How to Choose the Best Roofing Underlayment

Roofing Underlayment

When choosing the best roofing underlayment, consider durability, and climate sustainability like temperature resistance. In addition, compare initial costs and long-term benefits as well as ease of installation and associated labor costs

Asphalt-saturated felt is cost-effective but less durable. Synthetic underlayments excel in tear resistance and installation ease. Rubberized asphalt offers superior self-sealing and mold prevention, ideal for extreme climates. 

Match the underlayment to your climate: synthetic for humid regions, reflective for hot areas, and rubberized for temperature extremes. Consider initial costs versus long-term savings. Synthetic options may be pricier upfront but offer durability and lower maintenance over time. 

This guide explores critical factors to consider when choosing the best roofing underlayment. Call (631) 827-7088 if you have more questions or need help choosing the best roofing underlayment. Clearview Roofing and Construction roofer will answer your questions and offer more guidance.

Key Takeaways

  • Assess climate suitability to ensure peak performance and longevity based on regional conditions and seasonal variations.
  • Consider the durability factors, such as tear resistance, self-sealing properties, and mold prevention.
  • Evaluate temperature resistance to ensure stability and integrity in extreme weather conditions.
  • Compare initial costs and long-term benefits, factoring in lifecycle costs and potential savings.
  • Examine ease of installation and associated labor costs to determine the most cost-effective option.

1. Consider the Durability of the Underlayment

Consider the material’s resistance to wear, tear, and environmental stressors to guarantee long-lasting protection. Your assessment should focus on the underlayment’s ability to withstand mechanical damage and durability. This means you should consider puncture resistance and tensile strength.

Roofing underlayment often faces potential damage from foot traffic and sharp objects during installation. High puncture resistance ensures the material remains intact, maintaining its protective barrier against water infiltration. Underlayments made from synthetic materials, like polypropylene or polyester, offer superior puncture resistance compared to traditional asphalt-saturated felt.

Evaluate tensile strength, the material’s ability to resist tearing under tension. This is particularly important during installation and in high-wind scenarios. Underlayments with high tensile strength, often reinforced with fiberglass or scrim, are less likely to tear, ensuring continuous protection.

Furthermore, underlayment durability also depends on UV resistance. While the primary roofing material usually provides UV protection, underlayment can be exposed to sunlight during installation or repairs. UV-resistant underlayments will degrade slower when exposed to sunlight, extending their lifespan.

Lastly, consider the underlayment’s ability to handle thermal expansion and contraction. Materials with high dimensional stability won’t warp or buckle under extreme temperature variations, avoiding gaps that could compromise the roofing system.

2. Asses Climate Suitability and Temperature Resistance

Consider regional differences and seasonal variations when selecting the appropriate underlayment. Each climate imposes unique demands on roofing materials, and a one-size-fits-all approach won’t suffice. Understanding the climate suitability of roofing underlayment ensures peak performance and longevity of the roofing system. 

In regions with high humidity and frequent rainfall, such as the Pacific Northwest, synthetic underlayments like polypropylene or polyethylene are preferable. These materials offer superior water resistance and are less prone to mold and mildew compared to traditional asphalt-saturated felt. Additionally, synthetic underlayments generally have a higher tear strength, making them more durable under harsh weather conditions.

Conversely, the primary concern is UV resistance and heat tolerance in hot and dry climates like the southwestern United States. Underlayments with reflective properties can help mitigate heat absorption, extending the roof’s lifespan. Asphalt-fiberglass underlayments are a good choice as they combine durability with some degree of UV resistance.

Seasonal variations also play an important role. In areas with significant temperature fluctuations, like the Midwest, we should opt for underlayments designed to expand and contract without losing integrity. Rubberized asphalt underlayments are particularly effective in these scenarios due to their flexibility and self-sealing properties, which prevent leaks caused by thermal cycling.

3. Compare Initial Costs Like Labor Costs and Long-term Benefits

Evaluating the cost of roofing underlayment involves comparing the initial material expense and the long-term benefits as well as potential savings on maintenance and energy efficiency. When we analyze cost, we must account for the immediate outlay and the overall lifecycle costs associated with different types of underlayment.

