Measure the total rise of the stairway from the upper finished floor surface to the lower finished floor surface. Divide this number by 5 inches and round up the result. This is the number of steps. Divide the total rise by the number of steps for the individual riser height, which will be less than 5 inches.
Place the square on the right end of 2-by-12 with the corner of the square pointing away from you and the long leg of the square on your left. Align the 10 1/2-inch mark on the long leg and the riser height on the short leg with the front edge of the board. Draw a line from the corner along each leg of the square to the edge of the board. This makes the cutout for each step. Repeat this for each step, aligning the square on the board edge and the mark for the previous step.
Lower the riser height of the bottom step by moving the last line drawn to the right by the thickness of the treads. Draw a new line parallel to the first on the right side of the last line, all the way across the board. The bottom step is at the left side of the board. At the top step, extend the first line drawn across the board. Cut all the way across the board on these lines when cutting the stringers.
Cut the lines on the stringer layout with the circular saw to the point where the leading edge of the blade just touches the corner of the marks. Use the hand saw to finish each cut. At the top and bottom, follow the cut off line across the board. Use the stringer as a pattern to mark and cut additional stringers. A 32-inch wide stairway requires three stringers and one additional stringer for every additional 16 inches of stair width.
Place the stringer hangers over the end of the stringers and attach them using 1 1/2-inch 10D nails. Nail the stringer hangers to the header at the top of the stairway using the same nails and align the tops of the stringers with the level. The stringer center to center spacing should not exceed 16-inches. Complete the stringer attachment with four 3 1/2-inch deck screws driven at an angle through each stringer hanger, through the stringer and into the header.
Place a stair tread on the stringers. Drill countersunk holes for deck screws through the tread into the stringer. Attach the tread to the stringer with 2 1/2-inch deck screws. Place a riser on the tread against the stringer. Drill countersunk holes for deck screws and attach the riser to the stringer with 2-inch deck screws. Repeat this for each step using 3 screws per stringer for treads and 2 screws per stringer for risers.
Things You Will Need
- Tape measure
- Framing square
- 2 by 12 lumber
- Circular saw
- Hand saw
- Stringer hangers
- 1 1/2-inch 10D nails
- 3-inch deck screws
- Drill with deck screw driver
- Counter sinking drill bit
- Stair treads
- 2 1/2-inch deck screws
- Stair risers
- 2-inch deck screws
- Using 5-inches for the step and riser calculation is only a suggestion. If the stairs don't need to be that shallow, use a higher number such as 6 or 7-inches.
- Stringer hangers have holes for nails and angled guides for screws. Use a nail in each hole and a screw in each guide.