Measure the opening of your shed’s entryway in length and width. Measure and cut three horizontal support boards to the width of the entryway minus 1 inch.
Divide the width of the doorway minus 1 inch by four to find the number of vertical boards needed. Measure and cut this number of boards to the height of the entryway minus 1 inch.
Lay the vertical boards out on a flat surface side by side. Align the cut ends along the top and bottom to make the boards flush. Place the three horizontal boards perpendicularly across the vertical boards.
Adjust the horizontal boards so one runs flush along the top and one along the bottom, and set the third board to run across the middle. Insert screws through the horizontal boards and into the vertical boards at each point where they intersect.
Measure the diagonal space between the horizontal boards on the top half and bottom half of the door. Cut two boards to the diagonal length. Cut each end of both boards on a 45 degree angle.
Position the diagonal boards to come together in a sideways V shape over the vertical boards with the center horizontal board between them. Insert three evenly spaced screws through each diagonal board and into the vertical boards underneath to secure them.
Attach a hinge to one side of the door over the ends of each of the horizontal boards with screws. Stand the door and hold it to the entryway of the shed. Position the door to run one-half inch above the ground to ensure it doesn’t scrape the ground or floor. Secure the other half of the hinges where they align with the wall.
Secure your preferred style of latch or lock to the side of the door opposite the hinges to help hold the door closed when you aren’t in or using the shed.