HOW TO BUILD A WALL (3)

Further bracing of the wall is made by horizontal pieces of 2-by-3 nailed between studs.The location and number of these also depend somewhat on the wall covering to follow. For the average 8' high wall, two cross braces equally spaced suffice. These will support  all sheet materials (plywood, plasterboard,etc.) but if the covering is to be of full-length vertical boards, a single brace their own width so that nailing into their ends through the studs with 10d or 16d nails is possible. This eliminates a lot of to nailing. Use two nail into each end.
    Framing a doorway. The wall is now taking shape.Time to get on to the more intricate steps. Go back to the marked-off doorway and cut out the plate, You can use the two studs as a guide for the saw. Measure the height of the door you intend to use. Standard size are either 6' 7' 8' high. Add 1" to the height to allow for the frame,and-if you plan to use a threshold-add 1" more. Cut two short studs to this combined length and nail them to the two full-length studs on each side of the opening. Be sure to put one nail through into the cut-off ends of the plate. Cut two pieces of 2-by-3 the width of the opening  above these short studs, nail them together and insert, Keep the narrow dimension of these pieces vertical. Nail through the side studs into this lintel, or header, as the piece is called. A short studs, called a cripple, is then erected between the header and the top plate. Other opening in the wall are handled in the same way. If the opening does not extend all the way to the sold plate, as in a pass-through, for example, fit a double 2-by-3 into the bottom of the opening. Short studs extend to the sole plate from the bottom one and from the upper one to the top plate.