DIY River Pebble Fireplace

Apply thin-set mortar to the surface of the fireplace with a trowel. Begin in the center of the fireplace and work in small, 2- or 3-foot sections at a time to avoid having the thin-set dry before installing the pebbles.

Place a sheet of pebble tiles on the wet thin-set. Gently press on the surface of the tile to create a bond with the thin-set. Set subsequent tiles close to the tiles that have been previously installed, interlocking the rocks on the edges of the tiles.

Apply more thin-set to the surface of the fireplace, as needed. Continue the installation process, following the instructions in Step 2.

Allow the tiles to set for 24 hours.

Seal the tiles with a penetrating sealant. Use a sponge to apply the sealer to the surface of the pebble tiles. Allow the sealer to dry for 12 hours.

Use a grout floater to apply a sand-based grout to the surface of the tiles. Work in small, 2-foot sections at a time. Work the grout into the spaces between the pebbles. Allow the grout to dry for about 30 minutes.

Remove excess grout from the surface of the pebbles with a firm-bristle brush.

Wipe a damp sponge across the surface of the tiles to further remove the grout from the surface of the pebbles.

Apply another coat of penetrating sealant to the pebbles with a sponge.