Hi, I'm upgrading the basement bathroom and need to move the shower drain about 8 inches. The previous shower drain came above grade just enough to clear the old concrete basin. I believe the old shower was built about the same time as the house was built, in 1956. All the old piping is 2 inch cast iron.

To begin my project I dug a trench around the old drain. I have dug down about 18 to 20 inches. The trench is wide enough for me to work in, about 2 by 2 feet wide.

I have found a perfectly intact cast iron trap that has been underground for all these years. The drain was working fine before I started this project, so I assume that it is draining OK now.

As I said I want to move this drain about 8 inches so I bought at Home Depot one of those PVC 2-inch floor drain with trap by PlumBest(part#D50-200). So now, can I have a floor drain with two(2) traps? The existing cast iron trap and the one that comes built in to the new drain. Is it OK to keep the old cast iron trap in this cicumstace or should I cut the old cast iron pipe then rebuild it with PVC all the way to the new drain? Does it hurt the water flow to have two traps? My job would be easier to keep the old pipe intact as much as possible.

Sorry! You may not double trap any fixture. The cast iron trap's got to go.
Good luck. Tom

Hi, I'm upgrading the basement bathroom and need to move the shower drain about 8 inches. The previous shower drain came above grade just enough to clear the old concrete basin. I believe the old shower was built about the same time as the house was built, in 1956. All the old piping is 2 inch cast iron.

To begin my project I dug a trench around the old drain. I have dug down about 18 to 20 inches. The trench is wide enough for me to work in, about 2 by 2 feet wide.

I have found a perfectly intact cast iron trap that has been underground for all these years. The drain was working fine before I started this project, so I assume that it is draining ok now.

As I said I want to move this drain about 8 inches so I bought at Home Depot one of those PVC 2-inch floor drain with trap by PlumBest(part#D50-200). So now, can I have a floor drain with two(2) traps? The existing cast iron trap and the one that comes built in to the new drain. Is it ok to keep the old cast iron trap in this cicumstace or should I cut the old cast iron pipe then rebuild it with PVC all the way to the new drain? Does it hurt the water flow to have two traps? My job would be easier to keep the old pipe intact as much as possible.
I'm a newbee to this site so I hope that I'm doing this right. I want to thank, you, Speedball1 for your super fast answer and help. Your user name really describes the speed with which you answer people's questions.

Thank a lot!