Patching a Concrete Block

Aging concrete block will need to be repaired as soon as possible as it can get damaged from the weather and other elements. It is important to repair the old concrete as it will help to bring it back to its function and looks. You can do this minor repairing job with less experience as patching or caulking jobs will only take less than 30 minutes to finish. Here are the steps on how to path a concrete block.

You will need:

  1. Ready -mix concrete
  2. Pointing Trowel Mortar
  3. Caulking Gun
  4. Adhesive Caulking

Concrete Block


  1. First, mix a bag or a half of ready-mix concrete. If you are mixing large amounts of concrete, wear steel toe-capped boots for foot protection.
  2. You have to work it quickly to prevent the concrete from hardening before the job is finished. Take the pointing trowel and load it with the ready-mix concrete. Use a board to remove excess concrete and with a trowel held at an angle parallel to the missing mortar between the old concrete blocks.
  3. Fill the gap with fresh concrete. Scrape the point of the trowel to make a smooth edge and to finish off the repair. Leave it for overnight to cure.
  4. Fill the adhesive caulk into the caulking gun and snip off the tip at the desired width. The caulk will help to fill in deep cracks in the old concrete block wall. Pull the trigger of the caulking gun until a drop of adhesive caulk forms at the tip. Place the tip at the top of the crack in the old concrete block wall and start to squeeze carefully until some of the caulk appears.
  5. Continue to squeeze the gun until the entire crack is filled with the caulk. Smooth off the edge with your wet fingertip.
  6. Fill a tube of mortar and concrete caulk into a caulking gun to fill a hole in an old concrete block.
  7. Cut off the tip of the tube and squeeze until a drop appears at the tip of the tube. Fill the hole from the bottom up in a sideway’s motion by squeezing the caulk gun.
  8. Use enough of caulk to fill the cracks and leave the caulk to cure, according to the product’s directions.

Image Credit:

Flickr CC

Additional Reading:

Building with Masonry: Brick, Block, and Concrete

Concrete Block Construction for Home and Farm