A water test is a quality control check performed on any shower installation before setting tile. It consists of stopping the waste line with a test plug and filling the base of the shower stall with water to check for leaks. You can quickly check the test plug by filling the pipe and drain with water up to the height of the KERDI-DRAIN integrated bonding flange or KERDI-LINE channel body (or a little below). If the plug is watertight, then you can continue filling the assembly. The water level is marked and the assembly is left for a specified amount of time (24 hours is typical). If there are no leaks, the shower passes.
We recommend waiting a minimum of 24 hours after setting KERDI to begin water testing. This will allow the thin-set mortar to reach final set and ensure watertight performance at the seams under normal curing conditions (i.e., room temperature). If temperatures are much lower (e.g., around 50 or 60 degrees), then it is best to wait longer.
If you are building a barrier-free shower, then you will need to provide a temporary dam (e.g., a 2x4 and silicone sealant) at the threshold.