Lead flashing problem

[vivacian]

The old lead flashing above my bay window has not been tracked in to new mortar in places. Instead it has been laid flat against the wall and the mortar kind of skimmed over it, to create the appearance of a good finish.

Should I chase out the new mortar (when the new wall is set) and hope that the lead is long enough to fit in to the gap OR can I bodge it with lead sealant?

You'd chase out the mortar and insert a long enough piece of lead, this can form an apron over the top of the lower piece of lead or you can completely replace it. Having two pieces can help with expansion and contraction anyway but it more likely to lift in the wind.
I think the Lead Sheet Association still have a load of leaflets online covering most detailing you'd need.

Thanks, I’ll have to have a think about how to prevent lift.