Help with Toilet drain rough-in

[Dutch6575]

Hello, I am attempting to install a toilet and join to an existing drain under a concrete slab. Where the existing drain is located, I have limited space to work in a corner of the existing bathroom (In the picture, the lefthand wall is a vanity that will be removed, I will have plenty of space for the toilet after). I have already cut the existing 3" drain and spliced in the combination wye with pipe stubs and fernco fittings.
Is this an acceptable setup to for a toilet drain? Would you recommend a more appropriate setup?
Under each of the fernco fittings, there is an approximate 1/4" gap at the splice. Is this amount of gap between the existing drain and splice acceptable, or should I fabricate a new one? I am a DIY homeowner and any information would be very much appreciated. Thank you.

 

[Jeff H Young]

1/4 inch gap a bit wide but it should be ok Id make it tighter next time you can always cut a bit more off. on above ground fernco use the type with a shielded metal

 

[Sponsor]

 

[Dutch6575]

1/4 inch gap a bit wide but it should be ok Id make it tighter next time you can always cut a bit more off. on above ground fernco use the type with a shielded metal

Ok. Thank you. Does the setup seem ok? Are the fittings appropriate? Too Many turns? Would I expect problems with the amount of bends and type of fittings present?

 

[Reach4]

What is coming into the combo from the right (existing drain)? If only bathroom drainage, fine. If it is non-bathroom waste, it is not fine.

 

[Jeff H Young]

looks to me you coulda used a 45 instead of a 90 but I think it will flush ok . assuming you gave the combi grade and all that good fall

 

[wwhitney]

Are the fittings appropriate?

Without comment on the performance or whether a cleanout would be required, those are the appropriate fittings for the underground path you have selected (I'm assuming that's a LT90 between the combo and the closet bend).

However, as Jeff mentioned, the rubber coupling on the 3" stack above the slab, in the upper left of the picture, is the wrong fitting. That style is only for underground use. The above ground style is about 2" long and has a full metal shield over all the rubber.

Cheers, Wayne

 

[Jeff H Young]

The underground while not ideal is done , its relatively short so a closet auger will get through it. I really dont expect a problem and would not rework it

 

[Serkan]

What is coming into the combo from the right (existing drain)? If only bathroom drainage, fine. If it is non-bathroom waste, it is not fine.

So a kitchen waste can’t be upstream of a toilet drain? Why is that? Only asking to learn.

 

[Reach4]

Toilet must be vented before merging with kitchen waste. A good way to wet vent the toilet is to have a vented lavatory or/and shower drain join the toilet waste before the toilet waste joins the kitchen waste. That is wet venting.

 

[Dutch6575]

Toilet must be vented before merging with kitchen waste. A good way to wet vent the toilet is to have a vented lavatory or/and shower drain join the toilet waste before the toilet waste joins the kitchen waste. That is wet venting.

Thank you very much for the replies. They are greatly appreciated. I will switch the above ground fernco to the appropriate one. Upstream of this (to the right of the existing drain) is a toilet and two showers, then a 3" vertical vent through the roof, then a washing machine. Would this be ok?

 

[Master Plumber Mark]

I just have to ask, is that standpipe the toilet drain coming out of the floor ??

it appears to be hugging a nearby wall.... are you planning on removing that wall
or what am I missing here>>?? Normally most toilets have to be at least a 10 to 12 inch rough
out away from the back wall to fit correctly... you will not be able to even install a flange on what I see

dont worry about the ferncos in the underground
they will work ok....

so what is the plan here??

 

[wwhitney]

it appears to be hugging a nearby wall..

From the OP: "(In the picture, the lefthand wall is a vanity that will be removed, I will have plenty of space for the toilet after)"

Cheers, Wayne

 

[wwhitney]

Upstream of this (to the right of the existing drain) is a toilet and two showers, then a 3" vertical vent through the roof, then a washing machine. Would this be ok?

