You've grown tired of that unsightly, outdated wallpaper and decided that this weekend is the perfect time to cover it. But is it really necessary to strip the old wallpaper before covering it with paint or new wallpaper? If the paper is torn, and peeling, ripped or bubbling you will definitely need to remove it. Likewise, if the old wallpaper has a bold pattern, otherwise the colors could bleed through. Also, you can't paper over old wallpaper with vinyl, foil, and plastic papers.
However, if the paper is in good condition and you plan on priming over any darker colors, you could get by without stripping off the old wallpaper. Either way, your walls will need some preparation before you can paint or wallpaper.
Deciding Not to Strip
If you decide to paint or wallpaper over the older paper, you will still need to do some preparation. Make sure you repaste and roll any loose seams. Then, spackle and sand all nicks, rough spots or overlapping seams. Finish up by washing the wall with a solution of ammonia and water or TSP and let it dry completely.
It is always advisable to use a good primer before painting over wallpaper. But this may need to be done before you can wallpaper as well as the old paper may bleed ink. To test your old wallpaper, moisten a small piece of it with a clean sponge. If any ink comes off the sponge, you will need to use a vinyl-to-vinyl primer over the old wallpaper first.
Deciding to Strip: Removing Vinyl or Strippable Wallpaper
Before you try any method, test to see if your wallpaper is vinyl or made of a strippable material.
Vinyl wallpapers are easily peeled off by lifting the bottom edge of the paper with your fingernail or a stripping knife. Then, peel each length straight up and off the wall. Vinyl wall coverings have a thin layer of backing paper that will remain on the wall as you pull off the top layer off. If it is not torn, this can be left on as a liner for the new wallpaper. If it is torn, you will need to remove it. The backing paper can usually be removed by soaking and scraping without needing to score it.
Deciding to Strip: Removing Other Wallpapers
Removing wallpaper is generally a three-step process: score, soak and scrape. This process can be very easy or very frustrating depending upon how many layers of wallpaper are on the wall and how well the surface was prepared before the old paper was hung. If it is done incorrectly, you might end up a wall with gouges and strips of drywall missing. Remember to be gentle with your walls no matter how frustrated you are with it.
Step 1 - Score
If you are not able to dry-strip or peel the paper on the wall and it has either vinyl or another waterproof surface, you'll need to score it. Washable and painted papers are made to withstand water. Abrading the surface will allow moisture to penetrate and break down the adhesive. Scoring can be done with coarse sandpaper, a serrated scraper, or a wallpaper-scarifying tool such as the Paper Tiger. Whichever method you use, be careful that you don't push too hard and end up damaging the wall. You can also use a razor to score a series of X's into the surface of the wallpaper. However, you must be very careful not to press too hard or you risk damaging the wall. This method also cuts the paper into smaller pieces that will make scraping it more time-consuming.
Step 2 - Soak
While many people will tell you that one method of soaking wallpaper is better than the others, in reality the right method depends on the type of paper you are removing. Wallpaper paste changes with different manufacturers and different years. If the first method you try doesn't seem to work well, try something different.
You will want to cover the floors and furniture before you begin soaking and make sure you are careful not to allow any water to drip into electrical sockets. Don't try to soak too much area at one time. If the wall dries out before you get to it, you will have to start all over.
The primary ingredient in soaking is water: the hotter the better. Water can be applied to the wall using a sponge, brush or canister-type garden sprayer. To speed up the soaking process, try adding a little laundry soap or liquid detergent to help loosen the paste. However, some people find that solutions consisting of fabric softener and warm water, or equal parts of vinegar and water work better. For best results, apply water at least twice until the paper is wet, but not dripping, and allow the solution to sit for about 15 minutes before moving on the next step.
If none of these methods work, you might consider using a chemical stripper. These are an enzyme-based product that will break down the chemical structure of the paste. They are available in gels and liquid form.
Step 3 - Scrape
Properly soaked wallpaper should be loose enough that even a ruler scraped across should remove it. However, smaller scrapers work better than wider ones because it can be difficult to keep constant pressure across the full width of the wider blades. If the pressure is not constant, small strips of paper will be missed. Consider using a three to four-inch-wide scraper.
If your budget allows, consider purchasing specially designed wallpaper scrapers. These tools are designed to glide along the wall without gouging the wallboard underneath. Plus, they have a doorknob-shaped handle that is easier and more comfortable to use than conventional scrapers.
Work from the top of the wall down. Remove all paper and adhesive thoroughly. Be careful not to damage the wallboard that will be extra-tender from the soaking. If there are multiple layers of paper, remove one layer at a time by repeating the process. If a piece is stubborn, soak it again and go back to it later.
Using a Steam Stripper
Some places rent steam strippers to the public. These are simple to use and can eliminate the mess of soaking and scraping. Steam passes through a plate held close to the wall, loosening the paper sufficiently so you can easily scrape it off as you go along. You have to be careful with the steamer. If it is left on the wall too long, the plaster is likely to lift and fall off in pieces. Some people have found luck using clothing steamers or even the steam setting on an iron. These are not practical for larger areas and should only be used for tricky or stubborn areas.
After you have removed the old wallpaper, it is a good idea to wash the walls with a household cleaner. This will ensure that all remaining paste is removed as well as any bits of paper. Allow the walls to dry overnight and you're done. With this process anyway. You still need to wallpaper or paint the walls. But at least you've taken the proper steps to insure that your new painting or wallpapering will last.
Although this might seem like a lot of work, remember that without the proper preparation your newly covered walls won't last. Failing to remove old wallpaper now could have disastrous results, especially if it starts to come down after you covered over it. If you think it's bad now, think of how much worse it will be to have to do it later and then repaint or re-wallpaper the walls.