How to Install Fieldstone Stairs

Mark the route of the steps and calculate the rise of the slope. Put a stake at the top of the incline and a tall pole at the bottom. Stretch a string between those, level it with a line level, and measure the distance from the ground to the string on the pole with a tape measure. This is the rise.

Measure the total length of the slope of the steps. Divide the rise by 9 and the length by 10 as a starting point for figuring the number of steps needed and the height of the risers or step up for each one. Step treads should be at least 10 inches wide and risers between 7 and 9 inches. Adjust those to fit your step design; a low slope can have wider treads and shorter risers while a steep slope needs higher risers. Base your steps on the size of stones being used; large stones can form an entire tread.

Outline the sides of the steps with stakes and mason's twine; make steps at least 36 inches wide if possible, for safer use. Set a stake at the location for each riser. Dig steps in the ground with a shovel, excavating the dirt to form treads and risers at least 6 inches deeper than the depth of the fieldstone. Border the step sides and mark the risers with plastic edging or wood.

Lay 2 inches of gravel on all risers and compact it with a hand tamper, following the step pattern. Cover the gravel with 2 inches of sand and compact it. Begin laying fieldstones at the bottom with the first tread level with the surrounding ground. Set it firmly into the sand and use a level to ensure the top is level. Adjust the sand base as needed.

Install other treads and risers depending on the type of stone and stair design. Put large individual fieldstones for both treads and risers with the edge of the stone extending slightly over the stone below. Form treads and risers from separate stones by laying one row the width of the step, slightly overlapping the tread below and placing a second row of stones on top. Make sure tread tops are level and the stones are firm and don't wobble.

Work to the top of the slope installing treads and risers, removing the riser boundary boards as you go. Sweep sand into the seams between fieldstones and around the edges to the board using a broom. Use polymeric sand, which hardens when dampened. Remove the side restraints and fill dirt to the edges of the stone steps.