DIY Toilet Drain in a Concrete Floor

Mark the location with chalk for your toilet on the floor of your concrete slab. Place the toilet at least 12 inches from the back wall to allow room for your toilet tank.

Cut a hole in the concrete at this location with the jackhammer. Remove broken concrete. Create another channel in the concrete for the toilet drain line. Run the channel from the toilet to your home's main drain line under the concrete.

Assemble a PVC drain line using 3-inch PVC pipe from the toilet to the main drain line. Cut the pipe to length with a hacksaw when necessary. Install a toilet flange on the end of the drain line where the toilet is going to be located. Once the drain line and flange are all set, disassemble the pipe and couplings, coat each in PVC glue and reassemble to form the drain line. Cut into the main drain line with a hacksaw, install a T-fitting and connect the drain line to the T-fitting with PVC glue.

Cover the drain line with gravel. Mortar over the drain and under the flange with cement and a hand trowel. The top of the flange must sit above the cement. Let the cement dry for 24 hours.

Install the flange-mounting bolts in the flange and set the toilet on the flange. Tighten the mounting bolt nuts with a wrench to secure the toilet to the flange.