Sewer pipes that are installed in homes are made of either ABS (acrylonitrile butadiene styrene) black plastic or white PVC. Pipes in older homes can be made of cast iron, clay or lead. When replacing an old, lead pipe with new, plastic sewer pipe, a flexible rubber coupling is used to join the two types of pipe together. Working with lead, although relatively simple, can be hazardous, and every safety measure should be followed while carrying out the job.
Mark the existing lead sewer pipe at the point where the new plastic pipe will attach to it (as much of the lead sewer pipe should be cut out as possible). Use a construction pencil to make the mark.
Cut through the lead pipe at the mark with a hacksaw. Alternatively, use a reciprocating saw. Be sure that the cut is straight. Remove any burrs or lead fragments from the cut using a utility knife. Cut the entire lead sewer pipe into sections following the same cutting process, and remove them.
Measure and cut to length the first section of PVC pipe. The cut can be made with a hacksaw, handsaw, power saw or mitre saw. Make the cut straight, and remove burrs.
Wet around the outside end of the lead pipe, and slip a flexible rubber coupling fully onto the end. Position the end of the PVC pipe against the lead pipe end, and wet the PVC pipe end with water. Push the rubber coupling halfway onto the PVC pipe end, so that half the coupling is on the lead pipe and half on the PVC pipe.
Tighten each of the metal hose clamps that surround the ends of the rubber coupling with a screwdriver. This will secure the coupling to both the lead and PVC pipe.
Cut a second section of PVC pipe to length, and remove burrs. Apply PVC primer around the remaining end of the first piece of pipe and one end of the second piece of pipe. Also prime the inside of a 180-degree (straight) PVC coupling.
Apply PVC cement to all three primed areas, and push the coupling onto the end of the first piece of PVC pipe. Push the cemented end of the second pipe into the remaining end of the coupling. Hold the pipe in place for 10 seconds while the cement sets. Now measure, cut, prime and cement all necessary sections of PVC pipe, joining them together with couplings, until the water fixture is reached.
If you are installing ABS plastic pipes, no primer is needed. However, use ABS cement to seal the joints. Plastic couplings are available in 30-, 45-, 60-, 90- and 180-degree angles. The end of the newly-installed plastic sewer line will attach via a P-trap to sinks, showers, bathtubs and washing machines. Toilets, however, attach to the sewer line with a closet flange.
When cutting through the lead pipe, place paper on the floor underneath the pipe to catch any lead fragments that might fall from the cut. Dispose of the paper after the cut has been made. Take all unwanted lead pipe to a refuse site that will accept hazardous materials. Wear work gloves at all times when dealing with lead pipe. Wear a face shield at all times when working with lead pipe. Shower after working with lead pipe, and clean hands thoroughly. Do not work with lead pipe when children or pregnant women are close by. Wash your work clothes in a separate wash to other clothes after working with lead pipes.