Yes or the rush of water in the 3 inch line from the bathroom upstairs would siphon out the floor drain trap.
Do floor drains have to be vented.
A floor drain installed with a trap and then the drain is piped immediately back down to a horizontal sanitary main which is entirely below the bottom of the floor drain with no vent plumbing zone professional plumbers forum.
This is best implemented if a fixture rests close to the stack and the top floor of your home allowing the stack to serve as a vent.
If you have to make plumbing repairs around your home it helps to understand your drain waste vent system dwv.
You can usually find these on back to back sinks the loop vent is a solution for many freestanding.
The fat pipes in your house make up the dwv carrying wastewater to a city sewer line or your private sewer treatment facility called a septic tank and field.
You probably want to use a common vent.
To keep the loop vent dry that is so that the vent can work without flooding the loop vent has to connect at the top of the fixture s vertical drain line and the horizontal portion of the revent pipe must be at least 6 inches above the flood rim of the sink or other plumbing fixture being vented.
Diy network explains the different types of drains traps and vents and how they work in a typical house.
This allows both drain lines to tie together in a sanitary cross.
Evergrump shutterstock sewer odor without getting too far into building science a general plumbing rule of thumb is that every drain needs a trap and every trap needs a vent.