Preparing to paint woodchip wallpaper....!

[Mumford]

Hi,

Firstly some background.

I live in a 2nd floor flat with an internal stairwell. This means that I have huge wall surface areas up to 5 metres in height.

Some of the walls are painted plaster, and I've painted them easy enough with a huge extension pole and some vinyl matt emulsion. However, I've yet to paint the largest wall - which is covered with woodchip.

Tapping some of the wall reveals a hollow sound, which, I think, means that although the paper is stuck to the plaster, the plaster itself (old style plaster - very thick, but not strong) is not that solid. If I take the paper off, there is going to be wall damage.

What I want to do is just paint over the woodchip. I'm absolutely fine with that because I'm getting ready to move. However, I don't want to get the woodchip paint wet with water based paint like the emulsion I've been using, and have it tear off the wall when I run a roller over it - and clearly I'm going to have to give it a few rolls because the surface is not flat, it being woodchip wallpaper.

I've done a bit of research, and one site says I need to use an oil based primer first, to mitigate the risk of the paper coming off when painted.

Is this true?

Essentially I need to know what kind of undercoat / primer to apply, and what subsequent paint to use. Also, how to use rollers and ensure that the wallpaper doesn't come off. If this happens five meters above me, then I'm going to have awful job on my hands. Getting up there for starters. It doesn't bear thinking about.

I'm hoping for some advice on what to do. I get the feeling that if I go stright for emulsion on this I'm going to regret it.

Cheers!