Things You'll Need
Brush strip draft excluders
By design, a pocket door is built to allow unencumbered access from one room to another. Since a door opening is basically a large hole in the wall, air moves freely from one space to another. Even when the door is closed, tiny gaps in a loosely-fitted door allow air to seep from one room into the other. Air from an unheated room infiltrating a heated room wastes energy and produces uncomfortable drafts. Apply a few simple techniques and some weatherstripping to make your pocket door airtight when closed.
Install a door stop and soffit on the door jamb. A door stop and soffit are narrow strips of wood that are nailed to the door jamb. The soffit is the strip at the top of the door frame and the stop is the strip on the sides. On a typical hinged door, the door stop and soffit prevent the door from swinging freely in and out of both rooms. Pocket door jambs do not have these stops but you can add them to help prevent air leaks. Close the pocket door and ensure that the door is level and properly aligned in its track on the floor. Place the door stop strip onto the jambs and nail them in with a few finishing nails. Repeat for the door soffit at the top jam of the door frame.
Add weatherstripping to the door stop and soffit. Weatherstripping is a thin, spongy material with self-adhering tape on one side. Select narrow weatherstripping that will not interfere with the movement of the door and placement of the door over the door stop and soffit. Remove the paper backing from the weatherstripping and apply the strips to the flat side of the door stop and soffit where the pocket door rests on the stop and soffit.
Install a brush strip draft excluder at the bottom of the side of the door. If the door is particularly drafty, install a draft excluder on both sides of the door. Place the strip onto the lowest inch of the door, allowing the brush bristles to extend slightly below the bottom of the door but not so low that the bristles will inhibit smooth operation of the door. Screw the strip onto the door with wood screws using the pre-drilled holes on the strip.
Your pocket door manufacturer may sell a pocket door jamb stock kit for your pocket door, greatly simplifying the door stop and soffit installation. If a kit is not available, most home improvement centers sell pre-made door stop and soffit wood parts.
To create an even more secure airtight seal, invest in a retractable draft excluder kit, sometimes called an automatic sweep. These kits can be expensive and difficult to install, but will reduce friction from the sweep moving across the floor. Follow manufacturer's instructions carefully when installing the kit.