Holes can be drilled into brick walls for various reasons, including running electrical wires, cables, or pipes through the wall. Changing the location of the pipe, wire or cable will leave a hole in the wall where dirt, water and debris and enter. Methods of filling the hole will vary depending on its size and location.
Holes in the Mortar Joint:
First, brush the surface and inside the hole using a stiff wire brush to remove any loose mortar and debris. Mix mortar and water to form a thick paste. Then, using a spray bottle, mist the brick surface and the inside of the hole with water, saturating the existing mortar. Use a small pointing trowel to pick up the mortar and force it into the hole. Pack it in as tightly as possible so that it filled until it is flush with the existing mortar. You can then use a pointing tool to shape the patch so that it resembles the existing joint.
Holes in the Brick:
Start by using a clean wire brush to clean the inside of the hole and the surface of the brick. Remove all dust and debris from the hole and the brick surface. Then, mix mortar mix and water with a concrete pigment or brick dust that is a similar colour to the brick you are filling. Continue adding brick dust or pigment as you stir the mixture if needed to achieve a matching colour. Then use a spray bottle to saturate the hole and the surface of the brick with water. Using a margin trowel or pointing trowel, pick up the mortar and tightly pack it into the hole until it reaches a level where it sits just above the existing brick. You can then use a brick to forcefully press the mixture into the patch to create a brick texture.
Using Silicone Caulk:
You can also use silicone caulk to fill holes in the brick. First clean out the hole and surface of the brick using a stiff wire brush, before placing a tube of exterior-grade silicone caulk in a similar colour into a caulking gun. Insert the tip of the gun into the hole and squeeze the caulk in until it is flush with the existing brick. You can then use a trowel to press matching brick dust into the wet silicone caulk to match the texture and colour of the existing brick.