New bathrooms, abandoning old underslab, etc.

[Mikha'el]

Hi all - I started a modest bathroom remodel a few years ago... but then we decided to move the master suite to a garage attic extension and EVERYTHING changed. Dug back into my notes and re-read the code (Texas IPC - but we have no AHJ) and the forums. Looking for advice/confirmation on a few things:

1. Abandoned under slab drain lines - not sure if these are considered "dead ends." There were 3 or 4 exterior cleanouts from the old tub, shower and double lavs - do I need to keep these or can I cut and cap? The old WC location is capped, not much I can do about that section, short of busting out a lot of concrete.
2. There was no cleanout at the base of the soil stack to the old 2nd floor bathroom... I'm moving the stack and assuming I need to add a cleanout? I'll be adding up to (2) 45s depending on where it makes the most sense to turn it up. There is an exterior double cleanout at the sewer/building connection.
3. Cleanouts at 2nd floor? I've seen comments that none are required, but don't find any exceptions in the code.

Thanks - I appreciate everyone's help!
Michael

 

[Tuttles Revenge]

You can cut and cap drains no problem. Caps have to be permanent tho.. no rubber jim cap or screw in expansion plugs. If the cleanouts are serving drains that are in use, then they need to stay. But if the line is abandoned then they can be removed.

I would add the cleanout on the moved stack.

Per the UPC.. IPC could be different, but i dont know.. others here are experts in that code.
Cleanouts are only required on the lowest floor of your home...

 

[Sponsor]

 

[Mikha'el]

Per the UPC.. IPC could be different, but i dont know.. others here are experts in that code.
Cleanouts are only required on the lowest floor of your home...

Thanks for reply!

The part I'm stuck on is "horizontal drainage pipe" (2018 IPC) which would imply ANY horizontal section, right?

...and the IPC doesn't appear to have the UPC exceptions:

That said, the house was built in 1989, I'm guessing it was UPC in those days.
And I won't be doing anything non-UPC in the rest of the system anyway.

 

[Tuttles Revenge]

All that get super confusing. I'm just not familiar with other codes. Theres lots of other guys here who are tho.

 

[Jeff H Young]

my code upc calls for end of line clean outs or any horizontal over 5 foot long. so if that stack for the second floor fits that criteria I would install one. also convienient for testing .
no additional cleanouts needed upstairs

 

[Mikha'el]

my code upc calls for end of line clean outs or any horizontal over 5 foot long. so if that stack for the second floor fits that criteria I would install one. also convienient for testing .
no additional cleanouts needed upstairs

Thanks - I have a convenient spot for a 2nd floor end-of-line in a utility room.

 

[Jeff H Young]

perfect !

 

[wwhitney]

The part I'm stuck on is "horizontal drainage pipe" (2018 IPC) which would imply ANY horizontal section, right?

...and the IPC doesn't appear to have the UPC exceptions:

But note that the UPC language refers to the aggregate change of direction, while the IPC language refers to the change of direction at an individual fitting. Seems like the IPC language basically means "don't use a horizontal long turn 90, unless you want to add a cleanout." But I guess two 45s with a non-trivial pipe segment between them would be OK without a cleanout?

Cheers, Wayne

 

[Jeff H Young]

But note that the UPC language refers to the aggregate change of direction, while the IPC language refers to the change of direction at an individual fitting. Seems like the IPC language basically means "don't use a horizontal long turn 90, unless you want to add a cleanout." But I guess two 45s with a non-trivial pipe segment between them would be OK without a cleanout?

Cheers, Wayne

The way I understand UPC is horizontal changes of direction require the clean out but verticaly offsetting does not count

 

[wwhitney]

Agreed, as it says "aggregate horizontal change".

