How to Build a Stringer for Steps

• 1

  Lay your carpenter square flat, with the point away from you with the smaller arm, or tongue, on your left and the larger arm, or blade, on your right. Wrap a string around the tongue at a distance from the corner of the square, equal to the depth of your treads.

• 2

  Pull the string diagonally across the square, and wrap it around the blade at a distance from the corner equal to the height of your riser. Adjust the string so that it runs straight from one measurement to the other.

• 3

  Lay the stringer board out flat with one long edge toward you. Measure up from the left end a distance equal to the height of the first step, and mark the board with a pencil on its front edge. Lay the square on top of the board in the same position it was in, in step one.

Marking the Steps

• 4

  Align the string with the front edge of the board, and the tongue, so that its left edge is on the left front corner of the board. Trace along the outside left edge of the square to mark the bottom cut. Reposition the square to complete the line across the full width of the board.

• 5

  Place the square so that the outside left edge is on the mark you made in step three. Align the square, so that the string is running along the front edge of the board. Trace along the back edges of the square to create a V shaped notch.

• 6

  Shift the square to the right, so that the left edge is even with the point that the tracing ended on the right edge of the first position. Align the string to the front edge of the board, and trace along the square again. Repeat this step for each step you need to make.

Marking the Top and Cutting

• 7

  Position the square so the tongue is against the back of the riser line for the last step, with the corner of the square on the front edge of the board, and the blade running away from you, perpendicular to the riser line. Trace along the top edge, and mark the end of the line at the depth of the tread.

• 8

  Adjust the square, so that the tongue is now on the new line, and the blade runs down to the back edge of the board to mark the back cut of the top step.

• 9

  Cut along the bottom and top lines with a circular saw to cut the stringer to length. Cut the top back corner off, along the back line you drew for the top step.

• 10

  Cut the V shaped notches from the front edge of the board to complete the stringer.