How to Run Conduit Before Pouring Concrete

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Things You'll Need

  • Chalk line

  • Shovel

  • Rake

  • Hand tamper

  • PVC conduit

Installing conduit under slabs provides a path for electrical wires to travel.

The best time to run conduit is before your pour the concrete slab. This allows you to install the conduit under the slab in a location where it is well protected. PVC conduit is typically used for these applications because it is weather-tight and doesn't corrode due to exposure to the acidic concrete. Installing conduit one size larger than you need is wise to accommodate future expansion of the electrical system.

Step 1

Chalk a line from the start of the conduit run to the end by holding the chalk line tight between the two points and snapping it with your fingers.


Step 2

Remove 3-5 inches of gravel along the chalk line with a shovel. Remove any large rocks and keep the base of the trench level.

Step 3

Lay the PVC conduit in the trench from the start of the run to the end.

Step 4

Fill the trench back in with the material removed. Rake the ground as flat as possible.

Step 5

Tamp the ground along the conduit with a hand tamper. Be careful not tamp so hard that it breaks the conduit.


Never use a mechanical tamper over conduit. The strength of this style of tamper will break the pipe.