How long horizontally can I run a drain line?

[Mark249]

My septic pipe is on one side of my home and my fixtures are on the other side about 30 foot away. Can I run 2" PVC from my shower and bathroom sink (which would be 2 lines) 30 feet to my 4" septic pipe? I also have to run a 3" toilet drain line horizontally across my basement too, is that too long of a distance?

 

[Reach4]

Yes, No, respectively.

The lines will be vented before the long run.

Bathroom sink (lavatory/lav) will be vented with a dry vent (real vent or AAV), and that will typically dry vent the shower and toilet.

Look around at posts talking about wet venting a bathroom group.

When you say across your basement, I presume these fixtures will be on the first floor and not in the basement. Usually the exit to a septic tank is above the basement floor, unless you have a very sloped lot.

Consider making a floorplan sketch including lav, toilet, shower, and the line to the septic.

 

[Sponsor]

 

[Jeff H Young]

no its not too long.

 

[Mark249]

I also have a stationary tub on the first floor which my washer machine water goes into, I need to run a 2" drain line horizontally 30' along my basement wall to a long sweep 90, and then another 30' to my sump pit, 60' total. Anything special I should do with that line?

 

[Jadnashua]

As long as you maintain the proper slope, you should be fine. Think about the sewer lines in the cities, they go for miles. They probably need some pumps to get stuff over hills and to prevent them from being required to get too deep to maintain the minimum slope. It's better to try to make it a little over that minimum as grading before backfill can be a little messy. What you do not want, are sections that are level, or are a belly, as gravity will try to keep it at that low point.

 

[Jeff H Young]

no problem, 1/4 per foot fall go as long as needed

 

[Mark249]

Thanks guys for all the help...