Arthur wrote:
is this a vile sin?

I've just started stripping a room that has one layer of paper on it
but its a hell.
The paper is quite dirty (I lived alone for many years and didn't
look at it) and after
wetting it, a top layer comes off (agonisingly) leaving what looks
like backing paper but
is actually a sub layer of the wallpaper. The sublayer comes off
easily after a little soaking.

Try hiring (or buying) a wall paper steamer, this makes things a lot easier,
especially if you 'score' the wall paper in a diamond pattern before using
the steamer on it.

The room is probably going to need skimming anyway so I could cheat
and remove the ragged
parts of the papering and treat with pva then hire a plasterer to
skim.

Not a good idea, the weight of the plaster will be taken by the wallpaper
and this is liable to peel off after a short while - besides, any half-way
decent plasterer will refuse to do this job, or if you insist on it, he will
make you sign a disclaimer so when the plaster falls off, you can pay him to
do the job again the right way.

Is this method a common skive?

No, there are many shortcuts but this one is a definite no-no.

Brian G