expansion joint in brick

My Brick Expansion Joint Is Spreading Apart. Is This a Problem?

A brick expansion joint on your exterior wall seems like there’s something wrong with it. The space between the two sides is spreading apart unevenly and causing the caulk to stretch beyond normal or the mortar is breaking loose. Something doesn’t seem right . . . 

At Anchor Foundation Repair, we have been inspecting and repairing Brazos Valley foundations since 1985. We’ve seen this type of issue before on our home visits and you’re right to be concerned about it. We can explain what is happening with your home when this kind of brick expansion joint issue is present.

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This article will explain the purpose of expansion joints in brick and reveal the meaning behind this kind of home problem. We will also *expand* on a few options for handling this issue. Sorry, puns are just a way of life around here . . . 

What Is Normal for Brick Expansion Joints?

You might already know this but brick expansion joints are purposely built into brick walls to help prevent or minimize cracking and other issues. Building codes have changed and improved over the years and brick expansion joints are one of those updates. 

normal expansion joint
Normal expansion joint

Homes built in the 90s and later use expansion joints on longer brick walls to allow for the normal thermal expansion of bricks. Expansion joints look like a vertical break in the usual brick pattern and it’s the only place on a brick wall where you can find a straight vertical line of mortar or caulk. There’s likely a nice picture somewhere close by showing you an example, right?

Creating this break in the brick pattern allows the expected movement from heat expansion to occur in the wall to theoretically prevent damage to your wall structure or mortar integrity. It’s a way to plan for expansion, control where it happens, and how much movement the wall can accommodate.

Some expansion joints are purposefully not filled with mortar and some do have mortar, caulk, or other flexible material filling the space. All these options are common and generally acceptable.

It’s normal for brick expansion joints to widen and narrow evenly throughout the year. Expansion joints should not be spreading so far apart as to pull the caulk apart or cause mortar to break loose or begin to degrade. Expansion joints should maintain a consistent parallel gap of about the same width at the top and bottom of a wall. 

If the joint is gapping beyond the expected, or it gaps wider at the top or bottom, it can signal a problem.

Why Would a Brick Expansion Joint Gap Irregularly?

expansion joint cracking
This one is starting to crack

There is only one reason for brick expansion joints to gap irregularly on your home. Changes and cosmetic flaws appearing in rigid finish surfaces like a brick veneer are great indicators. They tell us that something is happening with the unseen structure below and behind the outer finish. 

This concerning sign of expansion joints moving out of parallel and beyond normal width is caused by foundation settlement.

Expansion joint irregularities especially highlight foundation settlement when settlement is occurring at one corner of your home. You could also have settlement at two consecutive corners of the long wall where the middle of the wall is not sinking but the corners are pulling down. In other words, the entire home is not settling evenly. A section or corner has moved lower than the rest of the house.

Expansion joints will either gap wider than planned or gap wider at the top or bottom. However the symptom presents itself, it all means the same thing and neither is worse or better than the other. They all mean that your foundation is moving or has moved in a downward direction from when it was originally built.

When the Expansion Joint Is Wider at the Top and Narrow Down Low

expansion joint gapping

An expansion joint that is gapping wider at the top near the soffit and narrower down low near the slab often indicates that one of the corners of the wall has settled. It could also mean that settlement has occurred on both corners. 

This situation happens on brick expansion joints when they are present because there is already a natural break in the wall and the joint offers the least amount of resistance to the settlement forces.

When the Expansion Joint is Narrow at the Top and Wider Down Low

An expansion joint that is wider down near the slab indicates that the wall has a sag between the corners. So the middle of the wall is sagging, sinking, or settling rather than the corners. This is the opposite of the scenario above and is definitely more rare (we can’t even find a good picture right now!).

With sags in the middle of walls, we often find interior foundation settlement requiring interior foundation work. This is where you need support under the middle of the home in addition to around the perimeter. Interior foundation repairs are more extensive and expensive compared to more typical foundation repairs that take place along the exterior walls only.

