Got a Question I can't answer

ladymacbeth

On the forums I work for and if anyone can help me I"d be thrilled .
Someone has asked me how much room it takes to install a sunken or garden tub.
Do they require more room beneath them than a normal tub.
It makes sense to me that they would, but to be honest, having never done it, I don't know.
Do any of you have experience in installations of the garden tubs?
The question is located here if you want to answer it personally.
Thanks bunches for any information you can provide.

http://forum.howdididoit.com/showthr...?p=446#post446

scorrpio

As with many other home improvement questions, the answer is: it depends.

It is not just the tub, you know. You gotta have a drain, with a trap, sloping towards a stack. Trap alone extends 4-5" (at least) below tub bottom. Oh, and if this is a remodel, you are looking at some heavy plumbing work - potentially having to move a wye fitting a foot or so down on the main stack.

Then, there is a question of house structure. In my house, joists ar 2x8, since house is not large. Some houses might have 2x10s. In my case, I could recess a tub only 3" or so into the floor before trap began intruding into the room below. Given that most tubs are at least 12" deep, recessing it even half-way into 2x10 framing is no trivial task.

Further, the question of support. Tubs are heavy, especially when filled with water and the bathing person. Sistered joists, heavy blocking etc are usually specced for locations where a tub is to be placed. Here, instead, you are going to be cuting a sizeable chunk out of at least one joist in order to recess the tub. You MUST provide adequate support.

For tubs installed over unheated basement/crawlspace, the other issue is insulation. You want at least R19 below the tub if you don't want your bath cold within 5 minutes on a winter day.

In other words, a properly installed sunken tub will heavily intrude upon whatever is below it. If this is a new construction, planning a closet on the floor below might be a good idea.

Kingfisher

If you are wanting to retro fit a sunken tube it is a lot of work you can not just shave the joist to give you extra room. They were sized that way for a reason so you can't cut them down and add more water weight . A garden tube is not a sunken tub itself just a name that is used for large soaking tubs now days it can be raised, level or sunken. The right way is to reframe the opening into the floor system with a sunken space, but this is probably not cost effective. as it requires doubled joist on the out side of the opening extending back to the brearing points. If you do that then you could add a shallower floor in the opening to hold the tub using joist hangers. Also as Scorrpio pointed out the drain is below the tube and still needs to flow properly with a 1/4" of fall per ft. I think this is a hard thing to do in a simple bathroom remodel, more of a whole house renovation to make all the floor and plumbing work right.

ladymacbeth

You rock. Having never done it I didn't know. The tub was not my project but that of someone who had asked on another forum and I simply didn't have an aswer.. we had a sunken tub but it was already there when we bought the place, so i wasn't sure.
It makes sense that it would, given the nature of the thing.. LOL. . as in .. sunken.. but things aren't always what they seem.
I'm adding links from the other forum to your responses so they can come and read them for themselves.
Thank you for your comments and your help.