Replacing a Bathroom Floor With a Leaky Toilet

Turn off the shutoff valve behind the toilet, and then flush the toilet. Disconnect the supply hose from the bottom of the tank--unscrew it by hand.

Remove the nuts and washers from each side of the toilet base--use pliers. And carefully pull up the toilet and place it to one side.

Pull out any carpeting or linoleum in the area, and determine how much flooring has been damaged through the water leak. Cut the floor along the center of the floor joists closest to each side of the water damage, as well as cutting six inches past each end of the damaged area--the area cut out will either be square or oblong in shape. If the damaged area includes the toilet flange, remove the screws from the flange lip.

Remove the damaged piece of flooring and measure and cut a new piece of flooring to the same size. If the flange is damaged and is the source of the leak, use a hacksaw to cut through the sewer pipe six inches past the 90 degree elbow joint that is attached to the bottom of the flange. Then take out the flange and elbow joint, and remove any burrs from the cut sewer pipe with a tradesman's knife.

Apply the damaged piece of flooring as a template to mark the location of the flange hole in the new cutout piece of flooring. Use a 1/2-inch wood drill bit to cut out the new flange hole.

Measure and install pieces of 2 by 8 inch wood (use joist hangers and joist nails) vertically between the floor joists at each end of the cut area. Make sure half the 2 by 8 wood rests under the existing floor, and half under the new piece of floor.

Place the new piece of flooring into position, and connect it to the floor joists with galvanized 1 5/8-inch screws--install them 8 inches apart.

Push a new flange down into the flange hole. Glue the inside of the bottom of the flange, and the outside of the male end of a 90 degree elbow joint. Push the elbow joint up into the bottom of the flange. Hold for 30 seconds.

Measure the distance between the cut end of the sewer pipe and the inside bend of the elbow joint. Cut a new piece of sewer pipe to this length and remove burrs with a tradesman's knife.

Glue the end of the cut sewer pipe, the inside of one straight coupling, and the inside of the female end of the elbow joint-- and both ends of the new piece of pipe. Push the coupling onto the end of the existing sewer pipe, then the new pipe into the other end of the coupling.

Now push the opposite end of the new pipe into the elbow joint. Hold for 30 seconds.

Screw the flange lip to the floor with 1 5/8-inch galvanized screws. Insert the two toilet bolts vertically into each side of the flange, and place a wax ring on top of the flange.

Replace the carpet or linoleum and lower the toilet down onto the wax ring so that the vertical toilet bolts go through the holes on each side of the toilet base. Replace the washers and tighten the bolt nuts.

Reattach the water supply hose to the bottom of the tank. Turn on the shutoff valve.