The boards should be as long as the doors and about 1 inch (or 4 cm) wider than the track.
If installing two sliding doors, remember that the tracks should be twice as wide as each door so that you can slide two doors together on one track. If only installing one door, the track need only be as wide as the door, but keep in mind that you will want the track to be about twice the length of the door so that you can open it completely. They should occur every 6 inches (or 15 cm) or so, and should be located in the middle of the track. If you are attaching the track to softer or weaker material, measure more holes.
