What To Do About A Slab Leak

There are very few problems in your home scarier than plumbing problems. Most homeowners are worried about finding major plumbing issues in their homes because they can quickly become an expensive disaster. 

One particular problem that can go from bad to horrific is a slab leak and it’s one that you need professional plumbing repair as soon as possible. As soon as you think you might have a slab leak, even if you’re not sure, you should contact a plumber.

A slab leak is a leak that takes place in the foundation of your home. What makes slab leaks especially problematic is how difficult they are to notice until it’s too late. Slab leaks can also severely damage the structural integrity of your home if left unrepaired.

You should never try to DIY repair a slab leak. Instead, call a professional plumber for help. Follow along below as we explain what slab leaks are, how they start, and signs you might have one.

What Is A Slab Leak?

Most modern homes are built on a cement slab. This slab is part of your home’s foundation. As you probably know, damage to the foundation can damage your home’s structural integrity. 

The earth is always moving and changing. As the ground and earth move beneath your house, this concrete slab allows homes to shift along with it. When a leak occurs around that slab, it can soften the ground and cause that area to move a bit more than the rest of the house.

Poor Installation

Sometimes the construction team may accidentally damage pipes during installation. In these situations, bent and dented pipes may wear down when water rushes through them, causing a leak. Always make sure you have a quality plumber doing your plumbing installation. In older homes that you may be purchasing, always have a plumbing inspection performed.

Erosion & Pressure

Your pipes are underneath an entire house in the ground. That’s a lot of pressure and can lead to your pipes cracking as the ground moves during the changing seasons and even earthquakes. These types of slab leaks can be disastrous.

Pipe Corrosion

One of the most notorious plumbing problems is corrosion. As the pipes go underground and into the soil, the pipes may encounter the other metals that exist in the ground. A chemical reaction can occur, known as galvanized corrosion, which can lead to holes in your plumbing pipes and furthermore, leaks. If you suspect you have galvanized pipes, it may be time  for a pipe replacement.

Abrasion Of Pipes Over Time

We’ve all heard the sounds of pipes vibrating against another. As water flows through plumbing pipes, the pipes vibrate. When they’re encased in concrete or up against rebar, the pipes can wear down enough to leak.

What To Look For When Suspecting A Slab Leak


As we mentioned before, slab leaks can be difficult to notice. After all, how often do you go looking at your home’s foundation and pipes? However, there are some key red flags to watch out for that can save your home:

Unexplainable Puddles & Damp Areas

If you suddenly have puddles and damp areas forming around your house, it could be from a slab leak. These can occur inside the home in cabinets, on the floor, or coming out the wall. Around the outside of your home, you might notice it near your porch, entryways, spigots, and other spots. 

Unusually Hot Floor

It’s warm here in Oahu, but it’s not so hot that your floor is randomly warm in one spot. If your floor feels unusually hot, you may have a leak in your hot water lines. 

Running Water

If you aren’t using water but hear water running underneath your house, you may very well have a slab leak. Try turning off any water-using appliances and see if you still hear water. If so, you may have a slab leak. 

Mildew Buildup

What’s that smell? If you start to smell mildew around your house but can’t seem to figure out where it’s coming from, you may have a slab leak.


Mold is one of the most pervasive and detrimental issues you can find in your home. If you notice mold in your home, you may have a slab leak that’s growing mold in the foundation.

Unusually High Water Bills

Are your water bills getting higher and higher even though you don’t think you’re using any more water than usual? This could indicate you have a leak somewhere and it could be a slab leak. 

Decreased Water Pressure

Whenever you have any type of leak, you can experience decreased water pressure. If you’re getting less water pressure from your fixtures, you should call a plumbing professional right away.

Issues With Walls

Your walls can be a great indicator of issues in your pipes. If your walls are cracked, warping, dimpling, or discolored, they may have water damage caused by a slab leak.

What To Do When You Find A Slab Leak?

There’s a water shut-off valve located in every home. Find out where yours is located and should shut off the water as soon as possible. Then, call a plumber right away. Slab leaks are serious and must be repaired quickly.

It’s very difficult to determine on your own if you have a slab leak. A plumbing specialist will be able to detect if your home has a slab leak and the exact location of the leak using sonic equipment. This will minimize digging, tearing apart your home, and repiping.

535 Plumbing

Water leaks can be extremely wasteful and pricey. 535 Plumbing offers leak detection services for this very reason. With just one appointment, one of our team members will come to your home or business and examine for slab leaks. Are you worried about slab leaks? If so, give us a call your local Honolulu plumbers today at (808) 300-0535.