Kitchen Sink to Basement Bath Waste & Vent

[wrench187]

hi all,
I'm in the middle of a kitchen remodel and need some guidance to correctly route and connect a first floor kitchen sink (under a window) down to a bathroom group in the basement. The basement group will have a WC, and Shower. The vanity is on an adjacent wall. There is an existing 3" pvc branch waste line.

My question is how can I properly vent the WC, Shower and tie the vent up to the kitchen sink and out to the VTR?

I have attached a prelim diagram of what I'm thinking - and I'd like to get your input.

Thanks in advance.

 

[Mr_David]

you can not connect the vents below floor.
They need to connect 6" above flood rim of all fixtures.

You have to take the vents off the drain at a minimum of 45 degrees from horizontal to also prevent fouling.

Vent will need to be 2" for toilet and all the way to the roof

 

[wrench187]

Thanks so much Mr David! I appreciate the input and heads up!

I've decided to open up the rest of the trench to give me more flexibility and access for the new wye and vent connections. I may have some issues with the new shower trap and vent branch as it will be a 36" x 42" shower (center drain). That puts the drain location slightly to the left and centered on the existing san-tee which someone else put in a while ago before I bought the house.

It's a pretty tight squeeze to get all the waste, trap and venting into - would you have any other suggestions on WV routing?

 

[frodo]

..............

 

[wrench187]

Thanks Frodo - my issue is crossing a 1.5" and 2" pipe in a 2x4 wall. I don't think I'll have enough furring to make the cross. How is this dealt with in a 2x4 wall - where pipes need to cross and remain independent runs?

I guess this brings up the cont. 2" vent to roof - I have exterior 2x4 wall framing. With a 1.5" rim joist, this leaves me exactly 2" to interior face of framing. Is it acceptable to have the vent right at the face of framing (backside of gyp board)?

Routing the vertical waste and vent around the floor joists and top of foundation is going to be tight - i guess that's why they make sweeps

My kitchen sink (left basin) dimension to the vertical waste is around 34" to 36" after san-tee is used.

 

[frodo]

1 .5 and a 1.5 will not cross in a 3.5 wall the 1.5 is the inter diameter the actual outside diameter of a 1.5 pipe is

1 1/2 pvc id is 1.610
od is 1.900

2'' id is 2067
od is 2.375


2 1 1/2'' pipes are more than 3 1/2'' 3.800 to be exact

you need a 2x6 wall if pipes are crossing

 

[frodo]

a little trick i do is drill the rim joist 1/2''

hard to explain in words...

drill down from above thru the 2x4 plate
then go down stairs yo will see that the hols is partial covered by the rim joist
take your drill and drill the rim joist 1/2'' debth, just enough for the pipe to clear

does this make since to you?

 

[wrench187]

Thanks again! You read my mind and yes it does make sense. Since the rim joist is not a true structural member, I agree - I don't see the harm in taking a bit of it our with the drill.

I believe you're saying drill into the rim joist, perpendicular, approx 1/2 deep and just enough height to have the pipe clear.

This have been a great help and I appreciate the input. I'll continue to post as I work through the waste and vent work

 

[frodo]

i use a 2 9/16 self fed bit drill down thru floor

then sideways for fitting to fit happy drilling...watch for nails they are a MF

 

[Zanne]

I'd like to add that it would be a good idea to add metal plates over the spots on the studs where the plumbing will be going through-- especially if it is going in to 2x4s. This way, if anyone tries to nail something in to the stud, it won't hit the pipes. You probably already knew that, but I wanted to mention it just in case.

I can't recall what the plates are called though.

 

[frodo]

I'd like to add that it would be a good idea to add metal plates over the spots on the studs where the plumbing will be going through-- especially if it is going in to 2x4s. This way, if anyone tries to nail something in to the stud, it won't hit the pipes. You probably already knew that, but I wanted to mention it just in case.

I can't recall what the plates are called though.

nail plates

 

[wrench187]

..............

Wondering if this option is an acceptable approach...
Putting the WC vent downstream of the Kitchen waste tie in...
Just thinking out loud here - maybe not acceptable, as the waste from the WC will pull a vacuum on the Kitchen waste line and maybe pull water out of the Kitchen sink trap

 

[frodo]

......................

 

[wrench187]

nail plates

Not sure if I'll have enough depth in the 2x4 wall to add a 2" cleanout - would the cleanout cover / plug stick out beyond the drywall?

I definitely see the benefit of having a clean out for the kitchen sink, but the location is right at an exposed wall (not covered by cabinets or anything)

 

[wrench187]

Frodo - I think I understand what you're saying about the elevation of the WC vent. Basically the WC vent should be coming out of the top or more than 45 degrees to the branch line. This will give me some room to run the vent past the kitchen waste which should tie in with a Wye and approx horizontal

 

[wrench187]

Hi all,
I'm needing clarification on the shower vent and WC vent. If I come off the main branch with a 3x3x2 wye and roll it to 45 deg, I'll still need to run the 2" vent horizontal to get it over to the exterior wall.

I understand the vent cannot run horizontal until it's 6" above the fixture.

How do I get the vent pipes back over the exterior wall if I'm needing to stay under the slab and without going horizontal?

Does anyone have a good example / pic?

Thanks again

 

[wrench187]

Hi all,
Here's where I'm at with things - any comments or punches in the nose would be appreciated.
One thing to note - I'm some what forced to take the kitchen waste and vents up at the locations shown. These are the locations where I need to come up through the first floor to avoid window framing and stairs above.

Thanks!

 

[wrench187]

Made a couple changes:
The san-tee vents for the WC and shower are now Wye's (rolled to 45 deg).
I'm hoping this is the way to go for the DWV group.
It will be a bit tricky getting the vents and waste over to the wall and angled / elevated correctly.

Also attached a two-storey diagram

Any input would be very much appreciated - thank you

 

[wrench187]

This is an ongoing design - with some input from others - I've moved the Kitchen waste and WC vent further downstream so I don't have to loop back around to get into that stud bay

 

[wrench187]

Does anyone know if I can run a 1.5 vent off the kitchen santee and tie into the 2" vent stack?

From the kitchen sink - 1.5" waste
to
2x1.5x1.5 santee
going up with 1.5" vent with a couple 1.5" 90s and tie into the 2" vent stack.

All my waste and vents going to basement are 2"