Tub Shoe not Level

[AndyB7]

I'm stuck and want to do this right. I'm replacing a tub and the drain assembly and trap also needs replacing to align with it. Problem is the accumulation of angles ending at the tub shoe. I’ve included an image of a dry assembly to illustrate, with numbered references in the details below. (P.S. I'm just a humble homeowner trying to learn new skills, please explain any acronyms/trade terms you use and help a brother out ;-)

Problem:

Tub shoe (4) is off level by 3.6° due to the accumulation of:

• 1.2° angle (assumed) of the trap arm.
• 1.2° (90°-88.8°) angle of the quarter turn part of the trap (1).
• 1.2° (90°-88.8°) angle of the San Tee (3)

I know these angles are built in to the Tees and Elbows intentionally to ensure proper drainage pitch but for this assembly there are 3 instances of a 1.2 degree offset which all add up rather than cancelling each other out, so how to level the shoe? What am I missing?

Causes/Solutions Considered:

1. Use the wiggle room of the joint between trap arm and trap to recover the angle (this results in a bend over 90 degrees, which if allowed, why don't they make a 91.2 degree elbow (as opposed to 88.8) to help with this.
2. I used the wrong trap and/or other component in the assembly.
3. Invert the San Tee (3) (which is understandably counter to the installation instructions)
4. Add some kind of angle adjustment elbow somewhere in the sequence.

Further Info:

1. The trap components 1 & 2 came as a single item (Lesso from HD) Product Link: https://www.homedepot.ca/product/lesso-1-1-2-in-abs-p-trap-less-c-o-hub/1000116212
2. The tub drain components 3,4,5 came in a kit (OS&B from HD) and their instructions state that the sweep of the T should go in the direction of the trap, as pictured. Product Link: https://www.homedepot.ca/product/os...-kit-less-pipe-with-tee-/1000126824?rrec=true
3. Everything to the right of the image is original build, inaccessible and mostly invisible but I’m assuming correct angle of trap arm to vent/drain. There is certainly an angle in the correct direction.
4. Drain hole of the tub is dead level (parallel to floor) when tub is in situ on a levelled floor.
5. I’m in Ontario, in case code compliance is raised.

 

[wwhitney]

First question, for the tub you have, is the face of the outside area where the overflow seals actually at 90 degrees to the face where the drain shoe seals? That is not always the case.

Second, if the above is all dry fit, when you go to glue it up you do get a little wiggle room while the glue is still wet. So you could probably cock each joint half a degree or a degree. If you pay attention to which joint needs to go which way, you can probably get several degrees combined out of all the joints.

Lastly, there's usually a compressible washer between the tub and either shoe, which can compress asymmetrically to take up some angle deviation. I think there may be pre-angled washers available as well.

Cheers, Wayne

 

[Sponsor]

 

[AndyB7]

First question, for the tub you have, is the face of the outside area where the overflow seals actually at 90 degrees to the face where the drain shoe seals? That is not always the case.

Second, if the above is all dry fit, when you go to glue it up you do get a little wiggle room while the glue is still wet. So you could probably cock each joint half a degree or a degree. If you pay attention to which joint needs to go which way, you can probably get several degrees combined out of all the joints.

Lastly, there's usually a compressible washer between the tub and either shoe, which can compress asymmetrically to take up some angle deviation. I think there may be pre-angled washers available as well.

Cheers, Wayne

Thanks for the input, Wayne. Very much appreciated.

No, the overflow is not at 90 to the drain shoe but the drain kit also included an 8 degree adjustment piece for that - I just left it out of the dry fit illustration to avoid extra complication. I have already dry fit the assembly with both drain and overflow shoes satisfactorily flush relative to each other. My problem is the offset between that assembly and the trap arm.

I'm happy to try recovering 1 degree per joint if that's considered the proper approach, and also allow the gaskets/washers to take a BIT of the load as well. I just wanted to be sure I wasn't missing a better option and I hate the thought of cranking the drain and overflow threads against something that isn't flush.

I could additionally look at pre-angled washers but didn't want to introduce additional components on the assumption that a basic drain kit + trap is designed for the job in hand and shouldn't really need augmenting further - hence my suspicion that I'd screwed up somehow.

Could you please explain to me why the bend where the trap exits is 89 degrees? Surely this always connects to the trap arm which falls away at 1.2 degrees so a 91.2 degree bend here would put the 180 turn of the trap back to level. I get why the T is how it is but this <90 trap bend has me baffled.

 

[Breplum]

We will typically use a 1.5" shielded no-hub coupling for the overflow and one on the drain arm (not necessarily the shoe arm). That gives some give to the package

 

[AndyB7]

We will typically use a 1.5" shielded no-hub coupling for the overflow and one on the drain arm (not necessarily the shoe arm). That gives some give to the package

Thanks, that's an option to consider. What I find bizarre is that assuming the assembly I am installing here is fairly standard for a tub (i.e. 2 components with <90 degree bend going into a sloping trap arm) that tub shoe doesn't come as a +/- 93 degree bend, or at least with an optional 3 degree coupling, to square things up.

 

[GReynolds929]

If there is enough room to start the threads the threaded drain spud will pull it tight as needed.

 

[wwhitney]

Could you please explain to me why the bend where the trap exits is 89 degrees? Surely this always connects to the trap arm which falls away at 1.2 degrees so a 91.2 degree bend here would put the 180 turn of the trap back to level. I get why the T is how it is but this <90 trap bend has me baffled.

That's a very good question. I'm a bit surprised you were able to dry fit the street trap elbow into the trap u-bend so fully, ABS joints are normally an interference fit, so you can't dry fit them completely.

So my questions are: do you have any angular play in the joint in the current dry fit configuration? If you pull the joint apart by 1/4", does that get you any angular play?

It might behoove you to take your angle measuring configuration to the store and check other p-traps. Maybe you just have one from a bad batch.

Cheers, Wayne

 

[AndyB7]

That's a very good question. I'm a bit surprised you were able to dry fit the street trap elbow into the trap u-bend so fully, ABS joints are normally an interference fit, so you can't dry fit them completely.

So my questions are: do you have any angular play in the joint in the current dry fit configuration? If you pull the joint apart by 1/4", does that get you any angular play?

It might behoove you to take your angle measuring configuration to the store and check other p-traps. Maybe you just have one from a bad batch.

Cheers, Wayne

Thanks, Wayne, all sorted. I did as you suggested yesterday and compared my trap elbow with an alternative. The new one was exactly 90 so I'm a bit lost as to what went on there. Anyway, that extra degree meant I could get the shoe flush by cocking pipes into hubs a fraction on two different joins, and then also pushing down on the arm a fraction (making sure it still fell away). Still a bit surprised that the tub shoes don't compensate for the trap arm and tee angles to save all that fine tuning, but I think I'm in business. Really appreciate you taking the time to help me. (Today's fun was spending 3 hours trying to drain water from the pipes so I could solder on the pex sweat adapter lol. About to turn the water on - listen for the screaming lol. This project has properly kicked my ass. Cheers, sir.