Measure the width and height of the wall with a tape measure. Record the measurements.
Cut two two-by-fours to match the width of the wall. These are the top and bottom plates for the frame wall. Divide the width of the wall by 16. Cut this number of boards, rounded down, plus one, to match the height of the wall, less three inches. These are the vertical studs for the frame wall.
Place the top and bottom plates parallel to each other, set on the narrow edges. Place the vertical studs in between and perpendicular to the top and bottom plates. Butt the ends of the studs to the top and bottom plates. Space the boards 16 inches apart, starting at the right side.
Nail the studs to the top and bottom plates with 10d nails.
Raise the wall and move it into position. Nail the bottom plate to the floor in between each of the vertical studs. Nail the top plate to the ceiling joists where they intersect.