Repointing flashing on wall 

Old lead flashing on walls constructed of lime mortar will occasionally need to be repointed and secured to help prevent damp areas in the wall developing 

Firstly remove all the loose mortar, next re position the flashing into the gaps between the bricks. Then repoint in with new mortar using a 6 to 1 sand and cement mortar mix wit some plasticiser. With a lime mortar wall its best to use replacement  lime mortar to repoint the flashing and finish with a harder capping mortar