I am in the process of turning a spare room into a third bathroom. I have fairly straight foward route for getting rid of toilet waste. However, the soil stack/vent that I would like to connect to is about 25ft away. As I understand, there should be 1/4" drop for each horizontal foot distance away from the stack. In this case, to allow adequate drainage, I estimate the drop should be 6 1/2" for that distance.

The toilet would exit via a 90 degree to the straight horizontal waste line and then drop into the soil stack vent with a "Y" - I assume that would be acceptable. The vent at the toilet will necessitate running a pipe up to the roof (inside an internal wall). Can I use a couple of fittings to guide the vent around an upper floor joist (long story) to access the attic, where it will go straight up through the roof. Also, is it better to have the vent exiting nearer the apex of the roof rather than closer to the roof edge - I am situated in a heavy snowfall area. The higher up the roof the vent is, the less loading from accumulated snow.

Any comments would be appreciated - also any advice that might seem necessary.

Thanks in advance for your comments.