Project details
Skill
5 out of 5HardRequires lifting and setting heavy stone slabs.
Cost
$8 to $10 per square foot
Estimated Time
8 to 10 hours to install a 100- to 120-square-foot patio
In this video, This Old House landscape contractor Roger Cook helps a homeowner install a bluestone patio in an urban backyard.
Steps for Installing a Bluestone Patio
- Call the utility company to confirm that there aren’t any buried cables, wires, or pipes in the patio area.
- Use a shovel to remove all the topsoil, exposing the undisturbed subsoil.
- If you uncover a buried cable or pipe, encase it in sand, then lightly compact the sand with a hand tamper.
- Spread 3 to 4 inches of graded base across the area. (Graded base, or pack material, contains ¾-inch stone and stone dust.)
- Rake the base smooth, then firmly compact it with a gas-powered plate compactor. Run the compactor in two directions, first across the length of the patio, then across its width.
- Cover any buried cables or pipes with caution tape, then cover the tape with graded base.
- Add another 3 to 4 inches of graded base and compact it again. Repeat until reaching the proper grade.
- If a concrete footing protrudes into the patio area, chip away the concrete using the electric rotary hammer.
- Install a series of wood stakes and nylon strings to establish the height of the patio. Pitch the string down about ¼ inch per foot from the house, to ensure the patio will drain water away.
- Make a setting base for the bluestone by mixing in a wheelbarrow 9 parts stone dust, 1 part Portland cement, and a little water. Mix the ingredients with a shovel.
- Shovel some setting base onto the patio and smooth it with the brick trowel.
- Set a bluestone slab into place and tap it down with a rubber mallet.
- Add more setting base and set the next bluestone slab. Insert ½-inch-thick shims between the slabs.
- Drive metal ground stakes into the ground against the sides and ends of the slabs to hold them in place.
- After completing the first row of bluestone slabs, set the second row, making sure to stagger the joints between the slabs.
- Once all the bluestone slabs have been tapped down, remove the metal ground stakes, and pour polymeric sand into the ½-inch-wide joints between the slabs.
- Use a push broom to sweep the sand into each and every joint.
- Sweep away all the excess sand, then use a garden hose to spray a light mist of water over the entire patio.
- Wait five minutes, then spray the patio again.