As secure as brick walls may seem, eventually, there will be a need for a brick wall repair. Virtually all brick walls are vulnerable to cracking caused by such things such as expansion and contraction from changes in temperature, from shifting of the base on which these walls are built, and from using imperfect mortar that might deteriorate.
Given enough time, cracks will begin appearing in the brick of any brick wall. Often these cracks, if not repaired, can widen and eventually cause some of the bricks to become loose and drop out of the wall. But you can repair these cracks, whether they are in a garden wall or a house wall. Even if you are not an experienced bricklayer you will be able to replace broken or cracked bricks by following these steps.
Step 1 - Prepare the Cracked Brick
Locate bricks that are broken or have cracks in them large enough to fracture the brick and create separate brick pieces. Remove loose brick pieces. For pieces that are broken and loose from the primary brick but which you cannot remove, use a pry bar, or a chisel and hammer, to remove these pieces. This will likely leave brick dust and debris in the space left by the broken bricks. Remove the debris, along with dust, dirt, or sand left in the vacated space with a stiff-bristle brush.
Step 2 - Mix Mortar and Color
In a large bucket or container, mix mortar, sand, and water, and place a small pile of the mortar mix on a square board or piece of plywood about 15x15 inches. Add mortar color and mix it into the mortar mix until your new color closely matches that of the mortar in the brick wall.
Step 3 - Measure and Cut a Replacement Brick Piece
Measure the space into which you will insert your replacement brick piece, leaving a ¼ inch of space between the sides of the new piece and the sides of the older brick. This space will allow for the mortar you will later add. With your masonry saw and blade, cut a piece of brick to match the space you just measured.
Step 4 - Insert the Brick Replacement Piece
Before inserting the replacement piece, wet the brick so the mortar will better adhere to it when the mortar is applied. Next, apply your freshly mixed mortar to the replacement piece, then insert the replacement piece into the space you've made between the bricks. Use a trowel to push the mortar tightly into the space on each side of the replacement brick.
Step 5 - Complete the Replacement
Make adjustments in the position of the replacement brick, so that an equal space appears on each side of the new brick piece. Allow this piece to dry and cure for at least a week, during which time you should spray it with water.
Step 6 - Repair Remainder of Bricks
Use the procedure from the above steps to replace other broken bricks in your wall.