In the realm of roofing, where protection meets longevity, underlayment plays a pivotal role. It acts as a shield, safeguarding your home from external damage and ensuring the integrity of your roofing system.
While asphalt shingle roofs have long dominated the landscape, the rise of metal roofing has brought forth new considerations and challenges in underlayment selection and installation. But if you’re investing in a metal roof and not sure where to start, you’ve come to the right place! Today, we’ll cover:
- Metal roof underlayment materials
- Understanding what underlayment
- How to take care of your metal roof system.
What is Roofing Underlayment?

Roofing underlayment, often referred to as felt or synthetic underlayment, is a crucial layer installed between the roof deck and the roofing material. Its primary functions include providing an additional barrier against water infiltration, enhancing weather resistance, and serving as a temporary protection during roof installation.
Metal Roofing: Unique Underlayment Needs
Unlike traditional asphalt shingle roofs, metal roofing presents distinctive underlayment requirements. While both systems share the fundamental purpose of protecting the underlying structure, the nature of metal roofing demands enhanced durability and compatibility with the roofing material.
Metal roofs are more susceptible to expansion and contraction due to temperature variations, necessitating underlayment materials with superior flexibility and resilience.
3 Types of Underlayment for Metal Roofing
When it comes to roof underlayment, you havea variety of options, depending on your end goal. Here are 3 popular options to pair with your new metal roof:
1) Synthetic Underlayment:
Synthetic underlayment, crafted from polypropylene or polyester, offers excellent durability and resistance to tears and punctures. Its lightweight nature facilitates ease of installation and handling, making it a popular choice for metal roofing applications.
2) Rubberized Asphalt Underlayment:
Combining rubberized asphalt with fiberglass or polyester reinforcement, this type of underlayment provides exceptional waterproofing properties. Its self-adhesive backing ensures secure attachment to the roof deck, effectively sealing out moisture and preventing leaks.
3) Peel-and-Stick Membrane:
Peel-and-stick membranes feature a self-adhesive backing that adheres directly to the roof deck, creating a watertight seal. With its ease of installation and superior adhesion properties, this underlayment type is ideal for metal roofs with complex geometries or low-slope configurations.
Understanding Durability and Longevity
The lifespan of roofing underlayment varies depending on factors such as material quality, climate conditions, and installation practices. Generally, synthetic underlayment boasts a longer lifespan compared to traditional felt underlayment, with some products offering warranties of up to 50 years.
However, it’s essential to conduct regular inspections to monitor for signs of wear and deterioration, as prolonged exposure to UV radiation and extreme weather can degrade the underlayment over time.
Signs of Underlayment Damage
Detecting early signs of underlayment damage is crucial for maintaining the integrity of your roofing system. Common indicators of underlayment issues include:
- Tears or punctures
- Buckling or wrinkling
- Moisture stains on ceilings or walls
- Mold or mildew growth
- Visible signs of degradation or deterioration
Cost of Underlayment Installation
The cost of installing new underlayment varies depending on factors such as roof size, underlayment type, and labor expenses. On average, homeowners can expect to pay between $1,000 to $3,000 for underlayment replacement on a typical residential roof. However, opting for premium-grade materials or hiring specialized contractors may incur additional costs.
Can You Install New Underlayment Without Replacing the Whole Roof?
In most cases, it’s possible to install new underlayment without replacing the entire roof, especially if the roofing material is in good condition. However, it’s essential to assess the condition of the existing underlayment and address any underlying issues before proceeding with the installation. Partial underlayment replacement can extend the lifespan of your roofing system and mitigate the risk of water damage or leaks.
Caring for Your Metal Roofing System

To ensure the longevity and performance of your metal roofing system, proactive maintenance is key. Here are some essential maintenance tips to keep your roof in top condition:
Regular Inspections:
Schedule annual inspections to assess the condition of your metal roof and underlayment. Look for signs of damage or deterioration and address any issues promptly to prevent further damage.
Clear Debris:
Remove debris such as leaves, branches, and dirt from your roof to prevent water pooling and potential damage to the underlayment.
Trim Overhanging Branches:
Trim tree branches that overhang your roof to minimize the risk of debris accumulation and damage during storms or high winds.
Address Leaks Promptly:
If you notice signs of water infiltration or leaks, take immediate action to identify the source and repair any damaged areas of the underlayment.
Maintain Gutters and Downspouts:
Keep gutters and downspouts clear of debris to ensure proper drainage and prevent water from backing up onto the roof surface.
Protect Your Roof With Us!
In the realm of metal roofing, underlayment serves as a critical line of defense against the elements, providing essential protection and structural support. By understanding the unique underlayment needs of metal roofing systems and adopting proactive maintenance practices, homeowners can ensure the longevity and performance of their roofs for years to come.
Whether you’re embarking on a new roofing project or seeking to prolong the lifespan of your existing metal roof, investing in quality underlayment is a decision that pays dividends in terms of durability, reliability, and peace of mind. Got questions? Roof Medic has the answers you need. Contact us today to get your metal roof underlayment installed properly!