How to Fill Large Holes in a Brick Wall

How to Fill Large Holes in a Brick Wall

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Brick walls are of course very common. The material is not overly expensive, it’s easy to work with, and generally lasts for quite some time too. That said, bricks are not indestructible, and they do eventually break. Aside from normal wear and tear, a big impact could also break them. At one point or another, you may end up with some pretty big holes in your brick walls.

Today, we are here to discuss in detail all of the possible methods for filling those. In case your hole is not too large, you might also want to read about how to repair cracks in brick walls.

How to Fill in Large Holes in Brick Walls: The Best Way

There is only one way to truly repair large holes in brick walls, at least if you expect the results to last for a long time. The best way to fill large holes in a brick wall is to simply replace the bricks altogether. Now, this method is best used if the hole is at least as large as a full brick. If the hole is as large as one or multiple bricks, this is by far the best method to consider.

Most people would even use this method if just 50% of a single brick is damaged. Generally speaking, replacing whole bricks is easier than filling holes. Moreover, replacing the bricks with new bricks and mortar also produces the best, most durable, and most longest lasting results.

Follow the short guide below to get the job done.

Step 1: Gather Your Materials

To do this job, you will need certain materials. You will need to get new bricks (as many as you need), mortar, water, a bucket, a trowel, a hammer and chisel, a masonry brush (or a shop vac), and a towel or sponge with some water. To learn more about some of the tools, see my overview of basic masonry tools.

Once you have gathered your materials, you can move onto the next step.

Step 2: Remove the Broken Bricks and Mortar

Before you can start replacing bricks, you will first have to remove any and all broken bricks, as well as adjacent mortar. Pull everything you can out by hand. If some are still attached with mortar (broken chunks), you will need to use a hammer and/or chisel to remove them.

Once all of the broken bricks have been removed, you will then also want to remove any of the remaining mortar. Keep in mind that you need to use fresh mortar, so any dried and broken mortar that is present must be removed.

What you should have now is a hole with whole bricks on all sides, without any mortar inside of the hole.

Step 3: Clean the Area

Before you start putting in new bricks and mortar, you do want to clean the area. Just remove any possible debris. For this, you can use a brush, a shop vacuum, or you can even wash the area down. If you do wash the area, be sure to let it dry before continuing.

Once the area is totally clear of debris (and dry), you can start replacing the bricks.

Step 4: Add New Mortar and Replace the Bricks

Now you need to mix your mortar. So, get your mortar mix, a bucket, and some water. Follow the directions on the packaging as indicated to achieve the right consistency. Then, using your trowel, put about a 3/4-inch layer of mortar on the brick wall, in the hole, on the bottom (on top of the whole bricks that are still there).

If you are starting from the left side of the hole, also put mortar on that left side (or on the side of the brick that you are putting in). Remember, all bricks need to have mortar on all four sides. Once you have a layer of mortar put down, use your trowel to raise the edges. These ridges in the mortar will allow for proper brick placement. It also ensures that the mortar gets where it needs to go.

Now, simply place the brick as needed, and then push it down (and wiggle it) to make it flush with the other bricks. Keep repeating this process of adding mortar and bricks until the hole is completely filled and repaired. You may need to use a tuck point to insert some mortar in between the new bricks.

Remember, you want those joints to be 100% full of mortar. You don’t want any empty spaces between the bricks. Putting in the last brick of the puzzle can be messy. When you push that last brick into place, a lot of mortar is going to get squeezed out, but all you have to do is clean it.

Step 5: Finish It Off

Now, use the trowel, your finger, or a special mortar joint tool to wipe away excess mortar and to make sure that all of the mortar joints look nice. If you made a mess, now is the time to use some water and a sponge to clean things up. Once you have done this, you just need to wait for the mortar to dry and cure.

Alternative Ways of Repairing Holes in Brick Walls

Although actually replacing the bricks is your best bet, if that seems like too much work, or if just small chunks of brick and/or mortar are broken or missing, then there are some easier alternatives to consider.

Method #1: Filling Holes with a Brick-Mortar Mix

If it is just a portion of a single brick that is broken, your best bet is to simply fill it with a mix of mortar and brick dust. This is a very easy and fast process that is ideal for filling holes that are up to 50% of a full brick in size. Follow the simple directions as outlined below.

Step 1: Clean the Area

You will first need to remove any debris and loose chunks. This is best done by sweeping the area with a stiff wire brush. Make sure that 100% of the loose debris is removed.

Step 2: Mix Your Mortar

In a bucket, mix the mortar mix with water, as well as brick dust that matches the color of your existing bricks. You can either buy brick dust or just pulverize a spare brick that you have laying around. Just put a brick in a thick plastic bag and smash it with a hammer until you are left with nothing but brick dust.

Mix your mortar and brick dust with water until you have the right consistency.

Step 3: Wet the Hole

To make this mortar mixture adheres to the surface, you need to use a spray bottle to spray it with water. Make sure to completely saturate the surface that is being repaired.

Step 4: Fill the Hole

Using a margin trowel or pointing trowel, scoop up the mortar mixture and stuff it into the hole. Make sure to pack the new mortar into the hole as tightly as possible, until it is flush with the existing brick (or just above the existing brick).

Step 5: Push it Down

To ensure that it is tightly packed, and so that it looks nice, use an existing brick to press everything down as hard as you can.

Method #2: Filling Holes in Mortar Joints

If you just have holes in the mortar (missing mortar), then the repair process is very easy. You simply have to fill those holes with fresh mortar. Follow the simple steps as outlined below to fill in mortar holes.

Step 1: Clean the Area

Use a stiff wire brush to remove any loose mortar present.

Step 2: Mix Your Mortar

Get some mortar mix and mix it up according to the directions on the packaging.

Step 3: Wet the Area

To make the new mortar adhere to the old mortar, you need to wet the area. Saturate the area with water. Using a spray bottle will make this fast and easy.

Step 4: Insert the Mortar and Shape it

Using a pointing trowel, insert the new mortar into the gaps. Using your trowel or an appropriate tool, push the mortar down and shape it so that it is flush with the existing mortar. Now you just have to let it dry and cure.

Method #3: Using Exterior Silicone Caulking

If there are moderate size holes in your bricks, you can always fill them using exterior grade silicone caulking. It’s a quick fix, but it will hold for a few years. In addition to the below, also make sure to read through my exterior caulking tips.

Step 1: Clean the Area

Use a stiff wire brush to remove any and all debris. You may also want to use some compressed air to blow debris out of the hole.

Step 2: Insert the Caulking

Make sure to use exterior grade caulking. Using your caulking gun, insert the tip of the tube into the hole, squeeze the trigger, and fill the hole until it is flush with the existing brick.

Step 3: Finish It Off

Take some brick dust that matches the existing bricks, place it on your trowel, and press it onto the still wet caulking. This will help the repairs blend in with the existing brick.

Summary

There you have it people, the four ways to fill in large and small holes in a brick wall. Generally speaking, replacing the broken bricks is the way to go. However, it does of course depend on the extent of the damage.