Egress Window Condensation

Why Does Condensation Form on Egress Windows?

Condensation on or around an egress window typically occurs when warm, moist indoor air comes into contact with the cold surface of the window, especially during cooler seasons. While this can be a normal reaction to temperature changes, persistent or heavy condensation is often a sign of deeper issues.

Here are the most common reasons it occurs:

1. High Humidity in the Basement

Basements naturally hold more moisture than upper floors, especially if they’re not well-ventilated or have poor drainage. Everyday activities, such as laundry, showers, or running a dehumidifier improperly, can raise humidity levels, which leads to condensation forming on cool surfaces, like egress windows.

2. Poor Window Insulation

If your egress window isn’t properly insulated or sealed, it allows cold air to leak in and mix with the warmer indoor air. This temperature difference can cause the glass or the surrounding frame to “sweat,” especially during the fall and winter.

3. Inadequate Window Wells

A window well that collects water or allows rain to seep against the window can raise humidity near the glass. Over time, this damp environment encourages condensation and can also increase the risk of leaks or seepage.

4. Temperature Imbalance

Basements are cooler by design, but large swings between indoor and outdoor temperatures—especially if your HVAC system doesn’t adequately service the basement—can accelerate condensation. This is especially common during seasonal transitions when humidity is high but heating or cooling is inconsistent.

5. Poor Ventilation or Airflow

Egress windows often sit in tight corners of a finished basement. Without proper airflow or ventilation in that area, humidity can build up and linger, allowing condensation to form and stay longer than it should.

6. Failed or Aging Windows

Older egress windows may have compromised seals or double-pane systems that allow moisture to collect between panes. If you're seeing condensation inside the window, it’s likely due to a failed seal, and the window may need to be replaced.

Why It's a Problem

Egress window condensation may seem like a small issue, but it’s often a sign of a larger moisture imbalance in your basement. When condensation builds up repeatedly, it creates a damp environment that encourages mold growth, wood rot, and deterioration of insulation or drywall. Over time, this excess moisture can damage framing, weaken materials around the window, and lead to costly repairs, especially in finished basements where flooring and wall coverings are more vulnerable.

In many cases, condensation is the first visible warning that your basement is holding too much humidity or that there’s a ventilation or drainage problem nearby. Addressing it early helps protect the value of your basement space and prevents the spread of moisture-related damage throughout your home.

How '58 Foundations & Waterproofing Can Help

When you contact '58 Foundations & Waterproofing about condensation on your egress window, one of our Certified Foundation Specialists will perform a detailed inspection of the egress window and surrounding area. We’ll look for signs of high humidity, poor insulation, drainage issues, and any other factors contributing to the problem. Based on what we find, we may recommend solutions such as sealing or insulating around the window, improving drainage in the window well, or addressing ventilation issues within the basement. In some cases, we may also suggest a dehumidifier or additional waterproofing measures to help control moisture levels. Our goal is to find the source of the problem and provide a lasting solution that protects your basement from future damage.

Schedule a Free Inspection Today

If you’ve noticed condensation on your basement egress window, it’s time to have a Certified Foundation Specialist take a look. Contact '58 Foundations & Waterproofing to schedule your complimentary inspection and discover the ideal solution for your home.