Woodchip (ingrain) wallpaper has been used as a wall decoration since the 1920s. It's made from wood fibre in between two layers of paper. Many people decide not to remove this type of wallpaper because it's difficult to get off due to the material it's made out of. With a sharp scrapper, elbow grease and patience you can finally get rid of this wallpaper.
Try to determine when your woodchip wallpaper was installed. If it was installed on or before 1985, it may contain asbestos. If you're not sure when it was installed, contact a professional. Inhalation of asbestos fibres can cause serious illness including lung cancer.
Removing any kind of wallpaper is not a clean activity. To protect your floors, lay a dust sheet on them. This will collect any runoff water, wallpaper and paste that fall to the floor.
Loosen a corner of the paper and pull it. This should pull off the first layer of paper exposing the woodchip material. Try to pull off as much of the paper as you can. You will be surprised how easy the first layer can come off without any scrapping.
Combine the concentrate in a bucket with warm water. Follow the directions on the bottle for the correct measured quantity.
Score the remaining wallpaper. This is the toughest part of the process and will take time. Penetrating through the wood takes some elbow grease and can be a vigorous activity. An additional person to help with this step will speed up the process.
Soak your sponge in the bucket and apply the concentrate to a portion of the wall. The more concentrate you apply, the easier it is to remove the wallpaper. Do not hesitate to saturate the wall.
Allow the concentrate to soak into the paper and break up the adhesive. Let it set for 15 to 20 minutes.
Scrape off the wallpaper using the scrapper. Try to use it lightly so you don't damage the wall. If the wallpaper does not come off, reapply the concentrate and repeat this step. Woodchip wallpaper is stronger than traditional wallpaper so you may have to repeat this steps a few times.
Sponge off any remaining paste stuck to the wall.