What To Do About Expansion Joint Problems: 5 Options

ways to repair expansion joint issues

You’ve got some options on what to do about irregular expansion joint gaps in your home. Let’s list them quickly here and then we can elaborate on the options.

  1. Ignore the issue and do nothing
  2. Fill the gap with another material
  3. Repair with caulk (smooth or sanded)
  4. Re-apply mortar (also called tuck point)
  5. Raise the foundation using foundation repair

Let’s go ahead and *expand* on these ideas now . . . 

Option 1: Ignore the Gapping Expansion Joint In Your Brick

Suggesting that you ignore the issue sounds a little strange, but we’re just listing *all* the options here. But if the problem doesn’t bother you that much and isn’t getting actively worse at the moment, then you could just ignore it for a while until you decide if or how to proceed later.

Typically, expansion joints are placed on either side or back exterior walls, not the front of your house. Since the issue is likely not easily visible from the street, it might not be as urgent for you to handle immediately. 

Option 2: Fill the Expansion Joint Gap with Other Material

If you’re worried about creepy crawly pests getting behind your brick, you could fill the gap by stuffing something in the space to block the opening. This is an easy option because you’re working with something solid, not a flowing material like caulk or mortar that might require a bit of skill or hiring a brick mason.

filling expansion joints
Weep hole filled with steel wool

To keep away bugs, you can fill the opening with either steel wool (like they do with weep holes in brick) or something called foam backer rod. Backer rod is kind of a strange name to describe what is essentially a round tube of spongy flexible material that can fit into crevices, joints, and tight spaces needing to be sealed in construction.

Worried about water intrusion or draftiness as well as insects? The foam backer rod is a better choice for sealing out anything that might venture into the gap, be it air, water, or living things. 

Keep in mind that it’s not like this gap leads directly into your home, it’s just an opening in the outer shell. Things can get behind the brick, but they still can’t get in your house unless they find another opening that leads somewhere further to the interior.

Options 3 & 4: Caulk or Re-Mortar Your Expansion Joint

Refilling the gap with caulk or mortar are both cosmetic ways to mask the issue. This could work in the short term if you just want to make the problem disappear temporarily to look good for an event at your home. Eventually, the issue will reveal itself again if the root cause of the problem is not addressed.

Foam backer rod is often used in conjunction with caulk or mortar as a preliminary sealer and space filler. Caulk or mortar is then used on top of the *backer* for a finished look that is also well-sealed. But in this case, it’s still a quick cosmetic repair that doesn’t solve the source issue.

Option 5: Raise the Foundation with Foundation Repair

If you want to fix foundation-related expansion joint issues with a more permanent and lasting solution, raising your foundation back to its original elevation is the way to go. Foundation repair is the only solution that addresses the root cause of the problem.

repairing expansion joint gapping with foundation repairs

Foundation repair adds extra support under the length of your affected brick wall(s), corners, and any other needed locations. Foundation repair also raises the portions of the home that have settled back into their original position when built. After a foundation is repaired, you can confidently do some re-mortaring or caulking to seal up the joint the way it was before without the worry of it becoming an issue again due to further settlement.

Handling the Source of Your Gapping Expansion Joint

expansion joint under window frame
Expansion joints are also placed near window frames

Now that you know what has caused your expansion joint issue, what’s next? Well, you will need to decide if it’s time for foundation repairs or if you want to choose a more temporary solution.

At Anchor Foundation Repair, we have been inspecting and repairing foundations for 35+ years in Bryan, College Station, and surrounding Brazos Valley communities like Brenham and Navasota. We want to empower you with as much diagnostic information as possible so that you feel confident making repair decisions for your home.

Knowing when to get started with foundation repairs is a tough call for any homeowner. First, look around your home for other signs of foundation problems so that you can begin to get a handle on how much foundation settlement is occurring in your home.