Low-profile tub drain?

[ncgeo]

Is there some type of low-profile tub drain assembly available so I can avoid relocating an I-joist in the floor for clearance? This is for a Jacuzzi Espree corner whirlpool tub. I have ideas of cutting out the subfloor only (gaining 3/4") and raising the tub an inch but that still may not give me enough clearance. And cutting into the flange of the I-joist is prohibited. Ideally I need the drain line to hug the bottom of the tub with a very tight-turning drain elbow. Anyone aware of such a drain?

 

[hj]

drain

Kohler has several drains that go horizontal for such a use.

 

[Sponsor]

 

[Geniescience]

Turn tailpiece horizontally. Turn the "T" on its side.

Ron

I think any Geberit can have its tailpiece run horizontally too, although they don't show that in the literature. I did this. I turned it on its back. The hole in my concrete slab floor is not directly underneath the overflow standpipe. See https://terrylove.com/forums/showthread.php?t=7037&highlight=tailpiece

This will let you drill a hole wherever you want between the joists. I hope I have understood the problem and given you useful information; I am not a plumber.

David

 

[ncgeo]

I appreciate this info but unfortunately it won't fully solve my problem. I need to have the absolute lowest height drain line assembly so I can avoid notching an I joist (the tub drain is on one side of the I joist while the vertical drain is on the other side). Assuming the drain line is 1-1/2 inch (nominal) PVC I probably need about 2-1/4 below the drain cutout to accomadate the 1-1/2 PVC and 1/4 inch/ft drain pitch. Basically I'm trying to do an above the floor rough-in without significantly raising the tub.

I wish there were some type of special "oval" drain line to minimize the clear height needed under the tub to run the drain

I also thought of running the drain from the tub down a few inches so I could pass the drain line through the center of the 12" I-joist but then I may not have enough headroom for the trap.

 

[Geniescience]

solution provided.

ronald

i'm gonna respond immediately without being sure if I have understood everything you just said.

First, you only need less than 2 inches space.

Your PVC pipe needs to run sideways only a couple inches before it turns down to go through the floor, between two joists. (Right? Wrong? Correct me or explain more please.) So you don't need to add space for the 1/4" slope since the distance is negligible.

Since you can remove the subfloor, which takes more than 1/2 inch, you really really only need less than 1.5 inches.

One more big point: under the tub there is ALREADY tons of space. The tub drain hole is not pressed flush down to the floor. Am I right ? Have you seen this, and have you included this in these calculations?

Now, if all this is right, it seems to me that raising a tub by a little bit (even as much as 1.5") is perfectly OK and looks good. Just build the tub surround higher.

What did I miss or not get right?

David

 

[Geniescience]

Use space under tub, existing space for drain assembly

what I mean is that there is already space provided for any tub drain "assembly" and that from there you simply run horizontally, with the slight slope needed, over to wherever you choose to go down to the P trap.

I had this done. No complaints. A Master Plumber did it.

You do not need to raise your tub at all. The space is already there. For the drain assembly. Use it and run a horizontal drain to the right place that is available to you. Then turn drain down into P trap.

If you do raise your tub a little little bit, it won't look bad.

David

 

[ncgeo]

David -

I think you have the right picture. Raising the tub would probably do the trick but I'm trying to minimize that. As this is a whirlpool tub the run on the drain line is about 10". So I figured about 1/4" drop there. The drain line itself is probably about 1-3/4" OD. Then there will likely be some clearance between the drain line and tub floor (not sure since I don't have the drain kit in hand) The tub drain itself is only about 1" off the floor + another 5/8" for the subfloor. I figure I need roughly 2-1/2" clear height

Generally for above the floor rough-in of tub units they allow about 4" clear height to allow some working room.


Thanks, Ron

 

[Geniescience]

where to place the nut

ronald

one more thing, about the connection between the riser that comes from the tub overflow and the drain piece itslef. That connection has a big nut around it. You probably don't wnat to position it directly above the I-joist because then it will need space around it. You can place its location somewhere else, i.e. under the drain, instead of under the overflow. Then your wrench won't bump against the joist if and when it needs tightening or loosening.

also, this allows the tub to sit lower than otherwise.

david