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What is a Slab Leak and How Can it be Fixed?

Our modern homes have a mostly hidden network of plumbing pipes that carry water to most of the rooms. When a water leak occurs, it can be an annoyance, but in most cases it’s pretty easy to fix and the repair is not expensive. But, an exception is a slab leak, which is a very serious problem that homeowners need to understand. Locating and fixing a slab leak is best left to a professional plumber.

What is a Slab Leak?

The slab is a type of foundation that many new homes are built on. According to data released by the Survey of Construction, 63.2% of new single-family homes use a slab foundation. This method has risen in popularity since its introduction in the early 1900s because it’s practical, durable and cost effective to produce. The slab foundation is a slab of concrete that’s poured on the ground and then the new home is built on top. There are water lines located under the slab foundation, and if a leak occurs, you may not even realize that there is a problem for some time. A slab leak is a major plumbing problem and it cannot be ignored because it will get worse as time passes.

4 Common Causes of a Slab Leak
1.   Poor Plumbing Materials and Improper Construction Methods

Improperly installed plumbing pipes are a common cause of slab leaks. If pipes are dented, bent, kinked and cracked during construction, they become weak and compromised. They are also very prone to bursts if the water pressure changes. The content of the surrounding ground is also a factor when sharp material is present. Another key factor is the quality of the plumbing materials. In certain older homes, there may be galvanized or cast iron pipes in place that are prone to clogging and corrosion problems. Most new homes have PVC, CPVC or PEX pipes, which are made from various types of plastic compounds. These materials are very easy to work with and they are corrosion resistant.

2.   Soil Contraction and Expansion

When soil shifts under the foundation slab, it can cause damage to the plumbing pipes. The soil can contract and expand when the conditions of the ground go from dry to wet and then back again. This is especially true in areas with sandy soil, cracking clay and other types of ground that can be prone to lateral and vertical shifts. If a pipe is damaged, the water that’s released will cause more dramatic ground shifts that only get worse over time.

3.   External Pressure and Abrasion Problems

Water pipes are exposed to various materials, including soil, concrete, other pipes and more. They may rub up against them and hot water pipes are prone to expansion that can lead to water leaks over time. There are external factors that can increase the risk, such as soil erosion, tree root growth, earthquakes and underground water sources.

4.   Soil and Water Chemistry

Certain types of soil or concrete can have higher alkaline levels that can cause damage to the water lines. The makeup of the water can also be a factor if it’s too alkaline or acidic and this leads to corrosion.

2 Slab Leak Warning Signs Explained

A slab leak can destroy the foundation of your home and it’s important to recognize these two warning signs to take early action.

1.   Rising Water Bills

If you closely monitor your water bills, you may notice that they are rising over time. If you turn off every faucet and appliance in your home, you may be able to hear water moving under the foundation. Another concerning sign is a drop in water pressure that may happen quickly.

2.   Physical Indicators

There are some clear physical indicators that you may notice if you know what to look for. They are water stains, foundation cracks, gaps at the bottom of walls, water spots, mold and mildew growth, a burned-out water pump and a failed water heater. A very noticeable consequence of slab leaks is difficulty opening doors and/or windows. In very severe cases, people have noticed a fountain of water flooding into their homes.

4 Ways to Fix a Slab Leak
1.   Call Your Local Plumber

The first thing you need is a professional opinion on the nature and severity of the slab leak. They have the specialized diagnosis tools that locate the source of the problem quickly. A water line inspection using a video camera can be useful when you contact a slab leak repair service. Once you know the cause, you will be able to make informed decisions about a possible repair. Some repairs are less invasive than others and some are very disruptive, but necessary.

2.   A Trenchless Repair

This is the most desirable repair method because it’s the least invasive option. A camera inspection is carried out to ensure that this repair is possible. Access holes are then dug and inflatable epoxy pipe liners are fed into the broken pipe to seal it. This process only takes a few hours, but some curing time is required before the repair is complete. If the damage is more severe, pipe splitting may be the best option. This is where a new pipe with a slightly larger diameter is fitted over the existing pipes.

3.   Re-Piping or Re-Routing

If more than one pipe is affected, re-piping may be the best option and new pipes are installed to seal the water leaks. If you have a smaller number of damaged pipes re-routing can be used, but this can take several days and some demolition is needed. It may be necessary to break through the foundation slab and you may need to leave your home until the work is finished.

4.   Under Slab Tunneling

It may be possible to stay in the home during this repair process and any expensive floor coverings may be maintained. The repair crew digs under the slab with tunnels and the integrity of the home is unaffected. The repairs are then carried out and the removed soil is replaced in the tunnels.

In Conclusion

If you suspect a water leak under your foundation slab, it’s important to act quickly to mitigate the potential damage. The cost of the repair may be covered by your homeowner’s insurance and you need to check your policy before the repairs begin. If you notice any of the aforementioned signs of a slab leak, contact your local plumber today.