A customer has an existing patio that is slate layed in concrete. She tells me that she wants to repair/redo the patio using the slate thats already there. From what she tells me the slate will be able to be taken out because the joints are deteriorating. If the slate is able to be taken out successfully, would just clean the surface and relay with mortar?? I'm a little confused with the whole thing, any help or opinions would be greatly appreciated.