Wood Door Framing

Create the rough opening for the door by measuring the size of the finished frame and making the rough opening one inch taller and two inches wider than the outside dimensions of the finished frame. The finished frame consists of the jambs, top and threshold to which the door is directly attached with hinges.

Measure a header, also known as a lintel, that is three inches wider than the rough opening for the door. Make the header out of two pieces of 2-by-8 wood that are face-nailed together. Install two 2-by-4 king studs in the wall with a space between them that is equal to the length of the header. Place the header between them and nail it in by driving nails through the king studs and into the ends of the header.

Install the 2-by-4 cripple studs. These determine the height of the header. Cut the cripple studs to the height of your rough opening and nail them to the sides of the king studs that face the rough door opening. Install the header so it rests on top of the cripple studs.

Install the finished frame in the rough opening by setting it in place and placing pairs of shims between the outside face of the finished frame and the inside face of the rough opening. Slide the wedge-shaped shims in from both sides of the wall so they overlap each other and become wedged between the finished frame and the rough opening.

Make the finished frame level by adjusting the shims. When it is level, secure it to the rough opening by driving nails through the finished frame, through the shims and into the rough opening.