How to Install a Fiberglass Entry Door

In this video, This Old House general contractor Tom Silva shows how to upgrade an entryway with a brand-new, low-maintenance, energy-efficient door.

Steps:

1. Remove the old door from the opening by using a reciprocating saw to cut through the nails between the doorjamb and wall framing.

2. Cut around the interior of the doorjamb, too, freeing it from the wall opening.

3. Pry the old door and threshold from the opening.

4. Cut a 2×4 to span the doorway opening. Lay the 2×4 on edge along the rough sill.

5. Set a level on top of the 2×4, then slip shims underneath until the 2×4 is level.

6. From the top edge of the level 2×4, measure down ½ inch and mark a line.

7. Adjust a scribe to span from the rough sill to the ½-inch mark, then guide the scribe along the sill to draw a line along the 2×4.

8. Cut along the scribed line with a circular saw to produce a perfect-thickness filler strip.

9. Repeat Steps 4 through 8 to cut a second filler strip.

10. Set the filler strips onto the rough sill and check for level.

11. Fasten the filler strips to the rough sill with 2-inch (6d) common nails.

12. Press strips of adhesive-backed waterproofing membrane to the exterior wall area around the doorsill.

13. Apply a thick bead of silicone adhesive along the ends and length of the rough sill.

14. Temporarily screw two 1×4 cleats across the frame of the new fiberglass door. Allow both ends of each cleat to extend past the frame by at least 3 inches.

15. Set the new pre-hung door down onto the rough sill, then tilt it flat and flush against the wall.

16. Center the door in the opening. Check the threshold for level. If necessary, slip shims under the threshold.

17. Use a 48-inch level to check the hinge-side doorjamb for plumb. If necessary, tap shims between the doorframe and wall framing to plumb up the door.

18. Once the hinge-side jamb is perfectly plumb, drive 3-inch long weather-resistant screws through the jamb and shims and into the wall framing. Secure the jamb in three places: top, middle and bottom.

19. Secure the upper door hinge with the two long screws provided by the door maker.

20. Screw the latch-side jamb to the wall framing.

21. Install the deadbolt and lockset onto the door.

22. Fill the space between the doorframe and wall framing with minimal-expanding spray foam insulation.

23. Open and close the door several times to ensure it swings freely and latches securely.