This depends on your underlay. The Basic and Transitstop underlays are made of polyethylene and won’t be damaged by water. The SunHeat underlay is somewhat more susceptible to water due to its mineral base. However, small amounts of water spillage, like those commonly occurring in kitchens or bathrooms, won’t damage your floor or your underlay. Just make sure to avoid cleaning your vinyl floor with excessive amounts of water and don’t leave liquid on your floor for extended periods of time.