3 tiles on the front corner of our house have slid a few inches down, the first has been supported by the guttering. they all still overlap and the morter from the edge has also moved and cracked. A pro roofer will be needed to do the work but what could be the cause of this problem? thanks.
The edge tiles on your roof are probably only held in place by the mortar under the tiles. Many roofers cut the battens well back from the roof edge so there is no way to nail the tiles in place. Get the first metre or so of the battens replaced so you do not get a repeat of the same problem.