Replacing Drain Main, Easier To Go Around?

Bill in VaBeach

Hello Folks,

Remodeler here with a question for my plumbing pros. Over last year I have completely renovated one bathroom and installed hardwood, tile, and ceramic laminate in four rooms, and repaired a lot of termite damage to sole plate and studs of customers house. Guy calls me earlier this week to see if I can salvage any of this flooring work when the plumbers come in to replace the branch drain under his slab. It's rusted through. Runs from kitchen and laundry room to main drain at opposite corner of house (42-44 feet) and will ruin the flooring in three of the rooms I've done and require removal of kitchen cabinets. His plumber is insistent the slab has to be jackhammered. My plumbing associate concurs, but I asked him about dead-ending the branch drain on both ends and running it outside the foundation all the way around. He said can be done, but then have to worry about the grade and tie-in (perfectly flat terrain and sandy soil). Would be an 80 foot run. Doesn't think there is a code problem.

My question is: Is there a good reason not to run outside as opposed to jackhammering through a lot of new work? Would make sense to me, but there must be a reason it's not common practice.

Thanks!
Bill

Ron The Plumber

So as long as you have 20", or more is better, of grade from the point you exit the foundation and where you make this tie-in, it should be fine.

No long turns out side, use 45's to make up the long turns, and clean outs required every 135 degrees.

Bill in VaBeach

Ron,

Thank you! The outside run makes sense to me. Appreciate the technical details. I'm going to advise him to consider this seriously, it has to be much less expensive when all is said and done.

Bill