Which Roof Underlayment Should You Use for Maximum Protection
When most homeowners think about roofing, the first thing that comes to mind is probably shingles. But what many don’t realize is that the integrity of your entire roofing system actually begins beneath the surface. One critical component that plays a huge role in protecting your home is roofing underlayment, a barrier installed between the roof deck and your shingles. It might be out of sight, but it should never be out of mind.
What is the best underlayment for roofing? If you’re asking this question, you’re already ahead of the curve. Understanding your options means you’re making informed decisions about your home’s long-term safety. In this guide, we’ll explore the different types of roof underlayment, compare their pros and cons, and explain why synthetic underlayment is often the best option, especially when you’re working with an expert team like Everlast Exteriors, where quality always comes first.
What Is Roofing Underlayment?
Roofing underlayment is a water-resistant or waterproof layer that’s installed directly on top of the roof deck, but underneath the outer roofing material (like asphalt shingles or metal panels). Its purpose is simple but vital: to serve as a second line of defense against water infiltration.
Roofs are constantly exposed to rain, snow, wind, and temperature extremes. Shingles and panels offer protection, but if they’re damaged or improperly sealed, water can easily seep through. That’s where underlayment steps in. It helps keep moisture away from your roof’s decking, preventing rot, mold, and expensive structural damage.
Not only does underlayment serve as a moisture barrier, but it also improves fire resistance, provides extra insulation, and enhances overall roof performance. Choosing the right type ensures your home is protected year-round, especially in harsh climates.
What are the Three Types of Roofing Underlayment?
When it comes to selecting roof underlayment, there are three primary options: asphalt felt, synthetic, and rubberized asphalt. Each type comes with its own strengths and limitations.
1. Asphalt Felt Underlayment (Traditional Option)
Asphalt-saturated felt, often called felt paper or tar paper, is the oldest and most traditional form of roof underlayment. It’s made by saturating paper or fiberglass mats with asphalt to make them more water-resistant.
Pros:
- Budget-friendly and widely available
- Easy to find at most hardware stores
- Familiar material for many contractors
Cons:
- Prone to tearing, especially in windy conditions
- Can absorb water, causing it to wrinkle or buckle
- Limited lifespan compared to newer materials
Felt underlayment is still used today for budget-conscious roofing projects, but its performance under wet or extreme weather conditions can be inconsistent.
2. Synthetic Underlayment (Modern Favorite)
Synthetic underlayment is made from lightweight polymers like polyethylene or polypropylene. This modern alternative is engineered for strength, water resistance, and ease of installation.
Pros:
- Lightweight and easy to install
- Stronger tear resistance than felt
- Does not absorb water—repels moisture
- Offers a non-slip surface, improving safety for installers
- Holds nails better for superior waterproofing
Cons:
- Slightly more expensive upfront than felt
- May require more specialized installation knowledge
Synthetic underlayment is the preferred choice for most roofing contractors today, particularly for asphalt shingle installations. Its durability and resistance to environmental wear and tear make it a smart long-term investment.
3. Rubberized Asphalt Underlayment (Premium Choice)
Rubberized asphalt underlayment is considered the premium option. It features a sticky, self-adhering back that creates a waterproof seal directly on the roof deck.
Pros:
- Completely waterproof, not just water-resistant
- Great for leak-prone areas like valleys, eaves, and around skylights
- Self-seals around nails to prevent moisture entry
Cons:
- More expensive than both felt and synthetic
- Heavier and harder to work with
- Not always necessary for the entire roof
This type is best used in specific high-risk areas of a roof rather than as a full-system solution unless the budget allows for it.
What Is the Best Underlayment for Roofing?
When comparing all three, synthetic underlayment consistently comes out on top as the most practical and effective solution for most residential roofs, especially if you’re installing asphalt shingles.
Here’s why:
- It’s lightweight, making it easier and quicker to install.
- It’s more durable, with better tear resistance and overall strength.
- It repels water rather than absorbing it.
- It offers superior nail-holding capabilities, helping to maintain the seal integrity.
- It adds an extra layer of safety for roofers with its slip-resistant surface.
Although it’s slightly more expensive than felt, the value and long-term protection it provides far outweigh the cost difference. When you factor in reduced labor effort, longer-lasting protection, and reduced risk of water damage, it’s easy to see why synthetic underlayment is the best all-around choice.
Why Synthetic Underlayment Is Best for Asphalt Shingles
Asphalt shingles are the most common residential roofing material, and synthetic underlayment pairs perfectly with them. Roofing contractors, including the seasoned pros at Everlast Exteriors, often recommend synthetic for several key reasons:
1. Reduced Labor Time and Cost
Synthetic underlayment comes in larger, lighter rolls. Fewer rolls and lighter weight mean faster installation with less strain on your roofing crew. Even though the difference in labor cost might be small, it adds up during larger installations.
2. Better Moisture Protection
Felt absorbs moisture; synthetic repels it. This makes a major difference if your underlayment is exposed to rain or snow during installation. Synthetic underlayment doesn’t wrinkle or degrade when wet, giving your roof deck maximum protection before the shingles are even installed.
3. Increased Durability
High winds can easily tear felt underlayment. Once that happens, your roof deck is exposed to the elements. Synthetic, on the other hand, holds strong, especially in extreme weather conditions.
4. Safer Installation
Synthetic underlayment often features non-skid surfaces, providing safer footing for workers walking on sloped surfaces. This is particularly important for steep or complex roof designs.
5. Longer Lifespan
When properly installed, synthetic underlayment lasts significantly longer than felt, meaning better protection throughout the life of your shingles.
Make the Smart Choice for Your Roof
When it comes to choosing roof underlayment, the best option is one that balances durability, moisture protection, and cost-efficiency. While each type—felt, synthetic, and rubberized asphalt—has its role, synthetic underlayment stands out as the most well-rounded and future-proof solution for most homes.
It’s especially well-suited for asphalt shingle roofs and offers a longer-lasting, safer, and more efficient installation process. Combine that with professional craftsmanship from a reliable Oakville Roofing team like Everlast Exteriors, and your roofing system will be built to withstand the elements for years to come.
Ready for a Roof That Lasts?
At Everlast Exteriors, we don’t just build roofs—we build peace of mind.
Our expert Oakville Roofing team ensures every layer of your roof is installed with precision and care, starting with the highest-quality underlayment.
Whether you need a full roof replacement or just want to explore your options, we’re here to help. Contact us today for a free consultation and discover why homeowners trust Everlast for lasting results. Protect your home from the inside out—choose Everlast Exteriors.
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