I have a slab home can I lay this on that? Or does something have to be underneath before I can lay it?

Hello Samantha and thanks for your question. The Style Selections Charleston Oak Luxury Vinyl Plank already has an attached pad underlayment, so no other underlayment is required. However, if installing the plank on a concrete slab, we do require installing a 6 mil polyethelyne plastic vapor barrier be placed over the concrete prior to installing the plank. Even though the product is 100% waterproof, this will inhibit mold/mildew growth from occurring under the floor and causing the room to smell. We would always suggest reviewing the Installation and Warranty Guidelines (found in each carton or on the product page of the Lowe's website) prior to installation. Thanks again.