How to Mortar a Stepping Stone

Place the stepping stones in a linear path through your lawn or garden. Place the center of the stones approximately 20-to-24 inches apart to accommodate the natural gait of a person. Allow space between the stones for gravel or ground cover.

Cut an impression, using the flat head shovel, two inches greater than the depth of the stepping stone, starting 1 1/2 inches beyond each side of the stone. Remove the stepping stone and cut out the remaining earth, creating a very shallow hole where the stone will rest.

Tamp the exposed earth, using the tamper, in the shallow hole. Tamping the earth increases the compressive capacity of the earth and limits the amount of stone and mortar settling to occur.

Mix the mortar mix and water in the mixing container or machine. Follow the mixing instructions provided with the mortar mix. Do not over-mix the mortar or add too much water. Either can lower the load-bearing capacity of the mortar.

Lay and trowel a 2 1/2 inch deep mortar bed in each shallow hole. Set the stepping stones 1/2 inch into the center of the wet mortar bed with approximately 1 1/2 inches of exposed mortar around the perimeter of the stone. Allow the stone to follow the slope of the ground or level the stone using a hand-held level. Use the trowel handle or firm pressure to adjust the orientation of the stone. Trowel a slight slope into the exposed mortar, away from the stepping stone, to allow water to flow away from the stone.

Allow the mortar to set for 48 hours and replace the earth, ground cover or gravel around each stone. The longer you allow the mortar to set before using the stepping stone, the stronger the mortar bed and bond with the stone. So limit or block traffic over the stones as long as possible. The mortar should cure completely within 28 days, although the bond and mortar will continue to strengthen over the course of years.