It is very important to have a bathroom floor which is built with a material that is waterproof. Bathroom floor will always be exposed to water, and if it is not waterproof, damage will be done. You can either get waterproof flooring or use a sealant instead. Repairing or replacing damaged bathroom floors can turn out to be very costly. Thus an initial investment which is a bit costly would save you lot in the future.
Covering the base with a waterproof sealant is a good option, or use a waterproof material for the flooring. The safest option would be to get both the things done for the bathroom floor, which means that you will not have to worry about the floor for years to come. Laminating the floor is another good option to make it waterproof. You need to consider the various options for waterproofing and pick the ones that fit your budget.