When homeowners invest in standing seam copper roofing, steel roofing, or any premium metal roofing system, the focus is usually on what you can see – the panels, the seams, the flashing details, and the finished look. But the truth is, the long-term performance of copper roofing and sheet metal roofing depends heavily on what you can’t see: the waterproof underlayment underneath.
At Architectural Copper & Sheet Metal Ltd., Patrick treats roof underlayment as a first-class system – because most roof problems don’t start on the surface. They start below it.
The Underlayment Is the Roof’s Real Waterproofing Layer
Metal roofing is engineered to shed water fast, but Ontario weather can be unforgiving. Wind-driven rain, freeze-thaw cycles, ice damming, and heavy snow loads can push moisture into places you didn’t expect. That’s why roof underlayment installation matters so much. The underlayment acts as a continuous waterproof barrier that protects the roof deck from infiltration, especially at vulnerable areas like eaves, valleys, chimneys, skylights, and roof transitions.
If water ever gets past the metal – through an extreme storm, ice buildup, or a complex transition – the underlayment is what stands between your home and a leak.
What Patrick Uses – FT Synthetic High-Temperature Peel and Stick Underlayment
For metal roof waterproofing, Patrick uses FT synthetic high-temperature peel and stick underlayment. This type of waterproof underlayment is designed to bond directly to the roof deck, creating a sealed, self-adhered barrier. The “high temperature” rating is especially important for metal roofing because metal surfaces can heat up significantly in direct sun. A high-quality high-temp membrane is built to handle those temperatures without degrading, slipping, or losing adhesion.
This is the kind of detail that quietly protects a roof for years – and it’s one of the reasons a well-built copper roof underlay system can outperform cheaper installations in real-world conditions.
Where Underlayment Makes the Biggest Difference
Even the best standing seam copper roofing system relies on underlay in the most sensitive areas. Waterproof underlayment is especially important at:
- Eaves and lower roof edges where ice damming can occur
- Valleys where water concentrates and flows fast
- Chimneys and penetrations where copper flashing integrates with roofing
- Transitions and dormers where roof geometry gets complex
- Areas prone to wind-driven rain and drifting snow
In these zones, the underlayment isn’t “extra” – it’s protection against the exact conditions that cause most leaks on any roof system, including durable metal roofing.
Why High S / High C Clients Appreciate This Detail
Homeowners and building owners who value craftsmanship, reliability, and long-term thinking tend to care about the parts of the roof that most people never see. If you’re the type of person who wants to know the job was done properly – with the right materials, installed carefully, and built to last – underlayment is a major indicator of quality.
That’s why Architectural Copper & Sheet Metal Ltd. approaches metal roof waterproofing with the same precision used for copper flashing, custom metal fabrication, and architectural sheet metal cladding. It’s not about rushing to the visible finish. It’s about building a complete system that performs.
Underlayment Protects Your Investment in Copper and Steel Roofing Solutions
Copper roofing and steel roofing suppliers provide exceptional materials, but materials alone don’t create performance. The installation system does. A properly installed high-temperature peel and stick membrane helps preserve the roof deck, reduce leak risk, and support the long-term durability of the entire roof assembly. It also complements detailed work like chimney caps and flashing, custom fascia, and copper gutters and downspouts by keeping the substrate protected from moisture-related deterioration.
Request a Quote
If you’re planning a standing seam copper roofing project, considering steel and copper roofing solutions, or want to discuss roof underlayment installation for a new build or restoration, Architectural Copper & Sheet Metal Ltd. is here to help. Reach out to Patrick to talk through the right waterproof underlayment strategy for your roof.