How Big Should the Weep Holes Be in My Storm Windows?

Storm Windows

• Storm windows are most commonly made of vinyl, wood or aluminum, each with its own strengths and weaknesses. While aluminum frames require little maintenance, they are rapid heat conductors and inefficient for insulation. Wooden frames are good insulators, but expand and contract depending upon the weather, deteriorate with age and are higher maintenance than other types of storm window frames. You can install wood frames clad in vinyl or aluminum for maintenance reduction. Vinyl frames may warp in very hot weather or crack when it is very cold. Weep hole size in each type of window may vary.

Weep Holes

• There is no standard size for window weep holes. As the United States Department of Energy notes, all exterior storm windows must include weep holes at frame's bottom allowing water to drain out. While the weep holes may detract somewhat from energy savings because some air may enter the building, without them the main window frame will eventually rot, rendering the storm windows inoperable.

Precautions

• Weep hole sizes vary. Larger weep holes may offer pests such as insects and snakes an opportunity to enter the building. There are devices on the market that allow the weep hole to maintain its draining function without allowing small critters inside. If painting or remodelling, take care not to paint or caulk over the weep holes. If installing new storm windows, make sure the windows are not installed upside-down with the weep holes at the top rather than the bottom.

Maintenance

• Weep holes must be free from dirt or other clogging material in order to function. Cleaning out the weep holes should be part of general window maintenance. Check the openings several times a year, especially if a major storm is forecast or before your area's wet season. Remove fallen leaves, dead insects, grime, dirt and any other debris from the window on a regular basis. If the weep holes clog, open them with a soft brush, screwdriver or wire to remove the obstruction.