I appreciate any help in understanding a little more about this.
1. P-traps, S-traps, it's all good except for the one under the shower drain with a slab foundation. Are you supposed to set a P-trap down below the concrete before you pour the foundation?
2. Very simple question
Sink drains. You have a 1 1/4" drain, goes to P-trap, then on to the main house sewer pipe. How exact do you go from 1 1/4 or 1 1/2" to a 4" pipe, or even a 3" pipe, if you're only, say, 3 feet from the main 4" drainage pipe? Or, how do you get there at all for that matter. Seems so hard to find things that will fit together right. It's either thick or thin walled PVC pipe, or the fittings are made for it, or you need to go from thin-walled to thick-walled pipe and no fittings are made for it. Any help is really appreciated. I just can't find this most basic info anywhere. Thanks.