In article ,
Robin wrote:

Apologies for stating the obvious but much depends on the state of the
neighbour's ceiling. Eg if you are looking at old lath and plaster in a
state where one dropped brick would fill his bath it may call for some
care. I'd wondered about fitting a plasterboard "screen" and then
building the blocks flush to that.


It's likely crap lath and plaster - cottage is from 1890 and mine (or soon
to be mine hopefully!) are.

Got a couple of pics now of the issue:

https://tinyurl.com/wallinplace

Thats the front, where it's ok.

https://tinyurl.com/missingwall

shows the bit that's missing annoyingly :-/

Darren