I'm a carpenter, not a plumber, but I'll give it a try.
1. Yes, you can vent the sink drain into the shower drain.
2. Usually, they can share the same vent if the vent is within 5 feet of both fixtures.
3. The vent pipes usually would go straight up the wall (behind the fixture). I believe the rule states it has to go vertically for at least 6" above the highest 'rim' level before it can run in a horizontal direction.
1. Yes, you can vent the sink drain into the shower drain.
2. Usually, they can share the same vent if the vent is within 5 feet of both fixtures.
3. The vent pipes usually would go straight up the wall (behind the fixture). I believe the rule states it has to go vertically for at least 6" above the highest 'rim' level before it can run in a horizontal direction.
