Place the front (inner) door on the edge, facing backwards with the first door. Align the doors evenly against a square, then bring the hinges together. Screw the hinge plates to the front door. Repeat on the second pair of doors.
Check the gap between the door and the jamb on the hinge side; if it is uneven, change the position of the lower pivot pin on its support so that the door gap is even. Take a jamb side door and mark its inner edge 11 inches from the bottom, 7 inches from the top and centered between the two. Many retailers also sell folding door handles and knobs separately, so you can choose the best folding door handles that also fit your specific room decor. Attach the pivot plates (the pins that fit the rail and floor support) and the locking arms (the hooks that slide along the rail) to the top and bottom of each door assembly.
The combined measurement of both doors should be approximately one inch smaller than the total width of the opening and 1 to 2 inches smaller than the height of the door frame. This is necessary because hollow core folding doors are not as durable and do not stand the test of time. Reach out and press the spring-loaded wheel on the top of the door, turn the door in place to align the wheel under the rail, and then release the wheel to enter the rail. If you choose to stain the door panels, remove the hardware and hide any inserts as you would with paint; place the door panels flat on saw stands.
Refer to the manufacturer's instructions to determine how to properly install and hang doors so that they open the way you want them to. If everything goes according to plan, you should be able to install your folding doors in a few hours or less. Practical homeowners can add value and style by purchasing folding door kits, which allow for easy DIY installation. Sometimes, top-suspended folding doors have a lower pivot that mounts to the door jamb instead of having a floor rail; in these cases, the bottom rail is optional.
Louvered doors are an attractive alternative that can add a decorative touch to folding doors; the open slats of this style of door allow air flow into the closet area, preventing the musty smell of the closet. The first step in installing folding closet doors is to measure the opening of the cabinet door and then purchasing a kit of the correct size. Because many folding doors are installed in bedroom closets, models with mirror panels are quite common. Bring the doors to the rail and lift the side of the jamb to engage the upper pivot plate pin in the pivot socket.