Hi, We want to run a new washing machine drain line.
We're considering running a new line tying into the main. For ease, was going to run in a trench line outside the house and tie in outside, rather than
going through the slab. Is this acceptable?
Our old drain line has a hole in it, did not want to have to demo the slab.

speedball1

I assume you're going to use the same vent. Running the line outside 's acceptable. Make the drain line 2" and slope it a 1/4" to the foot. Good luck, Tom