Designed primarily for commercial projects, but widely used on larger, design-forward homes, Medallion-Lok offers crisp, narrow seams, concealed fasteners, and the refined profile architects love. And because it's part of McElroy Metal's standing seam family, it's backed by our commitment to long service life, premium coatings, and industry-leading testing.
In this blog, we'll walk through what Medallion-Lok is, who it's designed for, where it works best, how it installs, and how it compares to other standing seam options in our lineup. By the end, you'll know exactly whether this panel fits your next project.
Medallion-Lok is a concealed-fastener, snap-together standing seam panel built to provide the clean, contemporary appearance many designers want today. While its look is unmistakably sleek, the strength behind the panel is equally impressive.
Medallion-Lok is available with the industry's best-in-class PVDF finish, Kynar 500®. This coating offers exceptional long-term resistance to:
If you're designing for longevity and color stability, this finish is the gold standard.
Medallion-Lok can be ordered in all of McElroy Metal's architectural PVDF finishes, including Matte Black, Copper Penny, Brite Red, Patina Green, Regal Blue, Ash Gray, Texas Silver Metallic, and many more.
Explore full color options on our Color Visualizer to mock up your project in real time.
Medallion-Lok may be chosen for its appearance, but its engineering is what keeps it performing for decades. Every detail in the system supports long-term durability.
If your project needs documented compliance for high-wind regions, Medallion-Lok checks the boxes.
This makes Medallion-Lok a versatile option for both commercial structures and custom homes.
A factory eave notch can be ordered for a clean, finished transition at the eave, reducing field labor and improving appearance.
Medallion-Lok is one of the most versatile architectural systems in our lineup. While it's built for commercial-grade performance, it's frequently selected for residential and specialty applications where aesthetics matter just as much as longevity.
Medallion-Lok tackles several of the challenges that typically come with traditional roofing systems. Here's how:
Installing a concealed-fastener standing seam system requires attention to detail, and Medallion-Lok is designed to make that process as straightforward as possible with its snap-together seam and concealed clip system. To help ensure a smooth installation and long-term performance, here are the recommended underlayment and accessory considerations:
Snap-together standing seam panels require:
Medallion-Lok contributes to long-term environmental performance thanks to its materials, finishes, and lifespan.
Metal roof panels are recyclable at the end of life, reducing landfill impact.
PVDF finishes help maintain reflectivity over time, reducing cooling loads in warm climates when reflective colors are selected.
While lifespan varies based on climate and maintenance, Medallion-Lok is built for multi-decade performance when properly installed and maintained.
McElroy's "Operation and Maintenance Manual (Roofs)" provides complete guidance.
All resources are available on the Medallion-Lok page, including:
You may download these documents on our Medallion-Lok page.
For our current project at "Catalpa Gardens" (pic below), I chose to submit McElroy's Medalion-Lok because McElroy has "Old McDonald Yellow" as a color option. Half of this building we're working on is being covered in this color which is semi-standard for McElroy. Any other manufacturer would have cost us a large amount of money for "a custom color". Also, because your facility in Illinois is downstate and has much lower taxes than Chicago, we saved a good amount of money on taxes.
So basically, the architect picks the profile, and we can usually choose the manufacturer. For our current project, McElroy had the best value. - Ryan Hill of Knickerboker Sheet Metal
| Product | Best Use Case | Strengths | Choose When You Need… |
|---|---|---|---|
| Medallion-Lok | Architectural roofs/walls | Sleek narrow seam, PVDF finishes, snap-together ease | Beauty + performance for commercial or custom residential |
| Maxima | High-end commercial & structural | Mechanically seamed, high uplift, long panel runs | Highest structural performance |
| Meridian | Residential/light commercial | Economical, snap-together concealed fastener | Budget-conscious with architectural appearance |
| 138T | Metal-over-metal and metal-over shingle recover system | Patented 138T Clip creates a structural airspace: minimizes tear-off | A recover solution that avoids removing the old roof while improving energy performance |
| 238T | Commercial/industrial recover systems | Stronger version of 138T; taller 2⅜" seam; high wind uplift | A structural recover system for commercial buildings needing extreme uplift performance |
Installation over shingles is not standard. The roof deck must be evaluated, and many projects require re-decking or installing an approved overlay system. Always check local codes and the installation manual.
Yes. Medallion-Lok has UL 580 uplift approvals, UL 2218 Class 4 impact resistance, and Florida/Miami-Dade approvals. Always follow job-specific gauge and clip spacing requirements.
Medallion-Lok features Fluropon®/Kynar 500® PVDF paint—industry-leading for color retention, UV protection, and long-term appearance.
No. Lightning is influenced by structure height and location, not roofing material. Metal roofs are actually safer because they are non-combustible.
If you're designing a modern home, commercial project, or architectural structure that needs both performance and beauty, Medallion-Lok is an excellent fit.
Here's what you can do next:
When you're ready, McElroy Metal is here to help you build with confidence—one panel at a time.