To install movable stairs in your home, measure the height and width of the location you want to install the stairs; purchase stringers and boards; cut wood into required measurements; attach the 2-by-4 sections; and screw the upright posts in place. You need treated stringers, treated 2-by-4 wooden sections, 4-by-4 upright posts and 1-by-6 steps. A drill screwdriver, deck screws, a tape measure and a saw are also handy for the project.
Measure the height of the staircase with a yard stick, and write the measurements on a piece of paper. The standard width stair is 36 inches; however, you may use a larger width depending upon the purpose of the steps. After determining the number of needed steps, visit a lumber yard, and purchase the necessary supplies. You require two 1-by-6 boards for every step.
Cut 36-inch pieces from the treated 2-by-4 treated lumber. Place stringers 36 inches apart and, with the centers crossed, screw the two-by-four sections to the stringers with an X pattern. Use a saw to cut the 4-by-4 lumber into two upright posts, set the uprights in place, and secure the stairs with deck screws and a drill.
Cut 42-inch pieces from the 2-by-2 treated lumber. Place the pieces across the upright posts at the back, and fasten them together with screws.