The framing of a garage door is a relatively simple task for anyone with basic carpentry skills and a little help from some friends. Follow these simple steps to frame out the opening for your new garage door.
Frame the rough opening for the garage door to 3 inches wider than the garage door you have selected.
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. Cut four 2 x 4 trimmers to this length and nail two each to either side of the rough opening. These trimmers should be on edge just as the studs in the wall rather than flat.
Cut the header from 2 x 12 lumber and to a length of the rough opening plus 6 inches. Install the header on top of the trimmers and nail.
Nail or screw 2 x 6 jambs to the framing on the top first and then the sides of the rough opening. After installing the jambs, your garage door opening should now be the same size as the garage door. You are finished framing and ready to install the garage door.
If your garage has less than 12 inches of clearance between the top of the door opening and the ceiling, you will need to purchase a low overhead installation kit for the garage door.
When raising the wall, keep in mind that the wall will be very top heavy due to the headers and additional lumber at the top of the wall. For safe handling get plenty of help or use a tractor, forklift, or similar machine to lift the wall.