Four ways a shower leaks
The drain assembly under the tub or shower pan can loosen or crack, so water leaks only when the drain is running. The valve and supply pipes behind the wall are under pressure, so a leak there may drip whether the shower is on or off. Cracked grout, failed caulk and gaps around the tub spout let water into the wall only when the shower sprays on that surface. And sometimes it is simply water splashing past the curtain or door and soaking into the floor at the edge of the tub.
Telling them apart takes a little detective work, but it saves opening the wrong ceiling. Start with the simplest tests and work toward the ones that need a plumber.
Hand holding a thermal imaging camera showing a cool spot on a wall. Example of the work involved; the photo does not show a specific property or a job for this site.
Simple tests, one at a time
Fill and drain test
Plug the tub, fill it a few inches without using the shower head, then drain it. If the ceiling drips during draining, suspect the drain.
Spray the walls
With the drain open, spray only the tile walls with a handheld or a cup. A drip after this points to grout, caulk or tile.
Run the shower aimed at the floor
Point the head straight down into the tub so nothing hits the walls. A drip now suggests the valve, the shower arm or the supply pipes.
Check the edges
Look at the floor and baseboard where the tub meets the floor and at the door threshold. Wet subfloor at the edge means splashing or failed caulk.
Leave it off overnight
If the ceiling still drips or the stain grows with the shower unused, the supply side is leaking under pressure. Close the valves and call a plumber.
What usually happens next
- IfThe drain is leakingThenA plumber tightens or replaces the drain assembly, often through an access panel or a small ceiling opening below.
- IfGrout or caulk is failingThenRegrouting and recaulking may be enough, but if the wall behind the tile is soft, the surround may need rebuilding.
- IfThe valve or supply pipe is leakingThenA plumber opens the wall behind the shower or the ceiling below to repair it.
- IfWater is splashing outThenAdjust the curtain or door, add a splash guard, and dry the floor edge.
Common questions
Can I just paint over a dry stain?
Only once the leak is fixed and the ceiling and joist bay are confirmed dry. Painting over a damp stain hides a problem that will keep growing.
General information for Englewood, not a quote or professional advice. In an emergency, call 911.