Sethamin
New Member
I am replacing a storm line running to a roof drain, and it currently has no trap and connects directly to my main sewer line (combined sewer and storm lines are very common in my area). As long as I'm replacing it, I figure that I should do it properly and add a trap to it. How soon can the vent from this trap go horizontal? I assume that the "6 inches above flood rim fixture" standard doesn't apply here, since the "fixture" in question is presumably the roof, and if you were 6 inches above it, you'd already be vented.
I'm specifically thinking of having the roof drain drop directly into a trap, then having the vent rise briefly and then jog horizontally to meet up with the main vent.
I'm specifically thinking of having the roof drain drop directly into a trap, then having the vent rise briefly and then jog horizontally to meet up with the main vent.