Why It Happens
What Causes Bathroom Plumbing Problems
Most bathroom failures reduce to a short list of causes, and naming the right one is what makes the repair stick instead of repeat.
Hair and soap residue are the leading reason bathroom drains slow down. They bind at traps and bends into mats that narrow the passage a little more each week, which is why the symptom creeps instead of arriving.
Worn internal parts cause most toilet and faucet trouble. Flappers harden and warp, fill valves stick, cartridges score — each is a designed wear item, and each fails on roughly the schedule its material allows.
Mineral buildup works on showerheads, aerators, and valve passages in Poquoson's moderately hard water, restricting flow and stiffening controls years before the fixtures themselves wear out.
Failed seals — the wax ring under a toilet, caulk lines around a tub — let water escape where it does quiet damage. In a crawlspace home, that damage heads downward into wood that nobody inspects often enough.
One symptom, several possible causes: a slow shower can be hair at the grate or a restriction shared with the toilet. The visit's first job is telling those apart, because their fixes share nothing but the room.
Renovation changes the calculation in one more way: a bathroom being retiled is a bathroom whose valves, seals, and supply stops are briefly reachable. Work that would cost dearly through finished tile is inexpensive while the room is open, which is why the inspection list during a remodel always includes the plumbing nobody complained about.