The technique called "mortar wash" involves placing a coat of mortar over a brick, stone or concrete surface to either conceal the underlying material or partially conceal it. When used on brick, the technique results in a "painted" look that some homeowners find attractive. A mortar wash can be applied in thick or thin coats, with or without tint, to achieve a specific look.
Clean the brick, stone or concrete surface so it is free of dirt, mold and loose mortar.
Mix one part water to five parts pre-mixed mortar in a large pail. Add tint if desired. Stir until the mixture forms a smooth, stiff slurry.
Wet the surface you wish to "mortar wash" with water using a brush. Apply mortar mixture to the wet surface with a steel trowel in the thickness desired, working from top to bottom.
Wipe the surface with a dry rag, if desired, to expose underlying material in certain areas.
When the mortar wash is dry, sand it, paint over it, or leave it as is.