How To Run Conduit Under A Concrete Slab

How To Run Conduit Under A Concrete Slab
  • Author: Amanda Arnold
  • Posted On: October 5, 2022
  • Updated On: August 21, 2023

Depending on the construction project you intend to undertake, adding a conduit under a concrete slab may be a fantastic idea. However, it does need a lot of time and work. Many homeowners think about hiring a qualified plumber. Although this approach might be more straightforward, it can be costly.

You don’t have to spend all that money, and you don’t have to put up with old, insufficient plumbing. Conduit installation shields wires from cement deterioration and weight under or within concrete slabs. The electrical system can easily be expanded in the future by running more wires through the conduit.

Installing Conduit Under A Concrete Slab

It might be challenging to install a conduit through a concrete slab properly. But if you’re ready to put in the time and effort, you can do it independently from home.

  • Measure and Purchase Pipe
  • Mark Your Cut
  • Cut the Concrete for the conduit
  • Cutting Through Rebar
  • Remove The Concrete
  • Install the Conduit
  • Cover the Mouths of the Pipe
  • Fill the Trench with Soil and Concrete

Measure The Pipe To Run Conduit Under A Concrete Slab

The first step is to measure the pipe you need, after which you should buy it. It would be best if you had blueprints for your house or the structure to aid with some measurements. You should carefully examine the written measures before using a measuring tape to locate the pipe underneath the concrete slab.

The work can be done in the correct method this way. The lines can then be drawn using chalk or spray paint. This is a reliable method for estimating this component’s amount of conduit required. After that, you can buy the conduit.

Make sure they are at least of the same, if not superior, quality to the conduit already there. At this point, make an effort to be as specific as possible. This could prevent you from making numerous expensive blunders in the future.

Mark Your Cut For Conduit

For this to function, your drain lines must be set up in the simplest feasible way, with the fewest twists and turn possible. Establish the new line’s center, beginning at its commencement and ending there.

Before you draw two lines on either side of it to complete your mark, you must first use spray paint to create an X in the center of the paper.

Cut The Concrete Slab Under A Concrete Slab

It’s time to begin some more strenuous labor when you’re prepared. Being patient is a virtue during this process because cutting through concrete takes time. You may position the diamond blade on the wet concrete saw directly in the center of the drain line we previously utilized, where the X is located, and make a 4-inch deep cut.

Cut along both of the previously drawn lines as you did before. Please do not rush this stage because it will be noisy and take time to complete correctly. You’ll be sawing through concrete, so take breaks as necessary.

Cutting Through Rebar For Conduit

Rebar is a standard reinforcement for concrete slabs, which you’ll also need to cut through. These are intended to reinforce the concrete and guard against cracking. So bear in mind that dealing with and sorting through it all will take extra time and work as a result.

Remove The Concrete Slab

Once you’ve cut through both lines, you may need to use a demolition hammer and a sledgehammer. The concrete strip will be easier to break into pieces as a result. To create the necessary drain trench, you may first need to remove the leftover concrete fragments from the area.

The motorized digger or hammer drill will be helpful here. You must ensure you wear the appropriate safety gear throughout this time. This includes safety goggles and proper back support.

Installing The Conduit

We may now begin installing the conduit. Installing it directly into the drain trench will ensure that the pipe has adequate pipe support. The tubes need to reach at least six inches over the top of your concrete, so keep that in mind.

If you must spin or twist, ensure a high-quality pipe joint with the appropriate shape is placed. Measuring and marking everything beforehand is preferable to avoid having to stop and buy more supplies.

Cover the Mouths of the Pipe

After ensuring that each pipe is firmly in place, you can use tape to seal off the openings. It will be guaranteed that no debris may ever enter the pipe. Without doing so, you risk having much debris enter the region and obstruct the pipe, sometimes even before you can pour concrete over it.

If the debris does enter the space and the pipes, you will need to break the lines to locate the obstruction and then redo a portion of the work. To help prevent this issue, cover it well.

Fill the Trench with Soil and Concrete

It is time to complete this operation by covering the pipelines with a small amount of soil. To begin, you can use a hand shovel to fill the trench, ensuring that the backfill is level with the floor.

You will need to be able to level out the entire floor if the drain is higher than the existing floor. That will require extra time and work throughout the procedure.

It is time to bring in the concrete once you get it as level as possible. Concrete must be poured over the dirt, then left to solidify. How much concrete you intend to use during the process will determine how long it takes. During this period, make sure nothing disturbs it.


This is a lengthy process that demands much care and concentration. Don’t just jump in and hope for the best; otherwise, you’ll end up with a large mess and much money squandered.

Although you might hire a qualified plumber to complete the job, if you pay close attention and follow the above instructions, you should be able to tackle the installation yourself.

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Author: Amanda Arnold

Amanda has been working with ConstructionHow since 2021. Her experience spans over 5 years in the creative niche such as home decor and trends, landscaping, renovations, and custom architectural values. As a home designer expert, she has a keen eye for the latest home improvement trends with accurate facts that readers find impossible to ignore. Being invested in home-building trends is how she has gained her lucrative expertise exploring more to bring a positive ambiance for all homeowners (and even tenants!). Currently, she lives in a beautiful beach home, a source of fascination for her.