How to Cut in a Drain in the Garage

Run a carpenter’s level over the floor of your garage, watching for an indication of any slope in the slab’s surface. If you detect a slope, follow it downward to its lowest point and place a chalk mark on the slab indicating that point’s location.

Place the drain cover over the marked location, and trace a line around it with the chalk.

Determine the path you wish to take to dispose of the drained water. You’ll want to direct the water to a location away from your home downslope from your drain. Snap a chalk line onto the floor from the drain and along the path to the wall. Snap two more chalk lines running parallel to the first, both to the left and right of the original line. Space each new line 3 inches from the original, creating a 6-inch-wide space between the outer lines leading from the drain to the wall.

Put on a pair of steel-toed boots, work gloves, safety goggles, particle mask and earplugs for protection. Open the garage door and any windows for improved ventilation, and remove all items from the garage to prevent getting concrete dust on them. Any items you cannot remove cover in plastic sheeting.

Place the tip of a jackhammer onto the chalked circle with the jackhammer tilted slightly toward the center of the circle. Start up the motor for the jackhammer and then break through the concrete slab. Follow the line around the circle to cut out the section to make room for the drain.

Cut through any rebar found in the slab using a reciprocating saw.

Use the jackhammer to cut through the outside lines representing your pipe installation location. Cut along both lines, tilting the jackhammer inward toward the centerline to break the slab in as straight a line as possible.

Remove the concrete rubble to reveal the cut drainage circle along with the cut trench line for the installation of the drainpipe.