How to Install French Doors in a Shed

If the door is bigger, reframe the door with 2 x 4s. To begin, outline the measurements of the new door to the wall where the doors will be installed, adding ¼ inch on each side.

Draw another set of lines outside of these marks 1-1/2 inches to the left and right.

Remove any windows, studs or braces on the inside of these lines.

Install 2 x 4 vertical king studs on the outside lines to help support the roof. Use a level to make sure that all are plumb.

Cut jack studs to the height of the rough opening, plus 1/4 inch. Attach the jack studs to the king studs.

Install a double-thickness header of 2 x 6s. The header lies horizontally between beams to frame the door opening. Check that the underside of the header is level.

Make sure everything is square by ensuring the measurement of diagonals is equal. To do so, measure from the upper left corner to the lower right corner, then from the upper right corner to the lower left corner. The numbers should be the same.

Cut excess panels and sill plates with a reciprocating saw. You’ll cover rough edges with trim later in the project.

Set the new door in the opening to check for fit. You should have between 1/4- to 3/8-inch gaps around the frame. Attach additional lumber inside the frame to reduce the space if the gaps are too large.

Install additional flashing according to the manufacturer's instructions. You will cover the flashing with trim later.

Drive shims around the door as needed. A shim is a thin, wedge-shaped strip of wood or other material. To shim the door means to insert shims into the gap surrounding the doors in order to make the door plumb on both sides. Ideally, insert shims 6 inches from the corners and every 8 inches between. Insert shims behind the hinges, as well.

Check to make sure the door is square, level and plumb. Make sure it swings freely; adjust the shims as needed.

Drive one 3-inch screw in each hinge to secure the door. Cut and snap the excess shims with a utility knife so they're flush with or below the door frame.

The door sweep should overlap the threshold by 1/8 inch. If the sill cap is too low, turn the adjustment screw to raise it.

Close the inactive door and mark where the flash bolt touches the head jamb and sill cap. This mark creates the template for drilling.

Drill a 1/2-inch hole on the mark for the bolt and attach the strike plate with screws.

Trim the outside of the door. Apply sealant to the joint between the trim and the exterior wall.

Install a lockset according to the manufacturer's instructions.