Sealing Lead flashing to sandstone

[rosswalker]

Hi,

There is lead flashing on my window ledges, it is sealed on the vertical edges to the sandstone with some kind of putty substance. Unfortunately, this has started to crack and let water in. Can anyone suggest what I should use to seal the lead flashing to the sandstone?

Thanks in advance,
Ross

 

[Alastairreid]

Sounds like sand mastic.

http://www.masonsmortarshop.com/traditional-burnt-sand-mastic-5-litre-tub.html