Brick wall repair is often not as hard a job as it seems, and does not always require a professional mason. Elements like water, ivy and soft brick texture damage walls causing bricks to deteriorate, destroying both their strength and aesthetic beauty. Damaged bricks (broken or cracked) require maintenance which, in most cases, can only be done through their replacement. Not doing so will cause the bricks to absorb more moisture, which won't allow the wall to remain intact for long.
Below are the essential things that you require and the steps as to how you can replace the damaged bricks.
Step 1: Identify and Analyze the Bricks
Before you get down to the actual replacement, identify and analyze the damaged bricks, so that you can replace only those that need it and not damage surrounding bricks in the process.
Step 2: Find the Replacement
Finding identical bricks for replacement and keeping the pointing (the practice of fixing mortar joints between bricks) consistent may seem an obvious step, but it requires careful consideration. It is not always easy to find perfect substitutes for bricks in terms of their color and texture, especially if the ones you require are old ones. After you have purchased the bricks, it is important that you water them so as to increase their strength and make them compatible with the mortar applied to them.
Step 3: Remove the Damaged Brick
Scrape the old mortar around the brick with a cold chisel. Then remove the brick, using a cold chisel and a club hammer. If that does not work, use a power drill or a masonry cutting wheel to drill holes around the brick so that it crumbles out easily. After you have removed the brick, clear out the surface of the wall for any leftover scraps of bricks and mortar and spray it with some water.
Step 4: Applying Mortar
Mortar can be Porter cement-based or a mixture of lime and sand or a ready-to-use mortar mix from the market. However, the quantity of sand and water added will vary from one type of mortar to another and would have to be confirmed at your local home-improvement store. Once the mix is ready, dampen the area to be repaired with water. Apply mortar to the base and the respective sides of the cavity horizontally, and on top of the brick with a sharp trowel, making a layer of about 10 mm. Then, carefully slide the brick in the hole and tap it until it comes in line with the surrounding brickwork. With the handle of the trowel, make the new mortar joint similar to the joints in the rest of the wall to give the wall a uniform look.
Step 5: Keep it Damp
After the brick has been replaced, it is important to remove excess mortar, by hand or with a flat chisel. Keep the repair damp for about 2 to 3 days, so that the mortar can dry and cure completely (which usually takes 24-36 hours). Moreover, it is a good idea to cover the damp area with a plastic sheet, especially if the mortar use was extensive and therefore, moisture needs to be retained sufficiently.