In this video, This Old House landscape contractor Roger Cook creates a durable outdoor staircase.
1. Drive wooden stake into ground to establish height of finished staircase.
2. Use 4-foot level and long straightedge to mark the height of walkway at the top of the staircase onto the wooden stake.
3. Measure down from the mark on the stake to the driveway at the bottom of the staircase. Divide by 5½ inches—the height of a 6x6 timber—to find the number of steps in the staircase.
4. Excavate the staircase area with a shovel and dig an 8- to 10-inch-wide x 3-foot-long trench along each edge of the staircase. Space the trenches at least 3 feet apart, as measured from outer edge to outer edge.
5. Use a circular saw to cut two 3-foot-long sleepers from a 6x6 timber. Cut around all four sides of the timber, then finish the cut with a handsaw.
6. Treat the cut end of the timber with wood preservative.
7. Drill two ½-inch-diameter holes through each 6x6 sleeper; position the holes about 6 inches from each end of the sleepers. Set the sleepers into the trenches.
8. Pin each sleeper to the ground by using a 3-pound sledgehammer to pound two ½-inch-diameter x 4-foot-long rebars through the holes.
9. Cut two timbers to length for each step in the staircase. Be sure to cut the timbers long enough to span both sleepers.
10. Set two timbers across the sleepers to create the bottommost step in the staircase.
11. Cut and install two shorter 6x6 sleepers; set them on top of and parallel with the lower set of sleepers.
12. Fasten the timber steps and shorter sleepers to the long sleepers below with 12-inch-long timber screws. Use a drill to drive one screw through each end of every timber.
13. Shovel gravel behind the step to enhance drainage and prevent erosion.
14. Follow the previous three steps to build the remaining steps: cut two timbers and two short sleepers for each step and secure them with timber screws. Shovel gravel behind each step.
15. Once you've fastened the last, uppermost step in place, backfill around the staircase with well-compacted soil.