Is a vertical crack in brick veneer a foundation problem?

Reviewed by Preston, Oklahoma foundation repair consultant · Updated 2026-10-14

In short: A vertical crack of fairly even width in brick veneer, especially near a corner or along a long wall, is often caused by the brick itself expanding rather than by the foundation moving. Cracks that taper, wider at one end, or that sit where an addition meets the house, are more likely to involve foundation movement.

What does a vertical brick crack look like?

The crack runs straight up and down, through brick units or along the vertical (head) joints, with roughly the same width from top to bottom. It is common near outside corners, at offsets in the wall, and partway along long uninterrupted walls.

Why does brick crack vertically?

Brick grows and does not shrink back

Fired clay brick absorbs moisture from the air and expands permanently; most of that growth happens in the first weeks after firing, with a slower rate for years ¹. Brick is the only common building material listed with this kind of irreversible moisture expansion ¹. It also expands and contracts with temperature, at about 4 millionths of an inch per inch for each degree Fahrenheit ¹.

Brick industry guidance puts the total unrestrained movement of brick veneer at about 0.0009 times the wall length, combining moisture expansion (0.0005) and temperature (0.0004) ¹. Over a 25-foot section, that is roughly a quarter inch.

Concrete and concrete block behave the opposite way: they shrink as they dry, so they use control joints, while brick uses expansion joints ⁴.

What happens without enough expansion joints

An expansion joint is a deliberate vertical gap filled with a flexible sealant that lets brick grow without cracking. Brick industry guidance states that an expansion joint prevents cracking by dividing brick into segments, reducing the cumulative movement ². It calls for joints near corners, preferably within about 2 feet, at offsets and wall intersections, and spaced no more than 25 feet apart on walls without openings or about 20 feet on walls with several openings ².

Walls expand toward their ends, which can cause distress where they meet at a corner ². Brickwork pushing toward a corner can crack the first head joint on one side, and offset walls can rotate and crack without a joint at the inside corner ¹. If joints are too narrow or too far apart, diagonal cracks can form between windows or doors ¹. Inspection guidance notes that vertical cracking at corners of brick veneer can be caused by thermal movement of the wall ³. This group of causes is described under material shrinkage and thermal cracking.

When does a vertical crack point to the foundation?

Settlement and deflection cracks have a tapering shape ¹. Nearly vertical settlement cracks are described at the joints of bay windows, porches and additions ³; see differential movement at additions. For tapered patterns, see stair-step crack wider at top.

Cracking after ground shaking is a separate topic covered in seismic damage vs soil movement.

How is a vertical crack documented?

• Width along the length. Measure at the top, middle and bottom. Even width supports expansion; taper supports movement.
• Activity. A clean crack suggests recent movement, while a dirty or previously filled crack may be inactive ³.
• Location. Note the distance to the nearest corner, opening or existing sealant joint.
• Floor survey. If the crack tapers, compare with an elevation survey.

Related

• Material Shrinkage & Thermal Cracking (Mimic)
• Differential Movement at Additions
• Earthquake Shaking Damage
• Induced Seismicity in Oklahoma
• Stair-Step Brick Crack Wider at Top