Two inches
Shower drain goes into a trap under shower. Continue piping from trap to drain line.
It may be sitting in the trap which should be located directly below the drain.
Water won't drain from shower. Either trap or shower drain line is clogged.
Yes, but dont forget the pea trap.
No and yes. Amendment (not from a professional plumber!): If you were simply running the sink drain into the shower drain and if there was not a reduction in pipe size, I would think you would be able to do that. I think the reason you need a trap for the sink has to do with code that requires a trap be no more than 24" from the basin to the trap arm. That being said, the pedestal sink in my house does not have a trap until after it drains below the floor.
YES !!!!!!!! Minimum 2" P Trap Yes, and it needs a wye not a tee, and it needs to be vented properly.
It cant have more than 3 feet of length on it
If you reduce the soil connection to 2" and install a trap
see that vent is downstream from trap
You can use the existing floor drain lines most likely you will have to cut the drain line or add to it to line up with the hole in the shower. tubs have drains on one end while most showers have it in the middle. You can buy a 30" by five foot base from Mustee. Nice product, comes in left or right hand drain.
Yes, a shower needs a p-trap. If there is no p-trap installed then the sewer gasses have a clear path into your home. Any drain in your home needs a p-trap so there is standing water to block the gasses from floating through your drain and I to your house.Improved answerA trap does NOT have to be always "P" trap There are running traps J traps , LA traps depending on the application .. Showers and bath tub normally have a P trap main sewers and storm drains can have a running trap