The approximate opening should be 49 by 82 for a 48 by 80 inch door. The space between the floor and the bottom of the door may vary depending on the type of floor. Generally, the rough opening of the folding door should be 2 inches wider and 2 inches taller than the door itself, regardless of the size of the folding door. The approximate opening of a 48-inch folding door is 82 inches (2082 mm) higher and 50 inches (1270 mm) wider.
This rough opening allows 0.21 mm thick drywall to be installed on the top and on both sides of the door, a space of 38.1 mm under the door and 2032 mm for doors and hardware. It is important to have accurate readings when measuring folding doors, as any small error could cause problems during installation. If the door opening is smaller or larger than the previous readings, you'll need to choose a custom-made folding door. Keep in mind that most folding door sets don't come with a door frame kit, so it's quite common to use ¾ thick selected wood to create the finished door frame.
However, some manufacturers design folding doors with three, five, or six door options of different widths. Although there is nothing to stop you from placing your folding door knob anywhere you want, there is a suitable location to place it. The recommended minimum door width to allow people with disabilities to pass through is 36 inches. As has been said more easily, folding doors are made of different materials, such as aluminum, plywood, MDF, among other materials.
Therefore, the finished opening of the folding door should be 1.5 inches narrower than the rough opening of the folding door, due to the installation of the finished moldings. Keep in mind that these guidelines for finishing the opening of a folding door are typical frame standards used in the homebuilding business. Folding sets are available in a variety of widths (in multiples of 2 inches) and branch doors can be cut to any desired width. In addition, note that different styles of folding doors may require different spacing for reinforcements, ranging from 152.4 mm to 304.8 mm.
The final opening for folding doors involves attaching 1 inch x N molding boards to the 2 × 4 frame bolts of the rugged opening folding door. However, there are basic guidelines that manufacturers must follow when designing standard folding doors. Always check the manufacturer's or product specifications to confirm the approximate opening requirements for your particular folding doors.