Is PVC waterproof

Yes.

PVC stands for Polyvinyl chloride. It is water resistant and so it is waterproof.

It is a synthetic resin prepared by the polymerization of vinyl chloride.

PVC is used to make water pipes, floor sheets and tiles, water proof cartons, rain coats, shower curtains, and many items that need to be protected from water and fire.

It is also flame resistant. Chlorine is released when you burn PVC, and chlorine atoms inhibit combustion.