How to Replace an Outside Door Jam

A level door jam makes a door function properly.

When problems arise with doors, whether it is cosmetic or functional, the trouble typically lies not with the door but the interior frame or door jam. For most homeowners, the thought of replacing a door jam is a bit intimidating. Purchasing a prehung door unit allows you to bypass much of the difficult work involved in replacing a door jam. Iinstall the jam securely, and level it accurately, and you're most of the way toward a successful door jam replacement.

Things You'll Need

• Pry bar
• Reciprocating saw
• Drill
• Hammer
• Shims
• Level
• Nails
• 3-inch treated deck screws

Instructions

1. Pry the trim away from the inside of the door jam with a flat pry bar. Cut the nails attaching the jam to the wall frame on both vertical sides and across the top with a reciprocating saw.

2. Remove the screws from the sill plate, or threshold, at the bottom of the door, with a cordless drill driver. Hammer the old jam out of the opening toward the exterior. Be sure you are prepared to support it as it falls. Carry the old door out of the way and pull any nails left in the jam with a hammer or locking pliers.

3. Stand the new prehung door in the center of your opening. Drive one nail through the attached brick molding at the top of the door, into the frame behind to hold the door in place.

4. Wedge shims behind the top inside corner of the hinge side jam. Position a level on the face of the hinge side jam and tap the bottom of the door frame in or out until the bubble on the level is lined up in the center of the indicator. Nail through the jam and the shims into the stud behind, at the top of the hinge side jam. Add shims behind the bottom corner and nail through the jam and shims to fasten the jam in place. Repeat the leveling procedure on the opposite jam. Add shims at the top, level the jam, add shims at the bottom and nail.

5. Nail the brick mold to the frame along the sides and caulk around the edges with painter's caulk. Drive one 3-inch screw through each screw hole in the threshold into the wooden sill below the door. Drive the screws all the way in so that the heads run flush against the threshold, and press the threshold firmly against the floor. Caulk around the edges of the threshold.

6. Pull the nails through the back of the door casing that you removed in Step 1. This will prevent making holes in the face of the trim. Nail the door casing into position on the edge of the new jam. Use a hammer and finish nails to fasten the trim. Start at the top of the door, and line up the corner joints before nailing the bottom end of the casing. Fill the nail holes with painter's caulk or wood filler.

References

• "Trim Carpentry Techniques;" Craig Savage; Taunton Press; 1989
• Home Tips: How to Install Door Jambs