Double Vanity Problems

[HereInOhio]

I am replacing a double vanity in my bathroom but from my limited knowledge a few things were installed improperly. I'm looking for professional opinions of what is the best easy recourse.

Above is the picture of when I opened the wall. The problems that I see are the drains will create "S" traps and that the vertical to horizontal transitions are not long sweeps.

Looking through the forum I think to fix the S traps I could:
1) Run vents back to the vent pipe running vertically @ 42" high and stub the sinks out with sanitary tees. The issue is that is a load bearing wall so I'm worried too much is taken out already.

2) Run sanitary cross (not WYE as to not impede the vent) and just run new pipes to the sink at the correct height (18") like I have in the picture with the black pipe above? I will again have to drill through the load bearing wall.

Is this a major concern and is one of these ways preferred over the other or is there another (better) option? I thought of running the vent pipe straight up to avoid going through the studs but I really don't want to open up the upper half of the wall.

Regarding the short sweep 90's at the bottom for the sink drains I thought should be long sweep since they are transitioning from vertical to horizontal. I did see an exception for pipes that are under 2" this is allowed. This would be a lot easier if they left me some "meat" on the lowest 90 but I would have to open up access in the basement ceiling to get to this.

Thanks!

 

[wwhitney]

I'm not a professional, but here's my opinion. : - )

Bottom plates are basically non-structural, so if the bottom most 90 is currently above the plate, you could cut out the plate at the edge of the adjacent stud to get access to the pipe. That would let you cut out the entire mess and start off at the remaining drain stub up with a solvent weld coupling. Looks like the subfloor there needs a repair to properly support the stud that is to the right of the double san-tee. Once the subfloor is repaired you can piece in a short segment of bottom plate just for drywall backing (maybe use some adhesive against the backside of the drywall on the other side.)

Since the studs are already drilled, I'd suggest a san-tee for the righthand lav in the stud bay with the 3" stack, with a drain using the existing holes and a vent run over through new holes, at least 6" above the flood rim level of the sink. [Or since you are under the IPC, you could use an AAV under the sink if you really don't want to drill new holes.] Then for the left hand sink, just put in a san-tee at the correct elevation on the stack, and have a short horizontal trap arm segment in the wall.

I'm assuming that everything I see is 1-1/2", other than the 3" stack. Also, with two lavs draining into a 1-1/2" drain, that drain should not be wet venting anything downstream; a wet vent carrying 2 DFUs needs to be 2" under the IPC.

Cheers, Wayne

 

[Sponsor]

 

[Reach4]

Since the studs are already drilled, I'd suggest a san-tee for the righthand lav in the stud bay with the 3" stack, with a drain using the existing holes and a vent run over through new holes, at least 6" above the flood rim level of the sink. [Or since you are under the IPC, you could use an AAV under the sink if you really don't want to drill new holes.] Then for the left hand sink, just put in a san-tee at the correct elevation on the stack, and have a short horizontal trap arm segment in the wall.

How about two santees-- at the positions of the two existing upper bends. This would be an alternative to trying to put a santee in line with the existing vent pipe.

Then two new vents feeding the two santees. The new vents would join the existing vent pipe near the top of the photo. 1.25 pvc would be big enough for IPC, and that would let the new holes be smaller. The existing vent into the cross would be redundant. Maybe add a cleanout above the cross, since that cross and below would not be able to be rodded otherwise.

 

[HereInOhio]

I'm not a professional, but here's my opinion. : - )
Cheers, Wayne

Thanks for the reply. I did notice the bottom plate missing the section. The bit to the left with the pipe running through is actually resting on a joist on it's right edge so I really don't want to notch it. I'm fine going into the basement ceiling IF the short sweep is not acceptable and I need to. Really don't want to notch it with that small segment carrying some of the load of the joist in the middle.

It is 1 1/2" and only those two sinks, the pipe coming from the top is strictly a vent. I believe once it goes below the subfloor it ties into a 2" drain.

I don't believe the city allows AAV's. If the "s" trap will create a problem in your opinions I will have to figure out how to properly vent it. The wall already has holes of that diameter going through it so more a few feet up should be roughly the same I would think. I could sister the lower sections as well. I'm not completely opposed to drilling new holes if there's not another method.

