Your peel-and-stick wallpaper can fall off for multiple reasons, including high humidity levels, extreme temperature changes, poor installation, and even the wall surface. Textured walls can prevent the adhesive from fully sticking to the wall, making it more likely for the wallpaper to peel off. Low-quality wallpapers with weaker adhesives are also more likely to fall off prematurely.

Common mistakes when finishing basement walls include neglecting proper insulation, insufficient moisture management, and poor ventilation. Not addressing these issues can lead to mold growth, water damage, and discomfort. Additionally, inadequate planning, improper framing, and rushing the project can result in subpar outcomes. 

It's essential to follow best practices, seek professional guidance if needed, and prioritize thoroughness and attention to detail.

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. 

Yes, you can put wallpaper in a bathroom, but whether it's a good idea depends on several factors. Because bathrooms are high-humidity areas, it's crucial to choose a water-resistant wallpaper, such as one made of vinyl. Proper wall preparation is also critical to ensure the paper adheres well, even after many steamy showers. The wallpaper's placement also affects its longevity; it will hold up better on an accent wall or away from direct water contact, rather than immediately next to a shower. A well-ventilated bathroom will yield the best results.