High Temp Ice and Water Shield for Metal Roofs: 1 Minute to a Weatherproof Metal Roof

High temp ice and water shield is a specialized underlayment designed to protect metal roofs in extreme conditions. These roofing membranes create a watertight barrier that prevents water infiltration caused by ice dams, wind-driven rain, and fluctuating temperatures. Unlike standard underlayments, high temp shields are engineered to withstand the elevated temperatures commonly found beneath metal roofing panels, which can easily surpass 240°F (115°C) under direct sun exposure. They consist of a robust, heat-resistant modified bitumen layer with a self-adhesive backing, ensuring both seamless application and long-term adhesion to roofing decks.

For metal roofs, using a standard ice and water shield can lead to premature deterioration, resulting in water leaks and costly repairs. High temperature variants are not only compatible with metal’s thermal expansion and contraction but also prevent asphalt bleed-through—a common concern with asphalt-based membranes under high heat. This makes them crucial for slopes prone to snow accumulation, valleys, eaves, and other vulnerable transitions. Additionally, these shields often meet or exceed rigorous ASTM standards for temperature tolerance, making them a reliable investment for both residential and commercial buildings.

As a designer, I often emphasize the importance of selecting products that enhance both performance and aesthetic longevity. If you plan a renovation or a new build with metal roofing, integrating the right underlayment is as important as the roof itself. Incorporating a modern solution like an advanced 3D floor planner into your design phase can help visualize roof layers and detect areas needing additional protection, ensuring the durability of your entire structure.

Tips 1:

When specifying high temp ice and water shield, pay close attention to compatible adhesives and ensure proper overlap at seams. Also, always confirm that your chosen product is approved by the manufacturer of your metal roof system to avoid voiding warranties.

FAQ

Q: Why do metal roofs require high temp ice and water shield?

A: Metal roof panels absorb and radiate heat at higher levels than other shingles, requiring an underlayment that won’t degrade or lose adhesion at high temperatures.

Q: Where should high temp ice and water shield be installed on a metal roof?

A: It is best installed at roof valleys, eaves, around penetrations (vents, chimneys), and other leak-prone areas.

Q: Can I use regular ice and water shield under a metal roof?

A: Regular ice and water shield is not recommended, as it may break down under heat, leading to potential leaks and reduced lifespan of the roof structure.

Q: How thick is high temp ice and water shield?

A: Thickness varies, but most products range from 40–60 mils to provide ample waterproofing and heat resistance.

Q: What ASTM standards should high temp ice and water shields meet?

A: Look for compliance with ASTM D1970, which tests for heat resistance, adhesion, and waterproofing under severe conditions.