Help! : Possible Insulation Issues?

[robinbanks]

Note that their pricing can be quite random and inconsistent. Work out the per-cubic-meter price of the pallet you're buying

 

[rkinsella]

When we renovated the house there was a partition wall put in diagonally (don't ask) between the kid's bedrooms.
Show below during the renovation.



I was a bit suspicious of whether this got insulated ... especially when I saw this on cold days, see below.
Ignore the bigger problem on the left, that was sorted. Look where the red arrow is pointing on the right, the diagonal line across the roof.



Today, I put an Endoscope camera into that partition wall.
You can see the insulation above the kids bedroom on the top right, is absent above the partition wall itself.
You can see the black of the roof felt to the left of the insulation.

How do I sort this without taking down the wall entirely - "no more gaps" or something like that?

 

[robinbanks]

put in diagonally (don't ask)

Makes sense to me; if you have one rectangular room and two kids, a split that allows a long bed and a short desk in each works well

Take a section of plasterboard off, drill through the top plate and fill the void with expanding foam
Or strip the roof (concrete tile?) and insulate from above

 

[rkinsella]

Removing the tile doesn't help as there is always roof felt underneath.
I think I am going to remove sections of plaster board the length of wall.

 

[robinbanks]

roof felt underneath

My stanley knife would be absolutely unconcerned