How to Install a Pre-Hung Exterior Door

A new metal clad, wood or fiberglass entry door adds safety and security to your home, as well as a touch of added curb appeal. Installing a pre-hung front door makes a great first impression on your visitors and makes for a fun project that you can tackle on your own.

What Is a Pre-Hung Door?

A pre-hung door is one that comes already hanging in its own frame. It comes complete with a door slab, hinges and an outer frame that fits into your doorway. Don’t confuse these doors with slab doors, as those have no hinges, knob or frame.

Before Installing the New Pre-Hung Exterior Door

Before you remove your old front door, it is wise to have already purchased the new one. Check it for damage and make sure it will fit. Here’s what you’ll need to do before you purchase a new door.

1. Remove the interior trim around the existing door.

2. Measure the existing door opening. Purchase a new door that’s 1/2 inch less than the height of the opening and 3/4 inch less in width.

3. Be sure you know which way the door opens, and which hand you use to open it. The manufacturer may be able drill holes in the new door for the hinges and the lockset.

4. Read your new door’s manufacturer instructions. They should provide you with information regarding the removal of the factory-installed shipping braces or clips, and they will also help to clarify terms and identify parts.

Things You’ll Need to Install a Pre-Hung Door

  • Measuring tape

  • Level

  • Screwdriver

  • Reciprocating saw

  • Spray foam insulation

  • Shims

  • Finishing nails

  • Drill

  • Screws

  • Caulk

  • Hammer

  • Spackle

  • Nail set

Steps For Installing a Pre-Hung Exterior Door

1. Remove the existing door’s exterior trim in order to install the new door frame. Some door frames come with the exterior trim attached so you can discard the old trim.

2. Use a hammer and nail set to remove the hinge pins on your existing door. To remove the hinges, insert the nail set on the bottom of the hinge pin and strike it upward with the hammer until it comes out. Once the door is off the frame and set aside, remove the hinges from the doorframe.

3. Remove the nails that attach the sill and jamb to the house frame. Then, remove the shims between the door jamb and the house frame.

4. Remove the old door frame from the house frame. Then, place the new door in its final position to ensure it fits.

5. Make sure the subsill is square and level. If not, adjust it as needed by inserting shims. Also, check that the rough opening is square and plumb.

6. Measure the new door from the bottom of its sill to the bottom of the door to make sure it will clear. The pre-hung door will come with longer sides on the frame that extend past the door. This will allow you to cut each side of the door frame according to how level the floor is.

7. Weatherproof the area by applying a bead of caulk about one inch from the front and one inch from the rear of the rough opening, and on the underside of the doorsill.

8. To insert the door into the opening, work from the outside of the house. Set the bottom of the door against the opening, then lift it up into place. Temporarily place shims near the top of the frame to hold the door in place while you work.

9. Insert shims keep the door level in its opening. It’s best to install shims at the same height as the door hinges.

10. Check that there is even spacing around the doorjamb from the inside and the outside. From outside, check that there is a 3/8-inch to 1/2-inch space between the door and the jamb stop at the top, middle, and bottom. Make any necessary adjustments to the doorframe.

11. Insert additional shims around the frame following the door manufacturer’s instructions. For added strength, place shims at the lockset and deadbolt positions.

12. Open and close the door, checking that it swings smoothly. Make any necessary adjustments. Place a level on the vertical surface to check that the door is plumb.

13. Apply a small amount of expanding spray foam insulation in the gaps around the frame. Give it time to dry, then trim off any excess.

14. Reattach the door trim.

If you’re thinking of installing a new exterior door, Jabara’s Home Improvement has a large selection of pre-hung doors in stock. Call us today at 316-267-8833, or stop in and visit us at 1816 N. Broadway.