How to Install a Toilet Flange in Lead Pipe

Steve Sloane

Old houses can be a hassle to maintain. And lead sewer lines can be one of these repair headaches if old toilets have to be replaced. Converting the end of the lead line to fit a standard toilet flange isn't an impossible task though, and a little ingenuity can take care of the issue without requiring you to replace all the lines in your home.

Working with lead sewer pipes is a fairly simple process.
  1. Cut the lead pipe to one inch below the level of the sub-floor, making sure the cut is level.

  2. Push the instant set closet flange down onto the vertical lead sewer pipe until the flange screw holes rest on the sub-floor. Screw the flange to the sub-floor. The toilet is now ready for installation (follow the steps below if the lead sewer pipe is more than one inch below the sub floor).

  3. Measure the distance from the top of the lead sewer line to one inch below the surface of the sub-floor. Cut a piece of 4-inch PVC sewer line to that length.

  4. Place the rubber flange down over the old lead sewer line, then push the cut PVC sewer pipe down on top of the rubber flange. Connect the rubber flange to both the old lead line and to the new PVC line by tightening the clamp screws.

  5. Prime the top of the PVC sewer line, as well as the bottom of the flange. Wait for the primer to dry before applying PVC glue to both primed areas, and push the flange down onto the PVC line. Screw in the flange to the sub-floor. The toilet is now ready for installation.