New double vanity sink into toilet vent

[mbauer]

I'm wanting to reclaim a toilet drain in a master bath for a new vanity sink. I will be capping the toilet drain line under the slab and using it solely for the vanity sink. Does the attached plan look acceptable? That is 1 1/2" PVC leading to the 2" stack. Is there anything that I need to do from a code perspective as far as heights and lengths are concerned? I was going to build a partition wall so i don't have to cut any existing framing.

Thanks!

 

[Terry]

Two lavs require 2" pipe which then can split down to 1.5" for each lav.
Lately around here we have been used a 2" fixture fitting bushed down to 1.5" on three sides. Horizontal bends are long turn 90's, vertical to horizontal is a long turn 90 also. At some point you may need to snake those drains, so keep that in mind.

Normally wet venting with a 2" line works as long as the fittings in the ground and walls are correct.

 

[Sponsor]

 

[mbauer]

Thanks Terry!

I was wondering why you called this a wet vent. It that because of the toilet? I have already chipped away the concrete around the toilet flange and capped it off so the only thing on this vent is the new lavatory plumbing.

Is there a minimum height for the drain line running to the main stack from the double fixture fitting?
Is there a maximum length from the double fixture fitting to the main stack? Its about 4'.
I'll put 1/4" slope per foot on all horizontal drain lines.
I was assuming I could just pull the p-trap if I needed to snake the line, but will add the clean-out if suggested.
Should the clean-out be tied in right under the double fixture fitting?

Thanks for the help!

 

[mbauer]

I quickly dry fit this together and used hanger strap to put it in its approximate location. I wanted to make sure I'm on the right track as far as the fittings and general layout. Please excuse the sloppiness. I wasn't going for exact placement yet.

I am going to build a second wall instead of notching the existing framing.

I skipped the cleanout because I wasn't sure where it would be. Any suggestions about the placement?

Thank you for any advice you can give.

 

[Cacher_Chick]

Rough in height for vanity sinks are usually 16-18" above the floor. Turn your dry vent tee so the direction of flow is up, not down.

 

[mbauer]

Thanks for the help on the vanity questions.

Another question but his time for the shower drain. I need to extend this about 15" and I don't want to break up the slab any more to get to the trap. This is two long sweep 90 with an 8" horizontal run. I would cut the riser down to fit. Are there any other options if that doesn't work?

Thanks!
Matt

 

[Cacher_Chick]

Thanks for the help on the vanity questions.

Another question but his time for the shower drain. I need to extend this about 15" and I don't want to break up the slab any more to get to the trap. This is two long sweep 90 with an 8" horizontal run. I would cut the riser down to fit. Are there any other options if that doesn't work?

Thanks!
Matt

I am not clear what you are showing, normally a shower drain will be recessed into the floor. The trap needs to be directly below the drain. The trap arm must be horizontal without any vertical jogs in it between the trap and it's vent.

 

[mbauer]

Yea, sorry its not exactly clear from my picture. I was trying to move the existing drain line forward 15" without digging up the ptrap. I would have cut the vertical line and set that arm down in place below the floor if it was an acceptable solution. It wouldn't have been sitting above the slab.

It sounds like it won't work anyhow since the trap needs to be directly beneath the drain. That is right in a concrete beam so excavating and getting under it and back to turn the ptrap feels overwhelming. The concrete at that point is 10" deep and still going.

Thanks for the reply.

 

[hj]

You can do it that way, but if it ever stops up the plumber is going to say some nasty things about whoever installed it.

 

[mbauer]

You can do it that way, but if it ever stops up the plumber is going to say some nasty things about whoever installed it.

Thanks for the reply. Can you explain why this is an issue? I have read a bit about it and it appears to be a bad idea due to residual hair, grease and soap building up in the horizontal pipe and causing an odor. Does it also make it harder to snake the drain? I'm not trying to be contentious, just curious.

I'm going to rent a demo hammer and see how much deeper this goes and try to properly move the trap. Centering it would allow me to use a prebuilt pan but I'll leave it off center and build my pan around it if its too difficult.

Thanks!

 

[Cacher_Chick]

Thanks for the reply. Can you explain why this is an issue? I have read a bit about it and it appears to be a bad idea due to residual hair, grease and soap building up in the horizontal pipe and causing an odor. Does it also make it harder to snake the drain? I'm not trying to be contentious, just curious.

I'm going to rent a demo hammer and see how much deeper this goes and try to properly move the trap. Centering it would allow me to use a prebuilt pan but I'll leave it off center and build my pan around it if its too difficult.

Thanks!

For all of the reasons you just mentioned it is not a good idea. I don't run into any concrete more than 6" thick, so that would stink. Look at where the vent is vs. where the thinner area of concrete is. It might or might not be easier to cut in a new drain back to the vent.