Hello, I have an En-suite shower that was leaking from the valve, there was plenty damage to the dry wall behind. I've stop the leak, removed the valve and let it try for months. I think I have educated myself enough to fix the problem by replacing the backer board and tiles. But I'm reluctant to replace the shower tray. I'm pretty sure the tray itself is sound. My question, is it possible to only replace the backer boards and tiles without touching the tray? Thanks in advance.