Your doors are probably the easiest access winter has to your home. Although you may not be able to get the kids to close the door after a cold romp in the snow (you might try a bomber-hinged door), you should be able to keep old man winter from sneaking in around the cracks.
Of course, the easiest way to stop cold air coming in under the door is a towel or other contrivance pushed up against the base of the door. But this is a temporary and half-hearted measure. There are several ways to restrict this airflow with a sweep. There are many types of door sweeps available. Most are very easy to install and involve a metal bar with a strip of rubber-like vinyl that rides lightly on the floor as the door swings, but forms a seal against a raised threshold (see illustration above left). Installation involves purchasing a sweep that either fits or is wider than the door, cutting it to length if necessary, pre-drilling holes for screws and screwing in place.
Another way to keep air from seeping in under doors is adding a door bottom (see image at right). To do this you may need to shorten the door (don't try this with a steel door). To shorten a wooden door, take the door off its hinges and lay it on its side. Mark the amount you wish to remove with a straight-edge. Cut with a skill saw or very carefully with a table saw. The bottom can be screwed in after pre-drilling holes. The base or threshold is installed the same way. There is nothing to prevent you from installing both a sweep and a bottom.
To reduce air flow around the other parts of the door use weather stripping. This is a foam substance that has a sticky tape on one side. It is usually purchased in rolls. Simply measure the length of the area to be treated, cut the strip, peel the backing and push in place on the door's jamb. V-strips, (narrow metallic strips shaped like a "V") can also be installed on the jamb (the piece of wood that sticks out slightly from the frame and stops the door when you close it), or sometimes on the frame itself.
With these measures taken, you will be well-started in preparing your home for winter. Now let's turn to the windows.
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