(newbie) does toilet have to enter stack below where sink & shower do?

[graysqwrl]

I have a few more questions, if you don't mind.

1. what is the maximum drop from shower/tub to trap? I believe it's 24", but couldn't remember

2. Do I need to vent the shower, if both the toilet and the sink are vented? It's easy to come up from the sink and tie in, but the shower is going to take a lot of effort if necessary

3. I remember reading that the sink/shower run must enter the stack at a higher point that the toilet? Is this true, or did I just make that up?

4. If it is NOT TRUE, can I place a wye in the horizontal run from closet bend of the toilet to stack and allow my sink/shower/tub to drain into the stack through that arm?

Below is a rough diagram of how the flow of my bathroom is. Toilet, sink, & shower/tub all sit along the same wall.

Vent stack
|
|
Toilet <----- Sink <------------shower/tub
|
|
Main line

Thanks

[Redwood]

It depends on the code used in your area and how it is vented.

Every trap must be vented...

It would be handy to see a diagram of what you have....
Do you have an isometric drawing?

Where are you from so that we might have an idea of the plumbing code used in your area?