How to Lay Outdoor Slate

Slate tiles come in earthy colors.

Use slate to build an outdoor patio or walkway that will naturally blend with the environment. Slate comes in thin tiles or thicker stones, and works well in outdoor spaces. The stone is available in earthy colors. One of the simplest ways to lay slate is by installing the tiles in a sand bed.

Things You'll Need

• Slate tiles or blocks
• Tape measure
• Wood stakes
• Twine
• Shovel
• Gravel
• Power tamper (optional)
• Landscape fabric (optional)
• Sand
• Piece of lumber
• Chalk line
• Masonry saw (optional)
• Rubber mallet
• Garden hose
• Broom

Instructions

1. Measure out the dimensions for your patio or walkway. Then mark the corners with a wood stake. Border off the designated area by attaching twine to each of the wooden stakes.

2. Excavate the bordered off area. Use a shovel to dig down to a depth of 6 inches. This will accommodate 4 inches of gravel and 2 inches of sand. You may need to dig the hole deeper if you are using thicker than average pieces of slate. If you are using only slate tiles, 2 inches of sand will be adequate.

3. Pour the gravel over the surface of the excavated area. Tamp down gravel with a shovel. If you are working on a large area, consider using a power tamper to compact the gravel and make the surface level.

4. Cover the gravel with a layer of landscape fabric. This step is optional, but recommended. A landscape fabric will eliminate the possibility of weeds growing between the pieces of slate. Roll the fabric over the entire surface of the gravel. Cut the fabric to fit. Allow about 6 inches of overlap on each piece of fabric if necessary.

5. Add the 2 inches of sand over the landscape fabric or over the gravel surface. Next, use a garden hose to lightly dampen the surface of the sand. Use a piece of lumber to smooth out the sand. Drag the lumber over the surface of the sand until the sand bed is even and level.

6. Draw a chalk line down the center of the sand bed. Lay the slate tiles along this line. Press each tile into the sand, leaving about 1/8 inch between each tile. Use a rubber mallet to gently pound the tile into the sand. Once you have reached the end of the chalk line, begin laying tiles to the left and right. If you reach the end of the sand bed and a piece of slate will not fit, use a masonry saw to cut the slate to the necessary length.

7. With all of the slate tiles in place, add more sand over the entire surface. Use a broom to sweep sand in between the cracks in the slate. Lightly wet down the area again to compact the sand.

Tips & Warnings

• If you are using irregular pieces of flagstone, instead of tiles that are all the same shape, plan the installation. Perform a dry run next to the sand bed. Place the flagstones in the desired positions on the grass next to your excavated site. Then mimic that placement on the sand bed. Move each piece of slate one at a time and use the rubber mallet to pound the pieces of slate in to the sand. Follow the rest of the steps for laying the slate. Pour a layer of sand over the completed area, and then use a broom to sweep the sand between each piece of slate.

• Handle thin pieces of slate tile carefully. Slate can be fragile. When you lay the slate down, do not pound to hard with the rubber mallet.

• If you are using larger slate blocks, make sure all of the blocks are even with each other. If they are not level, just add extra sand or remove extra sand from below the pieces of slate until all the pieces are even.

References

• "The Black Decker Complete Outdoor Builder": Creative Publishing: 2006
• "Start-To-Finish Patios": Ortho: 2004

Resources

• Camara Slate Products