What Causes Slab Leaks?

Slab Leak

What Causes Slab Leaks?

Many homeowners may, at one point or another, experience a common and damaging issue: slab leaks.

For those lucky enough to have never encountered a slab leak, they are a source of annoyance introducing new issues. Imagine stepping into the living room and noticing a mysterious wet spot.

Who do you call, your insurer or your plumber? Will your floors be torn up? Will it produce mold necessitating water damage cleanup and restoration of flooring and walls? Will you experience future leaks?

Slab leaks are big hassles and one of the most aggravating plumbing problems our homeowners experience.

What Is a Slab Leak?

For homeowners that have a slab foundation, the probability of encountering a slab leak is very high.

But what is a slab leak?

Slab leaks are not leaks in the foundations themselves but a leak in the copper water lines underlying the slab.

Copper is the best material for running water through your home and is susceptible to leaks over time. They can develop pinhole leaks and/or degradation over time.

What Causes Slab Leaks?

Slab leaks are produced by several things, such as thermal expansion and excessive water pressure.

Thermal expansion is prevalent in every home with plumbing and is one of the leading causes of leaks in the copper pipe under the slab. Thermal expansion happens when water is continuously heated and cooled, as it is with typical tank water heaters.

Pipes will expand and contract causing the copper piping to brush against the concrete surface and can be the source of a pinhole leak in the pipe. Part of the Uniform Plumbing Code now requires an expansion tank on all water heaters to give a location to release the pressure, so it does not go back into the home.

Fluctuations in water pressure can also be the source of slab leaks as well as other leaking fixtures on the property. Homeowners can control water pressure coming into their homes with a pressure regulator that regulates the high pressure coming in from the city water. Water pressure in the house should be between 60 and 80 PSI.

Although slab leak detection can be rapid, they often develop slowly with a little pinhole leak releasing water over time. When it is a slow leak, homeowners may not realize that anything is wrong until the symptoms develop.

What Are The Signs of a Slab Leak?

The following are signs of a slab leak:

  • Excessive water costs, either a one-time jump or a gradual increase over time.
  • The sound of running water when no fixtures are in use or when the house's water supply is switched off
  • Warm spots on tile or wood flooring can occur in kitchens, bathrooms, and occasionally living rooms.
  • Wet stains on the carpet will form in living rooms, bedrooms, carpeted bathrooms, and even closets.
  • Mildew and wet odors, as well as mold along baseboards
  • Cracking or buckling along the foundation and the floors and walls.

While many indicators show in areas with apparent fixtures, such as the kitchen or bathroom, copper pipes run throughout the foundation, and slab leaks can occur anywhere.

How are Slab Leaks Detected?

To effectively detect a slab leak, specialized sonar-like technology is required. This is significant because direct repairs and rerouting options can change dramatically if the location is not precise. The scope of repair may also alter depending on which pipes are leaking and where they are linked.

Using electronic leak detection equipment, plumbers will trace the pipe and pinpoint the leak. Plumbers can use the device to identify the specific location of the leak beneath the layers of flooring, carpets, and the concrete foundation.

Plumbers are taught how to locate a leak and repair it precisely. It's crucial to pinpoint the exact site of the leak; if it's just a few inches off, the whole thing could be ruined.

How are Slab Leaks Repaired?

Once discovered, repairing a slab leak can be done in a number of ways.

Direct Repair

Direct pipe repair is possible using slab leak detection services, which can pinpoint the exact position of the leak. The plumber will cut out the leaky bit of the copper pipe and replace only that section of the line.

When it comes to direct repair, it's crucial to remember that if you have one slab leak, the chances of you having another are significant. When plumbers replace the damaged segment of the pipe, warranties do not cover future leaks in other parts of the line. And, if a leak occurs in one section, the pipe is already in a state where other leaks are likely to occur.

Direct repair is not an option for homeowners with a post-tension slab foundation for earthquake safety.

Copper Reroute

Rerouting the pipe, whether hot or cold, terminates the line in the slab and produces a new water line that will/can run through the walls, within the garage, or on the exterior of the property, depending on the location of the leak and the preferences of the homeowner.

The copper water pipe will be rerouted to guarantee no future slab leaks on the newly exposed line.

Copper pipe reroutes are more expensive than direct repairs, and reroute insurance carriers rarely cover solutions.

Whole House Repipe

The best approach for correcting the slab leak and preventing future slab leaks is to repipe the entire house or line. The plumber can replace all copper water lines that run beneath the slab foundation and terminate the leaky pipe or all lines underneath the slab foundation.

The most expensive repair option is repiping the entire house. Cutting into walls and potentially flooring and running all new copper lines is required for slab repiping, and copper is a costly material.

Insurance does not cover complete home repiping as a solution to slab leaks.

Slab Leak Prevention

Although there are no guarantees that leaks in copper water pipes beneath the slab foundation will not occur, there are several procedures that homeowners may take to reduce the chance of slab leaks and discover them early.

  • Check the water pressure going into the house from the city regularly. If the pressure is higher than 80 PSI, a pressure decreasing valve should be installed. If you have one, make sure to inspect it regularly to ensure it is in good working order.
  • Install a tank to expand your water heater (this is Uniform Plumbing Code and is required for all new water heater installations).
  • Check plumbing fittings regularly for symptoms of high water pressure. Small leaks and drips from pressure fluctuations can lead to hard water buildup and corrosion on fixtures, water connection lines under sinks and toilets, and water heater connections.
  • Monitor water usage and monthly water bills to spot any unusual increases in water expenses compared to water usage.