Drying wet patches on walls involves increasing airflow and addressing the underlying cause of the moisture. Here's a breakdown of how to do it effectively:
1. Identify and Fix the Source of the Moisture:
This is the most crucial step. Drying the wall will be a temporary fix if you don't address what's causing the dampness. Common causes include:
- Leaks: Check for leaky pipes (plumbing, central heating), roofs, gutters, or flashing around windows and doors.
- Rising Damp: This occurs when groundwater is drawn up through the wall. It often requires professional treatment.
- Penetrating Damp: Rainwater can penetrate walls due to cracks, porous materials, or damaged pointing.
- Condensation: Poor ventilation can lead to condensation, especially in bathrooms and kitchens.
2. Increase Airflow:
Good airflow is essential for evaporating moisture from the wall.
- Ventilation: Open windows and doors to create cross-ventilation.
- Fans: Use fans to circulate air around the damp patch. Position them to blow air across the wet area. Oscillating fans are particularly effective.
- Dehumidifiers: A dehumidifier removes moisture from the air, speeding up the drying process.
3. Remove Obstructions:
- Clear the Area: Move furniture and other objects away from the wall to allow for better airflow.
- Remove Wallpaper/Loose Paint: If the wallpaper or paint is peeling or bubbling, carefully remove it to expose the plaster underneath. This will accelerate drying.
4. Monitor the Drying Process:
- Check Regularly: Monitor the damp patch for signs of drying.
- Use a Moisture Meter (Optional): If you want to be precise, use a moisture meter to measure the moisture content of the wall.
5. Consider Professional Help:
- Severe Damp: If the damp patch is large, persistent, or you can't identify the source, consult a professional damp proofer or building surveyor.
- Structural Damage: If the damp has caused structural damage to the wall (e.g., crumbling plaster, wood rot), you'll need to get it repaired.
Factors Affecting Drying Time:
- Thickness of Plaster: Thicker plaster takes longer to dry.
- Severity of Dampness: The more saturated the wall, the longer it will take to dry.
- Ventilation and Temperature: Warmer temperatures and good ventilation speed up drying.
- Materials: Different wall materials (e.g., plasterboard, brick) have varying drying times.
Important Considerations:
- Safety: Be careful when using electrical appliances (fans, dehumidifiers) near water.
- Mould: If mould is present, clean it with a mould-killing solution after the wall is dry. Follow the manufacturer's instructions carefully. Wear appropriate protective gear (gloves, mask).
