Plan the perfect garden with our interactive tool →

What Do I Use to Fill Cracks in a Brick Wall?

Jupiterimages/Photos.com/Getty Images

When a brick wall develops cracks, they usually form along the mortar joints. These cracks may appear due to age and, most of the time, do not signify any danger. If you find hairline cracks in a brick wall, you can fill the cracks yourself. However, large cracks in a brick wall may indicate a serious problem with the building structure.

Masonry Cement

Masonry cement became popular in the 1930s, at about the same time when brick manufacturers began producing harder bricks. Masonry cement mix contains sand, ground limestone and up to 65 percent of portland cement, which is hard and waterproof. Modern brick workers prefer using portland cement because it is cheaper and widely available. Masonry cement also sets quickly. This material works well if your brick wall is made up of new, hard bricks. Using masonry cement for old bricks, which are porous and soft, may lead to problems.

Lime-Based Mortar

Before masonry cement came along, masons used lime-based mortars, which contain only sand and limestone putty. This mixture has stood the test of time, as sand and lime hold the bricks of the Egyptian pyramids together. Unlike the hard masonry cement, lime-based cement is flexible. It allows soft bricks to expand and contract with environmental changes. If your brick wall was erected before World War II, you may have to use lime-based mortar to get a strong bond between the brick and the new mortar.

  • Masonry cement became popular in the 1930s, at about the same time when brick manufacturers began producing harder bricks.
  • Before masonry cement came along, masons used lime-based mortars, which contain only sand and limestone putty.

Application

Before filling the cracks with mortar, you have to first clean the cracked joints. Use a grout saw for joints 1/4-inch wide or smaller, or use a chisel and a hammer for wider joints. Remove the loose debris with a stiff brush and wet the bricks until they drip. After the bricks dry, use a trowel to force the mortar into the spaces between the bricks. Once the mortar dries, brush off any excess mortar.

Professional Help

Some types of cracks signal that you have a serious structural problem and will need professional help. If the cracks form a stair-step pattern along the joints in the brick wall, then you need to call a structural engineer. Another sign of serious trouble is a long horizontal crack along the mortar joints of the wall. These signs may mean that the wall is about to fail. Simply filling the cracks will not solve the problem because they will reappear.

  • Before filling the cracks with mortar, you have to first clean the cracked joints.
  • If the cracks form a stair-step pattern along the joints in the brick wall, then you need to call a structural engineer.

Related Articles

Causes of Brick Delamination
Causes of Brick Delamination
How to Fix Tiled Swimming Pool Leaks
How to Fix Tiled Swimming Pool Leaks
How to Fix Rotten Raised Beds
How to Fix Rotten Raised Beds
Can I Patch a Cracked Brick?
Can I Patch a Cracked Brick?
How Serious Are Vertical Cracks in Brick Walls?
How Serious Are Vertical Cracks in Brick Walls?
Types of Brick Joints
Types of Brick Joints
Types of Mortar for Cement Board
Types of Mortar for Cement Board
How to Repair a Settling Sidewalk
How to Repair a Settling Sidewalk
How to Repair a Bluestone Patio
How to Repair a Bluestone Patio
How to Repair a Cracked Cement Driveway
How to Repair a Cracked Cement Driveway
Problems With Permanent Dental Cement
Problems With Permanent Dental Cement
How to Use a Brick Hammer
How to Use a Brick Hammer
How to Use Granite Around a Fire Pit
How to Use Granite Around a Fire Pit
How to Reset Flagstone
How to Reset Flagstone
How to Clean the Moss Off of a Brick Patio
How to Clean the Moss Off of a Brick Patio
Garden Guides
×