Framing in a door is fundamental to building. This step by step DIY guide teaches stick framing and prefabricating techniques. Includes glossary of terms.
The jack consist of two parts, a regular wall stud that holds the assembly in place (king stud), and a cripple that sits directly under the edge of the header and directly transfers the vertical load to the floor.
The header is the beam that transfers any vertical load over the door down to the cripple studs.
The rough opening for a door is equal to its size plus two inches (door size + 2″ = rough opening).
For our purposes we will add three inches to the height for the level of the header. A 6′ 8″ door needs 83″ off the floor to set.
Framing in a Door by Prefabrication
Layout the position of the rough opening on the top and bottom.
Cut two cripples 81 1/2″. Nail them to the sides of studs in an offset manner where their bottoms line up and their sides are flush. Turn the best side out.
Cut two 2 x 10’s (or other header material) and two 2 x 4’s five inches longer than the door size (door size + 5″ = header length).
Make a box beam (header) so the dimensions become 3 1/2″ x 12 1/4″ x the header length.
Nail the header to each jack with it laying in the floor. It is very easy to work with like this.
The entire assembly can now be stood up and positioned into its layout marks.
Toe nail the jacks at the top and bottom and on each side.
The door frame should be very close to plumb on both axis.
Put cripples in over the header to match the parent layout of the existing wall.
Stick Framing in a Door
There are instances when prefabricating a door frame just will not work. In these cases the door frame must be built in place.
Use the same formulas described above for cutting the framing members.
Build the header and jacks the same also.
Make accurate layout marks on the top and bottom of the wall plates.
Nail the jacks in first. Toe nail the tops and bottoms on both sides.
Nail in the header and finish it up with cripples over top of it on layout.