Bathtub drain and venting

[Serkan]

I have been browsing this forum to learn about plumbing as a homeowner.
Decided to make a post to ask some questions to pros here.

I am renovating an older house which is gutted to the bones. New plumbing, electrical, hvac etc.

I have a situation with the bathtub plumbing that I want to solve and want to make sure it is not against the code.

Right hand bathtub. Drain needs to go to the left. I want to have the vent going up in the plumbing wall (interior wall).

Bath tub will be no AFR.

Here is the questions:
1- Can a the p-trap be rotated the way it is in first picture?
2- Is adding wye fitting with dry vent right after the p-trap ok? Is there a minimum distance?
3- Is using wye fitting for dry venting the bathtub ok? (45 degree will get me into the plumbing wall, than another 45 and straight up)
4- Or does it have to be a sanitary tee on it's back, than 45? (I don't have room to do this. Can't drop lower than bottom of the 2x10 joist. 3rd picture)

Thank you.

 

[Serkan]

Instead of starting another thread, I also want to ask about toilet drain.

I made a sketch up drawing of the toilet drain which is 16' away from the vertical main stack. 3" horizontal drain will be in a bulk head on the living room ceiling (9 feet).

I am thinking of using a long sweep 3" at the toilet flange and 45 street elbow than long sweep 90 (street) leaning 45 degree.

I don't know how I can add a vent in this setup. I am planning to add the vent 7' down in the horizontal where sink and shower taps in.

What looks wrong in these drawing and what needs to be added or fixed?

 

[Sponsor]

 

[Serkan]

I think this is one way to get a vent in there. But two long sweep 90 s makes the setup too tall and will not fit in 2x10 joist cavity, unless I drop the horizontal 3" drain 2 inches down at the start. Which I don't want because the bulkhead will have to be 2" taller.

Trying to keep the bulkhead height at 8" max.

3 1/2" pipe diameter + 4" drop + another 2" will make it more something like 10"

Can I use medium sweep 90 elbows instead of long sweep?

Pink is OSB subfloor thickness 3/4"+5/8"

 

[wwhitney]

On the first post:

1) Yes, and that's a good solution.
2) The minimum distance is twice the pipe nominal diameter, measured from the trap weir (the point on the trap where if you slowly fill it, water first spills out into the horizontal drain) to the inside crook of the wye. It would be very difficult or impossible to violate that rule. Even 1" of pipe showing between the p-trap hub and the wye hub would definitely be enough; not sure if 0" (hub tight to hub) would be enough, but I try to avoid having hubs so close.
3) Yes, a wye is preferred.
4) Some US codes allow a san-tee on its back, some don't, not sure about Canada.

Cheers, Wayne

 

[wwhitney]

On the second two posts:

- Check your plumbing code. One US code allows the WC vent to be arbitrarily far away (but before or as it joins another drain). Another one requires it within 6' measured along the pipe from the flange.

- Directly under a WC flange, it's generally OK to use a regular quarter bend (at least, the radius of curvature of fittings sold as closet bends match quarter bends, not the longer radius of a long turn 90). Otherwise, if the elbow outlet is horizontal, it needs to be a LT90.

- In your drawings with the vent, would the vent end up too close in plan (as seen from above) to the WC to end up in a wall)? If that's not an issue, you have a variety of ways to do a vent takeoff. What is the clear width of the joist bay, and where does the closet flange end up within that width (how far from the closer (to the direction the drain will run in the bulkhead) joist to the center of the flange)?

- Lastly, often the simplest way to vent a WC is to wet vent it with a dry vented lavatory. So is routing the lav drain to join the WC drain in the soffit an option?

Cheers, Wayne

 

[Serkan]

@wwhitney Thank you so much for great, detailed responses Wayne. Really appreciated.

So drain and venting for bathtub is good. That is for the main bathroom upstairs.

The one with the shower is an en suite.

Here are some diagrams I made.

-The bathroom is 6'6"x 7'6"
-Yellow piping is 2" but I want to reduce it after the 2x2x1.5 sanitary tee. So the double top plate is not sacrificed.
-Orange is the toilet drain section with long sweep 90s with 60 elbow in the middle.
-Black horizontal is a 3" and runs almost 16' with 1/4" per foot slope. It will be in a bulkhead, 3" away from the exterior wall.
-Green is the vent for the toilet. It is 5' 10" from center of the flange to center of the 1.5" vent hub. Staight line, not counting the turns.
-I cannot pick the toilet vent closer. That is the only stud bay on the exterior wall I can bring the pipe into the attic.

Is there anything that doesn't look right? Do I need to add any cleanout in this section of the system?
I am probably going to hire a plumber but I like getting things done certain way. And I like to learn things.

 

[wwhitney]

Nothing is obviously wrong. Some of the details may depend on code provisions that in the US vary between between different codes, so I don't know what the Ontario code requires.

It may be possible to eliminate the green WC dry vent, depending on your WC venting rules, and rely on the lav to wet vent the WC.

