The position of the header and back jambs are very important.
How to install a 9 by 7 garage door.
A door of 9 x 7 2743 x 2134 mm needs an opening of 9 2 743 mm wide by 7 2 134 mm high.
The header must be flush on the same plane with back jambs.
Garage doors come in standard sizes with most basic roll up single garage doors measuring about 7 feet 2 1 m tall and 9 feet 2 7 m wide.
Measure the various areas where the door will be installed.
Because the doors are so large few home centers and only some garage door stores keep many doors in stock so expect to order one instead of buying it off the shelf.
High by 16 ft.
High by 8 or 9 ft.
For the headroom you should have about 10 to 12 of space depending on the spring system you re installing.
Standard single doors are 7 ft.
Make sure that the size of the opening matches the size of the door.