Whilst doing a bit of touching-up, I discovered that the genius who
extended my front hallway used white conti board to line the inside of
the walls and then plastered over it (for god's sake, why?)

A bit of sanding has revealed some of the white board and I need to
cover it up. Now if I start to key it using a sander, more and more
will get revealed as the plaster doesn't stick to it very well and
I'll end up doing the whole damn wall.

However, if I can paint over it I can make the best of a bad job
(ideally, I'd put a thin layer of some plaster-like material). But
emulsion isn't going to be too keen to stick to plastic.


Can anyone help with a suggestion for something to go over the
contiboard first?

Thanks

spog