New pitched roof fitted, unsure about those joints

[stevie1970]

Had a new pitched roof fitted above a doorway, but am a bit unsure about the quality. 2 pics below, taken looking down at the roof.

Are those gaps/joints likely to cause me trouble in the future with leakage ?

 

[Silentrunning]

If that is slate or tile, you are definitely going to have future problems. I think your big worry now should be wind. I have seen improperly installed roof tiles become projectiles in strong winds.