Removing plaster from solid brick

[Peter9791]

Hi All,
Large sections of my bedroom wall (external) had blown plaster. I think that it’s a case of many years of non breathable paint and a modern skim coat had basically suffocated the wall. It’s a lime pointed solid wall, with internal lime render. Anyway, I’ve decided to strip it all off back to brick, and eventually batten it and plasterboard it, using a breathable plasterboard and leaving it unplastered after.
I’ve got it down to this, how clean does it actually need to be and are there any health hazards of leaving any of that lime residue on ?
As I said it will
Pe plasterboarded with a gap and a vent. Also, what is best way to remove that final layer . Thanks

 

[Peter9791]

Also, does that brick look like it’s in good shape ? Or does it need anything done ?
Thanks

 

[JohnD]

the colour looks to me like damp sand and cement render, not lime.

Why is it damp?

 

[Peter9791]

Doesn’t feel damp, it’s dry to the touch. That’s what was left after breaking off the lime render. I just have to clean off the residue. I could be wrong but the house is 122 years old with solid wall so I am guessing that would be lime rendered to keep it breathable.

 

[Peter9791]

Also JohnD you might be able to see some of the Lime render still left beneath the plaster in the top right, and on the party wall to the left. Perhaps this is a coating of sand behind ? Thanks

 

[JP_]

I assume no insulation at all then? I'd insulate! (that's my answer to everything though!).
My bedroom wall, after removing chimney (was front room)

 

[Peter9791]

I don’t know what to do about insulation as I need to keep it all breathable. Any suggestions or advice would be great. Thanks

 

[JohnD]

What is on the other side of that wall?

The brickwork looks very shoddy with gaps between the bricks.

 

[Peter9791]

That’s back face of the external wall. It’s done in a header bond with some bricks laid sideways. So essentially another wall that is interconnected with it.

 

[Peter9791]

JohnD I assume you’re talking about my original picture and not the second one with the Kingspan ?

 

[JohnD]

Yes, I think your wall is worse than jonbey's

 

[Peter9791]

Well hopefully not, it still needs to be fully cleaned down, and will be covered anyway.

 

[cdbe]

Is that a recognised technique? I know people bang on about using lime and breathability etc but surely the wall can breathe from outside? Inside I'd want the wall sealed with a good coat of SBR slurry then a coat of waterproof render to fill all those open joints then a skim coat to finish or even better some celotex and plasterboard. Isn't this pretty much the standard remedial treatment for damp, solid, lime built walls in millions of old houses in this country? - it's worked fine in all mine. In a modern(ised) house I want the warm, moisture laden air mechanically or passively extracted out and not soaking into the walls.
I think your lime plaster has blown because it's 122 years old and it's had it.
Obviously if yours is a drafty, single glazed, no loft insulation, timber doored cottage heated by a couple of open fires then crack on.