Types Of Roofing Underlayment Explained (Pros & Cons)

By working as a barrier between the roof deck and the outer material, roofing underlayment is necessary for any roofing system. Though it goes unnoticed most of the time, its significance in preserving the interior of a home cannot be stressed enough. 

In this blog post, we will discuss each type of roofing underlayment in detail, weighing the pros and cons to help you make well-informed decisions for your roofing needs.

What Are The Different Types Of Roof Underlayment?

When it comes to protecting your home from the elements, choosing the best type of roofing underlayment can significantly impact your roof’s longevity and performance. Here are some types of roof underlayment you can go for: 

#1. Asphalt-Saturated Felt Underlayment

Often called felt paper or tar paper, asphalt-saturated felt underlayment is a conventional and extensively used roofing underlayment. It is made from a base of organic or fiberglass mat saturated with asphalt for waterproofing. Reliable for many years, it is still widely used today. This underlayment is essential for stopping water damage and providing roof installers with a safer surface to work on. 

The ability of asphalt-saturated felt to repel moisture and protect the wood sheathing from long-term damage is one of its main advantages. This traditional underlayment, which also serves as a temporary weather barrier during a roof installation, is frequently used in steep-slope roofing applications. 

Pros 

1. Effective Weather Protection: Acts as a reliable barrier against wind, rain, and hail, ensuring durability. Provides temporary weather resistance during installation.
2. Protective Layer During Installation: Safeguards roof components, minimizing damage. Easy for contractors to work with, streamlining installation.
3. Moisture Damage Prevention: Reduces moisture damage to the roof deck by preventing condensation from reaching the wood. 
4. Cost-Effectiveness: Offers a budget-friendly option while maintaining durability and reliability.

Cons

1. Prone to Tearing: Vulnerable to tearing during installation or in high winds.
2. Limited Lifespan: Has a shorter lifespan compared to synthetic underlayments.
3. Susceptible to Mold and Mildew: Can foster mold and mildew growth if exposed to moisture for extended periods.
4. Added Weight: Heavier than synthetic alternatives, potentially adding weight to the roof structure.

Installation Cost

 $0.05 and $0.50 per square foot

#2. Synthetic Roofing Underlayment

Synthetic roofing underlayment’s superior strength, tear resistance, and longevity in challenging conditions make it a preferred option compared to other underlayment options. Because of its high UV and moisture resistance, it is perfect for extended exposure during roofing projects. 

Synthetic underlayments are lightweight and simple to use. They frequently feature clear lines and overlap guides for a smooth installation. Recommended for regions with significant temperature fluctuations, they provide exceptional protection for diverse roof types. Constructed from polyethylene or polypropylene to improve robustness, longevity, and resilience to tearing, they also have outstanding resistance against water seepage.

Pros

1. Durability: Engineered to withstand harsh weather conditions, providing long-lasting protection for the roof structure.
2. Lightweight Composition: Significantly lighter than traditional materials, reducing the load on the roof and simplifying handling and installation.
3. UV Resistance: Resistant to UV radiation, allowing for extended sun exposure during installation without compromising integrity.
4. Moisture Resistance: Repels water effectively, preventing infiltration into the roof and reducing the risk of leaks and structural damage.

Cons

1. Higher Cost: Synthetic underlayments are generally pricier than traditional asphalt-saturated felt due to their advanced features and better performance. But their long-term benefits like durability and weather resistance can justify the initial expense.
2. Less Breathable: Some synthetic underlayments may not let moisture vapor escape as effectively as other options, potentially leading to trapped moisture and reduced ventilation.
3. Requires Careful Installation: Due to their lightweight and smooth surface, synthetic underlayments need careful installation to prevent issues like wrinkling or slippage, requiring strict adherence to manufacturer guidelines.
4. Availability Constraints: While synthetic underlayments are gaining popularity, some types or brands may not be readily available in all regions due to factors like distribution channels or local market preferences.

Installation Cost

$0.10 to $0.55 per square foot

#3. Rubberized Asphalt Underlayment

Made of asphalt and rubber polymers, rubberized asphalt underlayment is notable for its remarkable waterproofing qualities and longevity. With a backing that sticks to the roof deck directly, this self-adhesive underlayment forms a waterproof seal. It is more expensive than other underlayment choices, but in exchange, it offers unmatched waterproofing, longevity (up to 50 years), resistance to UV rays, and weather resilience. 

It performs exceptionally well in leaky locations like eaves, valleys, and around vents, chimneys, and skylights, providing strong protection against water damage. If there is damage, patching is possible, but getting to it for repairs might require removing some of the outermost layer of roofing materials.

Pros

1. Waterproofing and Durability: Rubberized asphalt underlayments excel in waterproofing and durability, providing a reliable barrier against moisture and enhancing the longevity of the roof.
2. Mold and Mildew Resistance: They’re resistant to mold and mildew growth, which helps maintain a healthier environment and prolongs the lifespan of the roof.
3. Self-Adhering for Easy Installation: Their self-adhering feature simplifies installation, ensuring a secure seal and further enhancing waterproofing capabilities.
4. Extreme Temperature Resistance: Rubberized asphalt underlayments can withstand extreme temperatures without degrading, ensuring consistent performance in varying weather conditions.