Where the red meets the black, you could use a quarter bend on the horizontal orange pipe to turn downstream the way the black is running, but at a 45 from plumb; and then a 45 to turn horizontal.

Cheers, Wayne

 

[Serkan]

@wwhitney

I think I will keep the green vent for the toilet just for better functioning. Not a big deal if I can fit a 3" wye and sanitary tee back to back in the joist bay.

I know what you are saying for the 45 elbow from the toilet flange to horizontal. If I do that I cannot get the distance i want for the toilet to side wall. which is 20" from the center of the flange to the wall.

If i put the 45 elbow to 20" distance than bulkhead has to be wider.
Long sweep 90s give me more adjustment as to where horizontal line starts.

 

[wwhitney]

That's not actually the configuration I was trying to describe. In the right hand configuration you rendered, if the short elbow is a 45, you could put the 45 after the 2nd 90 instead of before it. That might let you get a slightly narrower soffit.

Cheers, Wayne

 

[Weekend Handyman]

Plumbing code of Canada is a free download … just google …. Plumbing Code of Canada 2015 PDF. Also … check out the mathematic plumber on YouTube.

 

[Serkan]

That's not actually the configuration I was trying to describe. In the right hand configuration you rendered, if the short elbow is a 45, you could put the 45 after the 2nd 90 instead of before it. That might let you get a slightly narrower soffit.

Cheers, Wayne

Sorry Wayne, I am having hard time understanding your configuration. Can you make a simple drawing?
The bulkhead is going to be 8" tall regardless. 3 1/2" pipe diameter + 4" drop at 16' length

IMO 8x8 will look too boxy at the ceiling corner. 8x10 will look better. I can easily get the 10" width with LS90 configuration and 3" gap between wall and pipe.

Do you think the flow will be poor with the LS90 ->60 elbow -> LS90 leaning 30 ?

 

[Serkan]

Plumbing code of Canada is a free download … just google …. Plumbing Code of Canada 2015 PDF. Also … check out the mathematic plumber on YouTube.

I thought plumbing code is already in Ontario Building Code. Do plumbers in Ontario use Plumbing Code of Canada 2015? Thanks I will download it.

 

[Jeff H Young]

whats the point in rolling up and using a 90 and a 45? just shoot down joist bay and use a 45 to get to center of your toilet unless there is some obstruction you need to clear. 7 foot away from vent probebly good enough in canada but in USA some places allow others dont but it funtions I keep my studys to America so cant say about Canada for sure

 

[wwhitney]

whats the point in rolling up and using a 90 and a 45? just shoot down joist bay and use a 45 to get to center of your toilet unless there is some obstruction you need to clear.

Look at the last rendering in post #6, which shows a typical joist (not all of them). The black portion of the WC drain will be under the joists, and is going to be boxed out in a soffit. So the OP wants to minimize the soffit size, and needs to (going upstream) jump up into the joist bay from being under the joists.

Cheers, Wayne

 

[wwhitney]

Sorry Wayne, I am having hard time understanding your configuration. Can you make a simple drawing?

I will if this last attempt at text communication fails: Take your last rendering, the configuration on the right. Remove the LT90 you have as the closet bend.

Now you just have one (short) horizontal, which offsets down a bit while turning 90 degrees in plan. If you take that configuration, and turn the whole thing upside down (and rotate it around a vertical axis as required), you have the alternate solution that I described.

However, the upside is just that your soffit could be narrower. If you are making your soffit wider for aesthetic reasons, then that may not matter.

I have no opinion on which version will give a better flow if any. I would say the use of 60s is generally quite limited, so it would be better to use a 45 and a LT90 than a 60 and a LT90, all else being equal.

Cheers, Wayne

 

[Weekend Handyman]

I thought plumbing code is already in Ontario Building Code. Do plumbers in Ontario use Plumbing Code of Canada 2015? Thanks I will download it.

PCC is a model code. Jurisdiction are free to use it as is, to modify it, or come up with their own. If Ontario has it’s own, that would supersede PCC.

 

[Serkan]

@wwhitney

Sorry still not getting it. I think i am fixed on one configuration any other way is not registering to my brain. Lol. A diagram would be nice. Thanks…

 

[Serkan]

PCC is a model code. Jurisdiction are free to use it as is, to modify it, or come up with their own. If Ontario has it’s own, that would supersede PCC.

I see, well i am most definitely going to hire a pro because i don’t feel comfortable doing the whole thing. But i still want to learn as much as i can and design the plumbing routes myself for most fitting way in my build. I don’t think plumber is going to like when i tell him what i want, but it’s ok.

 

[wwhitney]

Sorry still not getting it.

Here, I just cropped your picture and flipped it around. The black box is no longer the soffit, it's actually where the pipe would be running between the joists (not shown). And the pipe drops down while simultaneously turning 90 degrees in plan. In this configuration the 90 degree elbow could be a quarter bend rather than a LT90, if desired.

The only advantage of this over what you drew would be if it fits better. Another option to have.

Cheers, Wayne