Plastering over wallpaper

Question from Glen: I am redoing a wall with wall paper on it. I am peeling off the old wall paper and I am going to plaster the wall. I have found a second layer of wall paper and my question is: do I have to peel off the second layer or can I just plaster over it? 

Jake's answer: Glen, It all depends on how well the paper is sticking to the surface below it. Not only in its dry state, but what happens to it when you apply moisture, like painting. If the paper is well adhered and does not come loose when wetted, I say leave the paper as is and proceed with your project. You might find that only a small portion of the paper comes loose. If that is the case, remove that loose paper only and apply a drywall compound at the edges to smooth out the transition. If you determine that the paper is adequate to paint over, use a fast drying paint like Kilz as your first coat. Have fun!