How to Build Stringers for Wooden Stairs

Get Measurements

• 1

  Place a board on top of your porch or deck landing, extending the end of the board over the edge of the landing area. Measure from the ground to the bottom of the board with a tape measure to determine the total rise. For example, if the measurement from ground to board is 48 inches. then 48 inches is your total rise.

• 2

  Calculate the number of steps necessary for the stringer. A typical step rise is 7 inches. The rise is the distance between each step on the stringer. In the example, divide your total rise of 48 inches by 7 inches for a result of 6.85. Round down to come up with a total of six steps.

• 3

  Divide the overall rise of 48 inches by the six steps for a result of 8 inches. This is the total rise of each step.

• 4

  Measure the depth of each stair tread. In most cases, stair treads are either two 2-by-4-inch boards or 2-by-6-inch boards. If using 2-by-4-inch boards, your tread is 8 inches. If using 2-by-6-inch board, the tread is 12 inches. This also determines the length of the stringer. In the example six 8-inch steps would require a 48-inch long stringer.

Form a Jig

• 5

  Make a jig with a framing square to mark the stair stringers. A framing square has measurements on both arms of the square. Put the framing square on top of a piece of 1-by-4-inch board with the point of the square extending over the side of the board.

• 6

  Find the 8-inch measurement on one side of the framing square for your step rise. Line up the 8-inch mark with the edge of the board. Clamp the end of the framing square to the board with a wood clamp.

• 7

  Move the opposite end of the framing square so the 12-inch tread measurement is at the edge of the board. Clamp the end of the framing square to the board with a wood clamp. The angled end of the framing square over the edge of the board is the jig for marking the stringers.

Cut and Install Stringers

• 8

  Lay a 2-by-12-inch board on a pair of saw horses. Cut the board down to 48 inches. Cut one end of the board at a 45-degree angle with a circular saw.

• 9

  Place the framing square jig against the side of the board, lining up the square with the high corner of the angle. Trace the outside outline of the square onto the board with a pencil.

• 10

  Move the square down the board, lining up the square with the end of the last trace line. Trace the square outline again. Continue doing this for each stair. In the example, you should have six outlines.

• 11

  Cut the outlines out of the board with a circular saw, taking care not to cut past the corners of the outline. Flip the board over and finish cut to the corners with a jigsaw or handsaw.

• 12

  Trace the outline of the first cut stringer onto the next board and cut it out just as you did the first. If your stairs are more than 36 inches wide, use three stringers.

• 13

  Install floor joist brackets onto the face board of your deck or porch with 2-inch lag screws and a socket adapter in a drill. Set the end of the stringer in the joist bracket with the cut risers facing up. Secure the stringer to the joist bracket with 12d nails and a hammer.