- Determine the vertical rise from the surface of the ground to the top of the slope. Use a hammer to drive a short stake into the top of the slope where your top step will be and a long stake at the bottom of the slope where the bottom step will be.
- Fasten the string to the top stake at ground level. Pull it out to the tall stake, making sure it’s tight. Attach a line level to the string and make adjustments to the string as needed for the bubble to read level. Then measure the distance from the ground to the string to find the rise of the slope.
- Divide the height by the thickness of the blocks (or the step rise) to find the number of steps. Calculate the tread using the recommended ratio for exterior stairs, which is 2 times the risers plus the tread equals 25 to 26 inches.
- Remove grass and any other vegetation from the slope with a shovel. Dig out a pad at the bottom of the slope for the base stone, adding a minimum of 4 inches of gravel. Compact it with a power tamper.
- Spread 1-2 inches of sand to make it level. Set the base stone level with – or slightly above – the grade. Tap it firmly into place with a rubber mallet.
- Dig out 4-6 inches of existing oil behind the base stone for the first step. Fill with well-drained gravel and tamp it with the power tamper. Spread 1-2 inches of sand.
- Place the first granite step over the edge of the base stone. Pitch the step slight so it’ll shed water. One-quarter inch per foot is recommended. Tap the granite into place with a rubber mallet. Make sure the step is stable and secure.
- Repeat the process for the remaining steps allowing for the desired riser and tread depth and pitching for drainage. Tap the treads firmly into place.
- Use a shovel and rake to grade the top of the slope so it’s even with the final tread. If needed, spread the dug-out material along the slope.
