How to Lay Flagstone on an Uneven Surface

Use a biodegradable ground-marking spray paint to lay out your walkway or other design. For areas that will require straight edges, such as a patio, use brightly colored string and metal stakes.

Cut grass and weeds, and remove dirt with a shovel. Dig 3 to 4 inches into the ground and discard whatever is removed. If you are creating a patio or walkway that will have flagstones butted up next to each other, remove the ground from the whole area that is within the string and metal stakes or spray paint. If you are creating a pathway with stone steps, place the flagstone on the ground and trace the shape of the flagstone with your shovel. Move the flagstone and continue to dig.

Pour approximately 1 1/2 to 2 inches of sand in the holes you dug out, depending on the depth of your flagstone. Use a shovel to flatten and level the surface. The sand creates a base on uneven ground.

Set the flagstones into place. Hold an edge of the flagstone and squat down to lower it to the ground. Squatting will put less strain on your back than bending. Position the flagstone in the correct location.

Utilize a mallet to push the flagstones against each other. If the flagstones look uneven, hit the top of the flagstone to move the sand beneath.

Fill any gaps in your walkway with previously removed grass or more sand. This will prevent the flagstone from moving and becoming uneven.