Before applying wallpaper, it is crucial to ensure the underlying surface is not excessively moist. Excessive moisture can cause the wallpaper to bubble, peel, or mildew. A moisture reading using a moisture meter can accurately assess the moisture level of the surface. The recommended moisture content depends on the material of the substrate.
For drywall, a moisture reading between 10% and 15% is considered normal and suitable for wallpaper installation. Readings below 10% indicate the surface is too dry, while readings above 15% suggest excessive moisture that could compromise the wallpaper's adhesion.
| Substrate | Normal Moisture Content (%) |
|---|---|
| Drywall | 10-15 |
| Wood | 6-12 |
| Concrete | <3 |
| Plaster | <10 |