How to Install Granite Steps
Granite is a strong, heavy igneous rock available from quarries as dressed or semi-dressed stone for construction projects. Semi-dressed granite, where the face of the stone is left rough, complements a landscape with a natural or rustic theme, and often serves as a distinctive site feature. Granite blocks are often used to construct an informal stairway, where the blocks can be used whole, simplifying the installation process. Stone work is labor-intensive and heavy, and cutting and filling the ground and positioning the stones take patience.
Determine the vertical rise from the surface of the ground to the top of the slope. Use the hammer to drive a short stake into the top of the slope at the location for the top step, and a tall stake or board at the toe of the slope, to represent the bottom step.
Fasten the string to the top stake at ground level. Pull it out to the tall stake, stretching it tight. Attach the line level to the string and adjust the string as necessary for the bubble to read as level. Measure the distance from the ground to the string at the tall stake 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 (R) plus the tread (T) equals 25 to 26 inches.
Strip vegetation from the slope with a shovel and move it out of the way. Excavate a pad at the bottom of the slope for the base stone, adding 4 inches minimum of gravel. Compact it with the power tamper.
Spread 1 to 2 inches of sand for leveling. Set a base stone level with or slightly above the adjacent grade. Tap it firmly into place with the rubber mallet.
Excavate 4 to 6 inches of the existing soil behind the base stone for the first step. Backfill with well-drained gravel, and tamp it with the power tamper. Spread 1 to 2 inches of sand.
Lap the first granite step over the edge of the base stone. Pitch the step slightly to shed water, sloping 1/4 inch per foot. Tap the granite into place with the rubber mallet. Make sure the step is stable and securely in position.
Prepare the base for the next step behind the first one, in the same way. Lap the second step over the first one, allowing for the desired tread depth, and pitching it for drainage. Tap it firmly into place.
Repeat the process for the remaining granite steps. Check frequently to ensure the riser and tread depth remains the same.
Grade the top of the slope so it's flush with the final tread, using the shovel and rake. Spread the excavated material along the slope, or use it as fill elsewhere on the property.
Things You Will Need
- Tall stake or board
- Short stake
- Line level
- Measuring tape
- Well-drained gravel, crushed or road mix type
- Power tamper
- Granite blocks, semi-dressed, 2-feet-wide minimum, 6 to 8 inches thick
- Rubber mallet
- Quarry stone is delivered on pallets that can be moved close to the area of work with a skid steer loader equipped with a forklift attachment.
- The first step can rest on the front edge on a patio or walkway, eliminating the need for a base stone.
- It's best to have an assistant to help maneuver the stones into place.