How to Lay Exterior Slate

Clear out the area where you want to lay your slate tiles or pavers, using a shovel and wheelbarrow. Dig down at least 6 inches, and clear out any rocks along with the soil. Cut out any roots that might present themselves, using an ax, and level the soil with a carpenter's level. Tamp it down with a tamping machine.

Frame out the opening with weatherproof lumber. Make sure the lumber stays straight by pounding small stakes on either side of the vertical boards, alternating sides as you go. Screw the corners together once you make sure the measurements are equal from corner to corner.

Fill in 3 inches of crushed stone and spread it out evenly over the base of the opening. Use the tamping machine to pack it firmly, and then add 3 inches of sand. Again, level it and pack it down with the tamper.

Set the slate in place, starting at one edge and working your way across the area. If your stones are not perfectly even, fit the pieces together as closely as possible. Use a level across the top to push thicker stones down into the sand until you have a level surface.

Pour more sand over the stones, and use a push broom to push and pull the sand into the cracks between the stones. Rinse down the stones with a hose, spraying them lightly and settling the sand between the cracks. Add more sand if necessary so you fill all the gaps.