How should I plug gaps where new breeze block wall meets old bricks?

[pedr0]

Hi all - this chilly weather has highlighted some drafts in my new kitchen extension!

I have a new external wall that runs along one side of the kitchen and then meets the original victorian brick wall (that used to be exterior) at right angles to form a corner of the room. I don't know exactly the construction of the new external wal, but on the inside I can see breeze blocks and on the outside I can see yellow stock bricks.

Right at the corner, where the breeze blocks meet the original external wall, there are gaps where the mortar is a bit sloppy and I can feel cold drafts through the holes. The air is really cold, so I believe it's coming from outside.

I've attached photos taken from inside the kitchen. In the photo, you might be able to see something shiny deep in one of the holes - that's not light from the outside, but some sort of metal fixing that seems to run vertically at the join.

So I've got two questions:
1) How should these two walls have been 'joined' so that the corner would be insulated? I presume that at corners I'm not just relying on mortar for insulation, am I?
2) What's the best way to plug up these holes to make for a well insulated home?

 

[^woody^]

Fill it with the plaster you will be plastering with

 

[Alastairreid]

The shiny thing in the space is a wall starter.

https://www.fastbuildsupplies.co.uk...l9t6yYg3DkqDkplBqTKZG91rAy8aFjPwaAlDXEALw_wcB

 

[pedr0]

Thanks guys. I'm not going to be plastering it though. I'm going to put a green wall on it, which starts with a sort of plastic board screwed/fixed to the breeze block. So I'll need to fill the gaps first.

So should I just use bonding to seal the holes.?

I'm surprised that we go to all this effort to thermally insulate the walls, but then not too bothered about creating a seal between insulation at the edges/corners. I realise that the area of the wall is massive compared to the edge, but I was under the impression that even small 'leaks' in your insulation can have a massive impact. Same logic as to why these tiny gaps are contributing to my whole room being 5 degrees or so lower.

 

[^woody^]

Flexible caulk or a polymer mastic.
Gouge it out a little first to remove any loose grains and allow more of the sealant in to bond and seal the gap