How to Lay Out a Staircase

Framing Layout

• 1

  Hold a plumb bob's string against the end of the outer face of the upper landing. Begin at either end. Drop the bob's weight to the lower story's floor and allow the weight to swing to a stop. Have a partner mark the location of the bob's tip on the floor. Move the string and bob to the upper landing’s opposite end and create a similar mark.

• 2

  Run a chalk string line between the marks. Pulling the line taut and snapping it against the floor transcribes the upper landing's position onto the lower story's floor. Measure the height between the upper landing and the chalk line on the lower story's floor with a tape measure. This height is the staircase's rise.

• 3

  Divide the rise by an individual riser’s desired height. The term riser refers to a step’s vertical portion. Risers between 5 and 7 inches are acceptable by most building codes. However, 7-inch risers provide a comfortable step for most individuals. The calculation’s result is the required number of steps in your staircase. Rounding the quotient up or down achieves a whole number of steps. Apportioning the quotient's remainder between the whole number of steps achieves the overall rise. For example, you might have to add one-quarter inch to each 7-inch step to achieve your rise.

• 4

  Multiply the number of steps by a tread’s desired depth. The term refers to a step’s horizontal portion. Ten- to 11-inch treads are comfortable for most individuals. The calculation’s result is the staircase's run.

• 5

  Stretch a tape measure from one end of the chalk line to the length of the of the staircase's run. Mark the location with a pencil. Move the tape to the chalk line’s opposite and create a similar mark. Snapping a chalk line between the marks lays out a line that represents the location of the stringer's bottom step on the floor.

Stringer Layout

• 6

  Lay the stringer material on a workbench or sawhorses. Attach a square stop to the carpenter's square's small side at the dimension that a single riser’s height. Attach a stop to the square’s large side at the dimension that represents a single tread’s depth. Butt the stops against the stringer’s edge. Running a pencil along the square’s inside edges lays out a zigzag line that represents a riser and tread.

• 7

  Slide the square down the stringer and align the riser stop with the previous layout line’s end. Running the pencil along the square’s inside edges lays out the next riser and tread set. Continue laying out subsequent tread and riser lines until the required number of steps is reached.

• 8

  Flip the square and align its small side with the last riser line. The square’s large side now runs perpendicular to the last rise line and parallel to the last tread line. Drawing a pencil along the large side's edge lays out the stringer’s bottom, which is also the last riser’s bottom. Reducing the last riser's height by the thickness of the tread material makes your bottom step equivalent in height to the other steps.

• 9

  Return to the first tread and riser lines. Align the square's small side with the first riser line and use the large side to layout a line for the top tread. Flip the square, align it perpendicular to the top tread line. Draw a line from the top tread line’s end to the stringer’s rear. This line runs parallel to the top riser and butts against the upper landing’s outer face.