No need to do a restorative cleaning as often if you seal.
Protects against stains, allowing you to clean up the mess before it penetrates into the grout or stone.
It will keep you stone or grout looking great for a much longer time.
Stone & Grout Sealer is water based, you do not want a solvent based sealer they smell very bad!
No, If the grout has a color seal on it, it will not have to be sealed. There is a thin layer of paint over the grout that will not let a clear penetrating sealer to soak into the grout.
One bottle will cover approximately 300 to 500 sq. ft. depending on the size of the tiles, and how porous the stone is.
No it will not, it goes on clear and dries clear.
It is a strong restorative cleaner, it will remove your sealer. But to be honest with you your sealer is probably long gone anyways.
Water-based, oil is to much of a mess and usually has a terrible smell.