J
jay
Looking at the pics and reading the problem listed in this thread there seems to be water ingress (rust stains bleeding from grout) causing a leak down stairs . the fix is rip it all out and go again providing the waterproofing is done correct (bringing it down onto the bath) any water ingress (through the grout) cannot travel any further than the bath.The silicone joint more than likely has failed due to movement from the bath or water behind the silicone thus if a waterproofing was used in the beginning then it wouldn't be leaking . the other option is to use epoxy grout to stop water ingress .