How were tub and toilets normally run in the 80's?

[NavySuit]

I live in Florida, so my house is slab on grade. All of the plumbing in the house is on the south side. I'm assuming they ran the main drain along this side and just tied into it.

I'm debating on whether to switch from a tub to a shower. I know a shower drain is supposed to be 2 inches. I'm willing to break up some concrete, but I do not want too far into it. I've seen some people just replace the trap to a 2 inch and tie into the 1 1/2 drain after that. Are the toilet and tub usually tied together and then ran to a main sewage line for the house and then ran to the city sewage pipe, or do are they usually run separate to the house main sewer? If the tub drain and toilet are sitting right next to each other, how much digging do you think I would have to do to be able to covert the 1 1/2 drain to 2 inch?

 

[James Henry]

Their's no way to know which way the drain goes without pulling the tub. You could hire a locating company that can pinpoint where your drain ties into the main line. they have to have equipment that can sense through the concrete where the end of the camera snake is.

 

[Sponsor]

 

[Terry]

Showers used to be run with 1.5" in the 60's.
I would keep the 1.5" and use a 1.5" trap, and enlarge to 2" for the shower drain above the trap. Unless you're running multiple heads you're fine.

A shower or tub drain either have their own vents before they enter the main line where a toilet would be running past, or they may use a lav vent for that if the wet portion of the lav drain is 2".