In message , Andrew Gabriel
writes
In article ,
(Tom Dixon) writes:
Currently dry-lining my old cottage, rubble / masonry walls. For most
of the walls I am putting insulation against wall held in place by
stud-work. However I need to glue / fix 20 mm insulation board and
plaster board directly onto the uneven reveals, and my feeling is that
they are sufficiently uneven that I need to smooth them off, to offer
a good surface to accept insultion etc. to provice a good level
finish.

Bonding plaster is a plaster undercoat that also sticks well to
almost everything (tools in particular;-). You should be able to
get it smooth, although not smooth as finish coat as it contains
some larger pieces (which would also mean it wouldn't work in a
thin layer).

However, it isn't waterproof. It will sock up water, and prolonged
or repeated exposure causes it to fall apart. If you want something
which will survive in the presence of damp, then you should use sand
and cement with a waterproofer. You could also add a small amount of
exterior/waterproof PVA into the mix.

I don't have a completely clear picture of what you are doing, so
I'm not sure if this is helpful or not.

I read it that the OP wants to smooth off the internal window reveals
enough so that they can stick the insulation /plasterboard to it.

I would have thought bonding would be fine here, but I'd probably use
sand /cement
--
Chris French, Leeds