You can wallpaper new plaster once it is completely dry.
Applying wallpaper to new plaster requires patience to ensure the best possible finish and longevity. The most crucial step is allowing the plaster to dry thoroughly. Based on general guidelines and the provided reference, MAKE SURE YOUR WALLS ARE COMPLETELY DRY. This drying process can take a maximum of 7-10 days, depending on the conditions in your home.
Why Drying is Essential
Wallpapering before the plaster is fully dry can lead to several problems:
- Poor Adhesion: Wallpaper paste struggles to bond correctly with damp surfaces, leading to peeling, bubbling, or lifting edges.
- Mould Growth: Moisture trapped between the plaster and wallpaper creates an ideal environment for mould and mildew to grow, which can damage the wall and pose health risks.
- Discolouration: Trapped moisture can cause stains or discolouration to appear on the wallpaper over time.
- Damage to Plaster: Uneven drying can weaken the new plaster itself.
How Long Does New Plaster Take to Dry?
As highlighted in the reference, the drying time for new plaster varies depending on various factors. While it can take a maximum of 7-10 days to be completely dry and ready for wallpapering, several conditions influence this duration:
- Thickness of Plaster: Thicker applications will take longer to dry.
- Humidity Levels: High humidity slows down the drying process.
- Ventilation: Good airflow helps moisture evaporate more quickly.
- Temperature: Warmer temperatures generally speed up drying, but avoid artificial heat sources that dry the surface too quickly while leaving the core damp.
- Type of Plaster: Different plaster mixes may have slightly different drying times.
Drying Time Snapshot:
| Stage | Appearance | Typical Timeframe (Guideline) | Ready for Wallpaper? |
|---|---|---|---|
| Newly Applied | Dark, wet | Day 0-1 | No |
| Drying Progressing | Lighter patches appear | Day 1-5 | No |
| Visually Dry | Uniformly pale pink/tan | Day 5-7 | Check! |
| Completely Dry | Uniformly pale/light | Up to 7-10 Days | YES |
(Note: These are general guidelines. Always check the wall itself.)
Checking if Plaster is Ready
Even if the calendar says 7-10 days have passed, it's essential to confirm the walls are completely dry. Visually, the plaster should have turned a uniform, light pale colour with no darker, damp patches.
Preparing the Dry Plaster for Wallpaper
Once the plaster is completely dry, you usually need to prepare it before applying wallpaper. This often involves:
- Sealing/Priming: Applying a 'mist coat' (a diluted emulsion paint, often 50/50 paint and water) or a dedicated plaster primer/sealer. This helps to seal the porous surface of the new plaster, preventing it from absorbing the wallpaper paste too quickly and ensuring the wallpaper adheres properly.
- Sizing: Some decorators also recommend applying a coat of wallpaper size after the primer is dry. This provides an even surface for the paste and makes positioning the wallpaper easier.
By ensuring the plaster is fully dry, following the guidance that it can take a maximum of 7-10 days depending on conditions, and properly preparing the surface, you set the stage for successful and long-lasting wallpaper application.