Is the picture with the black pipe above sufficient? There's another application I have going on where that would be ideal so I'm curious.

Thanks again.

 

[HereInOhio]

How about two santees-- at the positions of the two existing upper bends. This would be an alternative to trying to put a santee in line with the existing vent pipe.

Then two new vents feeding the two santees. The new vents would join the existing vent pipe near the top of the photo. 1.25 pvc would be big enough for IPC, and that would let the new holes be smaller. The existing vent into the cross would be redundant. Maybe add a cleanout above the cross, since that cross and below would not be able to be rodded otherwise.

I think we're saying the same thing as what I explained in #1 but I like your idea with the 1 1/4". The drain to the left I can still use 1 1/2" since it's in the same bay and open but the one on the right that would save some stud.

Thanks

 

[wwhitney]

I did notice the bottom plate missing the section. The bit to the left with the pipe running through is actually resting on a joist on it's right edge so I really don't want to notch it.

A medium turn (quarter bend) is fine for a drain going from horizontal to vertical, so if you don't need to deal with that elbow, it can stay in (assuming the spray foam all over all the fittings doesn't mean that all the connections leak). However, the hole in the subfloor and/or bottom plate does need to be filled, it's a fireblocking requirement that the joist bay not communicate with the stud bay.

If you need to deal with that elbow and are concerned about bottom plate continuity, you could cut the bottom plate back on each side of the current gap to the middle of the next joist, then patch the subfloor, then piece in a segment of bottom plate. If you're concerned about the two studs that would be temporarily floating during your repair, you can screw a 5' length of 2x6 or 2x8 or piece of plywood across 4 studs temporarily. But if the wall's not load bearing, I wouldn't be worried about that.

If the "s" trap will create a problem in your opinions I will have to figure out how to properly vent it.

Existing is definitely not OK. If the 90 below the double san-tee is not a LT90, that needs changing. Reach4's suggestion is otherwise fine, but I would think that since you have to cut into the 1-1/2" stack anyway, it's as easy to cut in one san-tee high and one san-tee low as it is to cut in a double san-tee high. [Edit: OK, you'd have to cut out the double san-tee, so it would be a bit more complicated. Still 2 rubber couplings either way (unless you can easily lift your upper vent segment 2".)]

Is the picture with the black pipe above sufficient? There's another application I have going on where that would be ideal so I'm curious.

Yes, that's good. Note the drain below the double fixture fitting (?) is 2", so that means it can be used for horizontal wet venting, if desired. If it is a drain only, it could be 1-1/2" under the IPC.

Cheers, Wayne

 

[Reach4]

So represented new santees as with red outputs with trap adapters.
B and G represents the short 90 bends which we wish were long. Congested down there at C. But at K, maybe you could put in a better fitting, but how do you get thru the hole at C to serve the right santee?

So how about adding a cleanout at D, which lets you rod B if it clogs.

E is alternate place for left santee.

Now maybe cutting out a lot more stuff works to drain the right santee, and let you get rid of that B and C area. That would be the better solution, which I think Wayne is proposing.

 

[wwhitney]

Right, I'm proposing cut at K and high on the stack, remove everything in between, build back up. LT90 at B, san-tee at C for new drain segment C-G (one of B/C may need to be a street fitting, as they are close to each other). LT90 at G, new san-tee and vent connection as drawn for righthand sink. New san-tee in the D-E area for left hand sink.

Cheers, Wayne

 

[HereInOhio]

I am following what you guys are saying. The left drain needs to stay over to the left where it's at due to drawers in the cabinet now allowing room to stub it out from the B-E pipe. Its stuck in my head that I should just cut through the studs and put a configuration in like the black pipes but you're saying the drain would have to be 2"? I know I'm contradicting myself with cutting through the studs but it seems like I have to anyways, the only difference is a hole for 1 1/4" vs. one for 1 1/2". IF I would need a 2" drain I will probably opt for like you have in the pictures.

