Can I add a free-standing tub to a shower without extra plumbing?

I suppose you could, but it’s really iffy.

For one thing, your average shower puts out something like 2.0 GPM (Gallons per minute) or less, because of government regulations. You average bathtub faucet will put out 2–3 times that, around 6 (or more) GPM. So you’ll have a much longer wait to fill the tub.
https://www.qualitybath.com/discover/post/18226/guide-water-flow-rates#:~:text=That's%20because%20kitchen%20faucets%20and,to%207%20gallons%20per%20minute.
“read this about flow rates”:

Second you’ll need to be 100% positive that the tub drain and the (original) shower drain are exactly lined up. Otherwise you will have drainage and potentially flooding issues.

THe final issue – how big is the shower right now? Would a tub even realistically fit? Are you talking built-in or free-standing, with legs?

My gut feeling is that this isn’t a good idea, but it could be made to work, if everything lined up.

@elbanditoroso I was not planning to line up the drains. The shower floor should be sloped to the drain. Are you concerned the water would drain from the tub very quickly and the slope and drain could not handle the onslaught of water quickly enough? I had not thought of that. I need to measure if a tub would fit. I just googled and there are some pretty footed acrylic tubs. I figure it needs feet so the water can drain out.

Yes, I am worried about overflow.

My two cents are that (1) using the shower to fill a tub would result in a much colder tub water temperature (I used to shower in a tub/shower combo and plug the drain to take a bath/shower and it was always too cold), and (2) the tub draining into the shower would not be ideal to me. It seems like it would be too much water at my feet in the shower. I’d want at least the tub to have its own water source and drain.

Logistically, is the showerhead on one side of the shower and the tub would be on the other? Where do you stand to turn on the water for the tub and can you avoid getting wet? I hate standing naked waiting for the tub to fill. Likewise, when you are getting out, the whole shower area floor will likely be wet from the tub drainage. It just seems to me that your feet would be soaking wet when you exit the shower area.

But I do really like the “wet room” tub in the shower area concept.

@Cupcake If you take a bath your feet are soaking wet. I don’t understand your complaint about that. I built my house in Tarpon with a wet room before they were becoming popular in the US. I really liked it, because you don’t have to worry about getting the shower floor wet. In that house the wet room was very open and huge and part glass. If I do it in this other house, the tub would be at the back of the shower, and not ideal, and I don’t think I would want to make it permanent and plumbed in. It would be for me.

It should fit, but I am not sure. The current sketch of the house can be expanded 4 feet, which will include the shower being expanded 4 feet, and a tub is about 3.5 to 4 feet wide including it has to be a few inches from the wall. I don’t know exactly how the walls change when they stretch the shower, that will matter a lot. If the stretch is straight back it should work, except for what @elbanditoroso pointed out regarding filling the tub and draining the tub. I could just be careful and drain it slowly. I think my shower drain probably has the same capacity as my bathtub drain, maybe more, but still the slope of the shower compared to a tub which contains the water like a bowl, is very different.

@JLeslie Maybe I’m not explaining myself well. I’m talking about standing (or even moving) water. When I turn off the shower, there is very little water on the floor of the shower and I can dry off my feet and step out of the shower. If the tub is draining as well, there will be much more water on the floor of the shower. That probably sounds fine to you but sounds unpleasant to me. Again, maybe I’m not explaining it well.

I came across this: https://www.bellabathrooms.co.uk/blog/can-put-shower-freestanding-bath/#:~:text=A%20plumber%20would%20likely%20have,and%20could%20lead%20to%20flooding. Check out the second question, “CAN I PUT A FREESTANDING BATH IN A WET ROOM?”, where they recommend against it.

I’m sure you could check with a plumber. You may need a larger drain in the shower.

@Cupcake The shower won’t be over the tub. Thie shower is about 6’X5” on the original floorplan maybe a little bigger. You actually stand in one side of it, so that is 3’x5’. It’s a walk-in that you turn a corner to get into it. It would become 6’X9’ if the expansion is what I am guessing. The water from the shower might sprinkle on it when I just take a shower.

It’s possible the builder automatically installs a seat in the shower, like the one I have now, and then that would create a problem. The other big problem seems to be what your article states, which agrees with what @elbanditoroso said about the slope of the floor and water going everywhere. Thanks for the link.

Yes, but you will need some work done to hold the curtain and the shower head.
It is done all the time with Claw Foot Tubs Shower configurations.

No curtain. It’s inside a large walk-in shower if I do it.

Earlier this year I replaced by old tub/shower with a glass door standup shower with a bench (for old people like me). I love it.

I have never been a tub person, so no loss :-)

@elbanditoroso Did you do it yourself? So many people here want to convert their standard tub shower to a shower in their secondary bathroom. I would prefer it too, because my 80 year old parents use it, and it would be safer.

I’ve been looking at the showers in hotels, and I feel like I could install the sliding doors if I get a plumber to tear out the tub and install the shower. Is that who does the work? A plumber? It would be an amazing business here. They charge a ridiculous price, and it would be so easy to undercut the people doing it now.

@JLeslie no, had a contractor do it. I’m good with computers, lousy with construction.

I saw a photo the other day of a tub inside a walk in shower room. I’m not sure where I saw it – my FB feed shows me a lot of design photos so maybe it was there, or maybe it was somewhere else. Come to think of it, it was probably an HGTV show.

I had my tub taken out about five years ago and had a contractor/tile guy build a shower in its place. I was going to put another tub in, but the tub I wanted looked funny because it was so high, so I decided since I’m not moving out of this house any time soon, the resale value forn not having a tub won’t matter to me. The walk in shower (not a zero entry shower) is so much easier to get into and out of than a tub. I had handicap bar put in horizontally and a vertical one right when you’re walking out. A friend asked me why I put handicap bars in the shower. I said when I’m 50, maybe I don’t need a handicap bar but maybe when I’m 75, I’ll need it. I actually will brab on to the vertical one when I step out.

@jca2 I love my handicap bars. I think it’s good for every age. I don’t use them a lot, but I do hang onto it sometimes when I shave and I use one to help get up out of the tub. If I do wind up needing it more it’s there.

It’s a luxury to have enough space for a separate tub. I also prefer not climbing over a tub every day for a shower, but I like to be able to soak sometimes too.

@JLeslie My other reason for getting the handicap bars now is that it was all done together when the guy built the shower. If I wait to get it installed in the future, I have to hire a guy, make an appointment, deal with the guy coming to do the job – big hassle and probably at least 100 dollars for the job.

@jca2 They now have ones you can suction to the wall. I just would be so afraid if it lost it’s grip when using it, it’s worse than not having one. I guess they must work though.

@JLeslie I wonder if it would compromise the integrity of the wall tiles. I wouldn’t trust it.