Feedback on DWV redesign (double vanity and washer) - code compliance

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Mikieboyblue

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How’s your tub and toilet vented ? Through that same 3” ?

If so it would’ve never passed inspection here originally.
Honestly, no clue. That is all under the slab on grade which was built in the 1980s and well before I purchased the property. There is one other vent on the kitchen sink wall and it is possible they are vented there. The waste discharge is to the left of the photo (to street, gravity) and the kitchen sink is on the wall to the right. There is a vent and cleanout almost below that white pex you see extruding from the wall.
 

Twowaxhack

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Honestly, no clue. That is all under the slab on grade which was built in the 1980s and well before I purchased the property. There is one other vent on the kitchen sink wall and it is possible they are vented there. The waste discharge is to the left of the photo (to street, gravity) and the kitchen sink is on the wall to the right. There is a vent and cleanout almost below that white pex you see extruding from the wall.
It’s probably all vented through that one 3” pipe except for the kitchen.
 

Mikieboyblue

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It’s probably all vented through that one 3” pipe except for the kitchen.
This would seem most logical as the kitchen vent is a 2" pipe and that a bathroom group can be wet vented. The old washer location would have resulted in the same which is certainly not code. Nothing I can do (or should be forced to do) to correct this.

Would reventing the washer, right lav, or both hurt at all?

Also, question for all the pros. When you do this type of work (adjusting a DWV), do you pressure testing it all again? To do that I would have to install a clean out in the stack below the first fixture to be able to plug it and back fill.
 

Twowaxhack

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Revent all you want but the fixtures you’re reventing IMO don’t need it.

The tub would need it, you’re going to have a washing machine and two lavs above it.

no, we dont test small additions.
 

Mikieboyblue

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Revent all you want but the fixtures you’re reventing IMO don’t need it.

The tub would need it, you’re going to have a washing machine and two lavs above it.

no, we dont test small additions.
Ok. Yeah, Not much I can change the tub. I'm not about to tear up the slab to that degree. That would probably do more structural harm than anything else. It is entirely possible the tub is vented with the kitchen sink. I guess I'd need to camera scope it to know for sure.
 

Zanne

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To clarify, a street fitting would likely not be against the rules because it maintains pipe size (instead of reducing in size) and fits inside another hub. Now that I think about it, it likely means you can't solvent weld something like a 3/4" pipe inside of a 1" pipe (if following the interpretation of it not being able to reduce in size).

So if you have a 3" street elbow and one end fits inside the hub of another 3" fitting, then it should be fine. At least that's my take on it.
 

Mikieboyblue

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Update: Dry fitted.

Anyone see anything wrong? (Besides the vent stack is not connected.)

I am thinking of a clean out just above the 45s on the washer revent.

20210909_192055.jpg
 

Twowaxhack

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If I put a cleanout, I’d put it on the 3”.

That pvc washer drain is never going to stop up.
 

Mikieboyblue

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If I put a cleanout, I’d put it on the 3”.

That pvc washer drain is never going to stop up.
Yeah, I've been debating that. I could put one just above the top ty. But I need to confirm my kitchen layout to be sure it will not be mid countertop and instead behind the refrigerator. I will be framing a laundry area 45" wide (outside wall to outside wall) from the corner where the box is going to toward the stack. After that is fridge (30") and then cabinets. It may just fit behind the fridge. Otherwise that stack is straight from the roof and at slab grade is a combo wye to the main below.

20210909_143157.jpg
 

Twowaxhack

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I understand, I’m just saying a 3” cleanout may be of some use one day, a cleanout for the washing machine will never be used. You can easily get a cable through that 2” trap anyway from the washer box.
 

Mikieboyblue

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This 1-1/2 Fernco came with a kink in the shear band. I was able to get it on pretty flat. Any concerns here? This is a vertical vent branch. The PVC may not be 100 seated due to tight tolerances, but is pretty darn close.

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