In article , Grunff
writes
wrote:

Hmmm. Actually I'd suggest plasterboarding over and skimming. You're
not going to lose much height in the room (!) and it's much less
mess-making. IMHO, YMMV etc...

Nasty, dirty bodge. The PB will never sit properly over the deformed,
non-flat lath and plaster. Taking down l+p is no fun, but it's the right
way.

and makes sure that there isn't a hidden cause for the mildew eg. leaks or
water ingress, dooo it.
--
fred
Plusnet - I hope you like vanilla