Waterproof render

[JHster]

I have an old Victorian house that has a room built on the back corner this was originally open at ground level like a large shelter perhaps a posh way of going to the outside toilet without gettnig wet. The upstairs was a room (it's a strange sort of add on only me and my neighbour have one!)
They have built a double brick side wall without a cavity with some bricks laid as strechers and capped it off with a fancy cement topper. The back wall is single skin.

I've taken the old plastic roof off and the capping and put on a lovely new roof I've repaired the single skin with blocks as it was falling down, I've added a new window in the single skin wall and going to build a stud 2nd wall with 100m Celetex insulation.

The problem is the side wall I've spent several days taking off the old plaster it was a very strong mix I'm guessing to waterproof the wall. This has taken the face off some of the bricks.

How can I seal this wall it has no damp proof and no cavity?

i was planning to K-rend the outside at the end of the job but it's the inside. the room was useless before too hot in the summer and too cold in the winter.

i thought waterproof render the inside and then 1st fix wiring then maybe batton the wall (to create a cavity) and then 25mm insulated plasterboard to finish with drylining.

Any ideas?

JH

 

[Alastairreid]

If the wall you removed the plaster from is dry, i would batten, insulate, vapour barrier, p/board and skim.
If it has been getting damp look at waterproofing from the outside.