I'm new to plumbing but looking to redo my master bathroom and wondering how much plumbing would be involved. If you are standing in the door of my master bath, the toilet is in the back left corner. The shower is about halfway inside the room on the right. There's also a large garden tub that we never use that I am getting rid of to use the space better. To best utilize the space, I want to swap where the shower and the toilet currently are. Water service isn't an issue as there's hot/cold near the current toilet for the garden tub.

My question is around the drains. How much work is it to make the current toilet the shower drain and the current shower a toilet drain. Am I looking at tearing up the subfloor and redoing lots of plumbing? No idea what I'm getting into here and may hire this part out, but hoping to get some idea from the good folks here. Thanks!

 

The drain lines and possibly the vent line for the new toilet location would have to be replaced. You can hook a sink up to the 3 or 4" drain line at the toilets old location but the new toilet location can not use old sink or tub plumbing so that portion would need to be redone.

 

Is that a major, costly undertaking? How much of the drain section would need to be replaced?

 

Definitely more expensive than just replacing what you have now!

The major item that will define the complexity (and cost) of the change is how the pipes are currently run, and which direction the floor joists run. If the existing toilet drain (3") can be extended a few feet within the same joist bay, it's an easy project. If the toilet drain needs to cross a few floor joists to get to its new location, you're talking a lot more work, including possibly framing.

Do you know which way the floor joists run now? Do you know where the main drain pipe for the bathroom goes down?

If you can sketch out a drawing of what you have now and what you want, we can point you in the right direction here. It may be worth calling a plumber for an estimate though regardless, he'll be able to discuss options and give you a price - something we won't really be able to do from here.

 

In fact I do have a drawing of the current bathroom. I don't know which way the floor joists run, but I don't think it matters because unless it's diagonal from the shower to the toilet which is highly unlikely, it will require dealing with the joists.



Not sure how to determine the main drain pipe either. There is a drain under the shower head, then in the garden tub, sinks, and of course the toilet.

 

You or a professional plumber will likely no really know a cost until they get the floor up and can see how the plumbing is routed. One big issue will be the orientation of your floor joists. The 3-4" pipe needed for a toilet can't be run through some joists because it requires cutting away too much wood. There is no way to tell until they get in there and take a look. The second big issue will be the vent pipe sizes that are buried in your walls. A toilet will require a 2" vent pipe run up through the walls but your sink and tub might only have 1 1/2" or none depending on the age of your plumbing.

 

Forgot to add the house is only 14 years old so it's relatively 'modern' as far as plumbing and such. Not a cheap development by any stretch but sometimes I do see signs of corner cutting.

It sounds like it may not at all be worth swapping the toilet and shower, which is a bummer. The layout of the bathroom is just piss poor in my opinion and wastes a lot of space. Our shower is tiny and that tub takes up so much space, but the window location makes it hard to extend the shower more than a couple inches back, but it's still narrow.

Anyone have any suggestions on getting a larger shower in that space?

 

Is this bathroom over a crawl space or basement where you can go underneath and see the plumbing and joists?

 

No it's a second floor master over the living room.

 

I'll just echo the others. You can't cut your floor joists. Now if the house incorporated open trusses for the floor, it won't be as bad. Cutting joists will weaken the floor system, and from what I see in your diagram, you may be crossing 3 or 4 no matter which way they run. It is a massive undertaking.

No one has asked yet, and I always get to do it. Why? What is prompting this move?

 

The space is poorly used in this master bathroom. Very very poorly used. The shower is very small. the garden tub never gets used because I am 6'5" and my wife is 6'0" and we don't fit. I can't expand the shower size where it currently exists due to the window (a couple inches won't help). If I could remove the garden tub and put the shower where the toilet is and toilet where the shower is I could use some of the garden tub space and have a really nice spacious comfortable shower. I just don't see any way of doing that without swapping shower for toilet.

 

Makes sense. Why not just tear out your tiny shower, convert the area to shelving and make a yuge shower where the garden tub is?

 

If you are going to gut the bathroom for a remodel anyhow it's not that big a job to pull up or cut open the floor so see what's underneath. Once you or the contractor can see then you can make an educated decision about which way to proceed. Before hand though I would prepare two plans. One moving the toilet and the other for leaving it where it is now.