How to Frame a Garage Door Opening

Measure the height of the door jamb between the floor and the top of the opening with a tape measure. The top of the opening is known as the header. Cut a piece of 2x6 to the length you just measured with a circular saw. Use 16-penny nails to fasten the piece of 2x6 flat to the inside edge of the door jamb. Go to the other door jamb and do the exact same process. When nailing the finished jamb boards in place make sure that the edge pointing toward the garage is flush with the inside dry wall.

Use a tape measure to measure the distance between the two finished jambs at the top of the door opening. Use a circular saw to cut a 2x6 board to your measurement. Have a helper hold up one end while you nail the other end in place on the inside header. Make sure that the edge of the header board toward the garage is flush with the jamb board edges. Finish securing the finished inside header board across the opening.

Go inside the garage and measure from the floor to the top of the door opening and then add 18 inches to that measurement. The additional 18 inches will accommodate the necessary headroom requirements for your garage door installation. Cut a 2x6 to the total measurement. Set the 2x6 against the inside wall of the opening, making sure that the edge pointing toward the opening is flush with the finished jamb boards. Use the nail and a hammer to secure the finished mounting jamb to the garage door opening wall. Repeat this step on the other side.

Measure the distance between the top of the mounting jamb boards at the top of the garage door opening. Cut a piece of 2x6 to the measurement and have a helper assist you in nailing the inside mounting header board into place at the inside top of the door opening. A piece of wood will need to be added from the mounting header board to the top of the garage if your garage door is operated by torsion springs above the door.

Mark the center of the garage door opening on the the mounting header board. Measure from the top of the headboard to the ceiling. Cut a piece of 2x6 to the measurement and nail it into place above the center mark placed on the mounting header board. Be sure to nail into solid board behind the wall and not just the drywall. Remember that this board will be used to secure fully loaded springs.