Understanding Slab Leaks: Causes and Symptoms

Anyone in Southern California knows that hard water and water leaks can cause significant damage. You might think your plumbing is OK, only to notice an uptick in your water bill or a few water stains. If you’re lucky, you’ll find the source of leaks right away. But what happens when you can’t find any leaks under your sinks or in your walls? It means you might have a slab leak.

If your home is like most in California, it was likely built on a concrete slab. Due to their design, household water and sewer lines often run just beneath this slab, meaning leaks can go undetected for a long time. Slab leaks can strike hot or cold water lines and appear on any drain line from any home appliance that uses water. In worst-case scenarios, they can go undetected for a long time, leading to extensive structural damage. This makes it essential for homeowners to know what causes slab leaks and how to identify them so they can call a professional plumber immediately.

What Is A Slab Leak?

A slab leak is an industry term for leaks that develop in the water lines running below a home’s concrete foundation. Such leaks are often the result of long-term corrosion in copper pipes and can range from just a few trickles to a significant crack in your piping.

Slab leaks are potentially dangerous because water under the house can erode the surrounding soil. Soil erosion removes support for the slab, putting a strain on it, which may cause cracks to develop. The water can then enter your home and further damage the foundation and the rest of the structure. Depending on the extent of the slab leak, you could experience severe water damage to flooring, walls, furniture, appliances, and more. If you leave a slab leak flowing too long, the risks increase. This is why it is vital to call a professional immediately so they can diagnose and fix the problem as quickly as possible.

Recommended reading: Slab Leak Detection Techniques

Causes of Slab Leaks

Several factors can damage the pipes underneath your home. Regardless of the cause, it is important to hire a professional plumber to correct the issue immediately. Some of the most common causes include pipe corrosion, abrasion, shifting soil, acidic water, or excessive pressure.

Pre-Damage And Poor Installation

It is common for some materials to get a little damaged when building a home, but if the pipes experience any damage, this could cause problems. A minor crack back then could quickly become a major leak as the water wears away at the material, or a dent could lead to a build-up of pressure that causes the pipe to burst.

If the pipes were incorrectly installed, they may not function as expected once an entire home is on top of them. The same goes for improperly poured concrete slabs, which can affect a pipe’s pressure.

Abrasion

Pipes naturally expand and contract as water flows through them, but doing so can strain the material depending on how your home was built. If the pipes were placed somewhere exposed to concrete, gravel, or even other pipes, they could start to rub against them until they eventually wear down, causing a leak.

Even things such as tree roots, earthquakes, soil erosion, or an underground water source can cause your pipes to develop problems over time.

Corrosion

Likewise, excessive hardness (high mineral content) or softness (low mineral content) in the water can corrode pipes. Soil and surrounding materials can also suffer from high acidity or alkaline levels, potentially damaging plumbing lines as the metals and minerals gradually eat away at the material.

Shifting Soil

Earthquakes are common in California and are known for their ability to shake objects off shelves and crack foundations, especially when they are strong. However, even the smallest earthquakes can affect your slab and pipes by causing the surrounding soil to shift and rub against the pipelines.

Soil can also move without earthquakes, whether due to weather, underground water sources, or something else. Expansive soil shift is a typical culprit for homes suffering from slab leaks. This natural swelling and shrinking of the soil happens when the ground conditions change from dry to wet, or when the weather is excessively hot or cold. Clay and sandy soil are particularly prone to shifting during weather changes.

Excessive Pressure

The pipes beneath your home can also crack due to excessive pressure. Causes of excess pressure range from heavy clay soil to seismic pressure caused by tremors or earthquakes. While most pipes can withstand some pressure, too much force on the total surface area of your pipes will take its toll and cause leaks.

Aging Home

In some cases, slab leaks are simply the result of an aging home. Cast-iron pipes were popular for most homes built before the 1960s. Though they have advantages, unprotected cast iron is easily corroded by water and minerals in the soil. Similarly, galvanized steel pipes were common in homes throughout the 1950s. Like cast iron, galvanized steel is strong but highly susceptible to corrosion and clogging. The special coating inside the pipes eventually wears off, leaving them vulnerable to rust and mineral buildup.

Newer homes now use plastic pipes such as PVC alongside flexible copper piping, both of which are corrosion-resistant and easier to work with. Using these materials can help prevent slab leaks in the future.

Signs You Have a Slab Leak

Many homeowners are unfamiliar with slab leaks, which makes it more difficult to detect if their homes have one. Slow leaks also present a problem, as they can go years without being detected. Changes might be so incremental that they go unnoticed.

So, how can you be sure you have a slab leak? Here are some telltale signs:

• Sudden spikes in your water bill
• The sound of running water, even when all faucets are off
• Moisture or mildew under carpeting
• Standing water around the perimeter of your house
• Unusually low water pressure
• Cracks in your baseboard or walls
• Damp or warm floors
• Mold and mildew problems

If you have one or more of these symptoms at your home, contact a licensed plumber immediately. Plumbers are equipped with acoustic, sonic, pressure, and other detection tools to locate water leaks in your pipelines. They can also perform visual inspections using fiber-optic cameras to check for slab leaks.

Hire Southern California’s Slab Leak Repair Specialists

While slab leaks are an unpleasant surprise, there are ways to get help and repair this issue before it becomes a bigger problem. Cali’s Choice Plumbing and Restoration offers expert leak detection services and slab leak repair in Orange, Riverside, and San Diego Counties. In addition to leak detection and repair, we also help with piping, water damage, and water heater repairs. Call us today!