This article will answer the question of how deep are plumbing pipes under a slab house? A slab house is defined as one that has the floors, ceilings, and sometimes exterior walls mounted on top of an elevated concrete foundation or base.

There are many factors to consider when determining how deep plumbing pipes need to be set in order to function properly for years without needing replacement.

What Is A Slab House And What Does It Mean To Be “Under” A Slab House

A slab house, also known as a floating foundation or “slab-on-grade,” is when the home’s main structural components are built on top of an elevated concrete foundation.

The entire structure is not connected all the way to ground level. So in most cases, plumbing pipes will be under your floor but they won’t extend down into the earth below it. They’ll just connect with what would otherwise be considered outside walls.

How Deep are Plumbing Pipes Under a Slab House?

The answer to this question depends on many factors, such as:

The size of the pipe

You should also consider how deep are plumbing pipes under a slab house for different sized piping, too. Smaller diameter piping needs to be buried deeper than larger pipes in order to function correctly.

The soil-like

Another factor that can affect how deep are plumbing pipes under a slab house includes what type of soil you have on your property, as different soils require different depths for proper pipe function.

For example, sandy and silty soils tend to shift more often so it’s important these types of soil have water lines installed at least 60cm below ground level so they don’t settle or shift over time due to lack of support from the surrounding earth.

Clay-based soils do not shift near as easily but still need their underground utilities supported properly by burying them at least 90cm below grade. Loosely packed gravel also requires deep digging, but not as deep as clay-based soils.

Location of your new pipe

If you want to know how deep are plumbing pipes under a slab house in order to install new piping, it’s wise o figure out where that location will be first. A plumber can help with this information and more as you plan your plumbing system for a new home or property.

The depth of your slab foundation

A good rule, overall, is to make sure the plumbing pipe comes out from under the ground at least 90cm below where your home’s concrete foundation begins (or if you’re building a brand new house then 60 cm should work).

This will ensure that there are no issues with settling or shifting your home’s foundation, which is what can lead to leaking and potential water damage over time.

Remember that the depth of water lines under a slab house varies greatly depending on where you live. Those living in an area with hard water will need their pipes to be buried deeper than those who don’t have issues with the build-up of minerals and other deposits.

Generally, the depth of water lines under a slab house is about 60cm or two feet. The exact number can vary depending on where you live and other factors listed above, but it tends to be around this range a lot of the time.

Remember, too deep isn’t always better as shallow pipes have been known to shift over time from lack of support from the surrounding earth! You can also read our post about the plumber’s helper tool and the number of elbows can a plumbing vent have if you want to learn more about the basics of plumbing.