🛠Corrugated Metal Roofing: Troubleshooting Common Problems
Corrugated metal roofing is a durable, cost-effective option for many buildings, but like any material, it can encounter issues over its lifespan. For building owners and managers, knowing how to identify and address these common problems is key to maintaining the roof's integrity and extending its life.
Here at Romes Construction, we've seen and solved it all. Here’s our guide to the most frequent corrugated metal roofing issues and how to fix them.
💧 The Leaking Roof
Leaks are perhaps the most common and disruptive problem. With corrugated panels, leaks often originate from the exposed fasteners or improper installation/sealing.
Loose or Deteriorated Fasteners: Corrugated roofs typically use screws with rubber (neoprene) washers. Over time, heat, UV exposure, and thermal movement cause these washers to degrade, or the screws themselves to loosen.
The Fix: Inspect all fasteners regularly. Tighten any loose screws, being careful not to overtighten (which can damage the metal). Replace damaged or missing screws with high-quality, new screws that have intact neoprene washers, ensuring a watertight seal. For severely degraded areas, a quality sealant applied around the fastener may also be necessary, but this should not be a permanent replacement for the washer.
Failed Sealant or Flashing: Sealants at panel overlaps, edges, and around penetrations (vents, pipes, chimneys) can dry out and crack. Poorly installed flashing is another major leak source.
The Fix: Remove old, cracked sealant completely. Clean the surface thoroughly and apply a high-grade, UV-resistant roofing sealant compatible with metal. Reinstall or repair flashing components, making sure all seams are properly secured and sealed.
🌡 Thermal Movement and Buckling
Metal expands in heat and contracts in cold. This constant movement can stress the system, leading to issues like:
Warping and Buckling (Oil-Canning): This visible waviness in the flat areas of the panels is often a cosmetic issue but can indicate stress. Restricting the natural movement of the panels (often through over-fastening) is a common cause.
The Fix: While oil-canning is difficult to completely eliminate once present, proper installation is the best prevention. Ensure your installer uses fasteners that allow for slight panel movement and accounts for thermal expansion gaps. Using a thicker gauge metal can also reduce the likelihood of this issue.
Corrosion, Chalking, and Fading
Despite their durability, metal roofs are susceptible to surface damage that leads to long-term deterioration.
Rust and Corrosion: This is especially a concern near the coast, in industrial areas, or where scratches expose the metal substrate.
The Fix: Regularly clean the roof to remove trapped debris, dirt, and chemical residue that can accelerate corrosion. For minor rust spots, gently remove the rust with a wire brush, then apply a rust-inhibiting primer and a touch-up paint that matches your roof’s color. For extensive corrosion, you may need to apply a protective roof coating or replace the panel entirely.
Chalking and Fading: UV exposure causes the paint resin to break down (chalking—a whitish residue) and the color to lighten (fading).
The Fix: While unavoidable over decades, using panels with high-quality, long-lasting paint systems (like Kynar 500® or Hylar 5000®) is the best defense. For existing roofs, cleaning and a re-coating application can restore the appearance and add a new protective layer.
Noise Issues
Corrugated metal can amplify the sound of heavy rain or hail, which can be a nuisance for occupants.
The Fix: For new construction or a total re-roof, ensure proper insulation or sound-dampening underlayment is installed beneath the panels. This provides both thermal and acoustic benefits. For existing roofs, adding insulation to the attic space below can help significantly reduce noise transmission.
✅ The Romes Construction Advantage
Maintaining a corrugated metal roof doesn't have to be a headache. By performing biannual inspections (spring and fall) and addressing small issues like loose fasteners and minor rust before they escalate, you can ensure your roof provides decades of reliable protection. When in doubt, call in a professional roofing contractor—like us!—to perform a thorough inspection and execute precision repairs