Deliver long-term performance on metal roof restorations

By Dani Sheehan. 

Learn how to provide a lasting solution on a leaky metal roof. 

Metal roofs are known for durability, but over time can begin to show signs of wear, from oxidation and corrosion to failed seams and compromised fasteners. Restoring these roofs requires a full system approach designed to stop corrosion, reinforce the substrate and protect the roof long term. 

In a recent field demonstration, Chris Huettig, technical director at KARNAK, walked through a complete metal roof restoration process, highlighting how KARNAK 404 Corrosion Proof Base Coat and 501 Elasto-Brite work together to deliver durable, energy-efficient performance.  

Step one: Preparation 

As shown in the demonstration, successful metal roof restoration starts with thorough surface preparation. This step is often underestimated, but it plays a critical role in coating adhesion and long-term durability. 

The roof was prepared using: 

• Mechanical abrasion tools, including scrapers and wire brushes 
• Drill-mounted wire brushing to address oxidation 
• KARNAK 799 Wash and Prep Rooftop, used to clean the surface and remove contaminants 
• Power washing to rinse away loosened debris 

Step two: Repairs and sealing 

Once the surface was clean and dry, sealants were applied to address common metal roof problem areas such as seams and laps, fasteners, transitions and penetrations. These repairs ensure the system functions as a waterproofing solution. 

The foundation: 404 Corrosion Proof Base Coat 

Designed specifically for metal roofs, 404 is an acrylic base coat formulated with rust inhibitors to help prevent future corrosion. This is a critical feature for aging metal systems, where untreated oxidation can continue spreading beneath a finish coat. 

The finish coat: Protection, reflectivity and energy performance 

Once the roof is repaired, cleaned and primed with a base coat, the finish coat becomes the first line of defense against the elements. KARNAK 501 Elasto-Brite performs in tough commercial environmental: 

• ASTM D6083 Type I compliant, meeting industry standards for acrylic coatings 
• Bright, highly reflective white surface 
• Energy Star rated for cool roof performance 
• Elastomeric properties to handle rooftop movement, temperature swings and long-term weather exposure 
• UV protection that slows degradation of the underlying roof system 

Together, 404 and 501 create a restoration solution that addresses metal’s biggest threat, corrosion, and protects the system from UV, heat and environmental exposure. This layered approach reduces the risk of premature failure and delivers predictable performance. 

Watch the video to learn more about KARNAK’s solutions, each designed to provide long-term performance through system-based restoration.