Restoration versus replacement
Restoration makes sense when the tiles themselves are structurally sound and what has failed is the surface and the mortar. It does not make sense when tiles are widely cracked or the battens underneath have gone. Deciding which one you are looking at is the first thing we do, and if the honest answer is that your roof needs replacing we will say so — recoating a failing roof buys a couple of years and wastes the money you would have put toward the real fix.