How to Repair a Brick Wall

Problem

Okay, so you hit your house with the lawnmower, and now your wife (or husband) is on your case to get it fixed.

Not to worry, depending on the severity of the damage, and your ability to use certain tools, you may be able to handle the job of fixing it yourself.

Excavation

First thing’s first. Broken bricks and old mortar must be removed. You can purchase a masonry blade for your electric circular saw that is designed to cut mortar.

*Advisory: Always wear safety goggles over your eyes and a particle mask over your nose and mouth when performing this task.

Carefully, cut into the horizontal mortar beds above and below the brick pieces that require removal. Take care not to cut into undamaged bricks. While cutting, you’ll actually have to cut beyond the areas actually needing removal so that the deepest part of the circular blade will cross the last short vertical joint touching the damaged bricks.

*Note: Save a few of the largest brick hunks to show to the brick store attendant.

After cutting through the horizontal joints above, between and below the brick pieces needing removal, you must punch through the bricks, creating a hole. This will simplify the removal of the rest of the damaged bricks. For this, you’ll need a hammer and a cold chisel in addition to the safety goggles.

A cold chisel is solid steel and I’ve found that any cold chisel with anywhere from a ½ inch blade to a 1 inch blade is perfect for this application.

Now, you’ve got all the cuts made, and you are ready to remove the bricks. I’ve found over the years, seldom does the saw blade reach all the way through the mortar beds so the bricks probably will not simply fall out for you.

Hold the chisel as close as possible to the center of the demolition area, then, sharply strike the head of it with the hammer. Repeat until the chisel punches through. After the initial hole is made, hold the chisel so the blade is vertical, and chip away at the top and bottom of the hole until you have clearly cut through the entire brick. Now, careful not to hit any undamaged bricks use the hammer to break up and knock out the rest. Use the chisel to carefully tap around the undamaged bricks, removing all mortar.

*Advisory: Care should be taken around undamaged bricks as adhered mortar will conspire to break them as you excavate the damaged ones

*Advisory: New Mortar will not stick to old mortar, so it’s imperative to remove all old mortar; above and below removed bricks.

Materials

It has been my experience that sometimes matching existing mortar color is impossible. The reason for this is age. On many buildings, mortar has weathered, faded and has simply changed from its original look. For this reason, you should take a close up color photograph of your brick wall to show to the brick store attendant. He should be able to assist you with finding the closest possible color match.

Prior to going to the brick store, measure the height and length of one of your home’s bricks so that when you do go, in addition to the largest saved brick hunks, you’ll have something tangible to give to the attendant for matching purposes. Unfortunately, in many cases the specific brick on your home has been discontinued. On the up-side, however, a closely matched brick style and color should be available for you to purchase.

Okay, you have your bricks, your mortar and now you need some sand. You can buy bags of sand at your local home supply outlet, or you can go to your local concrete company with a few 5 gallon buckets and fill them for less than $10.

Most brick repairs like this will require only a small amount of materials. Though you probably won’t need this much, one 70 pound bag of mortar requires about three 5 gallon buckets or 18 good sized shovels of sand.

Start out small scale. When mixing the mortar the ratio of sand to mortar is 3 parts sand to 1 part mortar mix. Begin with 2 shovels of mortar and 6 shovels of sand. Using a garden hoe, mix them while dry, then add about ½ gallon of water at a time; stirring each of them into the mixture until it is the consistency of mud.

Replacing Bricks

A brick mason’s trowel, a level, and a tuck pointer are ideal tools you’ll want for accomplishing the task of filling in the hole with bricks.
With the mortar and bricks within reach, scoop out some mortar with the trowel and set it on the bricks where the new bricks will go. At first, you may have a little trouble getting the mortar into the narrow spaces, but with a little perseverance you’ll get it.

Toothed out is what masons call the cobbled out voids left after bricks are removed. In most toothed out areas, some bricks will have to be inserted halfway into voids with just enough room, above and below them, for mortar joints.

Here, it will help you to place mortar on the top half of the brick that is being slid into the narrow space. In the event that it is the last brick you are placing, you’ll want to place mortar on top of the entire brick you are setting into place.

Periodically, as you fill in each row, use your level to ensure your newly place bricks are in line with the existing wall. To do this, hold the level horizontally; aligning its ends with the tops of existing bricks in that same row, and move the bricks down, squishing them into the fresh mortar bed if necessary (using the trowel). Then, hold the level vertically against the wall, ensuring none of the new bricks are sticking out, or falling back too far.

*Hint: Pushing small shards of brick into mortar beds will help hold falling out bricks in place.

For the mortar voids that will need to be filled, scoop up some mortar with the back of your brick trowel. Hold the trowel’s edge against the wall directly in front of the joint to be filled, and use the tuck pointer to swipe mortar from the trowel into the joint. Push it deeply into the joint, and repeat; gradually reducing the depth of the mortar until it is flush with the bricks face.

Finishing

Okay, you’ve got the bricks and mortar in place. You are almost done. Now, what kind of jointing does your wall need? Are the joints in your existing wall just ‘cut off’, slicked smooth, or raked out?

If the mortar joints are flush with the bricks, then perhaps you’ll need to simply cut off the squished out mortar with your trowel.

If the mortar beds are smoothed and slightly concave, then you’ll need to run a “barrel” jointer across the wet mortar joints. You can purchase a barrel jointer at your brick supply store.

If your existing wall looks as if the mortar has been shallowly scraped out, then you’ll need a “rake” or a “skate” jointer that can be purchased at your local brick supply center. Rakes and skates, which use the head of a nail or screw to scrape out wet mortar, give the same finished appearance.

Okay, the final step: In most cases, you’ll want to clean the bricks you just installed. For such a small area, a sponge and a bucket of clean water will work fine. Just dampen the sponge, taking care not to touch mortar joints, wipe each individual brick, and repeat until clean.

Okay, stand back and feel proud for a job well done.