I discovered a very wobbly patch of wall about a metre square below a window. The plaster had clearly come away from the brick, so I chipped it off with a view to re-plastering it. Towards the top of the wall there was about a 1cm gap behind the old bonding. The bottom part is in reasonable condition. The real issue is that the top layer of bricks are all completely loose and in places had rotten timber in their place.
To the right of the image you can see more gaps and expanding foam where there should be brick. The story there is that about 10-12 years ago a doorway was added. Instead of finishing off the end of the wall with new brickwork they seem to have stuffed it with foam and piled some thick plaster onto the side. Actually that thick plaster is pretty solid and the finish on the side is good, but that doesn't help the fact there's nothing to bond plaster to from the front.
So going back to my original plan of plastering the wall. How should I handle the fact there's no brick to bond to? Would you recommend plasterboard instead? Or should I repair the brick somehow and plaster as planned?
The surface of the finished wall is exactly one inch from the brick.
I should add that I am a novice plasterer to say the least!