Double doors can make a grand impression at the main entrance to a home, but if there is a gap between them they're losing a lot of heat. If the doors are solid wood, they are susceptible to swelling and shrinkage in response to changes in the weather, and these shifts are magnified in the case of double doors. By attaching a small overlapping extension to each of the doors, you can solve this problem.
Things You'll Need
Strips of wood, 1/2 inch by 2 inches
Screws, 1 inch long
Measure the height of your double doors at the point where they meet in the center.
Cut two strips of 1/2-by-2-inch wood to the length you measured in Step 1.
Apply one strip to the interior side of one of the doors, positioning it so that it spans the gap between the two doors and overlaps the edge of the opposite door. Attach the strip to the door by driving in a 1-inch-long screw every 12 vertical inches.
Place the other strip on the exterior edge of the other door, screwing it on so it spans the gap between the two doors on the exterior. You now have both an interior and an exterior strip covering up the gap between the doors and allowing for future expansion and contraction.
For added heat retention, apply weatherstripping to the faces of the strips that abut the opposite doors.