Splitting 1 bathroom into 2 smaller bathrooms

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MrHappy

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I am in MN which follows the 2020 UPC. I am splitting a 10x7 full bath into 2 smaller 5x7 baths (3/4 one side, full other side). To accomplish this the existing fixtures & drains will all have to be moved. There is an existing 1.25" vent which I'll be reusing (upping the size to 2") as well as the main stack which is 3" i'll be reusing. The room underneath the bathroom is an unfinished storage room so I'm ok with dropping pipes a bit lower to accommodate the weird layout

I attached a diagram of the proposed new layout, as well as the proposed plumbing diagram. Reading through the UPC I am most concerned with the vertical venting of the toilet. The code states 6ft is allowed from the flange to the start of the vent. Does that mean where it connects to the main stack, or does it have to get all the way up to past the lavatory above where it's no longer wet vented?

Anything else jump out as being incorrect? Note that some of the horizontal connections are marked as wye, but may become combo tees instead depending on the angle of the trap arms connecting in.
 

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wwhitney

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Basically looks great. The connectivity (order of fixtures coming in) is good. The 2" VTR and 3" VTR could obviously combine in the attic to a single roof penetration. And the pipes marked VTR can't have anything draining down from above (compulsory reminder, you probably know that).

On the right side, the 6' limit applies from the WC closet flange, measured along the pipe both vertically and horizontally, to the stack where the WC is being vertically wet vented. You can use a 3" wye at the stack to connect the WC, since the WC is not subject to the trap weir rule. Not sure if a 3" wye is better, but it's definitely not worse. A 3" san-tee is fine if a 3" wye won't fit for some reason.

On the left, the 6' limit is from the closet flange to the 3x2x3 wye, which is where the WC is horizontally wet vented. You can see that it's analogous to the right side, if the stack were turn 90 degrees to be horizontal.

I'm not sure if the 2" cleanout is needed; are you going to make it accessible?

Cheers, Wayne
 

MrHappy

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Basically looks great. The connectivity (order of fixtures coming in) is good. The 2" VTR and 3" VTR could obviously combine in the attic to a single roof penetration. And the pipes marked VTR can't have anything draining down from above (compulsory reminder, you probably know that).

On the right side, the 6' limit applies from the WC closet flange, measured along the pipe both vertically and horizontally, to the stack where the WC is being vertically wet vented. You can use a 3" wye at the stack to connect the WC, since the WC is not subject to the trap weir rule. Not sure if a 3" wye is better, but it's definitely not worse. A 3" san-tee is fine if a 3" wye won't fit for some reason.

On the left, the 6' limit is from the closet flange to the 3x2x3 wye, which is where the WC is horizontally wet vented. You can see that it's analogous to the right side, if the stack were turn 90 degrees to be horizontal.

I'm not sure if the 2" cleanout is needed; are you going to make it accessible?

Cheers, Wayne
I appreciate the rely! Glad to hear everything looks good as well!

As for the 2" cleanout, I thought it needed an access point since it is changing from vertical to horizontal there? All the drains will be in an unfinished room of the basement, so it will be accessible easily.
 

Storm rider

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You will need to add some dimensions to that plan to see if the fixtures have the correct spacing. It is difficult to fit a three piece bathroom into a 5x7 space.
 

MrHappy

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How does it go now? Were you able to finish the project already? I have a very similar thing to do and need some inspiration.
Read online some luxury bath reviews and not sure if i should contact them or someone else. There are many thing i can do by myself, but some thing definitely need to be done by professional.
It went well. Not 100% finished still as we are waiting on custom glass for the shower in one of the bathrooms.

The inspector didn't like having bathroom groups in separate rooms, so they made me dry vent the toilet (WC bathroom group 1 in my sketch). They still allowed vertical wet venting of the other toilet even though that was separate rooms though, so it just goes to show you how interpretation just comes down to the individual inspector.

