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What Causes Bricks to Crack?

cracked brick wall

Bricks are a common and durable building material, but even the sturdiest of structures can show signs of wear over time. One of the most noticeable and concerning issues is the development of cracks in brickwork. These cracks can appear for various reasons, ranging from natural settling and temperature fluctuations to more serious structural concerns.

Understanding why bricks crack is essential for homeowners and property managers who want to maintain the integrity and appearance of their buildings. In this article, we’ll break down the common causes of brick cracking and offer insights into how to prevent and address these issues effectively.

Common Causes of Cracked Bricks

From the effects of moisture and weathering to the impact of foundation shifts and construction errors, here are several common sources of cracked brickwork.

Layers of the soil animation.

Soil Conditions

Soil expansion or contraction occurs when the ground beneath a structure moves due to changes in moisture levels, erosion, or natural settling. This movement can put uneven pressure on the foundation, leading to stress on the brickwork. As the foundation shifts or sinks, the bricks, which are rigid and inflexible, may crack or separate as they struggle to adapt to the pressure.

hydrostatic pressure on foundation walls

Water Issues

Water issues, such as poor drainage, plumbing leaks, or prolonged exposure to moisture, can lead to brick cracking by weakening the mortar and the bricks themselves. When water penetrates the bricks or mortar, it can cause them to expand and contract with temperature changes, particularly during freeze-thaw cycles. This repeated expansion and contraction create stress within the brickwork, eventually leading to cracks.

Cracking home foundation with shifting concrete slab patio

Foundation Settlement

Foundation settlement occurs when the soil beneath a building shifts or compacts, causing the foundation to sink or move unevenly. This movement puts stress on the structure above, including the brick walls. As the foundation settles, the pressure can cause bricks to crack, especially if the movement is uneven or severe. These cracks often appear in a stair-step pattern and can indicate structural issues that may worsen over time if not addressed.

helical pier installation

Construction Work

Construction work, especially involving heavy machinery or nearby excavation, can cause vibrations and shifts in the ground that may lead to brick cracking. These activities can disturb the soil and foundation, creating stress on the brick walls. Additionally, if the construction alters the load-bearing structure or involves cutting into existing walls, it can weaken the brickwork, leading to cracks.

crew digging up tree roots

Tree Roots

Over time, tree roots can infiltrate small cracks or gaps in the foundation, gradually widening them and causing the structure to shift. This movement places stress on brick walls, leading to cracking as the bricks and mortar struggle to accommodate the changes in the underlying support. Additionally, roots can absorb moisture from the soil, causing the ground to shrink and settle unevenly, further contributing to foundation instability and brick cracking.

Do Cracked Bricks Require Foundation Repair?

Cracked bricks can be an indication of underlying foundation issues, but they don’t always require immediate foundation repair. However, they should not be ignored, as they often signal that the foundation may be shifting or settling unevenly. Brick cracks can be caused by a number of factors, all of which can impact the stability of your foundation. While small cracks might not be a major concern initially, they can worsen over time, potentially leading to more significant structural problems if the underlying cause is not addressed.

bowing basement wall

Brick cracks are just one of several common signs that your foundation might be in trouble. Other indicators include:

These symptoms often occur together, pointing to a foundation that’s experiencing stress or movement. If you notice multiple signs, it’s essential to have a professional assess the situation to determine whether foundation repair is necessary. Addressing the issue early can prevent more extensive and costly damage in the future.

How to Address Cracked Bricks

The exterior brick wall is cracking up to the window seal.

After discovering cracked bricks, it’s important to assess the severity and extent of the damage. Minor cracks might simply be cosmetic, but larger or widening cracks could signal underlying problems with the foundation. In this case, foundation repair solutions such as foundation piers, wall anchors, and carbon fiber support straps may be used to reinforce the foundation.

A qualified foundation inspector can determine if the cracks are due to settling, moisture issues, or other factors and recommend the appropriate course of action, whether simple repairs or more extensive foundation work. By staying vigilant and addressing issues as they arise, homeowners can help preserve the integrity of their homes and avoid more costly repairs down the line.

Protect Your Foundation with Groundworks

Crew measuring interior bowing wall with leveler.

Attempting to address cracked bricks without professional guidance might lead to temporary fixes that fail to address the root cause, potentially resulting in more extensive and costly repairs in the future. A foundation repair specialist from Groundworks can recommend the most effective solutions to prevent further damage and ensure long-term peace of mind.

Don’t let cracked bricks affect the overall stability of your home. Contact us today to schedule a no-cost foundation inspection from our expert team.

Cracked Brick FAQs

There are several reasons that you can have cracked bricks in your home. For the most part, because it’s typically a foundational problem, these are just different versions of the same concerns. Here are just a few of the reasons you might see cracked bricks.

  • Foundation Settling to One Side

Foundation settlement typically occurs in areas where the soil is heavily clay-based and expansive. When one side of the foundation has started to settle more quickly than the other, you’re going to have foundation problems of all types. One of the problems that you’re likely to see with the foundation settling in this manner is wall cracks as the weight shifts to one side of the foundation.

