Do It Yourself

I’m trying to coordinate a repair from a far distance - overseas. I am told the shower drain leaks because the fiberglass showerpan flexes (it was likely not bedded properly, installed by amateur house flippers that did not know what they were doing). A plumber came and replaced the drain pipe for a rediculously high cost. Did not fix the problem. They abandoned me.

One option is to remodel.. tear out the showerpan and redo the subfloor which is likely rotton wood (guessing). But I really want to avoid crazy costs. It seems to me like there should be a way to do some perhaps unconventional plumbing. A crawl space is below the shower.

I hate accordian drain pipes. Probably no self-respecting pro plumber would install one. But in the case at hand, it seems like it would solve the moving drain pipe issue.

Another thought, and what I hope someone can advise on: What about a short rigid drain pipe that goes into a rubber gasket-like fitting (e.g. like that in the attached pic), which then goes into a bigger pipe? Wouldn't that tolerate a slight amount of vertical movement as the showerpan flexes?

Fiberglass is a bad choice, no?

If I do bite the bullet and install a new showerpan, fiberglass seems like a bad choice. Why is that still being used? In fact, I think enabled metal showerpans are an older technology, but they seem more robust. I have one in a bathroom which is bedded on air (i.e. just the perimeter of the showerpan is supported). But the thing seems bomb-proof. It will never flex.

Why is plastic and fiberglass used? They require proper bedding, and the bedding can always fail later on. I’ve seen videos were ppl have to later on drill holes in the shower pan to inject expansion foam to add support after support is mysteriously lost. Fuck that. Is it that plastic and fiberglass are not as cold feeling when you first step on them? I cannot think of any other advantage.