Things You'll Need
The p-trap is the portion of your sink's drain system that protects your house from noxious sewer gases. The p-trap is curved to trap water in the body of the pipe, which blocks gases from escaping. The p-trap connects to a straight piece of pipe called the tailpiece, which leads to the drain above. Sometimes when a bathroom is remodeled and a new sink installed, the new p-trap does not line up with the tailpiece in a bathroom sink. You can remedy this easily by installing a flexible p-trap.
Open up the doors on the cabinet or vanity beneath your bathroom sink, if present. Remove anything stored there so that you can access the curved p-trap loacted beneath the sink.
Clean off the threads on the sewer pipe inlet that leads into the wall with a piece of steel wool. Remove any bits or pieces of caulk, putty or old plumber's tape. Wrap the inlet with a new piece of plumber's tape. Trim off the end with scissors.
Clean off the threads on the straight tailpiece located just underneath the bathroom sink drain. Remove any bits or pieces of caulk, putty or old plumber's tape. Wrap the tailpiece with a new piece of plumber's tape. Use the scissors to trim off the end.
Insert one end of the flexible p-trap over the sewer pipe inlet. Slide the coupling over the connection and tighten.
Stretch the other end of the flexible p-trap so that it slips into the tailpiece underneath the sink. Slip the coupling over the end and tighten.
Run the water in the bathroom sink above. Keep your eye on the flexible p-trap and ensure that it doesn't leak. Tighten any couplings, if needed.
Don't use any tools to tighten the couplings on the flexible p-trap. Tighten only by hand.