If you’re looking for an outdoor project that’s a bit off the beaten path, a pebble mosaic will give your yard, garden, or walkway a unique and unexpected focal point. Though the materials to build it are pretty basic—flat pebbles or cobbles from a stone yard (or ordered online); concrete mix, gravel, and stone dust for the base—your design can be anything but.
The mosaic should sit level with or slightly higher than the surrounding ground so that water won’t collect on top of it; take this into account when selecting your project site. Dig out an area at least 1 foot larger than your mosaic on all sides to a depth of 6 to 8 inches. Tamp 6 inches of paver base and a 1-inch layer of stone dust into the excavated area. Pour dry concrete mix into the center of the installation spot, and use a 2×4 to screed the mix to an even 2-inch layer that extends 2 inches beyond the mosaic’s footprint on all sides.