[hoye0017]

Where are you guys seeing the “fail” when using redgard? And can you describe the “failure”?

I can imagine it failing as a complete waterproofing solution in a custom shower pan, but look at the OP’s application.

It’s just vertical cement board walls over a prefab base. What’s gonna fail there? The only thing I can imagine is if the board is set right on the base and it wicks water up. And even then, that’s not the redgard’s fault.

OP, I agree you’re overthinking it. In that application, redgard is overkill, but I do the same thing in my showers. It’s an extra layer of insurance, but even without it, you could expect bone dry walls as long as you tile and grout properly.