Protecting Metal Panels from Rust

By: Mike Gwizdala, General Manager

When it’s time to replace an existing roof or add one to an under-construction building, metal panels are an attractive, high-performance alternative to traditional materials. A significant benefit of metal panels is rust-resistant coatings, which offer levels of protection to suit just about any environment. Capable of enduring hurricanes, hail, and wildfires, they can last up to 50 years when properly installed. 

Whether you’re a contractor or a property owner, understanding the basics of installation and ways to minimize rust of metal panels goes a long way. It helps achieve optimum product performance and longevity. 

As a leader in metal wall and roofing panel supply, we’ve compiled simple installation and care suggestions you can use before, during, and after installation.

Finished To Last

First, let’s dispel some myths. Metal panels, when properly chosen for their climate, are not prone to corrosion. They are manufactured using various types of metals, including galvanized steel and Galvalume®, which are treated with weather-resistant paints or coatings that are designed to safeguard against corrosion and wear. The exterior coating provides enhanced durability, strength, and resistance to moisture and chemicals.

It’s also important to note that choosing the proper metal panel for your needs is essential to the longevity and performance of the system. Certain climates require certain levels of testing to ensure that products can withstand the elements (including but not limited to wind speed, heavy precipitation, and chemical exposure). Building owners should work with licensed and experienced installers that are familiar with the codes and regulations in their region to find the best metal panel to suit the needs of their building while still meeting the local requirements for a long-lasting installation.

Keep An Eye Out For Shavings 

When installing screws into a metal panel, you’re going to generate shavings. They’ll cling to wall or roof sheeting and rust over time. Corrosion will move from the shavings to the metal panel surface, which ultimately degrades performance. 

Avoiding this issue is as easy as removing shavings from the work area after installation. They can be swept up or blown off. 

Cut With Confidence

Most metal panels are supplied in standard shapes and cut to size in the field. Before cutting, it’s important to understand what tools you need and how to cut effectively to avoid exposing the metal panel to the elements.

Protective coatings are applied to the surface of metal panels during the metal treatment process. During the panel fabrication, the Galvalume metal panels are cut to length either by shearing while flat before entering the roll former, or by means of a profile shear as the panels exit the roll former. Either method tends to “wipe” the Galvalume coating across the cut edge of the metal panels. This provides superior cut-edge protection from corrosion. These coatings also help retain color and improve longevity by achieving high levels of resistance to a range of deteriorating factors including UV light, moisture, extreme heat, acidic rain, debris, corrosion, and fire.

When panels arrive on-site, any needed field cutting should address the same concerns of protecting the edge of the steel from corrosion. Cut edges of metal panels need to be “touched up” with a manufacturer-accepted product to keep the panel protected against these same deteriorating factors. Additionally, using proper equipment such as aviation snips, electric shears, mechanical shears, or nibblers, will help you cut metal panels efficiently without causing unintended damage to coated surfaces.

Careful What You Write With 

Graphite, which is found in pencil lead, is harmful to Galvalume panels. The graphite breaks down Galvalume’s protective layer, which leads to corrosion. 

As a result, it’s best to avoid writing on metal panels with a pencil. Permanent markers, Sharpies, or dry erase markers are perfect. If pencils are used, make sure to remove markings without delay. 

Other Factors to Consider

Although metal panels offer outstanding elemental resistance and durability, they aren’t perfect. The most important item to remember is to make sure you are not adding something that will react chemically or negatively with the galvalume finish.

For example, HVAC units installed on a metal roof might drip condensation or leak. The moisture deposits onto metal panels, which corrode over time. Condensate should either be filtered before exiting onto the roof panel or drained by piping.

Troubleshooting Solutions

Most property owners select metal panels over other construction materials because they’re strong and durable. Sometimes, even when the best effort, dissimilar metal discoloration may occur. In the extremely rare instances where this happens, there are safe ways to resolve the situation. 

If it’s just a surface stain and the coating is undamaged, mild detergents are a perfect remedy. Some good options are Formula 409®, Simple Green®, and Soft Scrub® without bleach. 

Never use heavy solvents to clean up stains. They’ll remove paint and adversely affect the metal. If you see a rust stain on the roof, don’t go up there with paint remover, acetone, or other toxic solvents and start scrubbing. 

The Metal Panel Experts

EXCEPTIONAL® Metals supplies a wide range of metal panel products to contractors and builders across North America, including Galvanized steel and Galvalume-coated options. Lightweight, durable, and easy to install, they’re perfect for your next construction project. 

From commercial spaces, warehouses, banks, schools, universities, industrial complexes, manufacturing facilities, cold storage, airports, medical facilities, residential homes, and more, we offer metal panel options to suit any aesthetic and performance need.

Whether you’re an interested property owner or a contractor specializing in installation and upkeep, EXCEPTIONAL Metals is here to help you enjoy the benefits of metal panels. Contact us to learn more about the benefits of metal panels and how to protect them from corrosion.