More Rough Opening Tips
Verify the width and height of the door frame are each 1/2" smaller than the rough opening width/height.
Verify the rough opening is square. The diagonal measurements should be the same. Maximum allowable deviation from square is normally 1/4".
Verify the rough opening is level and plumb. The maximum allowable deviation is 1/8" to 1/4".
The rough opening sill must not be crowned or sagged.
Minimum double studs should be used at all rough openings.
The exterior face of the rough opening must be in a single plane.