Every bathroom remodel gets judged on the tile. But the work that decides whether that shower is still sound a decade from now happens before a single tile is set — and you'll never see it once the job is done.
Tile and grout are not waterproof. Grout is porous, and water passes through it steadily. That's fine, because it was never supposed to be the barrier. The waterproofing behind the tile is the barrier, and when it's done wrong or skipped, water goes into the wall cavity instead of down the drain.
A shower built correctly starts with the right backer — cement board or a foam board system, never standard drywall or greenboard in a wet area. Then a waterproofing membrane goes over it, either a liquid-applied coating rolled on in proper coats or a sheet membrane bonded to the board, with every seam, corner, and penetration sealed.
The shower pan matters just as much. It needs correct slope to the drain across the entire floor — not just near the drain — and the pan liner or bonded pan has to tie into the wall waterproofing so there's no gap where the two meet. Corners and the curb are where cheap jobs fail first.
How do you know if it was done right? Ask before the work starts. A contractor who takes waterproofing seriously will tell you exactly what system they use and will have no problem showing you the shower after the membrane goes on and before the tile covers it. If someone can't answer that question clearly, that's your answer.
M&J Demolition and Remodeling builds bathrooms across Pasadena, Deer Park, La Porte, and Greater Houston — waterproofed properly, every time. Call (832) 691-1171 for a free written estimate.