Multi-unit dwelling positive pressure back in water closets no solids

[B Com]

Pardon me I am an electrician. Don't hold it against me please. I've been out of the building trade for a few years retired. I live in a multi unit small building approximately 6 units. We are experiencing back pressure in the toilets like sewer gas. Is that a ventt issue. I seem to remember a calculation for fixture units like 1.5 each in order to size vents. Help me point me in the right direction I know how to run pipe and pull wires through it

 

[Twowaxhack]

If you’re getting positive pressure thats causing issues then you either have a vent issue or a partially clogged line that’s filling up sometimes. Without a vent the air must go some place…..

 

[B Com]

If you’re getting positive pressure thats causing issues then you either have a vent issue or a partially clogged line that’s filling up sometimes. Without a vent the air must go some place…..

Thank you for the input it's the answer I was looking for. Now I'm able to provide some Direction. Landlord is a new owner and first time endeavor. Does not understand necessity for preventive maintenance.

 

[MicEd69]

Does not understand necessity for preventive maintenance.

You didn't say if this 6-unit place is multi-story, but I assume it is. As your new owner doesn't understand preventive maintenance, I sure hope you are on the top floor! LOL.