How to Install an Exterior Door

Assuming the old exterior door has already been removed, first run two or three 1/4″ beads of caulk along the floor of the door opening. The caulk will help to prevent any air or water infiltration.

Installing Exterior Door

Next, place the new exterior door into the opening. The rough opening of the doorway should be about 2-3 inches wider than the door frame that you are installing.

Then put a 1/8th or 1/4″ shim under the door, on the side where the hinges are. This will help in the leveling process. Put a nail about one foot off the floor on the hinge side. The side that you just shimmed. Do not sink the nail, just in case you have to remove it later when squaring the door. Use a Level to Install Exterior Door Then using a level, such as the Stanley 42-240 24-Inch Professional I-Beam Level, place it vertically up the side of the door frame that has the hinges.

Adjust the door so that the level shows the bubble fully centered in between the two lines of the level.

While maintaining this level, put a nail into the door frame about a foot from the top. Again on the hinge side of the door.

Now place the level on top of the door frame and adjust the non-hinge side of the door up or down to get the top of the door level. While maintaining the level position put a nail on the top of the frame about 3 inches from the non-hinge side of the door. Do not sink it. Finally, place the level on the non-hinge side of the door and adjust the frame so that it is level. Put a nail into the top and bottom of this frame. Do not sink it.

Test the Newly Installed Exterior Door

Now try opening and closing the door. It should swing freely and close nicely with about a 1/8 inch gap showing between the door itself and the non-hinge side of the door. If not, you may have to make some minor adjustments. That is why you don’t want to sink these initial nails.

If the door works smoothly then sink these nails and add 2 more nails to each side. You should also ensure that you have 3 nails across the top.

Next using either spun fiberglass insulation or foam insulation insert the insulation between the door jamb and the jack studs of the door frame. Again, the insulation will prevent air infiltration.

Once this is done, you can install the hardware (door knob and lock mechanism).

Finally, install the interior door trim and your job is complete.