Window wells are an essential feature of many homes, providing natural light, ventilation, and protection for basement windows. However, one common issue that homeowners face is the rusting of their window wells. In this comprehensive article, we’ll explore the reasons behind this problem and provide practical solutions to prevent and address rusting in window wells.
The Causes of Window Well Rusting
Window wells rust primarily due to a process called electrolysis, which is the decomposition of metal caused by an electric current. This phenomenon occurs when two different metals come into contact with each other, creating a galvanic cell. In the case of window wells, the metal well is typically the least noble metal, meaning it is more susceptible to oxidation and corrosion.
The electric current that drives the electrolysis process is generated when the window well comes into contact with other metal components in the home, such as the window buck or rebar inside the foundation. The presence of moisture, particularly in the soil surrounding the window well, accelerates the decomposition process.
Factors Contributing to Accelerated Rusting
Several factors can contribute to the accelerated rusting of window wells:
Soil type: Certain soil compositions, such as those with high moisture content or high mineral content, can increase the rate of electrolysis and corrosion.
Grounding of concrete rebar: If the concrete rebar in the foundation is properly grounded, it can create an electrical circuit with the window well, leading to accelerated corrosion.
Contact between window well and other metals: When the window well mounting bolts or the window buck come into direct contact with the concrete rebar, an electrical circuit is established, and the window well becomes a sacrificial anode, leading to rapid rusting.
To determine if your window well is part of the home’s grounding circuit and susceptible to accelerated corrosion, you can perform a simple continuity test using a multimeter. If the readings between the house ground and the window well are within 10 millivolts of each other, the window well is likely part of the grounding circuit and will experience accelerated rusting.
Preventing Window Well Rusting
Preventing window well rusting is crucial to maintaining the structural integrity and aesthetic appeal of your home. Here are some effective strategies to prevent rusting:
Isolating the Window Well from the Electrical Circuit
One of the most effective ways to prevent window well rusting is to isolate the well from the electrical circuit. This can be done by breaking the connection between the window well and the concrete rebar. Here’s how to do it:
From inside the window well, cut through the mounting bolts using a reciprocating saw or other appropriate tool.
Pry the window well flange away from the window buck and insert non-conducting (plastic) shims between the flange and the buck, or use an isolator washer to separate the well from the mounting bolt.
Fill the void between the flange and the window buck with exterior-rated construction adhesive.
Perform another continuity test to verify that the circuit has been broken.
Once the circuit is broken, the window well will no longer be susceptible to accelerated anodic corrosion and should provide years of trouble-free service.
Proper Drainage and Waterproofing
Ensuring proper drainage and waterproofing around the window well is crucial to preventing rusting. Water seepage can contribute to the corrosion process, so it’s essential to address any drainage issues. Here are some steps to improve drainage:
Check for blocked or damaged drainage tubes buried underneath the gravel beneath the window well. Clear any blockages or replace damaged tubes.
Ensure that your gutter downspouts are properly directed away from the window well to prevent water from accumulating around the well.
Install a drainage system if one is not already in place. This involves augering a hole underneath the window well through the gravel, adding a drainage tube, and covering it with gravel.
In addition to drainage, proper waterproofing around the window well can also help prevent rusting. Use exterior-rated construction adhesive to seal any gaps or cracks between the window well and the foundation wall.
Painting and Coating Options
While painting or coating a window well can help protect it from rusting, it’s important to note that this is not a permanent solution. Rust will eventually eat through the paint or coating, leading to discoloration and peeling. However, if you have addressed the underlying causes of rusting, painting can provide an additional layer of protection.
When painting a window well, it’s crucial to use a high-quality acrylic latex paint designed for exterior use. Prepare the surface by thoroughly cleaning and removing any existing rust or corrosion before applying the paint.
Alternatively, you can consider using a rust-inhibitive coating or sealant specifically designed for metal surfaces. These products can provide longer-lasting protection against rusting compared to regular paint.
Replacing Rusted Window Wells
If your window well is severely rusted and the damage is beyond repair, it may be necessary to replace it entirely. When replacing a window well, consider the following factors:
Choose a material that is resistant to corrosion, such as fiberglass or stainless steel.
Ensure that the new window well is properly sized and fits securely against the foundation wall.
Install the new window well with proper drainage and waterproofing measures in place.
Consider adding a cover or grate to protect the window well from debris and prevent accidental falls.
Replacing a window well can be a more involved project, and it may be best to hire a professional if you are not comfortable with DIY home improvement tasks.
In conclusion, window well rusting is a common issue that can be addressed through proper prevention and maintenance. By understanding the causes of electrolysis and taking steps to isolate the window well from electrical circuits, improve drainage and waterproofing, and consider painting or replacement options, you can keep your window wells looking their best for years to come.