What preparation is recommended before wallpapering a new plaster wall?

• A. Wall sizing
• B. Plaster patching
• C. Primer only
• D. Sanding

Answer: (A)

New plaster walls are highly porous and can suck up moisture from the wallpaper adhesive unevenly, causing bubbles and poor adhesion. The best first step is applying wall sizing. Sizing seals the plaster pores and creates a uniform surface, reducing suction so the adhesive can cure evenly and the wallpaper sticks consistently. It also minimizes dust from the plaster and helps prevent future issues as the paper ages. After sizing, follow the wallpaper manufacturer's instructions, which may call for a primer on top of the sizing in some cases. Patch any cracks or damaged areas as needed, but that doesn’t replace the need for sizing on a new plaster surface. Sanding is not the preferred preparation before wallpapering, since it can create dust and roughen the surface; sizing is the correct initial step.