Drain vent question

[Spanky]

What are the general rules for vents? Can they run horizontally, as in going from one side of a room to the other? If so, can the exit the building vertically near the roof line? The kitchen sink in my house has no vent. In order to hook into the existing 4" vent for the rest of the house, I'd have to put the vent below the trap level in the basement(which I think is bad) and travel horizontally to the other side of the room in the basement to hook into the existing vent. Is this possible? I'm kinda a wits end, because I know to do it right means gutting the kitchen wall and the wall on the second floor as well. Any ideas???
Thanks

[DUNBAR PLUMBER]

When you vent a fixture according to code, it must be 42" above the fixture it serves before turning in a horizontal direction. Once it is past this measurement, you can turn any direction, just as long as it does not dip, and has a gradual rise to the vent stack or VTR.


Anything greater than a 45 degree turn in direction under 42" is considered flat-venting, which is considered against code in most areas. :o

[Spanky]

Direct translation....I get to try fishing a vent through the studs near the sink, then rip off the covering and insulation after the unsuccessful attempt. :( Thanks Dunbar