Traditional felt underlayment is usually less expensive upfront but may not offer the same durability or performance as synthetic options. High-quality synthetic underlayments, while pricier initially, often come with enhanced features like superior tear resistance and better water repellency. These features can translate to longer-lasting roofs and fewer repairs, contributing to long-term savings.

Installing felt underlayment can be more labor-intensive due to its weight and susceptibility to tearing. This can increase labor costs and the time required for installation. On the other hand, synthetic underlayments are generally lighter and easier to install, potentially reducing labor costs and installation time.

Some advanced underlayments offer reflective properties that can help reduce heat absorption in the attic space, leading to lower cooling costs. This energy efficiency can result in significant long-term savings, especially in warmer climates.

Maintenance costs shouldn’t be overlooked either. Synthetic underlayments often provide better protection against leaks and damage, reducing the likelihood of costly roof repairs. In contrast, felt underlayment may require more frequent inspections and repairs, increasing overall maintenance expenses.

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Types of Roofing Underlayment You Can Choose From

When choosing roofing underlayment, consider asphalt-saturated felt, synthetic underlayment, and rubberized asphalt. 

Each type has unique properties, installation methods, and maintenance tips that can influence your decision.

1. Asphalt-saturated Felt

Asphalt-saturated felt, often called felt or tar paper, is a traditional choice. It’s available in 15-pound and 30-pound weights. Installation involves rolling the felt out horizontally across the roof deck, overlapping each row by a few inches. Our roofing contractor secures it with roofing nails or staples, ensuring it’s tight and smooth. Maintenance-wise, it’s important to periodically check for any tears or loose sections, especially after severe weather.

When considering felt underlayment, focus on its material composition and installation process. Felt is typically made from either organic or fiberglass base saturated with asphalt, offering varied durability and water resistance.

Following proper nailing patterns and overlap guidelines is important to guarantee effective protection and longevity.

Material Composition

Felt underlayment, commonly made from a combination of asphalt and either organic or fiberglass base offers a reliable and cost-effective solution for protecting your roof structure.

For material composition, consider environmental impact and material sourcing. Organic felt is typically composed of cellulose fibers from recycled paper or wood, which makes it more environmentally friendly. However, the durability of organic felt can be compromised by its tendency to absorb moisture, leading to potential degradation over time.

On the other hand, fiberglass felt underlayment features a base layer of woven fiberglass, providing enhanced resistance to moisture and rot. This makes it a more durable option, albeit with a slightly higher environmental cost due to the production process of fiberglass. Both types of felt are saturated with asphalt to improve their water-shedding capabilities and overall durability.

When choosing between organic and fiberglass felt, evaluate the pros and cons of each with respect to environmental impact and the specific needs of your roofing project. Organic options are more sustainable but less durable, while fiberglass options offer superior performance at the expense of higher environmental costs. Understanding these trade-offs will help you make an informed decision.

Installation Process

Understanding the material composition helps us appreciate the steps involved in the installation process of felt underlayment, which demands attention to detail and proper technique to guarantee peak performance. 

First, we gather essential installation tools, including a utility knife, a hammer or pneumatic nail gun, and roofing nails or staples. Ensuring the deck is clean, dry, and free of debris is essential before we start laying the felt.

We begin at the bottom edge of the roof, unrolling the felt horizontally. It’s important to overlap each row by at least 2 inches to ensure water doesn’t seep through. When unrolling, we must align the underlayment flush with the eaves and secure it using roofing nails or staples, spaced about six inches apart along the edges and twelve inches apart in the field.

Safety measures can’t be overlooked. Our local roofer always wears non-slip shoes, uses a harness if working on steep slopes, and is mindful of weather conditions to avoid slips or falls.