No, because of the washing machine.

Reroute the washing machine to join the horizontal drain downstream of the WC in the photo in the OP, and then it would be OK, if the upstream bathroom fixtures are properly vented. So how are the upstream WC and (2) showers vented? A single vertical dry vent after all three of those drains join together does not work for venting them.

Cheers, Wayne

 

[Dutch6575]

From the OP: "(In the picture, the lefthand wall is a vanity that will be removed, I will have plenty of space for the toilet after)"

Cheers, Wayne

Correct. The vertical 4" pipe (standpipe?) coming up from the closet bend is very near a lefthand 'wall.' That 'wall' is the side of a vanity, which is to be removed. I have kept the bathroom vanity operable in the interim while I work. The vanity will be removed before toilet installation.
In the background is a vertical vent pipe extending through the roof. It is in the wall to the rear of the future toilet. To the future drywall face of the rear wall, the toilet flange center will be just over 12." Another actual wall of the bathroom is on the righthand side in the picture. It is just over 15" from the future toilet flange center.

 

[Dutch6575]

No, because of the washing machine.

Reroute the washing machine to join the horizontal drain downstream of the WC in the photo in the OP, and then it would be OK, if the upstream bathroom fixtures are properly vented. So how are the upstream WC and (2) showers vented? A single vertical dry vent after all three of those drains join together does not work for venting them.

Cheers, Wayne

Ok, thank you. I am learning a great deal.

I forgot about it, and failed to mention a 2" vent through the roof at the washing machine. The washing machine is about 8' upstream from the where I am working. Would this make a difference?

(downstream- 2" vent - current WC drain work - 2 showers and WC - 3"vent - Washing machine/2"vent -upstream)

The upstream WC and 2 showers are vented with a single vent just downstream of where I am working. The 3" vertical vent extending through the roof is just upstream and very near them.

 

[wwhitney]

Sorry, not following the upstream/downstream description. How about a floor plan showing all the horizontal drains and their connectivity? Vertical pipes (like vents) get portrayed as circles (their cross section), horizontal pipes as lines. Both bathrooms and the washing machine.

Cheers, Wayne

 

[Dutch6575]

Sorry, not following the upstream/downstream description. How about a floor plan showing all the horizontal drains and their connectivity? Vertical pipes (like vents) get portrayed as circles (their cross section), horizontal pipes as lines. Both bathrooms and the washing machine.

Cheers, Wayne

Ok. I will get one drawn up.

 

[Master Plumber Mark]

a washing machine dropping into a 3 inch drain will not have any affect on siphoning the toilet
because the washing machine hose is 1 1/4 in diameter and it cannot totally fill a 3 inch drain with water to
the point it will siphion anything... Also if you have a a bunch of vents its not gonna be an issue
because they are vents and they are venting everything...

 

[Dutch6575]

a washing machine dropping into a 3 inch drain will not have any affect on siphoning the toilet
because the washing machine hose is 1 1/4 in diameter and it cannot totally fill a 3 inch drain with water to
the point it will siphion anything... Also if you have a a bunch of vents its not gonna be an issue
because they are vents and they are venting everything...

Ok. Thank you.
From a learning perspective: While I recognize that splicing a drain with Fernco type fittings is an acceptable way to go, if the cuts are not perfect how does the interruption in a smooth pipe interior not grab toilet paper, etc. and cause a clog?

 

[Jeff H Young]

I just have to ask, is that standpipe the toilet drain coming out of the floor ??

it appears to be hugging a nearby wall.... are you planning on removing that wall
or what am I missing here>>?? Normally most toilets have to be at least a 10 to 12 inch rough
out away from the back wall to fit correctly... you will not be able to even install a flange on what I see

dont worry about the ferncos in the underground
they will work ok....

so what is the plan here??

I think Dutch 6575 had another thread and told me the walls were moving As I told him a toilet wont fit the space shown in picture