When it comes to the health and longevity of your roof, one element often overlooked is the roof underlayment. While shingles or tiles tend to steal the spotlight, the underlayment plays a crucial role in ensuring your home remains dry and protected.
We’re covering exactly how it does, by going over:
- What roof underlayment is
- Its importance
- The different types available
- Costs
- Installation methods
What is Roof Underlayment?
Roof underlayment is a water-resistant or waterproof barrier material that is installed directly onto your roof deck before the shingles, tiles, or other roofing materials are applied. It acts as an added layer of protection against water infiltration, providing a safeguard for your home against harsh weather conditions, leaks, and structural damage.
Why is Roof Underlayment Important?
- Weather Protection:The primary function of roof underlayment is to provide an additional layer of protection against water intrusion. This is particularly crucial in areas prone to heavy rainfall, snow, and storms.
- Enhanced Durability: Roof underlayment adds to the overall stability and durability of your roofing system. It helps to prevent shingles from sticking to the roof deck and provides a smooth surface for the installation of the final roofing material.
- Damage Mitigation: In the event of shingles being blown off during a storm or severe weather, the underlayment serves as a temporary barrier to prevent water from entering your home.
- Improved Insulation: Some types of underlayment offer added insulation properties, helping to keep your home warmer in the winter and cooler in the summer.
- Fire Resistance: Certain underlayments are designed to be fire-resistant, adding an extra layer of safety to your home.
3 Different Types of Roof Underlayment
Roof underlayment comes in various types, each offering distinct advantages and suited for different roofing needs. Here are the most common types:
1. Asphalt-Saturated Felt
Also known as tar paper, asphalt-saturated felt is one of the oldest and most traditional forms of underlayment. It is typically made from organic or fiberglass substrates saturated with asphalt.
✅ Pros:
- Affordable
- Provides decent water resistance
- Easy to install
❌ Cons:
- Can become brittle over time
- Less effective in extreme weather conditions
- Heavier compared to synthetic options
2. Synthetic Underlayment
Synthetic underlayment is made from polypropylene or polyethylene, offering superior durability and performance compared to traditional felt. It is rapidly becoming the preferred choice among homeowners and roofing professionals.
✅ Pros:
- Lightweight and easy to handle
- Excellent tear resistance
- Superior water resistance
- UV-stable, which means it can be exposed to sunlight for longer periods without deteriorating
❌ Cons:
- Higher cost compared to felt
- Requires specialized fasteners for installation
- Most are not breathable
3. Rubberized Asphalt
Rubberized asphalt underlayment provides a self-adhesive membrane that offers excellent waterproofing capabilities. It is often used in areas prone to ice dams and heavy rainfall.
✅ Pros:
- Self-sealing around nails and fasteners
- Exceptional water resistance
- Can be used in valleys and around penetrations for added protection
❌ Cons:
- More expensive than other types
- Can be challenging to install due to its self-adhesive nature
Underlayment Cost
The cost of roof underlayment can vary widely based on the type, brand, and specific requirements of your roofing project. Here’s a rough breakdown:
- Asphalt-Saturated Felt: Typically ranges between $0.15 to $0.75 per square foot.
- Synthetic Underlayment: Prices range from $0.20 to $0.85 per square foot.
- Rubberized Asphalt: Costs can vary significantly but generally range from $0.90 to $1.50 per square foot.
Keep in mind that these prices are for the material only and do not include installation costs, which can add significantly to the total expense. Labor costs will vary depending on your location and the complexity of the installation.
How to Install Roof Underlayment
Proper installation of roof underlayment is crucial for ensuring its effectiveness. While it’s always recommended to hire a professional roofing contractor, understanding the steps involved can help you oversee the process and ensure it’s done correctly.
1) Prepare the Roof Deck:
Ensure the roof deck is clean, dry, and free of any debris or protruding nails. This provides a smooth surface for the underlayment.
2) Install Drip Edge:
Start by installing a drip edge along the eaves. This helps direct water away from the roof and into the gutters.
3) Begin Rolling Out the Underlayment:
Starting at the lowest point of the roof, roll out the underlayment horizontally (parallel to the eaves). Ensure there is a slight overhang over the drip edge.
4) Secure the Underlayment:
Use roofing nails or staples to secure the underlayment to the roof deck. Be sure to follow the manufacturer’s guidelines for spacing and placement.
5) Overlap the Layers:
Each subsequent layer of underlayment should overlap the previous one by at least 2 inches. This ensures proper water shedding and prevents leaks.
6) Seal Penetrations:
For areas around vents, chimneys, and skylights, cut the underlayment to fit and seal with roofing cement or an appropriate adhesive. This helps prevent water from seeping through these vulnerable spots.
7) Install Additional Drip Edge:
Once the underlayment is in place, install a drip edge along the rakes (the sloped edges of the roof). This provides added protection and a finished look.
8) Inspect Your Work:
Before installing the final roofing material, inspect the underlayment for any tears, gaps, or misaligned sections. Address any issues promptly to ensure the integrity of the roofing system.
Learn More About Roofing Underlayment
Roof underlayment is a vital component of any roofing system, offering essential protection against water infiltration, enhancing durability, and improving overall performance. Understanding the different types, costs, and installation methods can help you make an informed decision that ensures the longevity and resilience of your roof.
At O’Donnell Roofing Co., we believe in providing homeowners with the best tools and information to safeguard their homes. If you’re planning a roofing project or need expert advice, don’t hesitate to reach out to our team. We’re here to help you every step of the way.
