Texturizing walls has its advantages: It hides imperfections, and it's a fast way to finish a wall without spending hours mudding and sanding.
Why Textured Walls Don't Work for Wallpaper
When gluing one surface to another surface, the more surface contact, the better.
Textured walls' numerous dips, holes, and gaps reduce the surface area that can contact the wallpaper. Wallpaper on textured walls will fall down easier than on flat walls, especially in warm and moist environments, like bathrooms.
Wallpaper seams don't just need to match up side to side: Depths also need to match. With flat walls, the depth is consistent from one sheet to an adjacent sheet. With textured walls, there are thousands of slight texture differences between adjacent seamed sheets.
Texture Is Repeated on Surface
The texture of the wall will show on the surface of the wallpaper. Even if you lightly apply the wallpaper, peaks and ridges will invariably show.
Tips for Putting Wallpaper on Textured Walls
It's highly recommended that you apply a skim coat to textured walls before adding wallpaper. If you'd rather not do that, observe a few tips for wallpapering directly on textured walls to help the paper stick better and last longer.
Apply on Flatter Textures
Orange-peel texture has rounded ridges and looks much like the peel of an orange. Knockdown texture is applied with a texturizing nozzle and initially is peaked and ridged before it is flattened, or knocked down, with a trowel.
With knockdown texture, wallpaper stands a better chance of sticking for the long term because there are more flat places for the wallpaper to stick.
Knock off High/Sharp Points
With any type of wall texture that will receive wallpaper, first run a wide drywall knife across the wall in the direction of the blade edge to knock off high ridges or sharp points. While mostly recommended for more bumpy textures like orange peel or slap-down, it's still helpful on knockdown textures.
Use Paper Wallpaper and Paste
With traditional paper wallpaper on texture walls, the liquid paste helps to fill in the gaps and other low spots on the wall. With peel and stick wallpaper, though, the wallpaper has no fill product. It must bridge from one ridge to the next.
To help the seam between adjacent papers meet, press firmly on the seam with a sponge or the flat of your hand.
It is critical to clean textured walls if you intend to directly install wallpaper. With reduced surface contact, you want those surfaces to stick as well as possible.
How to Correctly Prepare a Textured Wall for Wallpaper
Skim coating a textured wall is the proper way to prepare it for wallpaper. You can also remove the texture, but this is difficult, messy, and doesn't always remove all of the texture.
To skim coat textured walls, you'll need a wide drywall knife, clean microfiber cloths, TSP (a cleaning product), a drywall pan, drywall sander, and pre-mixed drywall joint compound.
Knock off Sharp Points
Run a wide drywall knife across the walls, starting at the top and working down. Move the knife in the direction of the blade.
Using clean microfiber cloths and TSP, thoroughly clean the walls. Even if the walls initially were clean, running the drywall knife across will leave debris.
Prepare Joint Compound
Add joint compound to a drywall tray. Push down the compound to press out bubbles.
Spread Joint Compound
Pick up the compound with the edge of the drywall knife. Spread the compound in long strokes across the wall. Hold the blade at about a 45 degree angle to the wall, spreading compound with the edge of the blade and not the flat section.
Continue until the wall is complete. Let the skim coat dry for at least two hours but preferably 12 or more hours. Keep the room warm and run a fan on low speed to promote drying.
Sand the wall with fine-grit drywall sandpaper. Sand just once, and do so only lightly. Clean off the drywall dust before applying wallpaper. You may want to touch up some areas after the first coat to better ensure the wallpaper sticks well.
Tips for Skim Coating Textured Walls
- For the limited amount of joint compound needed for skim coating, it's usually easiest to purchase pre-mixed joint compound.
- Begin skim coating at the edges. For example, to skim coat a wall but not the ceiling, start where the wall and ceiling meet, then work downward.
- Similar to painting a wall, work off of wet edges. If you run a skim coat over a halfway dry skim coat section, it will create clumpy sections that must be repaired.
- Start each stroke on a dry part of the wall. If you start on a skim-coated section, you'll create marks.