It is very small and definitely only a space for 1 person at a time, but this allowed us to put 2 bathrooms on one floor including a master ensuite, so well worth it for us.

It took a LOT of planning and creativity to fit everything into such a small space but it is definitely doable, feel free to PM me if you have other questions or want some pictures or anything like that
 

Jeff H Young

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It went well. Not 100% finished still as we are waiting on custom glass for the shower in one of the bathrooms.

The inspector didn't like having bathroom groups in separate rooms, so they made me dry vent the toilet (WC bathroom group 1 in my sketch). They still allowed vertical wet venting of the other toilet even though that was separate rooms though, so it just goes to show you how interpretation just comes down to the individual inspector.

It is very small and definitely only a space for 1 person at a time, but this allowed us to put 2 bathrooms on one floor including a master ensuite, so well worth it for us.

It took a LOT of planning and creativity to fit everything into such a small space but it is definitely doable, feel free to PM me if you have other questions or want some pictures or anything like that
Glad project moving along!
Inspector didnt like because the code is clear in UPC , I dont know why but thats how it is. and as far as the verticle wet vent is concerned thats an acceptable practice no issue at all. I would guess that most plumbers from UPC code andthe days of prohibited horrizontal wet venting still havent embraced it as being a proper system. I have mixed feelings and concede that almost all the time it vents fine
 

wwhitney

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Inspector didnt like because the code is clear in UPC
Yes, it is clear, a bathroom group is just a collection of fixtures with no requirement that they be in the same room. The UPC definition:


Bathroom Group. Any combination of fixtures, not to exceed one water closet, two lavatories, either one bathtub or one combination bath/shower, and one shower, and may include a bidet and an emergency floor drain.

Likewise, the horizontal wet venting rules only require that the bathroom group be on one floor level:


So the inspector was wrong on this one.

Cheers, Wayne
 

MrHappy

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Yes, it is clear, a bathroom group is just a collection of fixtures with no requirement that they be in the same room. The UPC definition:


Bathroom Group. Any combination of fixtures, not to exceed one water closet, two lavatories, either one bathtub or one combination bath/shower, and one shower, and may include a bidet and an emergency floor drain.

Likewise, the horizontal wet venting rules only require that the bathroom group be on one floor level:


So the inspector was wrong on this one.

Cheers, Wayne
That was my interpretation as well, but inspector didn't agree and I figured it'd be better and easier to make the relatively small change and stay on his good side rather than try and continue to argue the point since I'll likely have more renovations coming in future years
 

Reach4

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It appears that if there are two toilets, there are two bathroom groups.

IPC lets a bathroom group include two bathrooms, but I think UPC does not. MN code that you quoted seems to me to not include two bathrooms.
 

wwhitney

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IPC lets a bathroom group include two bathrooms, but I think UPC does not. MN code that you quoted seems to me to not include two bathrooms.
Agreed on all of that. But the inspector in OP's post today also required that a bathroom group consist of fixtures within a single bathroom. Which is not in the UPC, it's an additional restriction the inspector imposed with no basis.

Cheers, Wayne
 

Jeff H Young

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Yes, it is clear, a bathroom group is just a collection of fixtures with no requirement that they be in the same room. The UPC definition:


Bathroom Group. Any combination of fixtures, not to exceed one water closet, two lavatories, either one bathtub or one combination bath/shower, and one shower, and may include a bidet and an emergency floor drain.

Likewise, the horizontal wet venting rules only require that the bathroom group be on one floor level:


So the inspector was wrong on this one.

Cheers, Wayne
Great points Wayne! Im not exactly clear how some of the details are on the build are . But the UPC could make it a bit more clear I think there would be a better way to write this code explaining that a bathroom group has no requirement to be part of any particular bathroom I guess you could have several bathrooms with parts of them in a single bathroom group shower from one, a tub shower in another , and even an emergency floor drain in differant bathrooms and be a single bathroom group? Is that how you think it is ? I wonder too if that was the intent of the code or poorly writen?
 
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