Spread a 1 1/2-inch thick layer of mortar over the entire surface of the breeze block wall using a trowel.
Run a mortar rake over the mortar-covered wall to create grooves. This will enable the stones to sit more securely against the blocks.
Press 3/4-inch-thick stone tiles halfway into the mortar, spacing the tiles 1/2 inch apart. Allow the mortar to dry for 12 to 18 hours.
Spread a 1/2-inch-thick layer of coarse grout over the stone-covered wall, then scrape off the excess grout using a trowel. This pushes the grout in between the stones to fill in the spaces.
Wipe off the front of each stone tile using a damp sponge. Allow the grout to dry for 18 to 24 hours.
Apply an even layer of clear masonry sealant over the stone-covered wall to protect it from the elements.