New roof laid, old cement falling through?

Hi The cement you have seen is "Torching", torching was applied in the past to prevent draughts and keep out driving rain. In modern roofing these functions are performed by the underlay. When the existing roof was removed all the torching would have fallen off the tiles/slates and batten into the loft space and then removed and discarded so there should not be any still attached to the pitched area of the roof, if the roofer did not clear the loft space of the torching you would see this laying on you insulation and what ever was stored at the time, there may have been some torching left on the collar's which may have dropped onto your loft hatch. May I ask if how much was on you loft hatch and if you are able to send a number of photos of the of your loft space? Hope this helps? Pete

I would agree with Pete. This is old mortar which should of been cleared when it was done. This does not mean a shoddy job has been done just not a very thoroughly clean job. Again photos wold help?