• Can grout be used as a sealer in a walk in shower ?

Grout can be used to seal the gaps between the tiles providing it's laid properly to make sure no gaps are left.

However where tiles join other surfaces, such as the shower dish or the bath, you should use a flexible sealer like silicone not grout to seal the gap. This is because some movement in these areas is inevitable and if you use grout it cracks which creates leakage and damp problems.