There are several options, including stripping, steaming or spraying with chemicals, but to get the best results you will need to determine what treatment is most appropriate for your walls and wallpaper.
Original walls and wallpaper
Most walls are made of either plaster or drywall - plaster is hard and durable whereas drywall is more delicate and can’t tolerate much heat. Tap on the wall and if it sounds hollow you have drywall.
Wallpaper generally comes in either traditional or strippable form. If it is strippable you can remove most of the wallpaper by hand. Test this by trying to peel the wallpaper away from the surface; if it comes away without tearing continue to strip it by hand. If can’t strip it by hand you will need to use one of the follow techniques.
Score the old wallpaper
Before you treat your wallpaper you will need to perforate it. Take a small roller with spikes and punch small holes in the old wallpaper. This is also known as the scoring process, and these little holes let the solvent or steam to get behind the paper and dissolve the adhesive. The piercing tools are cheap and can be found in most hardware stores. If you have drywalls however you will need to use the perforating tool gentle as you could create small holes in the paper on the drywall.
Solvents are available in power to be mixed with water or as a gel. If you’re mixing the power make sure the water is very hot. Apply the solvent with a sponge, saturate the wallpaper and then give it time to soak in. When the paper starts to sag from the wall you know it’s working, but don’t saturate more than you think you can strip in 10 minutes. Be careful and protect your eyes and hands using these products, as most of them are caustic. If you don’t want to use chemical products, vinegar or fabric softener solutions are just as effective. It is recommended that you mix 40% vinegar or fabric softener with 60% water, but experiment with the solution levels.
If you have heavy stiff wallpaper that is difficult to remove think about using a steamer. To use you simply have to place the steamer on the surface of the wallpaper long enough for the hot steam to penetrate the paper. And once the paper is loosened you can used a scrapper to take the wallpaper away. Steamers introduce lots of moisture into a room so make sure you have the place well ventilated and you wear gloves and long sleeves to protect yourself from any dripping hot water. Steamers are available to rent for hourly, daily or weekly rates.
After your wallpaper has been treated start scrapping it away at the edge of a seam using a scrapping tool. It you struggle to scrap the wallpaper off, apply more steam or solvent. Don’t apply too much pressure when you’re scrapping as you may tear through the wall.
Once you are finished scrapping and the walls look clear prepare a bucket of hot water mixed with heavy duty cleaner. Use a sponge to lightly remove any traces of wallpaper or solution from the walls. Then wipe down the walls with clean water and towel dry and let the walls dry for a few days.