Using a bottle trap as well as a waterless in line trap

[Oscart]

Just about to start on our new main bathroom and have chosen a wall mounted sink with decorative black bottle trap which heads into the wall. As I have multiple wastes going into one stack pipe I would like to connect the sink waste into the bath waste feed to the stack… I’m worried about siphoning so wondered if I could use a belt and braces approach and install a inline waterless trap downstream of the bottle trap but before the feed connects into the bath waste feed into the stack? It would be buried in the wall

 

[ShaunCorbs]

Install an aav

 

[king of pipes]

Hhmmm that's not a great idea those traps are not designed to be hidden away in a wall especially buried , you will need a rethink on this one post some pics one of us will have a idea kop

 

[Oscart]

I could whack a Avv behind the sink in the stud wall? Or thinking about it I could enter the stack with the 2 sinks higher up the stack pipe than the bath etc? Still achieving the right fall

 

[king of pipes]

I could whack a Avv behind the sink in the stud wall? Or thinking about it I could enter the stack with the 2 sinks higher up the stack pipe than the bath etc? Still achieving the right fall

Sounds like a plan never a good idea combining wastes .