Exterior French doors should be sealed with weather stripping just like any other type of exterior door. A good seal will keep in cool air in the summer and help the house retain heat in the cold of winter. Weather stripping is one of the most affordable and least time-consuming home improvement projects, and the returns can be well worth it.
Things You'll Need
Spring bronze weather stripping
Measure the height of the door to which you wish to add the weather stripping. If you often keep one door bolted shut, consider attaching the weather stripping to that one.
Unroll the spring bronze weather stripping and cut a section with scissors to fit the door.
Line up the weather stripping along the edge of the door. Use the nails that come with the weather stripping to secure it to the door. There may be prepunched holes for each nail; if not, put in a nail every 2 inches for a secure fit.
Install a door sweep if the bottom of the door isn't sealed. Measure each door and trim each door sweep to size with a hacksaw.
Test the fit by holding up the sweep to the door. The flexible portion of the sweep should just barely touch the threshold. Mark the screw positions with a marker and drill pilot holes with a 3/32-inch drill bit.
Push the sweep down against the threshold and drive the screws through the predrilled holes. Open and close each door to test the seal.
Sweeps are only an option if the floor or rug is lower than the threshold.