Determine the slope of the path where the steps are to go. The slope will govern the step number and width to height ratio.
Measure the rise, or height of the slope, by horizontally stretching a leveled string or pole from the top of the hill to the same height at the bottom and measuring the distance between the ground and the string or pole at the bottom.
Measure the run by measuring the horizontal distance where the level pole or string is attached at the top of the hill to the same height at the bottom of the hill. The slope is the rise over the run.
Determine the ratio of tread to riser. Calculate these numbers using the desired, comfortable riser height and the following formula. The tread width plus the doubled riser height should equal 26 to 27 inches. For example, if the desired height for each step is 5 inches, the tread width should be 17 in order for the equation to equal 27.
Calculate the number of steps that you will construct. This will make planning and ordering or purchasing material easier. Divide the rise of the slope by the planned height for each step.
Excavate the rough slope and step dimensions.
Prepare the foundation for the base step. Timber or timber-edged steps require little foundation work besides digging trenches at the front and sides of the step for the timber. Make sure that the bottoms of the trenches are level and the soil is compact. If the soil is unstable, dig the foundation several inches deeper and fill it back in with crushed stone or gravel.
Set the material for the first step. Lay the timbers in the trenches. Extend the side timbers 6 inches further into the hill than the tread will be. This will allow for overlap with the second step. Make sure that the material used is level. Drill two holes in each of the three pieces of timber and pound in galvanized steel spikes to secure the timber to the ground.
Build the second and subsequent steps. Excavate the space needed for each step and lay the timbers. Attach a piece of timber, referred to as the riser, to the top of the side timbers using a galvanized steel spike. Place the side timbers behind this riser and continue up the hill in this manner.
Fill the space between the timbers on each step with crushed gravel, backfill or another suitable aggregate. You can do this either at the end or at multiple stages during step construction to allow greater mobility around the work site.