New tub location question

[Andrewjoseph]

Hello - I have been on the site for many years, and have always been able to search for and find an answer for any question I come up with.

I am remodeling my bathroom and hoping to add in a tub to a location where there was not one before. The shower currently has only a very small stall shower. Since it’s the master I’m hoping to get a tub in where an oddly designed vanity was before.

I cut the floor out and discovered a 2” drain line with a 1.5” vent wyed off, and they are basically exactly where I need the tub drain/venting. The drain/vent is currently from a floor drain underneath the washing machine.

I would 100x rather have a tub in the master than a emergency floor drain (that would not help at all right now as we have no drain pan hooked up to it) under the upstairs laundry.

My question is, can I abandon the laundry floor waste pipe and venting and convert this into my tub waste and venting? I am assuming I can, but was curious if there is anything I’m missing? I included a photo below. I would greatly appreciate any advice. Thank you!

 

[Andrewjoseph]

Hello - I have been on the site for many years, and have always been able to search for and find an answer for any question I come up with.

I am remodeling my bathroom and hoping to add in a tub to a location where there was not one before. The shower currently has only a very small stall shower. Since it’s the master I’m hoping to get a tub in where an oddly designed vanity was before.

I cut the floor out and discovered a 2” drain line with a 1.5” vent wyed off, and they are basically exactly where I need the tub drain/venting. The drain/vent is currently from a floor drain underneath the washing machine.

I would 100x rather have a tub in the master than a emergency floor drain (that would not help at all right now as we have no drain pan hooked up to it) under the upstairs laundry.

My question is, can I abandon the laundry floor waste pipe and venting and convert this into my tub waste and venting? I am assuming I can, but was curious if there is anything I’m missing? I included a photo below. I would greatly appreciate any advice. Thank you!View attachment 84527

 

[Sponsor]

 

[John Gayewski]

Your vent needs to be vertical. So you'll have to figure out how you can do that. You can abandon the floor drain as you wish,as long as they aren't required locally.

 

[Andrewjoseph]

Your vent needs to be vertical. So you'll have to figure out how you can do that. You can abandon the floor drain as you wish,as long as they aren't required locally.

Thank you for your reply. The floor drain is not required here.

Is the vent able to wye off and run horizontal for for 5 ft until it hits the outside wall, and then go vertical? That is how the floor drain is currently set up. That’s how the shower next to it is set up currently. But it was built in 86’.

I am out in the county so I’m less concerned with current code. But I do want it to drain correctly and not be an issue down the road. I could add a vertical vent in the interior wall, I just was not sure if it was imperative. Thank you very much for your input.

 

[John Gayewski]

Thank you for your reply. The floor drain is not required here.

Is the vent able to wye off and run horizontal for for 5 ft until it hits the outside wall, and then go vertical? That is how the floor drain is currently set up. That’s how the shower next to it is set up currently. But it was built in 86’.

I am out in the county so I’m less concerned with current code. But I do want it to drain correctly and not be an issue down the road. I could add a vertical vent in the interior wall, I just was not sure if it was imperative. Thank you very much for your input.

My opinion is that later that vent will clog and rendered useless. A compromise would be to add a cleanout access in the wall for future vent unclogging.

 

[wwhitney]

Is the vent able to wye off and run horizontal for for 5 ft until it hits the outside wall, and then go vertical?

No, the vent takeoff needs to be on the upper half of the horizontal drain pipe, and it needs to rise vertically (which includes up to 45 degrees off plumb) until it is at least 6" above the fixture flood rim.

Also, your second drawing with the new horizontal wye, the wye is backwards, as if the vent line gets water in it from a backup, the takeoff should be arranged for the vent to drain.

IPC or UPC? That will determine how far your tub drain can run before venting. Either way the maximum fall before the vent takeoff is one pipe diameter. You could use a 2" trap instead of a 1-1/2" trap if you need more length/fall before venting.

If the length limit works out, then one option for repurposing the current floor drain horizontal path for the new tub trap arm would be to replace the 45 where it turns downwards (into the wye on the lower horizontal running perpendicular to the joists, just below (in the photo) the yellow wire) with a wye. The straight inlet on the wye would be your vent takeoff, and it would be rising at a 45, starting off perpendicular to the joists. So then the question is whether you have the height to turn it and get it under the wall before the vent rises above the floor, given that it has to continue rising at a 45.

Cheers, Wayne

 

[Jeff H Young]

That type of flat venting was very common in My early days plumbing it was and is allowed by inspector approval but I stay away from it. if you do use the flat vent it should have minimum 1/4 "per foot fall , have a long sweep 90 at the wall and the wye should be rolled up on 45 degrees. the clean out is a good idea , Ive put many dozens of vents (or hundreds)in this fasion and I only guess that they worked ok but dont like the practice anymore its sort of theoretical as to whether they perform well or dont and I just lien toward being positive it will vent proper

 

[Andrewjoseph]

No, the vent takeoff needs to be on the upper half of the horizontal drain pipe, and it needs to rise vertically (which includes up to 45 degrees off plumb) until it is at least 6" above the fixture flood rim.

