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How to connect concealed tub drain on slab?? X-post frm bathrooms

Posted by nutherokie (My Page) on
Sat, Jan 16, 10 at 11:04

I just posted this in the bathroom forum then thought you plumbing experts might be able to advise me. I've purchased (but not taken possession of) the bathtub pictured below for the house we've just begun. The tub will be installed on a slab and our plumber can't figure out from the specs how the drain will be connected. The representative of the firm we bought the tub from says he just sells them, the plumbing is our problem. By the time we get the tub, the rough-in will be done and the slab poured.

Anybody connected a concealed drain like this without having under floor access? I'm attaching photos hoping someone can assure me I haven't just wasted a lot of money. Thanks!

Follow-Up Postings:

RE: How to connect concealed tub drain on slab?? X-post frm bathr

If the seller cannot supply a 'cut sheet' specifying the drain location and fill location I would cancel the sale.

RE: How to connect concealed tub drain on slab?? X-post frm bathr

Thanks for your input Brickeyee. The diagrams above plus the dimension specs I'm attaching below are all we have to work with. Our plumber called the seller a couple of days ago and apparently got a dose of attitude delivered with a British accent. I guess we'll try again Monday, but I'm not very hopeful. Of course I've already paid in full.

It's a reputable firm we're dealing with. I'm surprised they find it unreasonable to ask how the thing is supposed to be installed. Thanks again.


RE: How to connect concealed tub drain on slab?? X-post frm bathr

... methinks the seller is right.

You have said you have NO access under the slab. Is it a slab on grade? Is it a slab in a condo, and you don't want to break apart your downstairs neighbor's bathroom ceiling? Is is something else?

According to the diagram that comes with the tub, the P trap is under the slab. Although it's not shown in the illustration, it is nonetheless obvious to many people.

You (or your plumber) need to figure out is where you'll place the P trap, under the slab, which kind of pipe to use (tubular chromed brass, copper DWV, ABS, PVC, etc) and which associated slip joint ("lock nut") to use, and how you'll vent this line if it's being built new or rebuilt in any way -- and all that is a Master Plumber subject, not a tub sales subject.

My bet is that your plumber is not a Master Plumber, but a repair kind of guy who knows how to fix faucets and a whole lot more, too. There is nothing to gain by calling the tub people. There is almost no information provided in your diagrams posted above, in terms that would help us know how to advise you on how to connect the tub to the P trap. It does show the slip joint, "lock nut" which may be your key to getting the tub drain secure and watertight --- but only someone on site would know for sure.

Now, with no access under the slab, your big Question is how to raise the tub just enough that you'll manage to turn that slip joint shown under the tub and then make that gap look imperceptible later. Remember that you may want to be able to unscrew it one day too. Note that it is wise to be able to test it too -- and with no access underneath, you may be unable to test for leaks. This may be do-able, or maybe not...

I think posting a diagram showing the drain lines you have under your slab, including venting, will give the right information for plumbers to know if 1st of all you can hope to just tighten the slip joint shown.


RE: How to connect concealed tub drain on slab?? X-post frm bathr

That is a cut sheet, and the drain location is shown.

Any plumber should be able to work from that to position the slab cutout and drain lines.

RE: How to connect concealed tub drain on slab?? X-post frm bathr

Thanks davidro1 and brickeyee. I don't think his problem is with the p-trap or lines. It's figuring out how to tighten the drain beneath the tub since the foundation is slab on grade. Evidently he or another plumber will have to figure that out after we get the tub on hand. Thanks again.

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