Installing PVC sewer pipe for a shower is a fairly simple process once you make sure that the main sewer line is accessible to tap in to. Difficulties can arise if there's little space to crawl in to under the floor joists, and it's always best to make sure that you can first work in the confined space before starting the job.
Things You'll Need
- 2-inch PVC sewer line
- 2-inch PVC couplings
- PVC primer
- PVC glue
- Plumber's putty
- Hack saw or power saw
- 2-inch couplings
- Strapping and nails
Unscrew the nut and rubber washer from the bottom of the shower drain fitting and apply some plumber's putty around the underside lip of the top of the drain fitting. Drop the fitting into the hole in the shower base (the putty should be between the shower base and the shower drain fitting). From underneath, place the rubber washer and nut back on the fitting, and tighten.
Push a piece of 2-inch PVC sewer line (about 12 to 16 inches long) up into the shower drain fitting from below (don't glue anything yet). Then attach a P-trap (with the long pipe pointing vertically) up to the sewer line, using a 2-inch coupling. Point the other end of the P-trap toward the existing sewer line.
Work your way towards the existing sewer line, cutting the line and adding couplings as required. Make sure you connect the vent line to the sewer line, as stipulated by your local permit office. When you reach the existing sewer line, you will need a larger coupling the diameter of the existing sewer line that also has a 2-inch "spout" for the new sewer line to attach to.
Cut into the old line and connect the new sewer line. Check that the required gradient is correct, and if necessary shorten the 2-inch line that is pushed vertically up into the shower drain fitting.
Check that the new PVC line is correct before priming and gluing every coupling in place. Strap the new line to the bottom of the joists for support, if necessary. Wipe away any excess plumber's putty from the top of the shower drain fitting.