View Full Version : a Kitchen into a Bathroom: Drain Question

10-29-2011, 08:17 AM
Hi all!

Part of the remodeling I plan for my 1984 condo is turning the current kitchen into the main bathroom. Still in the preliminary design phase.

Here's the question I have:

Can the current kitchen's sink water-drain be used to drain BOTH the projected shower and vanities?

You can tell by how little I know that I won't be ding the work myself :rolleyes:. I'm only trying to educate myself as to the options I have.



10-29-2011, 08:54 AM
quote; Can the current kitchen's sink water-drain be used to drain BOTH the projected shower and vanities?

Yes, No, or MAYBE. It all depends on how THEY are installed and WHERE the new fixtures will go. You are NOT the one to make the decision. The installer will decide what drain lines he needs and can use once you decide on a floor plan and give it to him.

10-29-2011, 09:41 AM
Great question!

Like HJ mentions this is up in the air. You really need a ticket plumber to walk you through the draining and venting requirments of your home.

If it helps any there are new side outlet linear drains from Quick Drain that drain out the back of the drain vs the bottom. This allows them to be place in new locations when a fixed drain line is in place.

I'm installing my first right now in Vancouver and we just passed the rough in flood test stage.


This is a 26" drain (linear) and has a IAMPO Certification and is good to go anywhere in North America. The drain can be hooked up to cast iron, PVC, copper or ABS with a No-Hub fitting. With the drain water piping local codes will dictate how far this can be and with how many bends. Pipe size and distance to the vent stack will all come into play.

Hire a pro plumber for your remodel. You can still do a lot of the work yourself but a Pro has years of expeirence in the field - you can't read up on that in a couple of evenings.

John Whipple
By Any Design ltd.

10-29-2011, 10:21 AM
Thanks hj and johnfr whipple.

I'm not planning on doing any of the condo-remodeling work myself. An architect is working on the preliminary designs at the moment. A contractor will manage "the work".

I know I will not get to make the technical decisions, but I find myself spending a lot of time looking at the current floor plan trying to come up with design solutions.

A contractor who just handled a serious remodeling project in a different unit with the same floor plan as mine in the same building said (when I asked him if the current kitchen could be turned into a bathroom [the current bathroom is right East of the Kitchen; the kitchen will be become a bathroom, the bathroom closet space]):
"<you will have to move the adjoining wall to the east so the toilet and tub drains can be utilized as they can not be moved>".

The kitchen has has water and drain "connections" both for the sink and the dish-washer and was wondering if those could be turned into the vanity and shower plumbing "connections". That's why I asked.

The floor of the condo is concrete.


10-29-2011, 02:28 PM
A toilet drain line needs to be at least 3", whereas a sink can be in the range of 1.5-2" (2" is really needed for a kitchen sink). So, depending on where the 'main' drain line is, you may only have 2" drain lines in the present kitchen area, so to drain the newly positioned toilet, that is the bigger issue.

10-29-2011, 02:39 PM
Thanks jadnashua.

How far could the projected vanity & shower be from the present kitchen sink and still be able to drain adequately into the kitchen's sink drain?


10-29-2011, 04:55 PM
Some of the equation relates to where the existing line is, not in distance, but in elevation change. A drain needs to slope downwards at a minimum of 1/4" per foot...so, it depends on where that line is, and how high it is, and where the new stuff is being added. Then, you will probably have to tear up the walls to put in new vents for those newly installed fixtures. Then, on the drain line, you can always go bigger, but you can't go from bigger to smaller. A shower needs to be at least a 2" drain line (in the USA).