How to paint over wallpaper

Difficulty: Moderately Challenging

Things You’ll Need:
6" drywall knife
12" drywall knife
box cutter
dropcloths or runners
blue painter's tape
1 bucket of joint compound for an average room
2-3 tubes of latex interior caulking
dripless caulking gun
rags for wiping spills/drips

Lay out your dropcloths along your walls, and then tape all your base trim to keep from having to clean it up or repaint it later. If you are repainting the whole room this step is not necessary as you will be painting your trim after you paint your walls.

Use your boxcutter to cut all your seams, removing the thin strip where your wallpaper overlaps the next sheet. Then cut around any loose areas in your wallpaper; the loose paper needs to be removed so it will not cause bubbles under your joint compound. If bubbles do appear after you have put on the first coat of compound, they need to be cut out and covered again.

Caulk all of your ceiling lines, corners and base trim to seal the paper in. If you have seams that come together in the corner. Then using a good latex drywall primer (I recommend Sherwin Williams) you should prime all of the papered area.

After the primer dries thoroughly, using your 6" drywall knife run a generous coat of joint compound over all your seams and other areas where you have removed loose paper and than remove some of the compound, smoothing it out but do not skim it down tight. You want to make sure your seams are covered. Let dry approximately 24 hours.

Using your 12" knife you are now ready to skim all the seams you covered. This coat of compound can be applied lightly and then pulled down tight removing the majority of the compound. Pay special attention to the edges where the compound meets the wall paper. The more compound you remove the less you will have to sand (see my article on finishing drywall or greenboard). Caulk all of your corners, ceiling lines and base trim again if needed.

After the compound and caulk have dried thoroughly, you are now ready to sand, or you can sponge all of your seams and patches with a good sized sponge which is preferred, to eliminate the dust from sanding. Just dampen your sponge. You do not want to soak it, as this may run down the wall and get into your wall sockets causing a short or even worse a fire.

2nd coat of primer After you have finished sanding you want to prime all of the areas where you caulked and patched, and then after that coat of primer dries I recommend priming the entire room again so that you will not have any wallpaper pattern showing through your finish coat, The last coat of primer is only necessary if you want to paint your room with a gloss finish. Flat paints always hide imperfections much better than a gloss finish, and there are a lot of good washable flat latex paints on the market now.

Tips & Warnings
If you have textured wallpaper installed, you should apply the joint compound mixture on the whole wall. Let the joint compound dry and the next step is to get rid of the rough surface by sanding or sponging it.

Remember, just dampen your sponge. You do not want to soak it, as this may run down the wall and get into your wall sockets causing a short or even worse a fire.