In some designs a piece of finish lumber or trim attaches across the underside.
Garage door frame out.
By william machin a garage door jamb runs from the floor to the underside of the header at each side of the opening.
If the door is 7 tall frame the opening 7 1 5.
Cut four 2 x 4 trimmers to this length and nail two each to either side of the rough opening.
Frame the rough opening to 3 inches wider than the garage door size you have selected.
How to frame a garage door 1.
If you are installing a 9 wide door the opening will be 9 3 wide.
How to frame a garage doors opening in this case 9ft wide by 8ft tall.
Frame the rough opening to a height that is 1 5 taller than the door that you have selected.
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 for the garage door to 3 inches wider than the garage door you have selected.
Header the header is ideally a minimum 12 wide micro laminated beam that spans the width of the garage door opening.
Measure the distance from the bottom plate of the wall to a point that is 1 1 2 inches higher that the garage door height.
Woodworkers prefer it because they are lightweight effortless to cut stain and hit a nail into.