Once again, contact with moisture is the culprit here, though water-resistant varieties of wallpaper are less likely to become wet and develop mold. Using a high-quality exhaust fan or dehumidifier and leaving the doors or windows cracked after bathing will keep this issue at bay. 

Many peel-and-stick wallpapers aren’t moisture-resistant, so if you install them in high-humidity rooms, mold can grow behind the wallpaper. It’s best to reserve peel-and-stick wallpaper for bedrooms, living rooms, and other rooms with lower humidity levels. Not only does this minimize the risk of mold growth, but it also keeps the wallpaper from bubbling or peeling.

The average cost to install or hang wallpaper is around $575 per room or project, with typical prices ranging from $200 to $1,500. Costs can be higher for custom or luxury products. Since project size varies, it's often helpful to estimate labor costs per square foot, which generally fall between $1 and $7, with an average of $4 per square foot. The total cost depends on several factors, including the quality and type of wallpaper, the size and type of the room, and whether old wallpaper must be removed first. Opting for less expensive materials like peel-and-stick wallpaper or choosing to do the installation yourself can lower the overall cost. For the most accurate estimate, it is best to have a professional inspect the space and provide a quote.

Peel-and-stick wallpaper is designed to be removed without damaging walls, making it a good choice for renters or temporary design changes. However, damage to paint or drywall can occur under certain conditions. To prevent issues, the wall surface must be properly prepared before application—it should be clean, smooth, dry, and correctly primed or painted. Applying wallpaper to a freshly painted surface can cause the paint to peel off during removal. Additionally, removing the wallpaper too quickly or aggressively can also cause damage. For best results, always follow the manufacturer's instructions for both application and removal.