leaky roof fix
 

I have a sloping tiled roof on a small extension on hte back of my
house. Un fortunately it leaks in the corner. I have removes a small
area of the board ceiling and can see that the felt under the tile is
split and perished and when it rains the water comes through here. I
have tried patching it from underneath but you cant press on it
because it is unsupported from behind. I suppose I need to take the
tiles off and fix ne felt over top but the tiles are mortared in along
the edge.

Could somebody give me some advice on tackling this problem. Do I need
to chip out this mortar to get tiles off? How do I patch the felt?
Should the rain be coming under the tiles?

MTIA

Dan