Why do windows fog?
This is a typical issue with modern, insulated windows (two or more window panes). Over time, the seal between window panes can fail. This allows moisture to seep in between window panes – which can give the glass a foggy look. It also decreases the energy efficiency of the window. Window seals fail for a variety of reasons, including:
- Weather affecting windows (thermal expansion, air pressure from wind, etc.)
- Settlement (puts pressure on panes)
- Improper installation
- Poor maintenance (either deferred maintenance, or improper maintenance – such as pressure washing that might damage the window)
How to fix foggy windows
- Check your warranty. Window companies will sometimes offer window replacement if a seal fails prematurely.
- Replace the Insulated Glass Unit (IGU). A window contractor can replace the glass part of the window instead of the whole window (including the frame). This is usually the most cost effective method.
- Replace the entire window. Sometimes this is the best option if there are other window issues – such as an older window that has a warped frame.
- Defog the window. Some window companies use a method to drill a hole in the window, expel moisture, add sealant to the bottom, then seal the hole. We generally don’t recommend this option, as it may not fix the failed seal and can be a temporary solution.
According to HomeAdvisor, the average cost to repair a fogged window is $135. This can add up, especially if you have a lot of windows. Large & uncommonly shaped windows can cost much more to repair.
Many people choose to live with foggy windows. If you live in a mild climate and don’t have numerous windows, the energy loss may be negligible. Some foggy windows are difficult to see through, whereas others only have a light tint that is visible in certain weather/lighting conditions.
Residential Home Inspections
Foggy windows are one of the things we look for in a home inspection. If you’re considering getting a pre-sale inspection or an inspection for a house you’re buying, feel free to get in touch. We are an experienced, family-owned residential home inspection company servicing the greater Portland area.