Creating mosaic tiles from colorful river stones is a great project for your garden. River stones are naturally flatter and smoother than other types of stones, which makes them an excellent choice for making a mosaic tile that can be walked on. The project is fairly straightforward: use a mold for the mortar, arrange the stones in the mortar, and wait for the mortar to dry. However, there are a few risks if you don't do it correctly. Here are a few tips for making a mosaic tiles out of stones.
Rinse the River Stones When Selecting
To see the exact colors of the stones when selecting them for your project, you'll need to rinse the stones with water. Ask the stone supply center if you can take a bucket of water with you to rinse the stones with when making your color selections. You'll also need several containers to hold the stones to keep them separated based on color. The reason for this is because the colors can become muted when they dry, which can make it difficult to determine their true colors later when you are ready to put the stones into the mold.
Make a Removable Mold
You'll need some 2x4 pieces of wood and a sheet of plywood cut to the size that you want for your tile. Use the plywood as the base and arrange the 2x4s in a square to create the mold. Secure the pieces together with screws, not nails. When it's time to remove the tile from the mold, you'll simply unscrew the pieces. If you'd like a tile with rounded corners, line the inside of the square mold with flexible lawn edging to give your tile a rounded shape.
Put Rebar In the Mortar
When you put mortar in the bottom of the mold, you'll want to use thin rebar to give the mortar some strength. The tile will be heavy from the weight of the mortar and stones. By putting rebar into the mortar, you'll be able to pick the tile up without the risk of the tile easily breaking. Place strips of thin rebar at each edge and also several strips centered in the tile in both directions.
Put the Stones In Sideways
To prevent the stones from being able to pop out of the mortar in the future, place the stones on their sides in the mortar. If you place the stones with the flat sides in the mortar, there will not be enough grip from the mortar to hold the pieces in place. If any stones do pop out of the tile after the mortar has cured, secure the stones in their respective holes with clear waterproof glue.
Give the Tile a Smooth Surface
After you've placed the stones into the mortar, you'll want to make sure the surface of the mosaic tile is smooth, especially if the tile will be used as a stepping stone in your garden. To make a smooth surface, lay a larger piece of plywood on top of the tile and apply even pressure to the plywood. This will set the stones into the mortar while keep the top ends of the stones even to provide a smoother surface, which can prevent people from tripping when walking on the tile.
Decide if You Want to Use a Sealer
If you'd like the stones to permanently have a wet look, which will make the colors of the individual stones sharper, apply an acrylic sealer to the mosaic tile after the mortar has cured. If you'd like the tile to have a muted look that changes to sharper colors when it rains or when the tile gets wet, do not apply a sealer. If you aren't sure, you can always apply the sealer later if you decide that the natural look doesn't work for your garden.