Also, your second drawing with the new horizontal wye, the wye is backwards, as if the vent line gets water in it from a backup, the takeoff should be arranged for the vent to drain.

IPC or UPC? That will determine how far your tub drain can run before venting. Either way the maximum fall before the vent takeoff is one pipe diameter. You could use a 2" trap instead of a 1-1/2" trap if you need more length/fall before venting.

If the length limit works out, then one option for repurposing the current floor drain horizontal path for the new tub trap arm would be to replace the 45 where it turns downwards (into the wye on the lower horizontal running perpendicular to the joists, just below (in the photo) the yellow wire) with a wye. The straight inlet on the wye would be your vent takeoff, and it would be rising at a 45, starting off perpendicular to the joists. So then the question is whether you have the height to turn it and get it under the wall before the vent rises above the floor, given that it has to continue rising at a 45.

Cheers, Wayne

Could you tell me if my new photo will work please? I can add a vertical vent to connect to the existing venting above the floor rim on the adjacent wall.

I don’t fully understand how to align my p trap so it falls under the tub drain, and at the same time get the vent to head vertical at a 45 degree angle or more. The portion I’ve circled looks like it would be closer to 30 degrees rise after branching off at the wye. Is there another design that would work in that space between the floor joices?

Thank you for your help here.

 

[Andrewjoseph]

No, the vent takeoff needs to be on the upper half of the horizontal drain pipe, and it needs to rise vertically (which includes up to 45 degrees off plumb) until it is at least 6" above the fixture flood rim.

Also, your second drawing with the new horizontal wye, the wye is backwards, as if the vent line gets water in it from a backup, the takeoff should be arranged for the vent to drain.

IPC or UPC? That will determine how far your tub drain can run before venting. Either way the maximum fall before the vent takeoff is one pipe diameter. You could use a 2" trap instead of a 1-1/2" trap if you need more length/fall before venting.

If the length limit works out, then one option for repurposing the current floor drain horizontal path for the new tub trap arm would be to replace the 45 where it turns downwards (into the wye on the lower horizontal running perpendicular to the joists, just below (in the photo) the yellow wire) with a wye. The straight inlet on the wye would be your vent takeoff, and it would be rising at a 45, starting off perpendicular to the joists. So then the question is whether you have the height to turn it and get it under the wall before the vent rises above the floor, given that it has to continue rising at a 45.

Cheers, Wayne

Sorry to respond twice. I looked through some additional posts on here with photos. Does this new markup look right?

I will set my p trap perpendicular to the joists to allow me to connect to a new 2” vertical vent. This will allow me to branch the vent off at a 90 degree angle from the drain. Does this idea work out?

 

[wwhitney]

Not following your last drawing, seems like given your joist space available height you need to have the vent taken off the horizontal trap arm with the drain staying horizontal. Not sure what you are intending with the drawing, but I don't see how that would work.

The previous drawing can certainly work. You'd typically have the u-bend running perpendicular to the joists or back towards the vent wall. Then trap outlet elbow might be parallel to the joists, or at a 22.25 or 45 angle to the joists (which would make the wye vent takeoff pointed more towards the vent wall).

You are correct that with a wye vent takeoff, and the wye rolled 45 degrees off upright, the vent is only at 30 degrees above horizontal. For a short section between the wye and the vent wall, this seems to be generally considered as acceptable, even through 30 < 45. You'd use a 60 degree bend to turn the vent to vertical once under the wall. And depending on the tub, there can be some void space under the tub that would allow the vent to project above the floor/outside the wall plane.

Cheers, Wayne

 

[Andrewjoseph]

Not following your last drawing, seems like given your joist space available height you need to have the vent taken off the horizontal trap arm with the drain staying horizontal. Not sure what you are intending with the drawing, but I don't see how that would work.

The previous drawing can certainly work. You'd typically have the u-bend running perpendicular to the joists or back towards the vent wall. Then trap outlet elbow might be parallel to the joists, or at a 22.25 or 45 angle to the joists (which would make the wye vent takeoff pointed more towards the vent wall).

You are correct that with a wye vent takeoff, and the wye rolled 45 degrees off upright, the vent is only at 30 degrees above horizontal. For a short section between the wye and the vent wall, this seems to be generally considered as acceptable, even through 30 < 45. You'd use a 60 degree bend to turn the vent to vertical once under the wall. And depending on the tub, there can be some void space under the tub that would allow the vent to project above the floor/outside the wall plane.

Cheers, Wayne

Thank you very much. I appreciate your help greatly.