Make the rough opening for a pocket door two times the width of the door plus 1 inch with a height of 84 1/2 inches from the highest spot on the subflooring. While this opening looks very large, it must accommodate the door once it slides in the pocket to open.
In order for the door to operate correctly, the frame must be horizontally level, vertically plumb in all directions and not in the form of a helix. Use a carpenter's spirit level to check for plumb and level. Attach a string from one corner to the opposite corner of the frame and repeat with another string and the opposite corners. Adjust the frame until the strings touch lightly.
The track attaches to the top of the door frame. In most cases, there is no need for a threshold. Once the door hangs on the track, ensure it operates freely within the frame before finishing it.
Installation kits include two sets of split studs. These studs mount on the outer edge of the framing, leaving a passage for the door to travel when opening and closing. When attaching the finish material, choose nails and screws that are short enough that they do not extend through the split opening.