In some designs a piece of finish lumber or trim attaches across the underside.
Garage door frame out.
Frame the rough opening to 3 inches wider than the garage door size you have selected.
Woodworkers prefer it because they are lightweight effortless to cut stain and hit a nail into.
If the door is 7 tall frame the opening 7 1 5.
By william machin a garage door jamb runs from the floor to the underside of the header at each side of the opening.
How to measure the finished width and height use of 2x4s for the sides and header.
They are also rot resistant which means it will take decades to breakdown.
Frame the rough opening to a height that is 1 5 taller than the door that you have selected.
How to frame a garage doors opening in this case 9ft wide by 8ft tall.
Cut four 2 x 4 trimmers to this length and nail two each to either side of the rough opening.
Pine is an excellent choice for a garage door frame.
Header requirement 2 at minimum the header should be 12 wide with doubled 2 4 at opening and ceiling running the width of the door with a 2 4 in the center of the opening for the center bracket to attach to.
Frame the rough opening for the garage door to 3 inches wider than the garage door you have selected.
If you are installing a 9 wide door the opening will be 9 3 wide.
Header the header is ideally a minimum 12 wide micro laminated beam that spans the width of the garage door opening.