Shower and tub leak guides

How each part of a shower or tub fails, and what fixing it involves. Pick the guide that matches your timing: a leak with the water off, during a shower, or after the tub drains.

Why the shower head keeps dripping after it's off A steady drip with the handle closed almost always means water is getting past the valve, not a problem with the head itself. Here is how to narrow it down and what the repair usually involves.
Replacing a shower valve cartridge A cartridge swap is the most common fix for a single-handle shower that drips, sticks or won't hold temperature. The job is simple when the part matches and comes out cleanly; it gets harder when it doesn't.
When the whole shower valve needs replacing Replacing a valve body is a bigger job than a cartridge swap because the valve is soldered or threaded to pipes inside the wall. Here is when it is needed and how to keep the opening small.
Pressure-balancing vs thermostatic shower valves Both are anti-scald valves designed to keep shower temperature steady. They do it in different ways, and the choice affects cost, maintenance and how the shower feels.
When the shower suddenly runs hot or cold Temperature swings come from the shower valve, the water heater or the pipes between them. Sorting out which one is the first step, and some causes are a safety issue.
Leaking bathtub overflow gaskets The round plate under the tub spout hides a gasket that can leak only when the tub is filled high. It is one of the most common reasons a ceiling stains after baths but not showers.
When the bathtub drain itself leaks A tub drain leak happens where the drain fitting seals to the bottom of the tub or where it joins the pipe below. It leaks whenever water drains, so even a quick shower can trigger it.
Tub spout and diverter leaks A diverter that won't fully switch, or a spout that leaks where it meets the wall, can send water into the wall or down the tub. Most of these are small repairs if caught early.
Leaking shower pans and liners Under a tiled shower floor is a waterproof pan or liner that carries water to the drain. When it fails, water soaks into the floor and walls around the shower, and the fix is usually a rebuild.
Grout and caulk leaks around showers and tubs Cracked grout and caulk pulling away at the tub edge let splash water behind the tile. It's the cheapest leak to fix, provided a test confirms it's the source.
A water stain on the ceiling below the bathroom A ceiling stain under an upstairs bathroom can come from the shower, the tub, the toilet or the supply lines. Timing tells you more than the stain's location does.
Finding a leak behind the shower wall Water behind the tile can come from the valve, the pipe up to the shower head, the spout connection or water getting through the surface. Each is traced differently.
Hard water and Fullerton showers Fullerton's water carries minerals that leave white scale on everything they touch. In a shower that means clogged heads, stiff handles and seals that wear out sooner.
Low water pressure in the shower Weak shower flow can start at the head, the valve, the diverter or the pipes feeding the bathroom. A few quick comparisons usually show where.
Shower and tub access panels An access panel behind a shower or tub lets a plumber reach the valve and drain without touching tile. Many homes have one; many owners don't know where it is.
Hiring someone for shower or tub repair Shower repairs often involve more than one trade and sometimes a permit. A few checks before work starts keep the scope, price and responsibility clear.