Is this flooring really waterproof?

Yes. The rigid vinyl core is waterproof, and the planks are rated for above grade, on grade and below grade, so kitchens, baths and basements are fine. Standing water should still be wiped up rather than left.

Can I install it over an existing floor?

Yes, it is a floating click-lock floor, so it can go over most flat, sound hard surfaces. The plank is 4mm with an attached IXPE pad, and extra underlayment is not recommended at that thickness.

How does it compare with thicker rigid-core planks?

It is thinner at 4mm with a 6-mil wear layer, so it is lighter-duty than 12- to 20-mil planks built for heavy traffic. It suits homes and light commercial use, not busy commercial floors.

What is the warranty?

Limited lifetime residential and 10-year limited light commercial. The 6-mil wear layer is the main limit on how much traffic it is expected to take.

Does it need underlayment?

No. A high-density IXPE pad is already attached, and the maker advises against adding underlayment to planks 4mm and thinner.

Is it safe for a home with kids?

The flooring is described as phthalate-safe, and the matte, scratch-resistant surface is meant for daily household activity. Check the subfloor is flat before installing.