Laundry drain pipe help for s-trap location. Canada
Hi, I'm new here :) My house is very old and still has a 1 1/12 inch laundry drain pipe. It runs 40 feet across my crawlspace. I'm going to vent it and know how to do that correctly, but since the drain pipe is only 1 1/2 inches instead of the standard 2 inch and I need to re-locate it to the back wall, would it be more ideal to locate the s-trap lower than 24 inches from the top to offset possible back spill? I was thinking 36 inches or so but I'm not really sure.