This uneven sinking process puts undue strain on specific parts of the structure and it is in these places that cracks are most likely to form. As your house sinks even further, you will notice that these cracks widen and spread. As it becomes advanced, this issue can even cause sections of your home to break away from the structure as a whole.

  • Not Enough Strength in the Foundation

If the foundation just doesn’t have enough strength to support itself, it might start to crack under the weight of the home as a whole. The foundation can also crack due to hydrostatic pressure if it’s underneath the ground. Street creep and frost heave can also damage a weak foundation more significantly than an otherwise strong foundation.

A weak foundation can be caused by many things. First and foremost, poor design or substandard materials will leave your foundation weak and vulnerable to pressure of any kind. Second, if the soil under or around your home is unstable or weak, it won’t matter how strong your foundation is; it will begin to settle, subside, or crack as it struggles to find firm footing. 

  • Foundation Settling Faster Than Other Concrete

When your foundation starts to settle faster than any concrete it’s not connected to, you can see problems in both the foundation and the rest of the concrete. The concrete can start to settle and crack as it moves out of sync from the foundation, but the foundation can also start to crack as the concrete presses up against it.

To a certain extent, settling is a normal process for a house; all houses settle after construction and this process can cause cracks. Settlement, however, is an entirely different and ongoing process that is damaging to your home in a variety of ways. This is most often caused by problems under your home, for example, expansive soil.

There are many different types of cracked bricks you may see in your home. Typically, these cracks move in different directions. Knowing a bit more about the different cracks that you might notice will be beneficial in helping you to fix them.

  • Stair-Step Cracks

The most common type of crack you’ll often see in a brick wall is a stair-step crack. This type of crack goes up, then over, looking like a stair step, which gives it its name. It also makes it incredibly distinctive and easy to spot. This crack occurs because it’s the path of least resistance in most brick walls. It also occurs when the wall places most of its weight on one side, leading to the other side having little to no support.

Stair-step cracks form in the mortar between bricks because this is the weakest point in most structures. Mortar is also fairly brittle and porous, so once a crack forms and water gets into it, it can spread very easily. It may also start to crumble away, especially during periods of intense, dry heat or during the spring thaw after a hard winter. 

  • Horizontal Cracks

If you see a horizontal crack in the brick, chances are that the wall itself is starting to bend as a result of excessive lateral pressure. This may be a sign of bowing walls, as you might see in the basement, or it could be that the top is moving either inward or outward, often due to soil shifting. The horizontal cracks tend to be due to the inflexibility of brick and a huge amount of hydrostatic pressure.

If you find water pooling in the corners of your basement, or the walls which are bowing are wet, then there is a very good chance that expansive soil is the cause of your horizontal cracks. Soil problems are almost always at the root of foundational and structural problems. Thankfully there are plenty of professional solutions available to help you ensure your home stays what it always was.

  • Diagonal Cracks 

Diagonal cracks don’t occur very regularly in brick; it’s much more common to see them in drywall and poured concrete walls. However, when they do occur, it’s typically due to a problem with the weight of your home shifting. Essentially, it’s often the same problem as stair-step cracks, just in a different location and presented differently because of the materials at play.

Diagonal cracks can form as a result of hydrostatic pressure and bowing walls, but they are far more likely to form because of the same forces and pressures that cause stair-step cracks to form. It can be tempting to simply fill these cracks in, but it is far better for you to call a professional to make sure that the underlying causes are dealt with instead.

For the most part, cracked bricks do indicate an underlying problem with your home’s foundation. Despite this, there are still some situations where your cracked bricks might not indicate an overarching concern. Here’s what you should know about the situation.

  • Non-Indicative of a Foundation Problem

In general, the only time you may see cracked bricks that don’t have anything to do with a foundation problem is if they’re in a very specific area of the home and they happened because of an impact. An impact can cause cracks in the foundation that don’t necessarily indicate an underlying foundation concern. In this case, repairing the cracks themselves may be enough.

Depending on the size, depth, and type of cracks that you are dealing with, repair may take many forms. If sections of your home have sunk, for example, it may be best to lift them back into place before filling or covering the cracks. A professional will be able to advise you on this matter and make sure that you get a fitting solution that restores your home to its proper state.

  •  Indicative of a Foundation Problem 

If you see cracked bricks for no reason, it’s almost always because of a foundation concern. You should generally assume that brick cracks are a foundation concern. This foundation concern needs to be something that you manage early on because if you don’t, you’ll find it usually turns into something much worse. Foundation problems have a way of getting worse very quickly.

Other signs of foundation damage include persistent dampness, water pooling in your basement, mold formation, uneven floors, and gaps between your walls, floors, and ceiling. These last signs of structural damage are very serious and indicate that the problem is advanced. As such, you should get in touch with a foundation repair specialist as soon as possible.

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