Please pull a
Seattle plumbing permit and have an inspector look at this.
(1) I am going to remove the double T-Y and replace with 2 single Ys.
It's better to use separate Wye's on the horizontal, then you can "tip" them for the needed grade.
A double wye on the side never works, they need to be on the vertical.
(2) Add one P-Trap for the drain and one for the shower
And each will need to be vented to prevent siphoning.
These vents can tie together six inches above the highest flood level of the fixtures being used. If the lav counter is 32", then it would be 38" before the could connect together.
(3) Install a section for two no hub couplings and a clean out T with a meter box for easy access. I cannot connect to the out pipe (the one that goes to the sewer out of the house) because the pipe is out of round and will not fit a regular coupling. I did not want to bury these no hub fittings in concrete.
(4) Also, can I modify the main stack and put in two 45s to move the stack over about 7 inches? The modification to the stack would mean that it would no longer be straight vertical. Is this 'ok' if it is two slight 45 degree changes?
You can move the main stack using 45's
I want to finish this myself. It's a good way to learn. The reason I thought that the one P Trap would work for the shower is that I saw a schematic in a book that depicted two sinks using one P Trap, so I thought that the drain and shower would work.
What works for a kitchen sink with two bowls, is not at all like a floor drain and shower.
They each need their own trap, and each trap will need a vent.
All fittings below the flood level will need to be waste fittings.
Please pull a Seattle plumbing permit and have an inspector look at this.
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]Step 1. The “pre-glue†inspection (optional). Install the drain waste and vent system but do not glue the pipes and fittings. Call the inspection request line and make a “pre-glue†inspection request. The inspector will need to see the whole system. If the inspector finds the installation to be code compliant, you can then glue the system together. If there are corrections identified by the inspector, the corrections must be made prior to scheduling further inspections.[/FONT]
[FONT=Arial, Helvetica, Geneva, Swiss, SunSans-Regular]Step 2. Test the plumbing system for leaks. Test the drain, waste and vent systems and the water distribution system. The inspector neither performs nor provides the means for conducting the test of the plumbing system.[/FONT]
[FONT=Arial, Helvetica]To test the drain, waste and vent system, make sure that all pipes and fittings are properly glued. Plug all openings tightly and look the system over carefully to make sure all is ready for the test. Fill the system with water to the roof (or at least 10-feet high for a groundwork) and check the entire system for leaks.[/FONT]