I have a 1975 single level home built on a flat slab with NO crawl space. The tub drain has apparently broken and when the tub drains you can hear it hitting the fill dirt below. The walls are tiled.

Unknowingly this has been going on for sometime now and the house has settled on one end w/ cracks in the brick mortar and cracks in the drywall in several rooms. The tub is CLOSED for repairs and I'm trying to determine how best to approach the task... which will likely include calling a contractor or plumber. Would I do best to just remove the old porcelain (?) tub with a sledgehammer and have a plumber install a new one or is there any other angle to approach this?

Thanks in advance from a newbie to the forum.

In my area all our homes are slab homes. You do not have to change tubs. It's not the tub that's at fault. Take and cut a 14 X 14" square back of the tub and simply replace the piece that's leaking. Let me know what you find after you open it up. Goiod luck. Tom

Tom, thanks for the suggestion. What do you mean by "cut a 14 X 14" square back of the tub?" Would I be cutting within the tub itself or just above it where the water faucet is located?

Make your cut next to the floor line. Then you will be able to see what's leaking. We install tub access panels on all our new construction. Regards, Tom

What Tom is saying is to cut the wall out in the room located next to the drain end of the tub. That will expose the plumbing to you and you can inspect and the problem could be assable from the hole that you cut.
Now if your bath back up to each other on a common wall then that is another problem. So tell Tom what the situatiuon is and he will guide you through

Ah ha! There is a bedroom on the other side of the bathroom that I can easily cut through the drywall and do the inspection to determine the problem. Why didn't I think of you guys sooner?!

My schedule won't allow me to make the cut for several weeks... but now I do have a plan. I'll be back later and let you know what I found out.

Thanks again!