Windows are essential components of a home, providing light, views, ventilation, and insulation. Over time, though, various issues can arise. Here are some common residential window failures and their causes:

Seal Failure in Insulated Glass Units (IGUs):

Symptoms: Fogging, condensation, or mineral deposits appear between the panes of double or triple-glazed windows.

Causes: Seal degradation, manufacturing defects, or excessive pressure differentials can lead to seal failure, allowing moisture to enter the space between the panes.


Symptoms: Cold air seeping through the window, especially noticeable during colder months.

Causes: Degraded or missing weatherstripping, poor installation, warped frames, or gaps in the frame or between the window and the wall.

Operational Problems:

Symptoms: Difficulty opening, closing, or locking the window.

Causes: Warped frames, hardware failure, paint sealing the window shut, or settlement of the house causing misalignment.

Rot or Decay:

Symptoms: Soft, crumbling, or discoloured sections on wooden window frames.

Causes: Prolonged exposure to moisture due to poor maintenance, lack of proper sealing, or inadequate drainage.

Cracked or Broken Glass:

Symptoms: Visible cracks or breaks in the window pane.

Causes: Physical impact, thermal stress (extreme temperature fluctuations), or manufacturing defects.

Leaking Windows:

Symptoms: Water penetration around or through the window, especially after rain.

Causes: Poor installation, degraded sealants, faulty flashing, or clogged weep holes (in sliding or hung windows).

Excessive Outside Noise:

Symptoms: Increased noise from the outside, such as traffic or neighbour sounds.

Causes: Single-pane windows, poor sealing, or lower-quality IGUs.

Condensation on Interior Surface:

Symptoms: Moisture or droplets forming on the interior side of the window.

Causes: High indoor humidity combined with cold exterior temperatures. This isn’t necessarily a window “failure,” but rather an indication of indoor moisture levels.

Discoloration or Fading:

Symptoms: Fading of window frames, especially in vinyl or wooden windows, or discoloration of special window coatings.

Causes: Prolonged exposure to UV rays, age, or inferior quality materials.

Degraded Glazing Compound or Putty:

Symptoms: Cracked, missing, or loose glazing around the glass pane.

Causes: Age, exposure to elements, or poor-quality materials.

When encountering these failures, it’s essential to determine the cause to apply the proper remedy. Some issues might be addressed with simple repairs, while others may necessitate partial or complete window replacement. Regular maintenance and inspections can help homeowners identify and address problems early, extending the life and performance of their windows.