Increase Height of Sink Drain for Vessel Sink

[Mccallum]

Hey folks, I am installing a Kohler above-counter sink and it is asking for a drain that is 9" below the counter. Now the basement bathroom has the drain set at standard 18" off floor which is too low for this sink. To increase the height of this drain, I would like to use two 22deg elbows along with 1-1/2" ABS pipe while maintaining 1/4" per foot slope. We are only dealing with a ~22" distance between the sink and the standpipe. Trap weir is above the vent opening by ~4", which I thought was not permitted??

Do you cats see anything wrong with this p-trap configuration or do I need to cut the standpipe and raise up the sanitary tee to the proper height?

These pictures are wrong. The trap arm can only have a 2% grade on it.


Your help is greatly appreciated.

 

[Smooky]

You are creating an s-trap with those two 22.5 bends. You would be better off to just have a longer tail piece. Is the pipe that the sink is draining into a drain from fixtures above? If it is you will need a vent or an air admittance valve (AAV). The little drawing at the bottom of your post does not meet the plumbing code either. It is also an s-trap.

 

[Sponsor]

 

[Mccallum]

The vertical pipe above is only for venting...no fixtures drain into it directly.
I am not a big fan of AAVs so I think I might just cut the existing tee out...couple in a short riser 2" pipe with a new sanitary tee and use a fernco coupler above as I do not have any vertical play to glue in both ends.

This way..no s-trap and ace venting. Thoughts?

 

[Smooky]

That looks better.

 

[Mccallum]

Thanks Smooky.

 

[Standardairconditioner]

DIY think rubber couplers are so easy to install, until they do it and realize how immobile and rigid the vertical is.

I love using rubber couplers where they are in basements or open ceilings and homeowners can keep an eye on them as the decades roll by. You are compounding a problem situation by using rubber couplers unnecessarily and closing it up in a wall.

There is no reason for you to disturb that vertical when it is so much easier to just have the trap lower and tailpiece longer. Those parts can be all metal if you are afraid feet will be kicking them.

 

[hj]

WHO says you have to "raise the drain"? You can use it the way it is and just use a longer tailpiece to reach the lower trap.
Standard a/c. for your information "rubber couplings", i.e., "Fernco couplings", are NOT approved for use inside a building.

 

[RAckerson]

WHO says you have to "raise the drain"? You can use it the way it is and just use a longer tailpiece to reach the lower trap.
Standard a/c. for your information "rubber couplings", i.e., "Fernco couplings", are NOT approved for use inside a building.

Couldn’t you “raise the drain” but then, once inside the wall, simply turn 90 degrees down and reconnect with original drain line that’s vented and already plumbed at the proper slope? Or is that considered to be an s-pipe?

 

[Reach4]

1. You are responding to a 2016 post.
2. After a p-trap, the output must stay horiziontal (with the 1/4 inch per foot slope) until it has been vented. Only then you can turn down.

 

[RAckerson]

1. You are responding to a 2016 post.
2. After a p-trap, the output must stay horiziontal (with the 1/4 inch per foot slope) until it has been vented. Only then you can turn down.

Thanks for your response. Beginning to regret our choice to go with a Kohler vanity in our remodel of a half-bath. Kohler specs require I raise my old drain about 6 inches to accommodate their fancy design. I had no idea I’d run into this issue. Buyer beware.

 

[Reach4]

Same or worse with Ikea. Yes, vanities with drawers and shelves may call for modifications of vanity or plumbing.

 

[Tuttles Revenge]

Thanks for your response. Beginning to regret our choice to go with a Kohler vanity in our remodel of a half-bath. Kohler specs require I raise my old drain about 6 inches to accommodate their fancy design. I had no idea I’d run into this issue. Buyer beware.

Provide some more info and perhaps we can come up with a solution. There are more than one way to skin a cat.

Model of Vanity and current drain dimensions would help. Maybe some photos if its difficult to describe.

Modification can occur in the wall or in the cabinet or even to the cabinet. This is the joy and challenge of remodeling and why hiring designers and professionals with experience may increase some cost, but ultimately save time and frustration.