(Louisiana) What size pipe Sewer, Drain and fresh water supply lines
I just bought an older house that I plan to gut the kitchen and bathrooms. Long story short but it is a slab house that will have shoring done so underslab drain pipes will all get changed. I plan to get a core drill and drill the holes needed for the new pipe bc I know it is a different size. I did this on my last house and it worked well. So I'm not limited to how many pipes I can put to some extent if it makes the drains work correctly. I dont want to go back with what is there bc its a 50 year old house and they only used one 4 inch cast iron drain to dump two bathrooms into where the one 4 inch pipe is the only one that goes tot he roof to vent. Now I'm in Louisiana and the code is a little different. I will not be filing or getting inspected but I want to stick to code anyway. Lets pretend no plumbing is there now since I will be ripping it all out and starting over. I will be leaving the fixtures in place. I plan to put the new pipes through the roof as a new vent in plastic pipe and leae it stubbed out under the slab so the shoring guys plumber can take off from where I left off.
This is small bathrooms maybe 5' x 12' approx.
Here is what I need to know:
1. First I will start with the drain and sewer lines. I have two bathrooms where the wall that separates them is the wall that has a lot of the plumbing. In bathroom #1 on this wall there is a sink on this wall the line toilet is obviously through the slab but comes back and connects into the plumbing in this wall. The tub in bathroom #1 faces another wall but I'm sure comes back into the same plumbing under the slab.
In bathroom #2 on the wall with all the plumbing it has the sink, toilet and tub all on the same wall.
So If I want to have it drain according to code how should I run this and should the toilet have a different main line then the grey water lines?
2. I have a similar question about running copper pipe for water supply. The main line coming intot he house is 3/4" copper. The rest is galvanized so I'm going to go copper all the way. I know many suggest pex but I want to go copper. IN order to have good pressure and volume how far in should I run 3/4" before reducing to 1/2" at the fixture? Should I reduce to 1/2 and then stick with it or should I run 3/4 most of the way for every fixture and then reduce down to 1/2 within a few feet of the fixture?