When we do repairs on showers, we find we are more successful using an epoxy grout, even though it is trickier to work with than cement or premixed options. Showers are wet by nature. Epoxy grout will consistently set up in damp environments while premixed grouts will not dry properly if there is water at the installation site. Even when mixed correctly, cement based grout may absorb moisture from the shower pan, which can cause grout failure, or even prevent it from setting in the first place.
We use epoxy grout because it comes with several advantages. It can cure even if there is moisture in the environment, it is far more durable than other grout, and it does not need to be sealed because it is waterproof.
The reason your shower probably doesn’t already use epoxy grout is because it can be tricky to work with and more expensive than other options. Once the two part epoxy is mixed it starts to set within a few minutes. It can leave a haze that is difficult to remove if the installer is uncomfortable using it.
