Yikes!

In no way whatsoever do I recommend painting over wallpaper. It is a horrible mistake and years later, you will have a bad mess on your hands. So painting tip number one, don’t do it! But in all reality I don’t blame you for wanting to leave it up. Wallpaper is a huge pain in the butt!
I wish that they had never invented it in the first place because now, it is out of style, and we have to suffer the repercussions. But, being that hindsight is always 20/20; let’s figure out how we are going to deal with the problem.
Ok, so you just bought an existing home that has wallpaper in the bathroom that has not been painted over and a living room that has been. Lets deal with the bathroom first. Trust me when I say, it will be all that you will have the mental energy to deal with before you give one of us painters a call, or give up on the whole idea for awhile. If you plan to keep this home or even try to resell it one day, then you need to take it all down.. Most wallpaper that is still on your walls is old and outdated so keeping it probably is not an option for you regardless. Moreover, if it is painted, then it is tacky and looks like crap anyways.
The worst part is not that you have to take it down but the fact that the builders decided not to bother to prime under the paper or use any wallpaper prep sealer, and placed it straight onto the drywall so to cut on costs for the first owner but now it is going to cost you. In this condition, there is no way around it; this is going to rip the walls to shreds. We are just going to have to get started, and do the best we can.
First, find an edge, if you can, where it is lifted, and see if you can get more than a two-inch area to come off. If you are lucky then the wallpaper is vinal and it will come down in sheets and leave just the paper backing. Then soak it where you just pealed so we can try to get the edges to lift or get soft enough to get a putty knife up under and pull the next two inches. And as the saying goes, “Rinse, lather, repeat.” In other words, keep up the good work until all of the paper is completely gone. You never know when you might get lucky and it comes off so well that you are smiling instead of cringing.
Now you are looking at the wall, it should look great because the contractor did it correctly, or look like someone took a weed eater to it because, they didn’t. If it is in good shape then wash the excess glue off with hot water and prime the surface with a product called “Zinsser Guardz.”
Gaurdz will hold down anything that is loose and give you a surface to sand lightly and then paint. Guardz is latex based and shouldn’t smell too bad like oil based products will. If the wall is a weed eater wall then you are going to need to paint it with the “Gaurdz”, coat the entire surface of the wall twice with drywall mud before you sand, prime, and paint the surface.
OMG that sounds like a whole lot of good family time doesn’t it. I don’t recommend that you even try to get this far because if you put the mud on the wall, no contractor will touch it. We will not sand another person’s crazy looking mud job.

Ok, so the bathroom was the easy part

Now let’s go see what we have to do with the painted wallpaper in the living room. First, if the wallpaper is a textured paper, it has to come down or has to be painted the way it is because any patching will show up, and calking the holes and seams is all you have to fix it. The paper has been painted over so you don’t even have the option of water soaking into the paper. You can try to peel it but it isn’t going to budge unless of course they did it right when they built the house. Fat chance of that happening or the person that painted it would have just peeled it off himself or herself.

So now what?

To be honest with you, you probably just need to call someone that knows what to do, even though for us, it is just trial and error. We can’t even tell you a price until we get into the situation. It may require us to go and rent a wallpaper steamer which may or may not work depending on how many coats of paint are on the wall.

But just in case you want to give it a whirl.

You probably have seams that are lifted somewhere, so see what the paper is going to do. If it reacts as if it wasn’t put up correctly originally, then don’t peel too far from the edges of the seams. But you are going to have to peel it on both sides of the seam just enough to get the raise out of there or it will just keep raising on you. You may want to try to sand the raised edges with 80 or 100 grit sandpaper to see if that does the trick. The pictures on this page do not show prepping of painted paper because I would just take it down myself. These are pictures of a wall where the owner insisted the paper stay up. The paper was not textured so it looked good in the end because it was prepped it correctly.
Next, you want to paint the edges with an oil primer and let it set over night. Put the Gaurdz on the oil painted areas to multiply your chances of the edges not coming back, and then mud all of the seams twice before sanding. You are going to want to do the first coat of mud 6 inches wide and about 1/32 of an inch thick. Make sure that you take excess mud off from the edges each time or you are going to sand your butt off.
The next coat of mud should be about 10-12 inches wide in total, the same thickness and the same type of edges. Now you can put paint on the walls and hope bubbles in the paper don’t appear. If they do then you have to cut them out, peel the edges and do as you did with the seams. Did I mention that it is all one huge nightmare?
That is about the gist of the whole process. It is impossible to explain it all here on this page, so if you have any other questions, feel free to leave a comment and I’ll try to answer your specific questions here at Modern Mural.