Choosing the Right Underlayment for a Metal Roof (North Vancouver Guide)
When installing a metal roof, one of the most important decisions you can make is choosing the correct underlayment. The underlayment acts as a protective barrier between the roof deck and the metal panels—shielding your home from moisture, heat, ice dams, and wind-driven rain. In a climate like Vancouver, North Vancouver, and West Vancouver, where rainfall and seasonal temperature changes are common, the right underlayment plays a huge role in the performance and lifespan of your metal roofing system.
At Amex Roofing & Drainage Ltd., we help homeowners choose the best materials for long-lasting, weather-resistant metal roofs. Here’s what you need to know.
What Is Roof Underlayment?
Amex Roofing North Vancouver
Roof underlayment is a water-resistant or waterproof layer installed directly over the roof deck before metal roofing panels are installed. It adds an essential layer of protection against:
Water infiltration
Ice buildup
Condensation
Wind-driven rain
Temperature extremes
For homes in the North Shore, underlayment is crucial for preventing leaks and maximizing the lifespan of your metal roof.
⭐ Types of Underlayment for Metal Roofs
1. Asphalt-Saturated Felt (Traditional Felt Paper)
A classic option and the most budget-friendly.
Pros:
Cost-effective
Provides basic water resistance
Cons:
Prone to wrinkling
Can degrade faster in humidity
Less durable for metal roofs in Vancouver’s wet climate
Best for: Smaller projects or temporary protection.
2. Synthetic Underlayment (Most Recommended)
Made from polypropylene or polyethylene, synthetic underlayments are now industry standard for metal roofing.
Pros:
Lightweight and tear-resistant
UV-resistant
Mold and moisture resistant
Safer installation due to slip-resistant surface
Ideal for Vancouver’s rain-heavy seasons
Best for: Long-term durability and better performance under metal roofing panels.
3. Self-Adhering Membranes (Ice & Water Shield)
Peel-and-stick underlayment made from rubberized asphalt.
Pros:
Creates a watertight seal
Excellent for roof valleys, eaves, and penetrations
Prevents ice dam-related leaks
Superior protection against winter conditions
Best for: Areas prone to ice buildup and heavy rainfall—perfect for the North Shore.
4. Rubberized Asphalt Underlayment
A premium, high-performance option that combines asphalt with rubber polymers.
Pros:
Exceptional waterproofing
Flexible in extreme temperatures
Long-lasting
Excellent for metal roof systems in rainy climates
Best for: Homes that require maximum moisture protection and long-term durability.
⭐ Key Factors When Choosing Underlayment
✔ Climate
Vancouver’s wet, coastal climate requires moisture-resistant, tear-resistant underlayment.
Best options: Synthetic or rubberized asphalt.
✔ Roof Slope
Steep roofs shed water quickly
Low-slope roofs benefit from self-adhering membranes for increased protection
✔ Budget
Premium underlayments cost more initially but last longer and reduce the risk of future leaks.
✔ Manufacturer Requirements
Always follow your metal roofing manufacturer’s specifications to maintain warranty coverage and system integrity.
⭐ Why Proper Installation Matters
Even the best underlayment fails if installed incorrectly. Proper installation involves:
Smooth, wrinkle-free application
Correct overlap of seams
Fully sealed edges
Secure attachment to prevent water intrusion
Proper integration with flashings and penetrations
At Amex Roofing, our trained installers ensure every metal roof system is protected from the deck up.
⭐ Consult With Amex Roofing: Get the Right Underlayment for Your Metal Roof
Choosing the right underlayment is one of the most important steps in building a durable, weather-resistant metal roof. Whether you're installing a new metal roofing system or upgrading an older one, our team provides expert guidance tailored to your home’s design, climate, and needs.
📍 Serving North Vancouver, West Vancouver, and the entire North Shore
📞 Contact Amex Roofing today to schedule a consultation or request an estimate.
By Amex Roofing