Now suppose you do 90 degrees of horizontal change, and drop vertically a bit, and then do another 90 degrees of horizontal change. Is the "aggregate horizontal change" 180 degrees, or is each horizontal segment counted separately? : - )

Cheers, Wayne

 

[Jeff H Young]

I would see that as 180 degrees Wayne. I've had issues with inspectors trying to tell me I needed cleanouts because typical in a home here we are only 2 foot or 3 foot deep when running to the sewer lateral by the street could be 6 or 8 foot deep so pretty typical diving down with 45 degree fittings which wont count toward the 135 degree max.

 

[Mikha'el]

Happy New Year everyone!

I've drawn up a preliminary schematic - would appreciate any feedback.

(There'll be another lav, shower, washer, and kitchen sink on the ground level, but they will tie in elsewhere.)

Thanks again,
Michael

 

[wwhitney]

IPC or UPC? IPC does not allow vents to turn horizontal below the altitude 6" above the flood rim of the fixture served.

Also, looks like in various places you have flat dry vent takeoffs, the dry vent takeoff has to be above the centerline of a horizontal drain.

No particular need for a 4" vent through the roof, although if you're in a freezing climate, you are allowed to expand the vent size at the roof.

How about a floor plan showing the fixtures, which way the joists runs and their size, and where you can put the vertical drain(s) to the lower level?

Cheers, Wayne

 

[Mikha'el]

IPC or UPC? IPC does not allow vents to turn horizontal below the altitude 6" above the flood rim of the fixture served.

I'm going with UPC, assuming it is generally the more stringent code, and the original system was probably under UPC? We're in no-man's land, no county/city inspection.

Are you referring to the shower on the left?
Sorry, I didn't bother trying to draw the fittings exactly.
I was thinking about a wye with a 90 on top, but it could/should? be a rolled horizontal wye off the trap arm before it drops into the stack.

Also, looks like in various places you have flat dry vent takeoffs, the dry vent takeoff has to be above the centerline of a horizontal drain.

Didn't bother drawing it exactly, the vent takeoffs will be rolled up.

No particular need for a 4" vent through the roof, although if you're in a freezing climate, you are allowed to expand the vent size at the roof.

Don't know if they ran 3" or 4" in from the exterior cleanout, assumed the worst, and I'd like to keep it down to one roof vent - for aesthetics and maintenance purposes. The old system had 'em sprouting all over the place.

How about a floor plan showing the fixtures, which way the joists runs and their size, and where you can put the vertical drain(s) to the lower level?

I'll see if I can mark up this pdf for you.
-Joists are 14" I-joists (new) and wood web joists (old) running away from the viewer (SW to NE in plan view).
-The main stack is running up a furred-out 5'+ section of the old bathroom wall - the 2nd floor bathrooms are over I-joists.
-I'm running the stack vent offset through the web joists.
-There are other options, but this layout appears to provide the best access with minimum slab cutting.

 

[wwhitney]

Under the UPC, the total size of the roof vents has to be at least the minimum size building drain allowed. And a 3" building drain is adequate for up to 3 toilets, plus most anything else you'd typically find in a single family residence. So if you have 3 or fewer toilets (as it appears), then your roof vent only has to be 3", even if your building drain is 4". But if you prefer 4", that's fine.

A few more comments:

- for the shower/WC on the upper left, the UPC will allow the vent to go horizontal like that. Would be nicer to take of the vent under the wall so it can rise directly. [But the vent needs to be 2", minimum required by UPC for a WC.]

- ditto for the roman tub, assuming that the vent takeoff is rolled up so the horizontal vent ends up higher than the tub drain. [1-1/2" vent OK]

- that place where it looks like 5 lines are meeting at a point, by the other WC, I assume the horizontal (on the page) 3" line is not connected to the other 3 line segments. Then I think the WC wet venting is not quite right. The UPC limits horizontal wet venting to a single bathroom group, meaning up to 2 lavs, etc. So the shower is properly wet vented by the nearby double lav. But the WC connects to a branch with 4 lavs on it already. You need to connect the WC to a branch with only 2 lavs on it to have the WC wet vented by the lavs, and bring in the other 2 lavs downstream of that connection. And then the vent for that double lav has to be 2", since it's venting a WC.

