Keep your rolling doors clean and reduce the risk of corrosion with these tips. 

In certain regions, ice and snow are the norm during the winter months. These conditions are hazardous for people and vehicles. Like most businesses, you’ll likely throw down rock salt or ice melt on your driveways, ramps, and walkways to improve traction and prevent injury risks. 

While ice melt is necessary to avoid accidents, it can cause serious damage to garage doors. Here's how to remove salt stains from your doors and prevent corrosion to the curtain and mechanics.

Why do white salt stains appear on your garage door in the winter? 

Most importantly, you should have a good understanding of why salt can damage your commercial doors. This knowledge might encourage you to take a proactive approach to protecting your doors. 

The very first sign of salt damage are light stains on your door. Salt stains look like rough circles or ovals with thick, dry edges. If the salt has crystallized, the stain will be white, like the area has been bleached. 

Left untreated, damaged areas will show as reddish-brown rust spots on the bottom door sections. These spots will continue to grow and become more noticeable over time. Eventually, salt damage will begin to corrode the protective finish and paint, which will chip, bubble, or peel away, exposing raw steel or aluminum underneath. Hardware and other metal components can begin to rust and show signs of damage. In its most advanced stage, you’ll see pitting or holes in the metal. 

What is salt, and how does it work?

You’re probably familiar with two types of salt, road salt and sidewalk salt. The main ingredient in both is typically either sodium chloride (table salt) or calcium chloride. Road salt is less refined than sidewalk salt, with larger crystals and anti-caking agents, dirt, and minerals. Both types of salt will have a negative effect on your commercial doors. 

Salt works by accelerating chemical reactions, interacting with both your door and the surrounding environment. Road salt and water from precipitation speed up rust formation. When water and salt mix and meet metal doors, the salt's ions help oxygen and carbon dioxide turn the metal into iron oxide, or rust, making the door corrode faster than normal. While your door might have a protective finish, salt crystals can stick to its surface, causing discoloration and leading to paint damage over time if it’s not removed. 

How to prevent salt stains on commercial doors. 

Salt not only leaves stubborn stains on your doors, but can cause permanent damage. Which is why it’s important to take preventative steps. The most effective way to protect your doors from salt is to wash them frequently, especially before and during winter. 

To clean your door, use mild detergent (like dish or car wash soap), a soft clean cloth, warm water, and a soft scrubbing pad. Start by removing loose debris with a soft cloth and rinsing the door with a garden hose. Then, wipe down the door with a soapy water solution (using a small amount of soap and warm water) while spraying it to prevent water spots. For tough stains, use the soft scrubbing pad. Finally, rinse the door again and remove any remaining soap residue or dirt with a cloth, sponge, or brush. Either let your door air dry or wipe it down to prevent water spots.

If you have full-view doors with glass sections, use glass cleaner in lieu of detergent.  Pressure washing doors can strip the protective finish and paint, so it's not recommended.

By following these tips, you can help protect your commercial rolling doors from winter salt damage and keep them looking and functioning their best for many years to come.

Related: Troubleshooting Your Commercial Door: Why It's Not Closing Right & When to Call an Expert