Weather Proofing Old Doors

Many of the homes I inspect have beatiful original doors that have character, and many times makes the home with the historical charm, but many of them are also drafty. Unless the door is damaged, insulation and new weatherstripping should reduce drafts and heat transfer through the doorway.

  • Before adding weatherstripping, check the door for loose hinges and other hardware. A loose door lets in drafts in the winter, and it accounts for some heat losses in the winter. Tighten loose screws, including at the doorknob, or replace the hardware, doorknob and lock set if they are damaged.
  • If the door hangs crooked, the jamb has likely skewed as the house settled. Consult a qualified carpenter to straighten the jamb with shims, scribe the door to fit, or replace the door.

Install spray foam Insulation around the door jamb

  • Pry off the left, top and right interior door trim molding with the flat edge of a pry bar.
  • Twist the accompanying straw onto the nozzle of a can of spray foam insulation for doors and windows and shake the can.
  • Place the straw into the space in the wall where you pried off the molding and press the spray nozzle. Apply a line of foam from one end of the opening to the other and repeat across the top and down the other side. Spray foam insulation expands and dries firm. Wait for the first application to expand before deciding whether you need more to fill the cavity. Trim off excess foam in back after it hardens with a drywall saw or a utility knife.
  • Nail the molding back to the door frame.

Add exterior caulk to the exterior

  • Cut the nozzle on a tube of exterior-grade window and door caulk at a slight angle with a utility knife. If there is a seal inside the base of the nozzle, pierce it with a long, thin nail or another slim object.
  • Fit the tube into a caulk gun and depress the trigger several times until caulk fills the nozzle.
  • Place the slanted edge of the nozzle against the top edge of the left or right-side exterior door trim. Depress the trigger to make the caulk flow and pull the caulk gun down the edge of the trim slowly then smooth the caulk with your finger or caulking tool to make it look professional. Repeat the caulk application down the trim on the opposite side of the door, and again across the top. Seal both long edges of each piece of trim molding this way.

Install new weatherstripping

  • Pull the old weatherstripping off the door frame. If there are staples or nails, pry them out with a flat-head screwdriver or nail puller. Weatherstripping fits around the door frame with a rubbery portion touching the door.
  • Measure across the top of the door frame where you removed the weatherstripping.
  • Open a package of weatherstripping with a metal or wood flange and a cushioned, rubbery gasket on a worktable. Measure and mark it to the width of the top of the door frame with a pencil or marker. This type of weatherstripping has a long strip of wood or metal along one long edge, and it has cushioned rubber along the opposite long edge.
  • Slice through the rubbery portion of the weatherstripping at the mark with scissors or a utility knife and continue the cut through the wood or metal with a hacksaw.
  • Close the door and set the weatherstripping in place across the top of the door frame. The rubbery edge should butt against the door. Drive 1 1/2-inch finishing nails through the metal or wood strip with a hammer, spacing nails approximately 8 inches apart. If the strip has pre-drilled nail holes, you might need nails with a small head instead of finishing nails.
  • Measure and cut weatherstripping for the left and right sides of the door frame and fasten them the same way.

Door Sweep

  • Remove the screws in the old door sweep across the lower edge of the interior side of the door, if yours has one, with a Phillips-head or flat-head screwdriver. Door sweeps have a wood or metal strip along one long edge and a rubber fin along the opposite long edge.
  • Measure across the lower edge of the door. If your door had a sweep, measure where it was fastened. If there was no sweep, measure across the lowest part of the interior side of the door, not the bottom edge that faces the threshold.
  • Measure and mark a door sweep to this length and cut it with scissors or a utility knife and a hacksaw as you did with the weatherstripping.
  • Hold the door sweep against the lower portion of the door with the bottom of the rubber fin touching the threshold. Mark the door through the pre-drilled screw or nail holes in the door sweep with a pencil or marker.
  • Drill a shallow hole into the door at each mark with a drill and bit that is the same diameter as the accompanying door sweep screws. Don