- that 3" horizontal vent can be omitted, then you'll have (2) 2" vertical vents (one for each WC), and (1) 1-1/2" vertical vent, which can combine in the attic to a single 3" roof penetration.

- Under the UPC, the downstairs WC needs a 2" vent that rises up to join one of the upstairs vent at least 6" above the upstairs fixture flood rims for the fixture vented. The washer and kitchen sink will need 1-1/2" vents, as will the shower/lav. [The WC, shower and lav can be a single vent if properly wet vented.]

Cheers, Wayne

 

[Mikha'el]

2nd floor layout attached.

Still reading your comments...

I was under the impression that a WC doesn't need a vent if it's within (xx") of the stack?

 

[wwhitney]

I was under the impression that a WC doesn't need a vent if it's within (xx") of the stack?

I'm aware of no such allowances.

I assume the red band on your floor plan is a wall below? Can the main stack below be moved left or right within that wall (say, to the left edge of the shower), or does it have to be where it's shown?

Cheers, Wayne

 

[wwhitney]

OK, here's an option for you.

I'm pretty happy with it, except that wet venting the shower in the lower left seems hard or impossible to do in a reasonable manner, so I'm showing a dry vent for it (the circle). That could be a san-tee with a drop in drain elevation before the drain turns horizontal again, or it could be a horizontal take off (in which case it wouldn't be right at the corner). It could also be in a different wall of the shower.

If the drain down to floor below can be moved, or if there's enough height in your unusually tall floor system to have the two different wet vents at two different elevations so that the horizontal drains can cross each other, I could probably figure out a way to wet vent that shower.

Some notes:

- Green is 2" ; Purple is 3"
- The UPC requires that when wet venting a WC, the WC is the last fixture in the wet vent.
- The short segment right at each shower or tub drain just represents the u-bend of the trap (likely not to scale).
- UPC trap arms are limited to 42" for 1-1/2", 60" for 2", and 6' for a WC. So I drew the tub trap and trap arm as 2" because I think you'll need the 60". you'll have to check the length. If it's too long, you can swap the tub drain to the other end, or move the double lav san-tee up the page a bit, or add a 45 degree segment from the double lav san-tee up and to the left before that drain turns to go straight left.
- Each double lav gets a 2" vent; the shower gets a 1-1/2 vent. The area marked utility chase (which marking I cut off) can be used to bring vent(s) from downstairs up to the attic to combine with the 3 vents originating upstairs. Or you can just stick those vent(s) in convenient walls, since you shouldn't need to bring more than a 2" vent up from downstairs.

Cheers, Wayne

 

[Mikha'el]

OK, here's an option for you.

Thanks - that looks much tidier than my attempt.

If the drain down to floor below can be moved, or if there's enough height in your unusually tall floor system to have the two different wet vents at two different elevations so that the horizontal drains can cross each other, I could probably figure out a way to wet vent that shower.

The drain can go pretty much anywhere along that furr-out, and there's basically 11" vertical clear space in the joists. Will have to sort that out with the ground level toilet & vent location below.

The shower vent could go to the opposite wall, and there's an unused vent (from abandoned lav below) in the exterior wall that I could re-purpose

 

[wwhitney]

If you want to try wet venting the lower left shower, you could try something like this (sorry the purple doesn't show up on the red well, you may need to zoom in). But it's a bit awkward.

If you decide you're under the IPC, wet venting is easier. The toilet doesn't have to be last, so that eliminates the awkwardness for the lower left shower. And a wet vent can be for up to 2 bathroom groups at once, so for example you can put the upper (on the page) shower on the drain line with the lower (on the page) double lav, which is closer. And the trap arm limits are 6' for 1-1/2"and 8' for 2", which helps with the tub. Although achieving those limits requires a perfect slope of exactly 1/4" per foot, so it's better to leave yourself some leeway.

Cheers, Wayne