2 toilets 1 soil pipe

[PoorDYIer]

Hi
Please help
I am adding en-suite next to main bathroom. Please see attached picture. So the plan is to have 2 toilets next to each other separated by a stud wall.
Soil pipe would start in the main bathroom and go through the en-suite where second toilet would entry and then it would connect to outside soil stack that is vented above the roof. Distance from further toilet to the soil stack is about 2.5m.
Would I have any problems with it ? i.e. flushing would pull water from the other toilet ? Do I have to add AAC at some point in this case ?

Thank you

 

[denso13]

That should be fine to a vented stack.

 

[PoorDYIer]

Thank you for a quick answer.
So when would a vacuum effect apply in such situation ? if it would be further away from the soil stack ?

 

[denso13]

Yes, distance, fall and pipe diameter. 110mm pipes don't tend to suffer the same problem as smaller pipes.

 

[Madrab]

A flushing toilet wouldn't completely fill a 110mm soil pipe, only when the flow fills a pipe does syphoning become an issue.