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Slab Leakage: What Causes It and How to Fix It

The water beneath your home may leak through the concrete slabs. There are ways to notice this in time and fix it.

Crack in slab foundation

Most residential homes are built on a basement or a concrete slab foundation. These options are easy and affordable, helping homeowners build homes with structural integrity. However, homes built on concrete slabs may also suffer from slab leaks.

That’s what happens when water leaks from the pipes under a slab and gets into the basement unnoticed. Water goes into the cracks in the foundation, causing pressure and eventually damaging it.

What Causes Slab Leakage?

There are a few different causes of slab leakage but the basic reason behind them is always the same: water has entered the slab beneath your home and over time it’s reached the living quarters by going through the cracks in the slab. Knowing the exact reason behind the leak may help you resolve the issue faster.

Water Pipe Problems

All pipes expand and contract with changing temperatures. This is more often the case with the pipes that carry hot water because they are affected by the change in temperature from both within and outside the pipe. When the pipes burst or become unhinged, water may enter the slab.

The installation process includes wrapping the pipes in a protective layer to avoid this very problem. However, over time, this wrapping wears out and tears and that’s where water can leak into the slab and home.

Earth Settling

The earth may shift and settle beneath the concrete slab foundation. This is similar to what happens during an earthquake, but it happens gradually and over a long period of time. The shifting can cause the ground to put additional pressure on the pipes, making them leak or even burst.

That water will find its way through the concrete slab foundation and into the residence as well.

Chemical Reactions

Water pipes are usually made out of copper. This metal can react to other elements in the soil, mostly minerals and that may cause them to decompose over time. The process where this happens is known as electrolysis. This is also affected by the heat of the water going through the pipe.

Pipes that carry hot water usually corrode from the outside; pipes that carry cold water do the opposite. Either way, after a while the water will start to leak from the pipes into the concrete slab.

Weak Water Lines

Water pipes are laid underground and the pressure that the slab puts on them may end up damaging them and causing small cracks and nicks. These problems may not cause leaks right away, but over time, the pipes may weaken and burst.

When Was Your Home Built?

Homes that were built before the 1980s have a great chance of having slab leaks. That’s because the building codes back then didn’t require any moisture barrier between the soil and the slab.

For newer homes, this isn’t a common problem, since they are built with moisture barriers installed. When slab leaks happen in a home built after the 80s, it’s usually because of a problem with the pipes, rather than drainage.

How Can You Tell That You Have a Slab Leak?

When concrete slab leaks become a serious problem, you’ll notice the water coming into your basement, but that’s a bit late to do something about the leak. There are, however, a few signs that you should be on the lookout for other than the water itself.

High Water Bills

If the water is being spent and isn’t used in your household, it will register on your water bill. If your water bills are a bit higher than usual and you’re not spending more water, it’s possible that there are already some leaks below your home.

Keep track of your monthly spending and the price of water in your area to make sure that you’re not just using more water and that the bill isn’t a false alarm.

Mold and Mildew

Mold and mildew are often caused by excess moisture in your home. They thrive in dark and moist environments like basements and especially ones that are leaking water. Inspect your basement every now and then and you’ll be alarmed of leaks on time.

Check Your Pipes

The simplest way to find leaks is to check the pipes that may be leaking. For the most part, that means all pipes that you can get to because every pipe, no matter how well installed, may burst or leak at some point. Take the time to examine the water flow and to make sure there are no noticeable cracks. It’s best to do this seasonally since the temperature is most likely to cause the problem in the first place.

Here’s What to Do

There are a few different ways to address the problem and choosing one mostly depends on how willing you are to actually dig into the concrete slab.

The least intrusive way of going about it is to re-route the plumbing above ground. That way there’s no digging and you’re sure that the new pipes you’ve installed have no cracks in them and aren’t being pressed by the concrete.

This is the best option if you can’t reach the pipes without damaging the concrete.

Another way to go is to actually dig into the concrete and find the leak at its source. This is also the most disruptive option and one that will end up being the most expensive.

Make sure to order a free inspection from an expert plumber in your area. Not all slabs are the same and digging into a concrete slab foundation may require expert knowledge and experience, so that it’s done without endangering your home.

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