The house was built in the 1920's east of London. The inside walls are cold to touch and we are considering insulating them. The house was recently externally rendered without external insulation :( and therefore I am looking at internal insulation.
I drilled into the wall ~6 inches above the skirting board on the ground floor and was surprised that it took me 9cm to hit something hard which I think is brick work. I have been told the house has solid walls, please take a look at the photos below and let me know what you think the wall is made of?
Under the render is ~3 cm of grey material with a metal mesh. I have a piece taken off the extension non-original wall. Is the grey material likely to be cement?
The piece of wood is 20cm width which is what I am guessing is a single brick width solid wall
There is 9cm of material which creates yellowish very fine dust. Is this 9cm of plaster?
I have read articles about brick walls needing to "breathe" and horror stories of soggy insulation. How should I go about internally insulating the walls? Should I remove the 9cm of yellow material? I am looking at getting new windows as the current windows feel drafty.