How to Build Stairs Out of Landscaping Stones

Calculate the slope and the tread to riser ratio. Set a long, level wooden board on top of the slope so it extends over the drop and use a tape measure to measure the distance between the bottom of the board and top of the slope: the rise. Stand the board vertically and level at the bottom of the slope and measure the horizontal distance between the top of the slope and the bottom of the slope at the same height to generate the run. Determine the desired tread or riser size and calculate the accompanying measurement. The tread plus two times the height of the riser should equal 26 to 27 inches. For example, if the planned riser height is 5 inches, the tread should be 17 inches. Divide the slope's rise or run by the riser height or tread size to determine how many steps will be needed.

Excavate the rough shape for the steps. Dig the base for the first step to a depth of about 12 inches.

Tamp 4 inches of crushed rock or gravel into the excavated base step.

Pour 4 inches of concrete on top of the gravel and let it dry for at least 24 hours.

Place support stones on both sides of the step. Dig a space a few inches deep and several inches wide and place each support stone at an angle so it will be partly against both the base and the riser or next step.

Apply 2 inches of mortar to the top of the concrete, making sure some mortar reaches the support stones to set them in place.

Press the stones into the mortar, using the level to make sure they are even. Fill in spaces between the stones with mortar and use a rag to wipe away excess mortar.

Build the first riser. Apply an inch-thick layer of mortar to the back of the first tread, making it wide enough to accommodate the riser stones, and press riser stones of the necessary height into the mortar. Mortar the stones together, check for level, make any adjustments as needed and let the mortar set.

Excavate the area behind the riser. Remove about 6 inches of earth.

Tamp about 3 inches of gravel into the excavated area, adding more as needed so that the gravel reaches a height about 2 inches below the top of the riser in front of it.

Apply 2 inches of mortar to the top of the crushed rock.

Lay the stones on top of the mortared area. The stones should be placed so that there is 1 inch of overhang in front of the riser. Level the stones, mortar between them and wipe off excess mortar.

Repeat setting support stones, constructing risers and building steps using gravel, mortar and landscaping stone until the entire staircase is finished.