I am installing a second kitchen in my basement and have a couple of questions about the vent. I can go up into the attic by making one 6' horizontal run and then straight up through two stories. I am then about 5 or 6 feet away from a horizontal run(sloping the opproprate 1/4 " per ft) that is feeding other plumbing to the main vent out through the roof. This horizontal run is about 8 feet awat from the vertical vent that vents to the outside through the roof. Can I tie into this horizontal vent, or will that be too far away from the main stack? The other possible option is this. I am also about 10 feet away from a different stack vent that I can tie into that starts right in the basement, but I am not sure it was done right to begin with. It runs straight up from the waste drain about 10 feet vertically(with a sink and shower vented into it along the way). It then takes a horizontal run about 20 feet before heading back vertically and out through the roof. The slope on the 20 foot horizontal run follows the 1/4 " per foot code. Is this a proper stack vent with such a long run? If so are either of the above mentioned options feasible for me to vent the new basement kitchen or do I have to run a new vent through the roof? Thanks for any help... I am tired of staring at this trying to figure it out and progress has stopped until I get it solved.