When a tile is dislodged or missing it’s often caused by storm damage, or other contactors walking on the roof. It’s pretty easy for professionals to spot small gaps where one or two tiles have slipped or cracked.
A missing tile is not usually a critical defect, but repair shouldn’t be left for too long, otherwise the water will eventually get into the roof and damage interior ceilings.
If there are only a few slipped or missing tiles they can usually be refixed or replaced easily. There are different roof tile fixing specifications, when it comes to fixing loose roof tiles its always best to call in the professionals. Sometimes trying to fix tiled roofs on your own can lead to further damage and cause more leaks if not done properly. This can be expensive, always ask for help if you’re not 100% sure.