Gather the items that you will need to complete the task. These items include the two wooden panels of the Dutch door, ½-inch hinge jamb, ½-inch latch jamb, top jamb, T-astragal, four hinge pins, one latch, two barrel bolts, 11 #14-1-inch screws, 11 #14-2-inch screws, drill and screwdriver.
Check the location where you will be installing the door to ensure that the floor area is flat. The door will be placed in the center of that area. If the area for the door has not been cut out, construct an entry around 48-7/8 inches wide by 87 inches tall. Check to see that the posts are plumb.
Choose the side of the door that you want to place the hinges. Cut two pieces of 2-by-4-inch lumber that are 18 inches long. Measure 22 inches up from the bottom of the door frame and make a mark, then measure 65 inches up from the bottom of the door frame and make a second mark. Attach one piece of 2-by-4, centered on each marked spot.
Shim under the hinge jamb by ¼ inch before installing the jamb. Use four #14-1-inch and four #14-2-inch screws to put the hinge into place. Level the hinge as you install it, and check that it is plumb. Don't overtighten the jamb screws that are on the inside.
Take out the two panels of the door, and attach the T-astragal using four #14-1-inch screws. Use the holes in the T-astragal to locate the correct location to drill weep holes in the bottom of the two panels. Drill the holes 1/8 inch deep, which is just through the metal. Attach the hinge to the jamb to the upper location of the lower panel, and install the panel using hinge pins. Install the lower hinge to the jamb of the upper panel, and install that panel as well.
Put the top jamb into place using three #14-1-inch screws and three #14-2-inch screws, keeping the same exposure between the upper panel and the door frame. Install the latch jamb using four #14-1-inch screws and four #14-2-inch screws keeping the same rule in mind, and attach the latch. To install a door stop to service both panels, install the stopper ¼ inch below the bottom of the top panel. This will prevent either panel from swinging back. Wait to fully install the door before putting up decorative stripping if desired.