Can the drain move, or does the shower stay where the tub was?
Every layout question in a bathroom comes back to the drain. A tub drains through a small line at one end; a walk-in shower needs a larger drain, and if you want it centered or in a different corner, that line has to move. In a Tomball house on a slab, moving a drain means cutting and trenching the concrete, which is routine but real work and a permit item. If your older in-town home sits on pier and beam, the plumber can often get to the line from below, which opens up more layout options for less disruption. We confirm which foundation you have at the first visit.
Old drain lines in the houses near the historic downtown are worth a look before any new tile goes over them. Cast iron and galvanized lines from earlier decades corrode from the inside, and a slow drain that has been tolerated for years becomes a problem under a brand-new shower. We scope what we can reach and replace what is failing while the floor is open, since that is the cheapest moment it will ever be. Newer subdivision homes have plastic drain lines and rarely need this, so the plan there is usually just the reroute for the new shower location.










