Stone floor sealer is a highly-effective, water-based, fluoropolymer, impregnating sealer formulated to help protect your stone surfaces from water and oil born stains. Stone floor sealer provides an invisible barrier resistant to stains, while allowing the surface to properly breathe. All natural stone should be sealed with an impregnating sealer to protect the surface of the stone from oil and water stains. Sealing your grout stops dirt and grease from soaking in and staining the grout.