Why Should You Avoid Window Condensation?

cbeecherBuilding Envelope, Windows

Thousands of people wonder and ask each year about the door and window condensation. If you research the subject, you will find many different answers. Most window manufactures publish great articles on their websites. However, often it is hard to get an overall understanding of what is going at your house because there are many factors that cause condensation. Let’s start by explaining ways people see water condensation in their homes. The most common is water dripping off your drink on a hot day. It could be in the bathroom right after a shower or moisture running down your windows or doors when the temperatures outside fall below 40 degrees F.


While condensation may collect on the interior or exterior of energy-efficient windows, the units are really doing their job by helping serve as a barrier in the home. Windows themselves do not cause condensation. Glass is usually the first place you notice condensation because glass surfaces have the lowest temperature of any surface in a house.

Although there are many types of windows available on the market. Some windows lend themselves to more condensation than others. For an example, an all-aluminum window in the northeast could condensate in the cold winter months when the temperatures fall below freezing versus an all-wood window.


There are many factors that can play a role in why a window condensates. If the inside glass surface on a double or triple glazed window shows excessive moisture, you can be reasonably sure that the moisture is also collecting on your walls and ceilings. This means you should take steps to reduce the humidity level in your home. A lot of water vapor is created by humans. A family of four can add a half-pint of water vapor every hour to a home just through normal breathing and perspiration. And if you take a five minute shower; you produce another half-pint of water vapor. Gas and propane release a lot of moisture when they burn, so the fireplace will increase the moisture level in your home. Even cooking dinner on a gas stove can produce 2 ½ pints of water. It’s all a part of our lives and the places in which we live. To help control an excess amount of condensation in our homes you should consider measuring your humidity level. Humidity/moisture readers, called hygrometers are available in most hardware stores for as low as $20.00. If you should have a problem consider the following steps:


  • Use kitchen and bathroom fans.
  • If you have humidifiers, set it to the correct outside temperature.
  • If your home or basement is overly damp, use dehumidifiers.
  • If your home is built on a crawl area check to see if it has a vapor barrier and proper ventilation. Poly (plastic) can be laid over the dirt or gravel to help address.
  • Properly vent cloth dryers, stoves, gas appliances like water heaters and furnaces.
  • Open your window to vent your bathroom.
  • Lower your thermostat to 66-68 degrees F.
  • Open your curtains and blinds to allow more air to circulation around your windows.
  • Seal up any exterior cracks around your windows.
  • Replace older single pane windows with double or triple pane glass or the age-old approach is to add storm windows. Make sure you select the right type of windows for your region.
  • Install a Heat Recover Ventilator or Energy Recovery Ventilator. They ventilate your home or business with minimal energy loss. The mechanical ventilation system removes stale, polluted air from the building replaces it with fresh air.


It is also possible that your home/building is still drying out. New concrete, wood and other materials usually take 12 to 18 months to dry. The time of year or the amount of moisture your home/building was exposed to during construction can play a factor. Window condensation may be a warning sign. Some try to address the condensation on their windows when they have a greater problem behind their walls. Most people hate to imagine that water could be penetrating the exterior surface of their home/building. However, it can take 5-7 years before you detect water damages. Often an early sign can be mold growth on the walls or condensation on the windows. Mike Bowie further states “I have not seen many homes over my 35 years of inspections without some water penetration into the structure.”


Inspect the exterior of your home and look for places that water can penetrate, then seal that area. Be careful not to seal the weep areas of your windows. We at GCI have experienced staff that would like to help you trace your water condensation, damage, or mold with state of the art tools. Should your home need an investigation, GCI will travel to your location. We will work with your contractor or attorney to help you find a resolution. We can design a water-management plan to help prevent future structure damages. Please contact us today for a free consultation.

Written by Mike Bowie Senior Consultant for GCI