How to Hang Prehung Exterior Doors

Installing a door is simpler than you might think.

Home improvement has been on the rise for several years. The increase in available materials in the mega home improvement stores coupled with the surge in do-it-yourself media programming and publishing makes it easier than ever to learn how to improve your home. Installing a prehung exterior door may seem like more of an improvement than you can handle, but, with a little planning, it can be done with common tools in less than a day.

Things You'll Need

• Prehung exterior door unit
• Hammer
• Shims
• 16-penny nails
• Finish nails
• Drill
• Treated deck screws
• Caulking
• Door knob

Instructions

1. Place the prehung door unit, centered, in the door opening in the wall with the exterior trim or brick mold on the outside. Wedge shims between the top of the door frame above the horizontal jamb header to hold it snug against the wall frame. Drive one 16-penny nail up through the header and shims into the frame above.

2. Level the hinge side jamb by wedging shims between the outside of the jamb and the frame to steady it. Hold a level against the inside edge of the jamb. Move the bottom of the frame in or out slightly until the bubble in the level is centered. Nail through the jamb and shims at the top, into the frame. Wedge shims behind the jamb at the bottom and nail through the jamb into the frame.

3. Repeat the shimming, leveling , nailing procedure on the knob side jamb as well. Once both jambs are level add shims behind the middle of the jambs and nail through into the frame.

4. Nail the brick mold on the outside of the door through its face into the frame behind by using 2-inch finish nails. Drive one three inch treated deck screw through each screw hole in the threshold, which is the metal plate at the bottom of the door, into the wooden sill underneath. Drive the screws in firmly until the threshold is snug against the floor.

5. Cut door casing for the inside jambs. The door casing is the flat trim that runs up the sides and across the top of most residential doors. Cut the side pieces first. Miter the top ends at 45 degrees, one right and one left. Cut the molding to length so that the short side of the miter is ¼-inch higher than the bottom edge of the jamb header. Nail the side pieces to edges of the inside jambs.

6. Cut the top piece of casing to fit between between the top outside corners of the side pieces. Cut a 45 degree miter at each end, one right and one left. Nail it to the edge of the jamb header. Caulk around the edges of the threshold, casing and brick molding. Fill all the nail holes with painter's caulk or wood filler.

7. Install the knob in the hole in the door. Insert the striker bolt through the hole in the door's edge and screw in place. Insert the inside knob half through the striker and line it up with the outside half. Insert and tighten the two mounting screws. Consult hardware instructions for details. Attach the striker plate to the jamb with screws in the notch provided.

References

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