How to Make a Pebbled Garden Mosaic

If you've been wondering how to make a pebbled garden mosaic for your yard, you're in luck! This simple how-to guide details the process so you have the knowledge you need to let loose and be creative!
  

Materials and Tools:

• Pebbles
• Thinset (found in home improvement or masonry supply store)
• Sanded Grout (for ¼”- ½” tiling): comes in many colors (found in home improvement or masonry supply stores)
• Plain round or square stepstones
• 1-2 gallon pail or utility tub for mixing Thinset
• Small bucket filled with clean water
• Stirring stick or electric drill with mixing rod
• Dust mask
• Rubber gloves
• Nylon-bristled utility brush
• Sponge

Instructions:

1. Whether you are using store bought pebbles or stones you have collected, sort the pebbles according to color and size. 1” to 1 ½”diameter pebbles are ideal for stepping stones.  A 16” stepstone will require approximately 15 pounds of 1 to 1 ½” diameter stones. Make sure they are clean before beginning the project.
    
2. Decide on a design for your mosaic. Be creative and make up your own unique design or look at pictures for inspiration.
    
3. Mix the Thinset. For a 16” stepstone, you’ll need approximately 1 ½-2 dry quarts Thinset mixed with enough water to create a stiff brownie-mix consistency. Stir by hand until most of the lumps are gone (a few small lumps are okay).
    
4. Spread a thin icing of Thinset onto the stepstone and roughly trace your design using a stick or your finger.
    
5. Place a 6” diameter puddle of Thinset, ½”-3/4” thick in the center of the stepstone. Fill in your design by placing the pebbles on their edge, not lying flat. One-half to two-thirds of the pebble’s height should be submerged in Thinset. Use taller stones in the middle of your design to prevent tripping and pooling of water. Since you need to keep the stones packed closely together, you may have to try different stone combinations to ensure a tight fit. Place the stones you try in a bucket of clean water to wash them off before you try them again in another part of the design.
    
6. After the center is set with pebbles, spread a 3”-4” ring of Thinset around the center and continue working. As you continue placing pebbles, occasionally stop and turn the stepstone to look at the design from all sides. Thinset takes hours to set, so you have time to adjust the design and fix slumping stones as you go.
    
7. Cover the whole stepstone with Thinset and complete your design. Stones on the out edges may tend to slump outward, so press them towards the center.
    
8. Place the stepstone in a cool, dry location and allow to cure for 1 to 3 days. Curing is complete when none of the stones move when you try to wiggle them.
    
9. After the Thinset has cured, cover the stone with water and use a brush the clean off any excess hardened Thinset on the surface.
    
10. Mix grout according to manufacturer's directions until you ahve achieved a brownie batter consistency. Using a sponge, spread the grout over the step stone, making sure to fill the spaces between the pebbles. No voids or air pockets should remain. After all the gaps are filled, try to remove any excess grout and expose the tops of the stones. This will become easier as the grout begins to set. When the grout between the stones is firm but still pliable, use a wire bristle brush to cut into the grout around the pebbles and expose more of their surface. ¼" to ½” of their tops should be showing.
     
11. Rinse the stone with water and then allow to sure in a cool, dry location for 1 to 2 days.
     
12. After grout has fully cured, wash stone with soap and water. Your stones are now ready to be set in your garden or lawn.