You should add 2 1 2 to the height of the actual door.
Bifold door rough opening size.
A bifold door consists of a pair of panels attached to each other with hinges.
Framing rough opening sizes are really quite simple.
This allows for 1 2 inch thick drywall on both sides and at the top 80 inches for the doors and hardware and a 1 to 1 1 2 inch space under the door the space between the floor and the bottom of the door may vary depending on the type of flooring.
The opening size for a bifold door is measured from the finish face of the opening not the trim.
The required size of the finished opening for a 48 by 80 inch door is 48 by 82 inches.
Typically the rough bifold door opening should be sized 2 inches wider and 2 inches higher than the door itself regardless of the bifold door size.
For example a four foot wide 48 by six feet eight inches high 80 bifold set of doors would require a rough opening width of 50 inches and a height of 82 inches.
How to determine bifold door opening size.
Most bifold door openings are finished with drwyall.
The trim hangs over the edge of the opening to cover the gap around the edge of the door.
Getting the rough opening size right the first time will save you from frustration when installing your doors.
For example our aluminum bifold door system is available in a range of standard sizes to suit the most popular opening sizes and can be made to measure up to 20 panels 10 in each direction with a total span up to 65 wide and 10 4 tall.
This will give you room to space the door frame off of the sub floor.
Measuring a bifold door opening.
The rough opening should be 49 by 82 for a 48 by 80 inch door.