Moisture readings for internal walls are critical parameters for assessing the building’s overall health and identifying potential structural issues. Understanding the factors influencing moisture content ensures accurate interpretation of readings, enabling timely intervention and preventative measures.
How to take the readings?
First, determine the correct depth of the measurement. For internal walls, the reading should generally be taken at a depth of 10-25mm. The instrument should be held perpendicular to the wall, with firm pressure applied to ensure good contact. The moisture content is then displayed on the instrument’s screen.
Factors Affecting Moisture Readings
Environment
- Relative Humidity: High relative humidity levels in the air can lead to increased moisture absorption by internal walls.
- Temperature: Fluctuating temperatures can cause moisture movement within walls, affecting readings.
- Ventilation: Poor ventilation restricts moisture dissipation, resulting in higher moisture content.
Wall Materials and Construction
- Type of Material: Porous materials like gypsum board absorb and retain moisture more readily than non-porous materials like ceramic tiles.
- Wall Covering: Paints, wallpapers, and other coverings can create a vapor barrier, trapping moisture inside walls.
- Construction Method: Moisture can penetrate through cracks, gaps, and other imperfections in wall construction.
External Factors
- Leaks: External leaks from roofs, windows, or plumbing can infiltrate walls and increase moisture content.
- Condensation: Inadequate insulation or cold surfaces can cause condensation, leading to increased moisture levels.
- Ground Conditions: High moisture levels in the ground can transfer to internal walls through capillary action.
Acceptable Moisture Readings
Acceptable moisture readings for internal walls vary depending on the specific materials and climatic conditions. However, as a general guideline, readings below 15% moisture content are considered acceptable, while readings above 20% indicate potential moisture issues that require further investigation.