Hi Experts,

I'm adding a new second floor addition to my home. Currently there is no main stack in the home as the existing toilet sits almost right on top of sewer drain. So for the second floor I'm adding a new vertical pipe from first floor up to the second floor. This pipe will not run continuous through the roof due to the floorplan. This pipe is located roughly in the center of the house, just because of how the first floor is laid out. And on the second floor there will be on full bath on the front of the house and one on the back of the house. They will both drain horizontaly toward the new drain pipe at the center of the house. Now comes my question. I've read a lot about not being allowed to have a toilet upstream of anything else. Unfortunately in my design the toilets are the furthest away and have to drain past everything else. Is this a huge problem? Do I just need to provide individual vents for each fixture that is downstream of the toilet? Also, since the toilet won't be draining directly into waste stack/vent, does it need it's own vent? How would I tie the toilet vent into the 3 inch line coming off the toilet.

Thanks