Q: I live on the first floor of a three-family house. My heating bills are very high. When I was in the basement, I noticed light from my apartment showing through cracks in my hardwood floor. I would like to insulate this to prevent cold basement air from entering my apartment. Can you help?
A:If there are visible cracks in the floor, you should be able to seal them from underneath with caulk or foam sealer such as Great Stuff. This should reduce any cold-air infiltration from the basement and is more practical than attempting to insulate the entire basement ceiling, which usually contains a maze of ducts or pipes from a central heater, water-heater pipes, electrical wiring, and bridging to help strengthen the joists.
It will also help if you can warm up that cold basement. Many basements are cold because they are damp. Running a dehumidifier can help dry things out and improve the comfort. Many basements are also poorly protected against cold- air infiltration from outside. Places to check are basement entrances, windows, pipes that run through exterior walls and have unsealed gaps around them, and the joint where siding meets the foundation.
Also, if your apartment’s heating bills are very high, the basement might not be the main culprit. Examine your windows and exterior doors for gaps and cracks where heat could be escaping the apartment and cold air entering. These gaps can generally be sealed with weather-stripping, sold at most home centers and hardware stores.
The bottoms of exterior doors are a common source of cold-air infiltration; seal these gaps with inexpensive door “sweeps,” a type of weather-stripping. An inexpensive way to seal drafty windows is to install interior plastic-film storm windows, sold in kits along with instructions and materials for fastening them in place. The plastic is stretched tight with heat from a hair dryer to make it virtually invisible.
Carpets or thick rugs on the floors might also improve your comfort.
