of leaks, mold, rot, and roof deterioration. Safeguard your roof, attic, and home interior from costly water penetration with the enhanced fortification of a roof underlayment.
2. Add Another Layer of Protection
While asphalt shingles protect your home from wind, rain, snow, and intense UV rays, and they overlap, they tend to sometimes blow off when high winds prevail, opening the door to water damage. The good news is that if your asphalt shingles detach in a storm, your underlayment is there as a second line of defense against the harmful effects of moisture penetration. Ideally, it stays intact and safeguards your home from damage until your shingles are replaced.
3. Ensure Melting Snow and Ice Fully Drain from Your Roof
The greater Minneapolis and St. Paul areas are subject to quite a bit of snow each winter, so homes are at risk of ice dams forming on their roof. When warm air comes into contact with your roof deck, it causes snow to melt and run down your roof where it refreezes over your home’s eaves and forms ice dams.
The problem is—when snow and ice melt, water can get into any vulnerable areas of your roofing system and cause damaging rot, unhealthy mold and costly leaks in your attic and home interior. The good news is that your water-resistant or waterproof underlayment seals around your roof so water doesn’t penetrate your roof deck, but rather drains off your roof and into your gutters.
4. Shields Your Roof Deck from Weather Elements During Your Roofing Installation
Weather can sometimes be unpredictable, and the beauty of roof underlayment is that it is affixed directly to your roof decking, providing instant protection from water penetration even while the rest of your roof is being installed! Safeguard your roof deck from damaging water from the start by installing a reliable roof underlayment.
5. Position Your Roof to Align with Warranty Requirements
In the unlikely event that you need to use your manufacturer’s warranty, it’s important to meet their necessities. An underlayment is part of the warranty requirements of asphalt shingles. Also, building codes state you must have a roof underlayment.
Types of Roofing Underlayment
| Type | Best For | Pros | Cons | Cost Range | Lifespan |
| Asphalt-Saturated Felt | Budget projects | Affordable, widely used | Tears easily, less durable | $ | 15–20 yrs |
| Synthetic Underlayment | Most modern homes | Lightweight, durable, water-resistant | Higher upfront cost | $$ | 25–40 yrs |
| Rubberized Asphalt | Ice dam protection | Waterproof, self-sealing | Expensive | $$$ | 30–50 yrs |
Felt Underlayment
Also called “tar paper” or “asphalt-saturated felt,” felt paper’s makeup of asphalt, polyester, and plant fibers provides a flexible base with water resistance. While it resists water, it isn’t waterproof. It is used on steeply sloped roofs rather than low-slope roofs where water is more likely to pool. It is a cost-effective option, but not as durable as other underlayment materials, and it tears easily.
Synthetic Underlayment
This popular underlayment option is made of a synthetic base saturated in asphalt and coated with fiberglass to make it tear resistant and durable. Some synthetic underlayment materials are also slip resistant. This long-lasting option is flexible, waterproof, strong, and resists UV rays and mold growth. It also helps your roof breathe better than felt paper, making it a better long-term selection for your roofing system. This product is lighter, with more coverage per role, making it easier to install.
Rubberized Asphalt Underlayment
This top-of-the-line underlayment delivers the ultimate protection for your home from leaks and moisture damage. It is made of rubber and asphalt polymers that make it extra waterproof. It is ideal for low-slope roofs, roof valleys, eaves, around penetrations (like your chimney, vents, and skylights), and in other areas of your roof prone to water damage.
Rubberized underlayment has a sticky back with a protective layer that is removed before it is installed. The backing makes a watertight seal between your roof deck and the underlayment itself. With the extreme temperatures we experience in Minnesota each winter, this underlayment is a superior option to consider. Its self-adhesive, flexible, UV resistant qualities will give you confidence that your home is well protected even in the midst of a storm. It creates a non-skid surface, making it easier for roofers to walk around on it, and therefore is safer to install.
Add Beauty and Resilience to Your Home’s Protection with a Roof Replacement
An aging roof is more prone to leaks, and if left too long can cause extensive damage due to moisture infiltration. You deserve to have a roof that you can rely on to protect your house from water damage.
At Iron River Construction, we are a full-service Twin Cities roofer. We install industry-leading roofing products from Owens Corning to GAF® and more (including asphalt shingles or metal roofing!). With over 20 years in the industry, we deliver a superior outcome on every project. We’ve helped thousands of homeowners bring their remodeling vision to life so they can enjoy the lifestyle they desire. Learn more about how our roofing services can enhance the beauty and protection of your home.
