What is the correct mortar mix for sealing in lead flashing.
The wall containing the lead flashing 8 metres in length is open to all elements of the weather. ie would you add an aggregate to the mix?
For a standard mortar mix this normally on a ratio basis (usually around 3 or 4 parts building sand to 1 part cement) recommendations vary – but you don't want the mixture to be too wet or too dry.