Use drywall compound on paper for uniform finish

Q. The home we bought has wallpaper on the dining room walls, and we want to paint over it. Can that be done without the wallpaper peeling or bubbling up later on under the paint? If so, what kind of paint would you suggest?

— Mrs. Simmons, Spokane.

A. The answers depend on many variables, such as the type of wallpaper, how old it is, how it was hung, and its current condition, to name a few. Professionally speaking, I don’t think that removing wallpaper today is such a hassle with the high-quality chemical wallpaper strippers on the market. It’s still a messy process, but I think the painted wall turns out much better. However, now that I’ve said that, I probably would prep the wallpaper for paint if I knew there was a plaster wall beneath it.

You should know that painting the wallpaper will make it more difficult to remove later on because the paint will remove any porosity in the paper. Consider also that the more coats of paint you apply, the worse it will get.

To obtain professional results look for any loose areas in the wallpaper and cut them out with a utility knife. Then moisten these areas with a sponge and patch them with drywall compound. If you don’t moisten the areas before patching, moisture will be drawn from the compound, causing it to dry too fast and crack. It could also cause the paper to bubble.

Check all the seams and run drywall compound over them as well. Basically, apply compound to all cracks, seams, rough spots or indentations. If the paper is textured, apply a skim coat of drywall compound over it for a smooth wall. If you patch or repair any textured portion of the wall, you will need to skim coat the entire wall for a uniform surface.

After sanding the repaired areas with drywall sandpaper, go over the entire wall with 220-grit sandpaper. Brush down the wall with a fine-hair hand-held dusting broom and vacuum up the particles.

After you complete all these steps, you are ready to prime the walls for paint, the most important step in the process. Use only an oil primer to seal the walls and purchase the best. Do not skimp by purchasing an inexpensive product. Latex primer could cause the wallpaper paste to soften, causing the paper to bubble. Once the primer has dried, look carefully for any imperfections—this is a good time to correct them and don’t be afraid to sand down the primer again with 220-grit sandpaper. I always sand the second coat of primer with 220 grit just before applying the finish coat of paint.

It is also possible that the wallpaper will appear to have no texture, but a texture may show up after priming. The solution is to skim coat the walls or spray on an orange peel texture. If the first coat of primer went on heavy, you could spray the walls; I suggest doing it after applying the second coat of primer. Yes, you will have to apply a third coat of primer if you texture after the second coat. If you don’t, the texture will absorb moisture from the latex paint preventing you from achieving a uniform surface. The texture will display a duller sheen and it will not matter how many times you paint the walls.

Only you can determine whether it is worth all the work to paint wallpaper or if you should remove the wallpaper and possibly go through the prep process on the exposed walls. There are no guarantees which approach will require the least work. My suggestion is to flip a coin and go for it!