I have a shower stall with two slider doors. I had to disassemble the
frame recently. When it was professionally installed a number of years
ago, the vertical frame members were caulked with clear silicone on
both the inside and outside edges. The bottom frame member however was
only caulked on the outside. When disassembled I found a lot of mildew
underneath. I can understand why you would not caulk the inside edge
of the bottom frame because it could block the weep holes, but why not
underneath?