Score the damaged brick so it will break apart more easily for removal. Use a drill with a masonry-cutting disc to score lines along the surface of the brick and in the mortar joints surrounding the brick.
Use a mason’s chisel and hammer to break apart the damaged brick along the scored lines. Rap sharply on the chisel with the hammer, being careful not to damage surrounding bricks. Tip:Save fragments to use as a color reference when you shop for replacement bricks.
Chisel out any remaining mortar in the cavity, and then brush out debris with a stiff-bristle or wire brush to create a clean surface for the new mortar. Rinse the surface of the repair area with water.
Mix the mortar for the repair and tint if needed to match old mortar. Use a pointing trowel to apply a 1 "-thick layer of mortar at the bottom and sides of the cavity.
Dampen the replacement brick slightly, then apply mortar to the ends and top of the brick. Fit the brick into the cavity and rap it with the handle of the trowel until the face is flush with the surrounding bricks. If needed, press additional mortar into the joints with a pointing trowel.
Scrape away excess mortar with a masonry trowel, and then smooth the joints with a jointing tool that matches the profile of the surrounding mortar joints. Let the mortar set until crumbly, and then brush the joints to remove excess mortar.
For walls with extensive damage, remove bricks from the top down, one row at a time, until the entire damaged area is removed. Replace bricks using the techniques shown above and in the section on building with brick and block. Caution: Do not dismantle load-bearing brick structures like foundation walls—consulta professional mason for these repairs.
For walls with internal damaged areas, remove only the damaged section, keeping the upper layers intact if they are in good condition. Do not remove more than four adjacent bricks in one area—if the damaged area is larger, it will require temporary support, which is a job for a professional mason.