When you go to replace your shower or tub you may run into an issue trying to correctly align the drain to the plumbing.
Tubs are designed now a days so that the drain exits directly beneath the overflow from the tub. Any drain kit you find online or in store will have the tub drain exits at a right angle toward a “T” that connect to the overflow port and down to the exit sewage plumbing.
If for some reason your sewage plumbing does not exit at this location l, then you may find it necessary to rework the plumbing.
It’s important to have a P trap before exiting to sewage to prevent gasses and catch heavy object underneath.
If your current plumbing exits directly down beneath the tub into the P-Trap then you may find it easiest to find the correct fitting so that your new tub can do the same thing.
The 1-1/2″ Straight Tub Drain Shoe
After searching big box stores and online, I found it pretty hard to find anything out there. This neat little fitting is one of the only ones available that I could find.
Install it, double checking the correct height and put a sanitary T below it and shoots over the the overflow.
Building the plumbing to the overflow can be a bit space restricted at times. I found it necessary to put a 90 and two 45s so that I could jockey around the floor of the tub and house.
Measure twice, calculate by two different methods and take your time. You get one shot before installing a tub on top.
One advantage of having the tub drain exits straight down, (drain shoe to tub) is that in the later event of a clog it’s now real easy to stick something down into the P-Trap. There’s no bends or anything in the way.
Build out the entire thing on the tub before installing it. That way you know the piping is measured correctly for connecting the overflow to the sanitary T. Then the only thing to fine tune is the drain shoe to the T. This needs to be at the precise height for the drain. This can be adjusted by tuning the length of pipe between the shoe and T. An access panel can also be used to install and glue the overflow connections from the back.