Cons

1. More Expensive: Rubberized asphalt underlayments often come with a higher price tag compared to traditional asphalt-saturated felt.
2. Limited Breathability: They may have limited breathability, potentially trapping moisture under certain conditions.
3. Weight Variance: Some rubberized asphalt underlayments can be heavier than synthetic alternatives.
4. Challenges with Adhesive Backing: The adhesive backing can be difficult to work with in very cold or hot temperatures.

Installation Cost

$0.55 to $0.90 per square foot

#4. Fiberglass Reinforced Felt Underlayment

Made of fiberglass saturated with asphalt, it offers strength, affordability, and improved durability compared to other options. Its flexibility makes it suitable for various roofing applications. During installation, it is placed over the roof deck before shingles, providing a barrier against moisture and aiding in insulation. Available in different weights, such as #15 and #30, it caters to diverse protection and durability needs. 

Pros

1. Affordability: Fiberglass-reinforced felt underlayment is cheaper than synthetic options, offering budget-friendly roofing solutions.
2. Simplified Decision Process: With just two main types available—#15 and #30—choosing the right underlayment is easy based on thickness requirements.
3. Improved Permeability Rating: This underlayment has better moisture permeability than synthetics, ideal for addressing attic humidity concerns.
4. Cost-Effectiveness: Compared to synthetics, fiberglass reinforced felt underlayment offers a cost-effective alternative.
5. Enhanced Water Resistance: It serves as a reliable barrier against moisture, protecting both the roof deck and interior spaces.

Cons

1. Durability: While fiberglass reinforced felt underlayment is durable, it may not match the longevity of synthetic options.
2. Weight: Heavier than synthetic underlayment, handling and installing fiberglass reinforced felt may pose greater challenges.
3. Moisture Absorption: Though water-resistant, exposure to water over extended periods can lead to moisture absorption, causing problems like wrinkling and buckling.
4. Installation Challenges: The weight and slipperiness of fiberglass-reinforced felt underlayment can complicate installation, necessitating careful handling during roofing projects.

Installation Cost

$0.15 to  $0.70 per square foot

Also Read: The Anatomy Of A Roof: Understanding How Each Part Functions

Best Roofing Underlayment Manufacturers 

As a homeowner, a question that might come to your mind is: What is the best underlayment for roofing projects? To get a better understanding, let’s delve in to learn about the best roof underlayment manufacturers so you can make a proper decision: 

#1. Owens Corning

Quality roofing products, including underlayments, are what Owens Corning is well known for. The ProArmor® Synthetic Roof Underlayment is one of their best-selling items. The material composition of this underlayment provides superior resistance to tears and water intrusion. 

Because of its light weight, handling and installation are simple. Utilizing Fusion Back Coating Technology™, the ProArmor® Synthetic Roof Underlayment exhibits increased longevity and functionality. To further protect the roof and house from the damaging effects of sunlight, it offers protection against UV rays for up to 90 days.

#2. CertainTeed

CertainTeed offers RoofRunner®, a synthetic roofing underlayment renowned for providing superior protection to residential roofs. This underlayment is specifically engineered to serve as a water-resistant layer beneath asphalt roofing shingles, ensuring a dry and healthy roof deck. RoofRunner is known for its exceptional durability, reliability, and resistance to tearing and puncturing, guaranteeing long-lasting performance. 

Its multi-layer coated structure facilitates rapid roof deck drying, making it an excellent choice for projects requiring efficient moisture management. Moreover, CertainTeed offers RoofRunner® AIR, a breathable variant of this underlayment, designed to permit moisture passage, thereby preventing mold, rot, and structural damage over time.

#3. GAF

Another well-known brand in the roofing industry, GAF provides a range of roofing products, including underlayments. Among its noteworthy products is the GAF FeltBuster® Synthetic Roofing Felt. With its cutting-edge design and improved performance over conventional felt underlayments, this synthetic underlayment is a popular choice. 

Synthetic materials, such as polypropylene, are used in the construction of the FeltBuster® to provide enhanced durability and tear resistance. Its nailing pattern makes installation simple and ensures the material lies flat on the roof surface, avoiding wrinkles. Additionally, GAF offers customers the added peace of mind that comes with the option to add a limited lifetime warranty when this underlayment is installed with other qualifying roofing products.

Conclusion

Choosing the proper roofing underlayment is crucial and has a big impact on your roof’s performance and lifespan. Knowing the various kinds of underlayment available—from conventional asphalt-saturated felt to modern rubberized asphalt and long-lasting synthetic options—allows you to make a decision that fits both your needs and your budget. Whichever option you choose, maintaining and installing your roof correctly is essential to keeping it durable for many years to come. 

Put your trust in Rеnova Roofing & Construction for professional roofing services and excellent solutions to keep your roof in the best possible condition. Our team of experts offers complete roofing services, from installation to maintenance, guaranteeing dependable and effective protection for your home. Choose Rеnova Roofing & Construction for a long-lasting and secure roof. Give us a call today at (601) 647-3433.