Sewer pipe is generally made of either PVC (Polyvinyl Chloride) or ABS (Acrylonitrile Butadiene Styrene) hard plastic, though older pipes can be made of lead, clay or cast iron. Sewer pipes can crack or break if heavy weights are placed upon them or if they get old. Replacing the broken area of pipe is necessary as waste water dripping from the pipe can cause health hazards. Fixing the section of pipe requires cutting out the broken section and installing a new piece of pipe.
Mark the sewer pipe six inches on each side of the damaged area, using a marker pen. Cut through the pipe at both marks using a handsaw or hacksaw. If space permits, use a power saw. Make the cuts straight (at 90 degrees to the pipe) and remove any burrs or fragments around the cuts with a tradesman's knife.
Measure the distance between the two cuts on the existing pipeline. Cut a new piece of sewer pipe to this length (use either ABS or PVC pipe, depending on what the existing pipeline is made of). Make sure the new pipe is the same diameter as the existing pipe. Remove any burrs.
Wet the ends of the new piece of pipe, as well as the ends of the existing pipeline. Push a flexible rubber coupling all the way onto each existing pipe end.
Position the new piece of pipe between the cuts on the existing pipeline. Slip the two rubber couplings back onto the new piece of pipe, so that each coupling is half on the existing pipe, and half on the newly-cut piece of pipe.
Tighten the metal hose clamps surrounding each end of the rubber couplings, using a screwdriver. This will seal the couplings to the pipe.
For existing pipes that can be easily manoeuvred out of position, or for sewer pipes of a smaller diameter, one rubber coupling can be used, with an ABS/PVC straight coupling primed and glued to the end of the other existing pipe cut. The new piece of pipe is then primed and glued before it is pushed into the other end of the coupling, and the flexible coupling then moved over the other end of the new pipe, and tightened into place. Cut lead pipe or clay pipe with a reciprocating saw, and cast iron pipe with a snap cutter.
Wear eye goggles when cutting through the sewer pipe.