Vertical vs Horizontal Foundation Cracks: What Homeowners Need to Know

Quick Answer: Vertical vs Horizontal Foundation Cracks

Vertical foundation cracks are usually non-structural and caused by normal settling or concrete shrinkage, while horizontal cracks are typically caused by pressure from soil or water and may indicate structural stress on the foundation wall.

Understanding Vertical vs Horizontal Foundation Cracks

Not all foundation cracks mean the same thing. The direction of the crack—vertical or horizontal—tells you a lot about what’s happening behind the wall and whether it’s something routine or something that needs closer attention.

Vertical Foundation Cracks Explained

Vertical cracks are the most common type found in poured concrete foundations across Massachusetts, Connecticut, and Rhode Island.

What Causes Vertical Cracks?

• Concrete shrinkage during curing

• Normal settlement of the home

• Minor shifts in the foundation over time

These cracks typically form within the first few years after a home is built.

Are Vertical Cracks Structural?

In most cases, no.

Vertical cracks are usually considered non-structural, meaning they don’t indicate that the foundation is failing. However, they can still allow water to enter the basement, especially during heavy rain.

When Should You Fix a Vertical Crack?

• When water is entering the basement

• When the crack begins to widen

• When multiple cracks are forming

The most effective solution is polyurethane crack injection, which seals the crack from the inside and expands with moisture.

Horizontal Foundation Cracks Explained

Horizontal cracks are less common but more important to evaluate carefully.

What Causes Horizontal Cracks?

• Hydrostatic pressure from groundwater

• Expanding soil pressing against the wall

• Poor drainage around the foundation

These forces push inward on the wall, which can lead to cracking.

Are Horizontal Cracks Structural?

They can be.

Horizontal cracks are often a sign that the wall is under stress. Even if the crack is small, it may indicate pressure that could worsen over time if not addressed.

Warning Signs to Look For

• Bowing or leaning walls

• Cracks that run across the wall

• Stair-step cracks in block foundations

Do Foundation Cracks Need to Be Over 1/8 Inch?

This is one of the most common misconceptions.

The 1/8-inch rule is mainly used for vertical cracks as a general guideline to monitor severity. However, width alone does not determine whether a crack is serious.

For horizontal cracks, even small ones should be evaluated because they indicate pressure—not just separation.

What Causes Foundation Cracks in New England Homes

Homes in Massachusetts, Connecticut, and Rhode Island are especially prone to foundation cracking due to:

• Freeze/thaw cycles

• Heavy rainfall and snowmelt

• Expanding and contracting soil

• Hydrostatic pressure buildup

These environmental factors make crack formation common, even in newer homes.

When to Be Concerned About Foundation Cracks

You should have a crack professionally evaluated if:

• Water is entering your basement

• The crack is growing over time

• The wall shows signs of movement or bowing

• You notice multiple cracks forming in the same area

Addressing cracks early is always more straightforward than waiting for them to worsen.

How Foundation Cracks Are Repaired

The repair method depends on the type of crack.

Vertical Crack Repair

• Polyurethane injection

• Seals the crack permanently

• Stops water intrusion

Horizontal Crack Repair

• May require structural reinforcement

• Carbon fiber straps or other stabilization methods

• Often combined with waterproofing solutions

Serving Massachusetts, Connecticut & Rhode Island

At New England Foundation Crack Repair, we specialize in identifying the root cause of foundation cracks and providing the right solution—whether it’s a straightforward injection or structural reinforcement.

Not sure what type of crack you’re dealing with?

Schedule a Free Inspection by calling 833-NECRACK (833-632-7225) or contacting us online.