What Is Siding Oxidation? Causes, Effects, and Solutions

Siding is an essential part of any home’s exterior, providing both aesthetic appeal and protection against the elements. However, over time, homeowners may notice their siding developing a chalky, faded, or powdery appearance. This phenomenon is known as siding oxidation. But what exactly is siding oxidation, and how can you prevent or fix it? Let’s explore.

Does Your Homes Siding Have Oxidation? Probably So.

Siding oxidation occurs when the outer layer of siding materials—especially vinyl, aluminum, and fiber cement—reacts with oxygen, UV rays, moisture, and pollutants in the environment. This reaction causes the siding to break down and form a chalky residue on the surface. It’s most noticeable on older homes or homes exposed to intense sunlight for prolonged periods.

What Causes Siding Oxidation?

Several factors contribute to siding oxidation, including:

1. Sun Exposure & UV Rays

Ultraviolet (UV) rays from the sun degrade the protective layers of siding, breaking down chemical compounds in materials like vinyl and aluminum. Over time, this leads to fading and a chalky texture.

2. Moisture & Humidity

Rain, humidity, and moisture can accelerate the oxidation process, especially in humid climates. Water exposure can strip away protective coatings, leaving the siding more vulnerable to oxidation.

3. Air Pollutants & Chemical Exposure

Pollutants from vehicles, factories, and even household chemicals can speed up the oxidation process. Acidic rain and airborne contaminants can cause the siding to deteriorate faster.

4. Poor Maintenance

Neglecting regular cleaning and maintenance allows dirt and oxidation buildup to worsen, making the siding appear even more faded and worn out.

Signs of Siding Oxidation

How do you know if your siding is oxidizing? Look for these common signs:

• Chalky or powdery residue: Run your hand over the siding—if a white or faded powder rubs off, oxidation is present.
• Fading and discoloration: The siding may appear unevenly faded, with some areas more worn than others.
• Dull or lackluster appearance: Oxidation causes siding to lose its original shine, making it look old and worn.
• After your home is washed and begins to dry it may appear as if the siding is “streaked.” Nothing unusual there the first rain will even out the oxidation.

Can Oxidized Siding Be Fixed?

It’s possible to remove oxidation with a lot of work and possibly expense.  Removing oxidation requires manual agitation with a brush after applying the proper cleaners, dwell time and scrubbing every piece of siding from the bottom up.  This can easily turn into a full day or multiple day project.  Also, you never know exactly what the results will be until the full side of the house is done and fully dried.  Typically the side will be lighter after oxidation removal than the other sides of the home.

Painting or Replacing The Siding

For severely oxidized siding that cannot be restored very well, consider repainting (if the material allows) or replacing it entirely. This is often necessary for very old or highly degraded siding.

How to Prevent Siding Oxidation

While oxidation is a natural process, you can slow it down with proper maintenance:

• Regular Cleaning: Wash your siding at least once a year to remove dirt and contaminants.
• Use Protective Coatings: Some siding treatments and sealants offer UV protection and slow down oxidation.
• Trim Vegetation: Keep trees and bushes from rubbing against the siding, which can wear away protective layers.
• Choose High-Quality Siding: When installing new siding, opt for UV-resistant and durable materials designed to withstand oxidation.

Bottom Line

Siding oxidation is a common issue that affects many homes in Charlotte, particularly those exposed to harsh sunlight, moisture, and pollutants. While it can make your home look aged and neglected, it’s just what happens to siding over time.  Pressure washing removes organics like mold, mildew, algae as well the ever present dirt and spider webbing.  Oxidation removal is not included with a House Washing service.