Whilst stripping off the 4 layers of wallpaper in my bedroom I've discovered a patch of wall where upon removing the wallpaper I'm down to fluffy cardboard (I'm guessing it's the outside of a bit of plasterboard).
The patch in question is on the opposite side of the wall to the bath & is where I had to replace paper & reseal the bath when I first bought the flat (damaged seal was causing water to soak in to the wall).

What do you guys reckon would be the best way to deal with it?

So far I can think of either sealing the section with unibond or giving it a quick skim over with some sort of plaster (although I've never done plastering before & don't fancy doing the entire wall).


Ideas?

I've not done any plastering either but have done plenty of filling. If the area isn't too bad you could deepen the area by digging into the plaster and then use a filler followed by a bit of sanding to make it flush.

If the area is large then a skim with plaster may be the best option.

Hmm.
Tread carefully.
We just stripped a lavatory here at home. On the other side of the wall was the flue from the old boiler.
Over time, the condensation from the single-skinned flue had soaked into the wall and caused the plaster to blow.
Someone had just stuck up some hardboard and papered over it - of course in time, the board had blown and started to mildew.
So, after discovering this, the only course of action was to remove the board, dig out the rotten stuff and have the wall reskimmed.
I'd recommend getting someone in to do it - of course, being in London you'll have to wait forever for someone and it'll cost you a wedge.
It's not the sort of thing you'd want to just have a go at, a good skim is an art form.

The plasterboard looks OK (I resealed the bath about 3 years ago) & is dry it's hopefully just the cardboard outer that's damaged (could also just be coming off with the wallpaper that's on it).
I'll have a closer look & see if I know anyone who does plastering

There's also no plaster on the wall on top of the plasterboard. It just looks like it was fitted & painted then papered over.

As long as the plasterboard is dry you should be able to skim over it and rub it down afterwards. Gyproc make a product called Easyfill that's between a plaster and a filler. It's easy to apply with a wide caulking knife, and can be sanded down nice and smooth afterwards. If you're going to put lining paper on the walls I highly recommend using Wallrock Fibreliner - it's pricey, but covers a multitude of sins...

If you have any damp areas you can treat them with a coat of Zinnser BIN stain killer - it's shellac-based so dries in about 20 minutes and forms a good vapour barrier. Again, not cheap but very good.

HTH, Pete.