Clogged Sewer Trap...AGAIN!

[Scott Weaner]

One of my homes has had the sewer trap clog 3 times in the past year, with sewage backing up into the basement from the washer drain pipe. I would like to figure out how to do some prevention. 

Any ideas? I have thought about using a small amount of liquid sewer or drain cleaner periodically, but I don't want to do any damage to the not new cast iron pipes. I can't get a snake down to the trap unless I remove the cap.

[Ralph R.]

Scott Weaner Cast iron pipes sounds old. If the property has trees or heavy vegetation roots growing into the pipe can clog it. Have a plumber run a tv camera down the line to see what the problem is. Also a settling or sagging foundation can causes sewer lines to collapse or break causing blockages. RR