What is the Best Underlayment for a Metal Roof?

Choosing the right underlayment is crucial when installing a metal roof. The underlayment acts as a protective barrier between the metal panels and the roof deck, preventing moisture infiltration and enhancing the longevity of your roof. But with multiple options available, which underlayment is the best for a metal roof?

In this guide, we’ll cover:

• The different types of metal roof underlayments
• The benefits and drawbacks of each type
• How to choose the best underlayment for your metal roofing system

Why Does a Metal Roof Need Underlayment?

Underlayment provides essential protection against water damage, condensation, and extreme weather conditions. While metal roofs are durable, they are not completely waterproof on their own. A quality underlayment prevents leaks and enhances insulation, reducing the risk of mold and structural issues.

Types of Underlayment for Metal Roofs

There are three primary types of underlayment used for metal roofs:

1. Felt Underlayment

Felt underlayment, also known as asphalt-saturated felt, is one of the most traditional choices. It comes in two grades: 15-pound and 30-pound felt. The 30-pound variety is thicker and more durable.

Pros:

• Affordable and widely available
• Provides decent protection against moisture
• Easy to install

Cons:

• Can absorb moisture and deteriorate over time
• Not as durable as synthetic options
• Heavy and difficult to handle in large roofing projects

2. Synthetic Underlayment

Synthetic underlayment is made from woven or spun polyethylene or polypropylene materials. It is designed to be more durable and resistant to tearing compared to traditional felt underlayment.

Pros:

• Lightweight and easy to install
• Highly resistant to moisture and mold
• More durable and long-lasting than felt
• Offers superior traction for roofers during installation

Cons:

• More expensive than felt underlayment
• Some lower-quality synthetic underlayments may not perform well in extreme temperatures

3. Self-Adhering (Peel-and-Stick) Underlayment

This underlayment is a rubberized, adhesive-backed material that creates a waterproof seal on the roof deck. It is commonly used in areas prone to heavy rain, snow, or ice damming.

Pros:

• Provides the highest level of waterproofing
• Ideal for high-moisture and extreme weather conditions
• Self-sealing around nails and fasteners

Cons:

• More expensive than other underlayment options
• Requires precise installation to avoid air pockets

What is the Best Underlayment for a Metal Roof?

The best underlayment for your metal roof depends on several factors, including climate, roof slope, and budget. Here’s a breakdown of the best choices based on specific needs:

• For general residential use: Synthetic underlayment is the best all-around choice due to its durability and moisture resistance.
• For high-moisture or extreme weather areas: Self-adhering underlayment provides the best protection against leaks and ice dams.
• For budget-conscious projects: Asphalt felt underlayment is a cost-effective option, though it may not last as long as synthetic or peel-and-stick varieties.

How to Choose the Right Underlayment for Your Metal Roof

When selecting underlayment, consider the following factors:

1. Climate Conditions

If your area experiences heavy rainfall, snow, or extreme temperatures, a high-performance synthetic or peel-and-stick underlayment is recommended.

2. Roof Slope

For steep-slope metal roofs, synthetic underlayment works well because it provides excellent traction for workers and resists slipping.

3. Longevity

Metal roofs can last 40-70 years. Choosing a long-lasting underlayment, such as synthetic or self-adhering, ensures your entire roofing system remains protected.

4. Installation Process

Synthetic underlayment is lightweight and easier to install, while peel-and-stick underlayment requires precise placement to prevent trapped air pockets.

Work with Professionals for the Best Results

At S&K Construction and Remodeling LLC, we specialize in metal roof installations across Northeast Ohio. Our expert team ensures your roof is built with the best materials, including high-quality underlayment that enhances durability and weather resistance.

As an Owens Corning Preferred Contractor, we provide top-tier roofing services to homeowners looking for reliability and excellence. Contact us today for a consultation and get the best underlayment for your metal roof!