Top Causes of Concrete Pool Cracks (What Homeowners Should Know)

Posted on: March 20th, 2026 by affordablepoolrepair No Comments

Concrete pools are built to last. That’s the idea, at least.

But over time, even the strongest materials start to show signs of stress. A small crack appears… then another. And suddenly, you’re wondering whether it’s something minor—or something more serious.

In many cases, these cracks aren’t random. They’re the result of specific conditions, often connected to structural movement, moisture, or even issues around Pool Coping.

If you’re in Rye, NH, where weather fluctuations and soil conditions can vary throughout the year, understanding these causes becomes even more important.

Why Concrete Pools Crack Over Time

Concrete isn’t completely rigid—it expands, contracts, and responds to environmental conditions.

And when that movement isn’t evenly supported, stress builds up.

Eventually, that stress shows itself in the form of cracks. Sometimes small… sometimes structural.

Areas around Pool Coping are particularly vulnerable, as they experience constant exposure to moisture, pressure, and temperature changes.

1. Ground Movement and Soil Shifting

This is one of the most common causes.

The soil beneath your pool isn’t fixed—it expands and contracts depending on moisture levels and temperature.

In regions like Rye, NH, seasonal freeze-thaw cycles can cause the ground to shift repeatedly. This movement puts stress on the pool structure, leading to cracks over time.

It can also affect nearby Pool Coping, causing separation along the edges.

2. Water Pressure and Hydrostatic Forces

Water doesn’t just sit still—it exerts pressure.

When groundwater builds up beneath the pool, it can push upward against the structure. This pressure, known as hydrostatic pressure, can create cracks in the concrete.

Over time, this also weakens surrounding areas, including Pool Coping.

3. Improper Construction or Weak Foundation

Sometimes, cracks aren’t caused by time—they’re caused by how the pool was built.

If the foundation wasn’t properly compacted or reinforced, the structure may not handle long-term stress effectively.

This can lead to early cracking, especially near edges and coping areas.

4. Temperature Changes and Expansion

Concrete expands in heat and contracts in cold.

While this might seem minor, repeated cycles of expansion and contraction create stress within the material.

In colder climates like Rye, NH, these temperature swings can significantly impact both the pool structure and Pool Coping.

5. Water Infiltration and Moisture Damage

Water is both essential—and damaging.

When water enters small cracks, it weakens the structure from within. Over time, this leads to larger cracks and potential separation.

This is especially common around Pool Coping, where moisture exposure is constant.

6. Heavy Loads and External Pressure

Additional weight around the pool area—such as furniture, equipment, or even vehicles—can put pressure on the structure.

Over time, this added stress can lead to cracking, especially if the underlying support isn’t strong enough.

7. Lack of Maintenance

Small cracks don’t stay small forever.

Without regular inspection and maintenance, minor issues can grow into larger structural problems.

Routine care, including checking Pool Coping, helps prevent long-term damage.

Types of Concrete Pool Cracks

Crack Type	Description	Severity
Hairline Cracks	Surface-level cracks	Low
Structural Cracks	Deep cracks affecting integrity	High
Expansion Cracks	Caused by temperature changes	Medium
Settlement Cracks	Due to ground movement	High

Final Thoughts

Concrete pool cracks don’t happen randomly—they’re usually the result of ongoing stress and environmental factors.

Some are minor. Others signal deeper structural issues.

If you’re in Rye, NH and noticing cracks forming—especially near your Pool Coping—it’s worth taking a closer look before the damage spreads.

Because understanding the cause is what helps you fix the problem the right way—not just temporarily.