Cavity wall insulatioin repair.

[Al in nl]

Hi all.
 

I am wanting to repair a cavity wall which I am sure has Supafil blown in (its white fluffy and sure looks like it). After install, someone put a hole(~200x100mm ) in the wall just above the floor in the innerleaf to vent a gas fire. Can anyone suggest a means to repair this? prefereably with an eco material.
I was thinking of opening the inner leaf up higher up, and pouring vermiculite down. over simple?

 

Other info...

I have not looked further up the wall with an Endoscoop yet. I have looked at the wall with infrared and can guess where insulation is missing. Not as accurate as I wish - I did not have time to make a big inside to outside temp difference (heating system now not connected to gas)

 

There is a vent to outside but not opposite inner leaf hole. It is much further up wall.
I will be next week filling the holes up. The solution for the missing cavity wall insulation can wait.

thanks alex