A shower flood test checks that a shower pan is watertight before it's covered. The drain is plugged, the pan is filled with water to just below the top of the curb, the water line is marked, and the water is left to stand. If the level holds and no water shows up below or beside the shower, the pan passes.
It's one of the simplest steps in building a shower, and one of the most important. Here's how it works, and what to watch for as a homeowner.
The shower pan sits under the mortar bed and tile. Once those go on, the only way back to the pan is to tear them out. Testing the bare membrane means any problem is found while it's still easy to reach and fix. It's also why many building departments want to see the pan, often with water in it, before it's covered.
If the level drops or water shows up somewhere it shouldn't, the pan is drained, the problem is found and repaired, and the test is run again. A failed test isn't a disaster; it's the system working. The disaster is finding the leak after the tile is on.
A pass tells you the pan held water when it was tested. It doesn't guarantee the rest of the shower: the valve and supply lines in the wall, the drain connection below, the grout and caulk, and the shower door all matter too. And a pan needs a properly built mortar bed above it, with the drain's weep holes kept clear, to keep doing its job.
As long as the job or the inspector calls for, often about a day. Requirements vary, so check with your building department or contractor.
Can you flood test a shower that's already tiled?Not in the same way. Water on finished tile soaks into the grout and mortar, so the result is hard to read. A true pan flood test is done on the bare membrane.
Who does the flood test?Usually the installer of the pan. We flood test every hot mop pan we build and have it ready for the inspector.
Building a shower in Orange County? Read about our flood testing & inspection, or get a free estimate.