Starting at the bottom I will probably connect a Long Sweeps (green) 90 right off A keeping the left drain close to where it is. I would put in a sanitary tee (pink) at the same level as the pipe C-H-I-G and connect to that. I will eliminate the D-E section because it would essentially not be needed and would either 45 the vent to be inline (blue) with the left drain and tie in the vent for the right drain with an upside down sanitary tee or I would use a double elbow to tie them both in at the same level. Would that work?

 

[HereInOhio]

This is what I am thinking would be the easiest if I could get away with a 1 1/2" drain and get over drilling through the studs again. Not sure how I'll get the pipe though the 4 studs that are grouped so close together though.

 

[wwhitney]

The left drain needs to stay over to the left where it's at due to drawers in the cabinet.

You can move left hand sink san-tee to the left if you still have enough left-right room for the long turn 90 at the bottom of the stack to connect to the medium turn 90 that is remaining.

But the sink san-tee doesn't have to face straight out the wall. It can face out at 45 degrees if that clears your drawers, or it can face to the left, with a quarter bend to come out of the wall. So those options would allow you to keep the san-tee in line with the vent pipe above. Same thing is happening at the right hand existing layout, where the 90 is rotated 45 degrees and there's a 45 degree elbow outside the wall framing.

Cheers, Wayne

 

[wwhitney]

Last picture is a no go, the vent for each lav has to stay vertical to a height of at least 6" above the sink flood rim.

Cheers, Wayne

 

[HereInOhio]

Last picture is a no go, the vent for each lav has to stay vertical to a height of at least 6" above the sink flood rim.

Cheers, Wayne

I think my drawing was confusing. The black scribble on both would be pipe I eliminate. The blue line in the last would be the drain. The current vertical vent would serve both fixtures. Would that be acceptable? Pretty much the same layout as the original picture I posted with the black pipe.

 

[wwhitney]

Yeah, that would be fine.

But I'd suggest going with a separate vent takeoff reconnecting higher up. Because with a double san-tee, a cleanout is a good idea, while with separate san-tees you don't need it. Also because it gives you the option to use 1-1/4" for the vent, and so drill smaller holes.

Your choice.

Cheers, Wayne

 

[HereInOhio]

Yeah, that would be fine.

But I'd suggest going with a separate vent takeoff reconnecting higher up. Because with a double san-tee, a cleanout is a good idea, while with separate san-tees you don't need it. Also because it gives you the option to use 1-1/4" for the vent, and so drill smaller holes.

Your choice.

Cheers, Wayne

Makes sense. I was thinking about getting the pipe in there with the way I was wanted and I don’t see that happening. The 1 1/4” should be able to be manipulated enough.
Thanks again for your help.

 

[HereInOhio]

Yeah, that would be fine.

But I'd suggest going with a separate vent takeoff reconnecting higher up. Because with a double san-tee, a cleanout is a good idea, while with separate san-tees you don't need it. Also because it gives you the option to use 1-1/4" for the vent, and so drill smaller holes.

Your choice.

Cheers, Wayne

Quick question. The vanity I have is a double vessel bowl 72” vanity with 2 rows of drawers in the middle. The cabinet is open on each side with a shelf area for towels. The hole for the vessel bowls are in the granite above each of these sections but the holes for the faucet is behind the drawers. I know normally you want your supply lines above the drain.

Is it against code to have the drain higher than 18” or to not have the supply lines directly above the drain and offset?

 

[Reach4]

Is it against code to have the drain higher than 18” or to not have the supply lines directly above the drain and offset?

No, and no.

 

[HereInOhio]

No, and no.

So I am good to plumb it for the vanity any way I desire?

 

[Reach4]

Quick question.

So I am good to plumb it for the vanity any way I desire?

I am sure I could think of many ways you could plumb a vanity, so I would answer, "that's silly". However feel free to conclude that you could wear a straw hat while doing the work.

 

[HereInOhio]

I am sure I could think of many ways you could plumb a vanity, so I would answer, "that's silly". However feel free to conclude that you could wear a straw hat while doing the work.

Sorry I should’ve worded that better. I just wanted to make sure you were saying “no” meaning it is not against code.