First time poster, here.

I'm questioning the feasibility of a bathroom reno project. I am wanting to add a shower stall in an upstairs room adjacent to the bathroom. It will mean "bumping" it into this next room. I do not want to lose one of the means of egress, i.e., a door, which is what I would have to do to get a shower stall in the existing bathroom. Not being a plumber but wanting to better understand feasibility of this scenario, I have come to you. I am attaching photos which I hope will illuminate the details. The BIG question is: can a galley sink and shower drain be toed in to the 3" stack drain?

existing toilet and bath sink; these remain as is


Approximate 7' +/- from proposed center shower drain to existing stack

Room the shower stall would be "bumped" into. It would be on the very left hand side of the photo. A countertop would be built in to right of shower wall and a small galley sink would be added. The stack is framed out in 1" pine in the right corner.

 

The general concept seems doable.

The shower would be a 2" drain, which allows it to be up to 8' away from the vent/stack. It looks like it would be within that distance.

The bigger issue is drilling through joists. It looks like those are old pine floors, which would imply to me that the joists go across the room (following the lined rules on your drawing). That means you'll need to drill through 5 or so joists - which could significantly affect the structure.
Do you know the size of the joists? Are they newer 2x which are 1.5"? Or ar they older 2 or 2.5" rough cut ones?

 

Hi and welcome! I moved your post into its own thread, it'll get more traction as a stand-alone thread/question.


Originally posted in: Drain Pipe Slope Calculation from DoItYourself.com Weekender

 

Thank you for your reply, Zorfdt, and doing my housekeeping by moving the post to a more appropriate spot.

Yes, you are absolutely correct on the joist issue. I know this from when I replaced the toilet, which had been formerly sitting on a wooden donut glued to the old flooring - all part of a joist avoidance/ slope related hack.

My joist avaidance hack for the shower is not much better. But, nevertheless:

The shower unit I am contemplating is a "Slim Line" fiberglass one piece with separate fiberglass base. If the thicknedd of the poured base was increased to allow the necessary slope for drain - 1/4"/foot? - then it would be something close to 3/4"-1" over the course of eight feet to tie in to the vent stack. It would mean a modest step up in to the shower.

My plan is to build a countertop/ shelf unit next to the shower stall. I could remove the pine flooring under the cabinet and run the pipe above the joists, covering it with a false bottom and kick board/ baseboard trim. Hack, yes.

As most places, plumbers are scarce here. I am hoping to be able to get a plumber to look at it but it could be awhile. I'm hoping to educate myself and check for feasibility. Feel free to tell me this sounds like a bad idea. 😁 Thank you for your consideration. Maureen

 

I'm going to defer to others here about joist solutions. There are possibly some options including bracing or reinforcing brackets - but I don't have much experience with them.

8' is the max the vent/drain to the trap. If you're close to that 8' mark, you may want to include a vent. It should be pretty easy since your sink is right there too.