Understanding Roofing Underlayment

While in the market for a roofing repair or installation, it’s important to understand that there are many components critical to the structural integrity of your roof. One such component is roof felt underlayment. Roofing felt comes in multiple different varieties and various levels of quality. And it’s important to understand the differences between each, and how they can affect the durability and effectiveness of your roof.

What is roofing underlayment, and why is it necessary?

Roofing underlayment is an essential component of your roof. It acts as a waterproof or water-resistant barrier that is applied underneath the roofing material to provide a level of protection that shingles alone can’t match. Shingles are the first line of defense against the elements, blocking wind and precipitation. However over-time shingles become worn and damaged. The application of underlayment ensures that no moisture leaks into your home. It is essential to preventing water damage and mold growth, especially in our North Carolina climate.

Varieties of roofing underlayment, and their differences.

There are three primary types of roofing underlayment used in the roofing industry today: tar felt, synthetic felt, and ice & water shield.

Tar Felt Underlayment: Tar felt is an asphalt-based material, that was the standard before synthetic products were standardized. Available in 15 and 30-pound variants, the size is dependent on how much oil is retained in the felt itself. The 30-pound variant is naturally better at preventing moisture absorption due to the thickness in particular. However, tar felt being a low-cost solution does not come without its drawbacks. The asphalt contains volatile compounds that will dissipate over time, and eventually cause the felt to become fragile and moisture-absorbent. In hot and humid environments the life expectancy of the asphalt diminishes at a much quicker rate. While tar felt is a low cost and efficient underlayment solution, the North Carolina climate exponentially lowers the appeal of tar felt.

Synthetic Underlayment: Synthetic underlayment is similar to tar felt in its purpose but is lighter and more durable. Built to withstand volatile climates, it has a longer lifespan compared to that of tar felt. Synthetic is notably 33% stronger than 30lb tar felt underlayment, and far more resistant to UV exposure. In the event of shingle blow-off, synthetic underlayment can last up to 180 days with direct UV exposure, whereas tar felt can begin to bubble and wrinkle, within just 24 hours of UV exposure. Making synthetic underlayment a wise choice in our subtropical climate. Synthetics are also much faster to install, in comparison to tar felt. Coming in lighter and larger rolls it drastically improves the time of installation. For example, a 2700 square foot roof, can require up to 14 rolls of 30lb tar felt underlayment comparatively it may only take 3 rolls of synthetic. Making synthetic notably faster and more efficient in the installation process. Whether it’s tile, shingle, or metal, synthetics are the most popular form of roof underlayment, and for good reason. Due to the durability and effectiveness of synthetics, it is a superior alternative to tar felt underlayment.

Ice & Water Shield: Ice and Water shield is the gold-standard of underlayment material and the best choice for our climate. Designed for areas where ice dams and severe storms are common. This form of underlayment is designed to endure the most extreme of climates and regions. It acts as a durable and waterproof layer able to withstand the most severe conditions, essentially making your roof “weather-proof”. Ice & Water shield also has the ability to self-adhere to punctures, ensuring that no moisture will penetrate the sheathing. Unlike tar felt, Ice & Water underlayment has little to no asphalt content. Alternatively utilizing fiberglass, polypropylene, and polyethylene to maintain its durability for decades. This form of underlayment guarantees that you’ll have the most water-tight roof available, ensuring that your roof will last for years to come.

What is right for me?

It’s important to take into account which form of underlayment will best ensure the structural integrity and quality of your roof. All three forms of underlayment have their purpose, however, with varying qualities, one may be better suited for your region than another. Regardless, roofing underlayment is an important component of any roof, and it’s important to treat it as such to avoid unnecessary damage to your home in the event of extreme temperature, extreme weather, or natural disasters.

Fortitude Roofing takes great pride in educating homeowners. We do our best to inform and serve the communities around us. We love hearing from you and we invite you to connect with us on Facebook & Instagram for an inside look at our industry and the communities we serve. Our estimates are provided with a no-obligation guarantee, so if you’re in the market for roof service, please call us at (252)515-1016 to schedule an appointment.

Areas we service:

Morehead City NC - Emerald Isle NC - Atlantic Beach NC - Havelock NC - Beaufort NC - Newport NC - Swansboro NC - Jacksonville NC - New Bern NC - Havelock NC - Trentwoods NC - Peletier NC - Stella NC- Hubert NC - Richlands NC