How to Replace a prehung exterior door with This Old House

Watch this video from This Old House to learn how to install a prehung door.

Steps:

1. Use drill/driver to back out door hinge screws; remove door

2. Remove screws and/or nails from the hinge-side doorjamb

3. Push old doorframe out of the opening, and discard

4. Install Z-flashing over the door casing at the top of the opening

5. Apply thick bead of caulk along the sides and top of opening

6. Set the new prehung door into place, pressing it tight against the framing

7. Check the threshold for level; slip shims under threshold, if necessary

8. Temporarily screw through hinge-side jamb, then check spacing around inside of door

9. Insert shims into spaces between the hinge-side jamb and wall framing

10. From outside, pull back weatherstripping, drill pilot holes and drive masonry screws through hinge-side jamb and into masonry wall (use decking screws for wood wall)

11. Repeat the procedure for latch-side jamb, making sure to place screws behind weatherstripping

12. Close door and check the space between latch-side jamb and door edge; tap in shims, if necessary, to create consistent spacing

13. Use utility knife to trim all shims flush

14. Install lockset

15. Apply bead of caulk around the exterior of the doorframe, including under the threshold