Installing closet folding doors is a practical way of increasing usable floor space in most bedrooms. They can also be used to close off tight areas such as laundry, bathroom and hallway closets. Additionally, multiple-panelled, bifold doors can become a temporary and stylish means of separating two spaces such as living and dining room areas. Installation is straightforward. Most homeowners with basic skills will have no trouble fitting bifold doors across any standard doorway.
Measure the width and height of the door opening with a steel tape measure. Many closet openings are slightly shorter than standard doors; if your closet opening is less than 80 inches high, cut the doors to fit. If this is the case, buy a pair of solid folding doors rather than lighter, hollow-core doors.
Trim the door panels if necessary. Unfold the panels and place the door on a pair of trestles. Mark the cut line 1/4 inch less the opening height on the long outer edges of each panel, using the tape measure and a carpenter's pencil. Join the lines with a straightedge.
Measure the distance from the inside edge of the circular saw blade to the long outer edge of the saw surface plate. Mark a line across both doors at this distance from the cut line. Use a pair of "C" clamps to clamp a straight plank across the doors with the edge of the plank on the line. This will act as a temporary saw fence to ensure an accurate cut across the open door panels.
Cut off the waste with the circular saw. Position the long edge of the saw surface plate against the fence plank. Switch the saw on and push it smoothly across both panels while holding the edge of the surface plate against the plank. Sand the cut surface smooth with a piece of 120-grit sandpaper wrapped around a sanding block.
Finish the door panels with a coat of indoor enamel paint, using and a fine lamb's wool roller. Allow 24 hours drying time.
Measure the midpoint on both sides of the door header. Join the pints with a pencil line. Center the header track across the top of the door opening by placing the screw holes over the line. Use a correct size self-centring pilot drill bit and a cordless drill/driver to drill the attaching pilot holes. Fit a screwdriver bit into the drill/driver. Use it to screw the header track to the upper door jamb with the screws provided in the folding door accessory kit.
Slide the upper pivot bracket into the downward facing channel of the header track following the instructions provided. Screw the pivot bracket into place 1/4 inch from the upright face of the right hand door jamb with a Phillips screwdriver.
Hang a plumb bob from the right hand upper pivot bracket to the floor. Use the tip of the plumb bob as a reference point and mark the centre-line of the lower pivot bracket. Extend a line from this point toward the doorjamb with a pencil and a carpenter's square.
Place the "L" shaped lower pivot bracket on the floor. Push the short, upright leg of the "L" into the corner between the floor and the door jamb. Position the bracket so that the serrated slot in the middle of the long leg is centred on the line on the floor. Use the self-centring pilot drill bit and drill/driver to bore each pilot hole as described above. Use the screws provided to attach the lower pivot bracket to both the floor and the door jamb.
Insert the straight nylon guide pin into the pre-drilled hole on the top right edge of the door. Tap the pin into place with a hammer. Install the mushroom-headed, spring-loaded guide pivot into the left-hand hole the same way. Repeat by tapping the adjustable pivot into its hole on the bottom right of the door. The end of this pin is shaped somewhat like the end of a drill chuck key so that the teeth can fit securely into the serrated slot of the lower pivot bracket. If you removed the hole when you cut the door down to size, follow the manufacturer's instructions and drill a new hole to match the hole in the upper edge of the door.
Fold the door in half and fit the right-hand guide pin into the upper pivot bracket. Lift the door and fit the adjustable lower pin into the floor-mounted serrated pivot bracket. Follow the instructions provided and insert the spring-loaded guide pivot into the upper track.
Adjust the door alignment by lifting the door and setting the lower pivot into a serration approximately 1/4 inch from the door frame. Adjust until the gap in the right-hand edge of the door is evenly spaced. Screw the adjustable lower pivot pin up or down to help adjust door height and vertical alignment.
Mark the position of the doorknob on the left side of the door, 36 inches from the floor. Drill a hole and use the hardware provided to attach the doorknob to the door.
Install a four-section door by repeating the above steps on the left-hand side of the opening. Join the two header tracks together with the hardware and centre-stop provided before installation. Follow the installation guidelines and install alignment brackets on the inside edges of the doors so that both doors interlock when closed. Install the centre alignment brackets 18 inches from the floor after fitting both bifold door sections.
Wear safety glasses, workman's gloves and a dust mask when working with a circular saw.