How do you calculate the flood level of a toilet?

[santhony7]

I know that vents need to be 6" above flood level rim before they can be horizontal but what is the flood level rim of a toilet since the P-trap is in the toilet? Sorry if it is a dumb question.

 

[Terry]

Flood level is the top of the bowl. However, inspectors look at all the plumbing nearby and often want it six inches above the highest fixture, not the lowest fixture. For that reason, plumbers will run their horizontal vents at 42" which is six inches higher than a 36" counter.

 

[Sponsor]

 

[hj]

42", OR 6" aboe the flood/overflow level WHICHEVER IS HIGHER, is the code "standard" in most cases to cover the possibility that a 36" kitchen sink would be connected to the line.

 

[Cjlambert]

Sorry if it is a dumb question.

No problem. Generally we use a tape measure to “calculate” a fixture’s FLR.

 

[hj]

Or just look at it.