How to Install an Exterior Double Pre-hung Door in a Stucco House

Check the threshold of the doorway for level. If it's uneven, nail shims to it.

Cover the threshold and bottom edges of the side jambs with adhesive-backed aluminum tape. Place one strip covering the front edge of the threshold and 2 to 3 inches up the side jambs. Place the second strip behind the first strip so it covers the back edge of the threshold and the bottom few inches of the side jambs. Overlap the edges of the strips of tape.

Apply two thick beads of silicone caulk across the threshold. The caulk seals the joint along the bottom edge of the pre-hung double doors and prevents water from entering your house.

Place the bottom edge of the double doors against the front edge of the threshold, with the top of the doors leaning out away from the house. Have an assistant help you with this as the doors can be heavy and difficult to maneuver.

Push the top edge of the doors into the hole in the wall, while centering the door inside the framing. Drive two nails partway through the flange around the doors and into the framing around the edges of the hole located in the upper corners of the doors.

Check the doors for square by measuring diagonally across them in both directions. The doors are square if the measurements match. If they don't match, square the doors by installing shims between the frame around the door and the framing along the hole in the wall. Adjust the shims as needed until the doors are square. Trim the shims with a utility knife.

Nail the doors in place by driving nails through the flange every 6 to 8 inches around the perimeter of the doors.

Cut a 2-by-4 board long enough to fit across the top of the doorway.

Place a strip of aluminum tape across the top of the doors, covering the joint between the flange and the wall.

Glue a drip cap to the 2-by-4 board with carpenter's glue. The drip cap protects the wooden framing from water damage. Nail the drip cap and board into place above the doorway.

Nail the side trim to the sides of the door frame. Seal the joints between the door and the exterior wall with a thick bead of caulk. Apply the caulk around the entire perimeter of the door.

Cover the framing of the pre-hung doors with a coat of primer if the framing is made of wood, and allow it to dry. Paint the framing after the primer has dried. If the framing is made of metal or composite, you can skip this step.

Apply spray foam insulation into the gaps around the door on the interior of the house. Install the interior casing around the perimeter of the doors.

Install the door lock and handle following the manufacturer's instructions if they were not already pre-installed.