No home owner ever wants to discover they have a slab leak under their house. Slab leaks can cause significant issues with the foundation of the home and usually result in a costly slab leak repair.
If a slab leak repair is neglected, a slab leak can cause serious problems, including creating a crack in the foundation, a large water bill, bad smells, low water pressure and uneven floors.
You may not be aware, but there are a number of pipes that run beneath a home’s concrete slab foundation. These pipes connect to the main water supply lines of your local municipality and the sewage system.
As your house ages, pipes may begin to corrode and crack. It can be difficult, or even impossible, to spot signs of water damage under the foundation slab.
We have put together a list of the common causes of slab leaks, common warning signs, how to perform slab leak detection and the best way to fix slab leaks.
What is a slab leak?
A slab is a concrete foundation used to build houses. This concrete slab is incorporated with water, sewerage, and gas lines (i.e., underground pipes). Cracks and holes can develop as the pipes under your property age. If a pipe located below your slab foundation is damaged, water can leak from the pipe.
The soil around your house will absorb moisture, causing the ground to become unstable. Concrete slab foundations will crack and become unstable if the ground below your house is too wet. The foundation of your home will begin to move if the concrete slab leak isn’t fixed immediately. This can cause cracks in the floors and walls of your house.
What causes slab leaks?
Earthquakes
The ground vibrations from earthquakes can cause severe damage to the concrete slab below your home. Pipe joints can become loose due to vibrations from earthquakes. Additionally, cracks and holes can form in pipes due to the ground movement.
A slab leak can be detected if you hear sounds that sound like running water. A hot spot on your floor is a sign of a leaky hot water pipe. Slab leaks that involve leaky hot water pipes will cause mold and mildew in your floors, walls, ceiling, or basement.
Water is highly acidic
Hard water may be very acidic depending on where you live. Hard water has an average pH of between 1 and 4 pH. The pipes below your slab foundation can crack and degrade if the water is too acidic. Many homeowners opt to have their water softened to prevent this problem.
Copper pipes that are deteriorating
Because older homes were built with a plumbing system containing copper and Orangeburg sewer pipes, slab leaks are more common in these cases. Copper pipes can be corroded by high salt levels, acidic water below pH 7.0, high amounts of liquefied oxygen and incorrect grounding of copper hardware to copper pipes.
Abrasion
The water running through the pipes from your foundation to the sinks and appliances in your home can cause the pipes to move. This then causes the pipes to rub against the concrete slab. The pipes may also rub against other objects, such as dirt and gravel.
The friction between a pipe and the concrete foundation can cause damage to your pipes’ exterior. A water leak may form near your slab foundation if the exterior of your pipes walls is too thin.
High water pressure
High water pressure can lead to pipes cracking or collapsing below your slab foundation. High water pressure can be detected by dripping faucets and rattling sounds when water is turned on. A water pressure gauge can be used to determine if your household’s water pressure is too high. This gauge measures the PSI (pounds per square inch) of your water lines.
The pressure rating in your city or suburb should range from 40 to 80 pounds per sq inch. Your water pressure can be higher or lower than the average and cause slab leaks. Installing a water pressure-reducing valve to protect your pipes is a great way to prevent this problem from happening.
Disintegrating Orangeburg Pipes
Cracks in the ceiling or walls could indicate a slab leak. This type of leak can be found in older properties built with Orangeburg sewer lines. Orangeburg pipes are more susceptible to chemical exposure than other types of piping materials. They will deteriorate faster than other types.
Orangeburg pipes are connected with bitumen cement, which does not act well when exposed to chemicals such as bleach and drain cleaners.
Slab leak warning signs
Look for the following signs of a slab leak:
High water bills
A water leak below your home can cause excess water to leak from your pipes. This water will then be absorbed by your ground. A slab leak will then obviously increase your water bill.
Low water pressure
A large amount of water can escape from your shower or sink if there is a leak beneath your concrete foundation. Low water pressure may result if this is the case. A pipe leak near your foundation could be the cause of your water pressure drop.
Wet floors
Wood floors are the most vulnerable floor material to water damage from a leak. The slab leak must be fixed immediately to prevent wood floors from becoming warped and discolored.
Slab leaks can also cause irreversible damage to your carpet. A pipe leak can be identified by dark spots or moisture in the carpet. Before you conclude that there is a problem with your slab foundation, examine the type of carpet odor. The wet spot may be due to a pet accident or spilled drink.
Strange Odors
Carpeted homes are more susceptible to mold growth. The padding beneath your carpet will absorb moisture if a slab leak occurs. To prevent mold and mildew growth, the padding must be replaced if it becomes too moist.
You should not attempt to remove the water from your carpet using a vacuum. Most carpet padding is too moist to be vacuumed up. To prevent mold growth and unpleasant odors in your living or dining areas, replace the carpet and padding immediately.
The sound of running water
If your hot water heater makes a constant hum, it is likely that you are hearing water running nonstop. The hot water heater will try to compensate for water leaking from the pipes. It will continue to run until it runs out of water. A hot water heater that is constantly running is wasteful and costly.
How to test for a plumbing leak in your home
There are steps you can follow before calling a professional plumber to check if there is a leak. This step-by-step guide will help you test your home for hidden water leaks.
- First, ensure that all water fixtures and water-using devices in your home have been turned off. The irrigation system and water fixtures should not be running.
- Locate your water meter box outside. You will find it near your front curb in a concrete box with a lid marked “water meter”. To open the meter box, you might need a key. Sometimes all you need to open the meter box is a flathead screwdriver. The water meter might be inside in colder climates. It is usually located in the basement.
- Take a good look at the face of the meter after you have removed the cover. The majority of water meters have a red or blue triangle that rotates when water is moving through the pipes. This is also known as the low-flow indicator or leak detection dial. You may see it as a star or gear. You may have a leak if the leak detection dial is moving. However, very small leaks may not cause the dial to move.
- If the leak detection dial is not moving or you meter does not have one, take down the number on the dial and wait for 30 minutes. Then, check the meter again. If your water meter shows a higher number than usual, it is likely that there is a hidden leak.
This will not tell you definitively if you have a slab leak but it will let you know that there is a leak somewhere in the home.
Three methods for slab leak repair
There are many ways to fix a slab leak below the ground. Depending on where the pipe is damaged, the best method to repair a water leak can vary. The cost of fixing a foundation leak can range from a few hundred dollars up to several thousand dollars. We have listed 3 methods to repair a slab leak in your foundation.
Re-piping
A couple thousand dollars will be spent to remove concrete from the foundation in order to replace a damaged or corroded pipe. Rerouting a new pipe outside your concrete foundation or attic will save you the hassle of removing your floors. Accessibility is a major advantage to installing a new pipe rather than replacing a damage pipe in your foundation.
Replace a section of the pipe by drilling
If only a small section of the pipe need to be repaired, a common solution is to drill through a concrete slab to replace the damaged section. However, this option is not popular with homeowners as it involves removing tile or wood floors to access the concrete slab.
Install pipe lining
You can fix a water leak under your foundation by putting a thin epoxy layer inside your copper or galvanized steel pipes. The epoxy lining will cover any cracks or holes.
