If you have a natural slope in your land, you may wish to consider putting in steps to improve the safety of movement up and down the grade. Rock is a durable, natural material for building steps in a landscape that can make any pathway seem more welcome. When choosing rock for your stairs, it is very important that the rocks you choose for your treads and risers be of uniform thickness. You can use thicker rocks for risers and flagstones in a similar color and texture for the treads.
Outline your steps in the soil with spray paint. Drive a stake into the center top and bottom of the staircase.
Tie a string to the stake at the top of the staircase. Place a bubble level on the string and pull it straight outward over the stake at the bottom of the staircase. Use the bubble level to keep the string level and measure the distance from the string to the ground over the stake. Then measure the length of the string between the two stakes.
Calculate the total number of steps you need to build in order construct steps that are 6 to 8 inches high. This size of step is a comfortable height for climbing. Divide the rise in inches by the height of the steps in inches. To build steps that are 6 inches high to fit a staircase that is 12 feet high, you will build 24 steps. To calculate the run, take the total number of steps and subtract 1. Then divide the remaining number of steps by the length of the run to calculate the tread depth. For example if you are building 24 steps to cover a rise of 24 feet (288 inches), you will make each step 12.5 inches.
Hand-pick stone from a stone supplier so that each rock is uniform thickness. Flagstones for treads should be between 2 and 3 inches thick. Use wallstone, which is between 6 and 8 feet thick for risers. If your treads rise by 6 inches, purchase wallstone that is 6 inches thick.
Dig a trench for the first stone riser. The trench should be deep enough that the flagstone tread sits on top of the stone at the correct height for your step. Dig straight back from the riser to create a level surface for your flagstone to sit on. Dig a trench for each riser deep enough that each riser and tread sit the same height in relation to the step below them. Wedge stone chips under the stones if they shift.
Mix 1 part compost and 1 part soil. Brush the mix over the stone steps so that it works into the cracks.