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Do I have to move the drain?

I'm getting ready to completely gut and remodel my kitchen and want to move the kitchen sink about 8 feet from the west wall to the north wall. Is there any way I can use the existing drain (perhaps going under the sub-floor which has to be replaced anyway), or will I have to relocate the drain?

Re: Do I have to move the drain?

So what you are wanting to do is put a 90 on the pipe stub up in the west wall and run it horizontal around the outside of the wall until you get to the north wall? Right? Don't do it it. It is against code. Your kitchen sink will clog up or simply not drain right. The structural integrity of all those wall studs will be comprimised. Being on an outside wall and if you live where it freezes, so will the pipe. Where is your vent for the sink? If you are going to do it yourself, be careful. Process of elimanation. Good luck.

Re: Do I have to move the drain?

Actually, I hadn't thought of doing it that way at all. I thought to perhaps route the pipe from the new sink location, through the floor and across and over to the existing drain. Just didn't know if it was possible to do it that way. The biggest problem that comes to mind in doing it the way I thought to would be having enough slope to allow gravity to carry the water on across the kitchen to the drain itself. Any thoughts anybody? Thanks!

Re: Do I have to move the drain?

There will be 3 considerations for relocating the sink :

  1. the vent
  2. the drain
  3. water supplies

Once you've determined how to run the vent then the drain becomes more tricky depending how the floor joists are running.
Personally I wouldn't run the drain pipe "through" the floor joists since this would involve notching and drilling holes in the joists .... there are rules and common sense that govern this without compromising the structure and the need for re-enforcement.

You need to have at least a 1/4 inch slope for every foot of run which would be a 2 inch difference in an 8 foot run .

Drilling and notching of standard wood members is subject to the following:

  • Notches in joists, rafters, and beams may not exceed one-sixth of the depth of the member, may not be longer than one-third of the depth of the member and may not be located in the middle third of the span.
  • Notches at the ends of a joist, rafter, or beam may not exceed one-fourth the depth of the member.
  • The diameter of holes bored or cut into joists, rafters, and beams may not exceed one-third the actual depth of the member. Holes may not be closer than 2 inches to the top or bottom of the member or any other hole located in the member. Where the member is also notched, the hole may be no closer than 2 inches to the notch.

If there are other items run through the joists already ... wires , water pipes .... this will restrict any more holes and notches.
The new location may have the opportunity to run the pipe in the space between joists .... running parallel.
If they will run perpendicular ... you should consider running them below the joists.
This would depend on what's below the kitchen floor and accessibility.

Hope this helps. :)

Re: Do I have to move the drain?


Thanks so much for your reply. I've been thinking a bit more about this, and think I may have another option for the drain that would be a shorter distance. My husband, son and I were talking this morning and wondering what the drop per foot had to be and you've answered that as well. New question: Is it possible to have the kitchen sink and the laundry share the same drain? They are on separate drains with separate clean outs as they are right now. Thanks.

Re: Do I have to move the drain?

Is it possible to have the kitchen sink and the laundry share the same drain?

You had better check your local building code as to whether that would be allowed.
Around here the kitchen sink and laundry are not allowed to share the same drain.

Re: Do I have to move the drain?

That's probably why they don't now. So many things in this house weren't done properly, I'm surprised there are separate drains for anything :) Thanks for your help!

Re: Do I have to move the drain?

Your welcome and good luck with the project.

Let us know how it turns out.:)

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