2. Synthetic Underlayment

Synthetic underlayment is a more modern option, made from polyethylene or polypropylene. It’s known for being lightweight, tear-resistant, and offering superior water resistance. Installation methods for synthetic underlayment are similar to asphalt-saturated felt, but it’s often easier to handle due to its lighter weight. Clearview Roofing and Construction roll it out and overlap the seams, securing it with cap nails or specially designed fasteners. For maintenance, synthetic underlayment is generally low-maintenance but should still be inspected for any damage or wear over time.

Material Composition

Leveraging advanced materials and technologies, synthetic underlayment offers superior durability and weather resistance compared to traditional options. These synthetic benefits stem from its composition, which uses polypropylene or polyethylene. This makes synthetic underlayment highly resistant to tearing, cracking, and UV degradation—key factors that contribute to its longevity.

Installation and Benefits

One of the primary advantages of underlayment is its lightweight nature. Synthetic underlayment is generally lighter than asphalt-saturated felt, making it easier to handle and install. This can reduce labor costs and installation time, which is a significant benefit for contractors. Additionally, its slip-resistant surface enhances safety for workers during installation, particularly on steep slopes.

Synthetic underlayment also excels when it comes to moisture protection. Its superior water-shedding capabilities ensure that it acts as an effective secondary barrier against leaks, especially in regions with extreme weather conditions. This robust moisture resistance helps in preventing mold and mildew, thereby contributing to a healthier roofing system.

Moreover, synthetic underlayment provides excellent UV resistance, which is important if the underlayment is exposed for extended periods before the final roofing material is installed. This UV resistance guarantees that the underlayment maintains its integrity and performance, even under prolonged sun exposure.

Lastly, synthetic underlayment is designed to be compatible with various roofing materials, including asphalt shingles, metal roofs, and tile. This versatility makes it a preferred choice for diverse roofing projects. By opting for synthetic underlayment, we’re investing in a durable, reliable, and versatile solution that offers long-term protection for our roofing systems.

When choosing between synthetic and felt roofing underlayment, evaluate the pros and cons of each regarding environmental impact and the specific needs of your roofing project. 

3. Rubberized Asphalt Underlayment

Rubberized asphalt underlayment is the premium choice. It offers self-sealing properties around nails and excellent waterproofing. It’s commonly used in areas prone to ice dams or heavy rain. 

Material composition

As the name suggests, rubberized asphalt is made from asphalt and rubber polymers.


The installation process for rubberized asphalt underlayment is straightforward, making it a popular choice for professionals and DIY enthusiasts. Its reliability and ease of application make it a valuable solution for various construction projects.

Installation requires peeling off a protective backing and adhering the underlayment directly to the roof deck, ensuring a watertight seal. 

Achieving peak performance with rubberized asphalt underlayment starts with meticulous surface preparation and adherence to manufacturer guidelines. We ensure the deck is clean, dry, and smooth. Any debris or moisture can compromise the underlayment’s adhesion and effectiveness. Next, we check for protruding nails or fasteners and ensure they’re flush with the deck.

Achieving peak performance with rubberized asphalt underlayment starts with meticulous surface preparation and adherence to manufacturer guidelines. First, we must ensure a clean, dry, and smooth deck. Any debris or moisture can compromise the underlayment’s adhesion and effectiveness. Next, we check for protruding nails or fasteners and ensure they’re flush with the deck.

For installation, follow these preparation steps:



Surface Cleaning

Remove all dust, debris, and sharp objects.


Ensure the surface is completely dry.


Verify the deck is smooth and free of damage.

Once the surface is prepped, we roll out the rubberized asphalt underlayment, starting from the eaves and working our way up. We overlap each row by at least 4 inches to guarantee proper waterproofing. Using the correct fastener types is essential. We recommend corrosion-resistant nails or staples spaced according to the manufacturer’s specifications for rubberized asphalt.

Fastener Type

Recommended Use

Corrosion-resistant nails

General attachment


For areas requiring additional hold

Applying a consistent, firm pressure during installation ensures optimal adhesion. By following these preparation steps and using the correct fastener types, we can maximize the durability and performance of the rubberized asphalt underlayment. We also follow residential building standard codes to ensure compliance. 


