Cover flashing on random stone wall

[Coops]

Hi Folks, hope all is well.. anyone got any ideas on how to detail cover flashings on a new double pitch porch abutting an existing old random stone wall? 

The sensible option seems to be a simple raked flashing tucked into a single saw cut, but this would deviate from standard stepped arrangement used in brickwork or uniform facing stone....any ideas would be appreciated.. BTW tiles are plain clay 

 

Cheers 

Edited November 2, 2021 by Coops

[Russell griffiths]

As you said, saw cut. 

[Coops]

4 minutes ago, Russell griffiths said:

As you said, saw cut. 

Thanks, I needed the validation?

[Cpd]

9 hours ago, Coops said:

The sensible option seems to be a simple raked flashing tucked into a single saw cut,

I now like to cut out a gap of about 10- 15mm (or whatever matches existing mortar joints) and then use the same colour mortar finish as whats on the wall, I find you get a much better seal with the mortar joint as a single cut has to be filled with some sort if mastic and if not done right can be a point of failure. I use a weak mix with lime in it to help it match the movement of the lead. There are probably some very good mastic / gunks that are designed for this these days….. I just do what I have found works for me.