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How Deep Are Plumbing Pipes Under a Slab House?

How Deep Are Plumbing Pipes Under a Slab House?

A house can either be built on a slab or a crawlspace foundation. If you decide to build your house on a slab, more than likely, you’ll bury the plumbing under the slab for aesthetic purposes and the protection of the pipes.

So, how do you know how deep to bury them? It depends on where you live, the moisture in the soil, and how cold it is where you are. Read on to find out more.

Why Is Plumbing Done Under the Slab?

You may prefer to run your plumbing under the slab for aesthetic reasons: in days gone by, all the hardware and plumbing of the house may have been more exposed. Now, it’s all able to be hidden, giving the home a cleaner, more minimalist look. Plumbing pipes bring fresh water to your home, but they also carry waste away from your home; so, keeping the pipes underground keeps awful smells from permitting your corridors.

In colder places, pipes are buried deep underground to keep them from freezing in the cold, but you won’t need to worry about that in southern states. However, abrupt changes in the seasons can shock the pipes and make them susceptible to bursting.

Pipes are also susceptible to damage by the weather, stray animals, or other physical damage. Keeping the pipes underground protects them from harmful elements, making repairs less likely to be needed.

Is Plumbing Always Run Under the Slab?

The short answer is: not always. If the house has a basement, plumbing can’t be under a slab. If the soil has a lot of moisture, or what the house is being built on is unstable, these materials aren’t suitable for pipes, which means they’ll be better protected above ground.

Running plumbing under the slab is also more expensive than placing it above ground. So, if cost is a concern, you can consider placing the plumbing above ground.

Another option is to create pockets in the slab to run plumbing through, giving them easier access for repairs than if they were completely underground.

Factors That Determine Plumbing Depth

Plumbing Regulations

Different states have different regulations about how far you’re allowed to bury pipes underneath the ground. Every different area will have local building codes. This is something your contractor should be aware of when working on your house. If you build against the codes, you may be stuck having to repair and redo the plumbing.

Plumbing Blueprints

Soil Structure In Your Area

Soil type is also something to consider when building a slab and running plumbing underneath. The soil must be structured and sturdy enough to support the slab and the underlying plumbing. If the soil has too much moisture, is too loose, too abrasive, or unstable, it will not provide enough support for the slab or the plumbing underneath.

Changes In Temperature

How cold it gets in your area will determine how deep to run your plumbing. In warmer, southern states, you will only need to run your pipes about 12″ inches underground. There is no risk of freeze damage, so they don’t need to be deep. However, if the pipes are too close to the surface, the water won’t be cold during the summer because it’ll be too exposed to heat above the ground.

For colder places, pipes will need to be deeper in the ground so pipes can be protected and the water can be heated up enough.

How To Identify Leaks in Plumbing Under the Slab

Even with proper installation and everything up to code, leaks under the slab can still happen. Luckily, there are ways to notice a leak that doesn’t include tearing up your concrete slab.

Some signs of leaks include cracking floors, water leaking inside your home, water leaking in the yard, poor water pressure, sounds of water running when all of the taps are closed, or your water bill is abnormally high. You may also notice uneven flooring caused by cracks in the slab foundation.

Plumbers have ways of detecting a leak under a slab, such as pipe cameras, ground microphones, or pressure sensors.

Slab Leak Prevention Tips

Proper Installation

Making sure everything is up to code, and the installation has followed your local guidelines, is one of the best ways to prevent leakage. Building codes were designed with safety and longevity in mind, so it’s best practice to build under those directives.

Learn the Signs of a Leak

Knowing the signs of a slab leak may clue you into a problem before it’s an insurmountable issue. If your carpets are mysteriously wet or hardwood becomes water damaged, it could signify a leak. Likewise, water bills that are higher than normal and declining water pressure can be a sign of leakage as well. A water heater that’s continually running may also be a sign that there’s a leak.

Regular Inspections

Even if everything seems fine, it’s smart to schedule semi-regular inspections to see if there are minor leaks. Finding leaks early can circumvent a disastrous leak in your home later on. Plumbers have more resources to detect leaks early. By using microphones and cameras, they can physically check the integrity of the structures underground, which takes out the guesswork.

Watch The Trees

Large trees can threaten your slab, and deeply growing roots can crack the slab and damage the plumbing. If there’s an existing crack, the roots can grow in the direction of the crack and damage the plumbing.

How large trees are on the outside is an indication of how large and deep the root system is. If the trees in your yard are growing too large, consider getting them uprooted and removed, so they don’t cause damage to your plumbing.

Don’t Use Chemical Drain Cleaners

These cleaners work quickly and effectively. But they can eat away at your pipes and cause ideal conditions for rust and corrosion, quickly leading to a leak. Either limit drain cleaner usage or use an enzymatic drain cleaner instead. You can also use an electric auger.

Use Water Softener

Installing a water softener can prevent sediment buildup in your pipes by removing the minerals from the water. Sediment buildup can cause a clog which can eventually lead to a burst or leakage. It would be most effective to install a water softener on the main water line, but you can install it on separate fixtures in the home as well.

Lower Your Water Pressure

If the water pressure in your home is too high, it can eventually cause damage to your plumbing, which can lead to a slab leak. If you hear many clanging or banging sounds when you turn your water on, this could signify high pressure. Noticing your faucets are leaking when someone is taking a shower or doing laundry can also be a sign of too high pressure.

You can check your own water pressure at home with a water pressure gauge, which is typically on a spigot on the main water valve either inside or outside of the house. If the pressure is too high, a plumber may give you a pressure-reducing valve that lets you manually control your home’s water pressure.

Is the Plumbing Damaged Under Your Property? We Can Help.

All Dry USA is prepared to detect and fix your plumbing problems. With premium detection equipment and certified technicians, we’re ready to help with anything from big leaks to small ones. Call us today!


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