Replace bathtub with double vanity

[woolybear]

Hi,
I want to replace a free standing bathtub with a double vanity. I am assuming the bathtub has a p-trap under the concrete floor. Can I put in a p-trap for the wash bowls without causing problems? I thought maybe a AAV vent between the two traps might be ok.

Any other suggestions?

 

[woolybear]

or... perhaps I could use the underfloor trap. Is there a limit to the tail pipe length (drop) before the p-trap?

Hoping for help.

 

[johnjh2o]

You can't use the tub trap it would be too far below the new sinks. There should be a vent for the tub that you may be able to use for the sinks.

 

[phishfood]

But then the old tub trap would have to be permanently capped off, or removed and capped off.

 

[phishfood]

Also, yes, there is a 24" maximum vertical drop from the fixture to the inlet of the trap.

 

[woolybear]

You can't use the tub trap it would be too far below the new sinks. There should be a vent for the tub that you may be able to use for the sinks.

Thanks John
I can't locate a vent for the tub. The floor is concrete and the walls double brick. Was hoping for a solution without digging up the floor.

 

[woolybear]

Is the idea of an aav between the traps a none starter? Figured it would alleviate any siphon effects.

 

[phishfood]

Code specifically prohibits a double trapped fixture.

 

[woolybear]

Thanks phishfood. I guess it's going to be a more difficult job than I'd hoped.