I used this on a poorly installed toilet pedestal for aesthetic reasons, so I can't say if the product is waterproof. The floor surface was uneven due to poor installation and I didn't want to just use a ton of joint compound to cover it up. The tape went over any bumps and made the surface smooth and clean. All in all, the tape worked great. The only criticism is the poor instructions. As mentioned in other reviews, if you go into corners you need to use a hair dryer to make it more flexible. You also need to pull the tape taut when going around corners or you'll end up sticking. Only remove the backing after aligning the tape where you don't want it to stick to itself and make a mess. Plus, it's easy to use and works great.