Rubberized asphalt underlayment is highly regarded for its exceptional waterproofing capabilities and durability. This material prevents water leakage, a critical factor in maintaining the structural integrity of any roofing system. By forming a seamless barrier, rubberized asphalt underlayment effectively stops water from penetrating the roof deck, reducing the risk of mold growth and subsequent damage.

Regarding durability, rubberized asphalt underlayment outperforms many alternatives on the market. Its robust composition resists tears and punctures, ensuring long-term performance even under harsh conditions. This resilience makes it particularly suitable for areas prone to heavy rainfall or snow, where the risk of water ingress is heightened.

Moreover, rubberized asphalt underlayment’s self-sealing properties provide an added layer of protection. When nails or fasteners penetrate the underlayment, the material seals around them, preventing water from seeping through these potential weak points. This feature is invaluable for maintaining a watertight roof system and enhancing mold prevention efforts.

It offers superior temperature resistance and is particularly suitable for environments with high moisture levels that require added protection.

This underlayment is engineered to withstand high thermal loads, ensuring it remains stable and functional in scorching summers and freezing winters. Its thermal efficiency is excellent, effectively reducing heat transfer and helping to maintain indoor climate control, which is vital for energy savings.

Rubberized asphalt underlayment is also known for its superior fire resistance. Unlike traditional materials, which may degrade or catch fire under high temperatures, rubberized asphalt retains its integrity and provides an additional layer of protection. This fire-resistant property is particularly beneficial in areas prone to wildfires or applications with stringent safety codes.

Furthermore, rubberized asphalt is resistant to high temperatures, so it won’t become brittle or crack in cold weather nor soften and lose adhesion in extreme heat. This makes it a versatile choice for various climates.

Call (631) 827-7088. Our Long Island roofing experts will help you choose the best roofing underlayment for your home’s needs.

Frequently Asked Questions

How Does Roofing Underlayment Impact Energy Efficiency?

When considering how roofing underlayment impacts energy efficiency, focus on heat retention and thermal regulation. High-quality underlayment is an extra barrier, reducing winter heat loss and minimizing summer heat gain. It enhances the building’s overall thermal regulation, lowering energy consumption.

What Maintenance Is Required for Roofing Underlayment?

When discussing the maintenance required for roofing underlayment, we focus on moisture control and damage inspection. Regularly check for any water infiltration or tears and verify that the underlayment remains intact and fully adhered to prevent leaks. Proper moisture control involves ensuring adequate ventilation to avoid condensation buildup. Addressing any damage promptly helps maintain the roof’s integrity and prolong its lifespan.

Are There Eco-Friendly Roofing Underlayment Options Available?

Yes, there are eco-friendly roofing underlayment options like organic Felt available.

We should look for materials sourced sustainably, such as recycled or rapidly renewable resources. These underlayments must withstand harsh weather while reducing environmental impact. Options like synthetic underlayments from recycled polymers or organic felt are excellent choices. They offer longevity and eco-conscious benefits, making them practical and responsible choices for modern roofing projects.

How Does Underlayment Affect the Overall Weight of the Roof?

When considering how underlayment affects the overall weight of the roof, we need to look at the material density and load distribution. Heavier materials like synthetic underlayment can add weight, impacting structural load calculations.

Conversely, lighter materials distribute less load, making them ideal for older buildings. We should always balance material density with load distribution to guarantee the roof’s integrity and longevity while meeting specific building code requirements.

Can DIY Enthusiasts Install Underlayment?

It’s not recommended that DIY enthusiasts install underlayment. Clearview Roofing and Construction is a licensed roofing contractor in Nassau (H18H7230000) and Suffolk (55260-H).  We have the right installation tools and follow strict safety precautions. We can secure the underlayment using a utility knife, chalk line, and roofing nails or staples. We also wear safety gear like gloves and harnesses to prevent accidents and follow manufacturer guidelines to avoid voiding warranties and compromising roof integrity.

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