Jettied ledge repair

[amantadine]

Good afternoon. I was in the process of securing and repairing the subfloor floorboards. Towards the end of the room there is a jettied ledge. There are gaps in between the exterior brickwork and the horizontal timber of the ledge itself. I am at a loss as to how best to repair the gaps. I am fairly sure the rest of the brickwork has a lime mortar (1930s semi detached property).

The picture from inside the room has the last floorboard removed, there is approximately a 16cm gap from the visible floorboard to the wall.

From my research so far I have come across the following repair options:

1. Lime mortar to cover the vertical gap (applied from the inside) and flexible exterior sealant on the outside.
2. Oakum caulking to fill the gap inside and then burnt sand mastic externally
3. Timber weatherboard pieces between the black timber joists externally (secured to the jettied ledge at the top).

The height of the gap varies from about 10-20mm, and the depth is approx 10mm.

 

[Lower]

I'b put a timber moulding in between the joists outside the building and paint whatever the dark colour the external joists are. It's always going to be a cold spot though so high tog underlay and carpet would be advisable.

 

[amantadine]

Thank you, presumably some damp proof course between the timber and the vertical brick wall as well. I agree about the cold, is always cold there in the room, so will definitely need to tackle that problem from the inside somehow

 

[amantadine]

There is an area of brickwork that needs repair as well. Given the age of the property I think it may have lime mortar, Here is a sample of what was sitting on the bricks itself.