Roofer or lead worker to repair valley?

[thornmproblem]

We've got roof valleys with lead base and the mortar has started to crack and crumble. I haven't inspected it so I don't know if any of the lead itself needs to be repaired, but the mortar does.

I'm wondering if the best person for the job would be lead specialist or a general roofer?

I can't tell, from my guess is that some movement (changes in temperate) might have contributed to it.

 

[^woody^]

Roofer. Proper roofer though.