Windows, doors, and skylights are often a weak energy link in home construction, accounting for a significant portion of a home's heat loss in the winter and heat gain in the summer.
Many complaints about condensation or frost on windows and doors and about drafts or temperature discomfort in a house are actually caused by air leaks. Although new technology has greatly improved the energy efficiency of modern products, any fenestration (opening) will be far less efficient than the surrounding wall structure—especially one that is properly insulated and air-sealed. Because new windows and doors are relatively expensive, it is important to determine when repairs make sense and when replacement is the right choice.
When to repair windows and doors
As homes age, building materials age as well, losing strength, flexibility, and usability. This disintegration process can be slowed considerably, and—surprisingly to many people—replacement of windows and doors may not be necessary if the problems are not structural. Simple maintenance and inexpensive repairs (like caulking, weather-stripping, and painting) can extend the life of windows and doors considerably—and for much less than the cost of new components.
Many older homes have windows and doors that were installed to the standards of their day; as building knowledge has improved, so have the methods of installation. Even relatively new installations can suffer from inadequate materials or poor installation, however. Here are some common problems and fixes:
Types of weather-stripping
Weather-stripping comes in several sizes and shapes (often designed for specific uses) and may be made from metal, plastic, vinyl, rubber, felt, or foam—or a combination of these materials. Extensive testing has shown that tubular weather-stripping provides the best seal. However, on doors or swinging windows, this type requires the most closing pressure, which may be difficult for children, the disabled, or the elderly. Silicone, neoprene, urethane, or rubber strips are better in these situations. Open-cell foam and felt strips need to be very tightly compressed to create an adequate seal. They will keep out dust, but are inadequate air barriers. Therefore, the installation of neoprene, urethane, silicone, or rubber weatherstripping is recommended, because these materials create good air-seals with minimum closing force at all temperature ranges and have long, useful lives.
Many window and door manufacturers have replaceable weather-stripping kits that can be ordered and easily installed; check with the manufacturer or your building supply store for information about your specific units. You can also buy weather-stripping by the foot or in kits at a local hardware store or home center. You can calculate the amount of weather-stripping you’ll need by measuring the perimeter of all the windows and doors to be weather-stripped. It’s a good idea to add five to ten percent more for waste.
However, before you buy anything, determine what kind of weatherstripping you want to use. If possible, remove a small portion of the existing weather-stripping (or take a picture) to compare it with what is available. Checking the size of the gap between the fixed and moveable sections of your doors and windows, as well as thinking about the amount of expected wear and tear in these areas, will help you decide which material is the most appropriate.
Window hardware - As windows are used over time, the hardware can become loose or worn, leading to incomplete sealing when closed. Tighten loose screws or reposition hardware slightly to make a firmer attachment. If damaged, replace closing hardware with parts from the manufacturer. Some replacement parts are available through hardware stores as well.